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Pérusse, Daniel. „Succès social et succès reproductif dans les sociétés modernes : une analyse sociobiologique“. Anthropologie et Sociétés 12, Nr. 3 (10.09.2003): 151–74. http://dx.doi.org/10.7202/015043ar.
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Résumé Succès social et succès reproductif dans les sociétés modernes : une analyse sociobiologique Dans cet article, nous présentons l'hypothèse sociobiologique voulant qu'il existe une relation positive entre le succès social et le succès reproductif chez les individus. Cette question se révèle particulièrement significative en ce qu'elle récapitule le rapport entre le comportement culturel et ses déterminants évolutifs. Nous proposons un modèle théorique détaillé de la relation, et nous en vérifions la validité par une revue des recherches pertinentes effectuées au sein des sociétés modernes, où le rapport entre les deux formes de succès apparaft le moins évident.
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Lefebvre, Louis. „L'imitation à l'origine de la culture“. Anthropologie et Sociétés 12, Nr. 3 (10.09.2003): 93–107. http://dx.doi.org/10.7202/015040ar.
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Résumé L'imitation à l'origine de la culture Les racines animales de la culture humaine se trouvent dans l'apprentissage social. Cet article décrit une série de travaux récents sur l'imitation et les traditions culturelles chez les oiseaux et les mammifères. Les implications de ces études pour notre compréhension de la culture humaine sont discutées. La théorie coévolutive fournit un scénario plausible des origines de la culture humaine. La question de savoir si des pratiques culturelles particulières contribuent au succès reproductif est plus problématique. Les objections logiques à l'application du concept d'adaptation biologique à la culture sont soulignées.
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Bollmann, Kurt, und Heinz-Ulrich Reyer. „Reproductive Success of Water Pipits in an Alpine Environment“. Condor 103, Nr. 3 (01.08.2001): 510–20. http://dx.doi.org/10.1093/condor/103.3.510.
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Abstract To understand the evolution of avian reproductive strategies it is important to assess how differences in reproductive success are related to timing of the breeding season, quality of nesting territories or breeders, or to a combination of these factors. Over three years, we studied the reproductive performance of female Water Pipits (Anthus spinoletta) in a temporally and spatially variable alpine environment. The study area covered two valley slopes that differed in the probability of nest predation, food availability, and climate. Nest predation and harsh weather were the main proximate causes of differences in female reproductive success. Because these two environmental factors were locally unpredictable, individual females could best optimize their seasonal reproductive success by choosing the “right” breeding time. The average number of young fledged per season was inversely related to the date of initial breeding and increased from females with only first attempts, through females with replacement clutches, to females that raised two broods. Hence, the main advantage of early breeding lies in the chance of rearing a second brood after the first has fledged, or of producing a replacement clutch if the first fails due to predation or harsh weather. Éxito Reproductivo de Anthus spinoletta en un Ambiente Alpino Resumen. Para entender la evolución de las estrategias reproductivas de las aves es importante determinar cómo las diferencias en el éxito reproductivo se relacionan con el comienzo de la época reproductiva, la calidad de los territorios de nidificación o los reproductores o con una combinación de estos factores. Durante un período de tres años, estudiamos el desempeño reproductivo de hembras de Anthus spinoletta en un ambiente alpino temporal y espacialmente variable. El sitio de estudio comprendió dos laderas que diferían en la probabilidad de depredación de nidos, disponibilidad de alimento y clima. La depredación de nidos y el clima severo fueron las principales causas proximales de la diferencia del éxito reproductivo de las hembras. Debido a que ambos factores ambientales fueron localmente inpredecibles, cada individuo hembra podía optimizar el éxito de su período reproductivo eligiendo el tiempo “correcto” para reproducirse en la temporada. El número promedio de juveniles por temporada se relacionó inversamente con la fecha del inicio de la reproducción y aumentó desde hembras con sólo un intento de cría, pasando por hembras que reemplazaron sus nidadas, hasta hembras que criaron dos nidadas. Por tanto, la ventaja principal de reproducirse tempranamente en la temporada está dada por la posibilidad de criar una segunda nidada luego de la partida de los primeros juveniles o de producir una nueva nidada si la primera falla debido a depredación o clima severo.
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Porneluzi, Paul A. „Prior Breeding Success Affects Return Rates of Territorial Male Ovenbirds“. Condor 105, Nr. 1 (01.02.2003): 73–79. http://dx.doi.org/10.1093/condor/105.1.73.
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AbstractI examined the hypothesis that male Ovenbirds (Seiurus aurocapillus) make breeding dispersal decisions based on prior breeding experience at a site. I determined the reproductive success of color-banded male Ovenbirds at sites in fragmented and unfragmented landscapes in Missouri from 1992–1995. I documented which individuals returned and I recorded their reproductive success upon return as well as the success of birds new to each plot. I obtained similar results in both landscapes. Males with different histories of reproductive success returned at different rates. Only 2 of 22 males that were paired but failed to raise young returned in the following year, whereas the return rates of unpaired males (41%, n = 37) and males that successfully raised young (54%, n = 57) did not differ significantly (P = 0.19). The patterns were more consistent with the hypothesis that return rates were due to decisions about dispersal rather than difference in survival of individuals in these groups.El Éxito Reproductivo Previo Afecta Índices de Regreso de Machos Territoriales de Seiurus aurocapillusResumen. Examiné la hipótesis de que individuos de Seiurus aurocapillus hacen decisiones de dispersión reproductiva basadas en las experiencias reproductivas previas en un sitio. Determiné el éxito reproductivo de machos con anillos de color en lugares en terrenos fragmentados y no fragmentados de Missouri entre 1992 y 1995. Documenté cuáles individuos regresaron y su éxito reproductivo al regresar, y también el éxito de pájaros nuevos en cada sitio. Obtuve resultados semejantes en ambos paisajes. Los machos con historias de éxito reproductivo diferentes presentaron índices de regreso diferentes. Solamente 2 de 22 machos apareados que no produjeron cría volvieron al año siguiente, mientras que los índices de regreso de machos no apareados (41%, n = 37) y de los machos que produjeron crías exitosamente (54%, n = 57) no difirieron significativamente (P = 0.19). Los patrones concuerdan más con la hipótesis de que los índices de regreso se deberieron a las decisiones de dispersión y no a la diferencia de supervivencia de individuos en estos grupos.
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Kilpatrick, A. Marm, Dennis A. LaPointe, Carter T. Atkinson, Bethany L. Woodworth, Julie K. Lease, Matthew E. Reiter und Kevin Gross. „Effects of Chronic Avian Malaria (Plasmodium Relictum) Infection on Reproductive Success of Hawaii Amakihi (Hemignathus Virens)“. Auk 123, Nr. 3 (01.07.2006): 764–74. http://dx.doi.org/10.1093/auk/123.3.764.
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Abstract We studied the effects of chronic avian malaria (Plasmodium relictum) infections on the reproductive success of a native Hawaiian honeycreeper, Hawaii Amakihi (Hemignathus virens). Chronic malaria infections in male and female parents did not significantly reduce reproductive success as measured by clutch size, hatching success, fledging mass, number of nestlings fledged, nesting success (daily survival rate), and minimum fledgling survival. In fact, nesting success of pairs with chronically infected males was significantly higher than those with uninfected males (76% vs. 38%), and offspring that had at least one parent that had survived the acute phase of malaria infection had a significantly greater chance of being resighted the following year (25% vs. 10%). The reproduction and survival of infected birds were sufficient for a per-capita population growth rate >1, which suggests that chronically infected Hawaii Amakihi could support a growing population. Efectos de las Infecciones Crónicas de Malaria Aviaria (Plasmodium relictum) en el Éxito Reproductivo de Hemignathus virens
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Kosciuch, Karl L., Andrew C. Kasner und Keith A. Arnold. „Annual Reproductive Success of Culvert-Dwelling Cliff Swallows in East-Central Texas“. Condor 103, Nr. 4 (01.11.2001): 879–85. http://dx.doi.org/10.1093/condor/103.4.879.
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Abstract Most studies describing reproductive biology of an avian species provide some measure of annual reproductive success (ARS), frequently reported per nest or per egg. These measurements do not indicate the success of average females in the population. We report conventional measures of reproductive success along with ARS(b), number of broods successfully reared per female, and ARS(k), number of young successfully reared per female. We calculated ARS for four culvert-dwelling Cliff Swallow (Petrochelidon pyrrhonota) colonies in east-central Texas from 1982 to 1985 (n = 1805 nests) and compared our calculations of ARS with those reported for other regions. We analyzed differences in number of fledglings per female to estimate variation in ARS among years and among culverts. In east-central Texas, ARS differed significantly among years and among culverts. We attributed variation in ARS to predation and abiotic factors. Consistent reporting of ARS would facilitate comparisons among populations or species over multiple scales. Éxito Reproductivo Anual de Petrochelidon pyrrhonota que Forman Colonias en Puentes del Este-Central de Texas Resumen. La mayoría de los estudios que describen la biología reproductiva de especies de aves proveen alguna medida de éxito reproductivo anual (ERA), la cual, se reporta frecuentemente por nido o por huevo. Estas medidas no indican el éxito reproductivo de las hembras promedio de la población. Nosotros reportamos medidas convencionales de éxito reproductivo junto con el ERA(b), número de nidadas exitosamente criadas por hembra y ERA(k), número de juveniles exitosamente criados por hembra. Calculamos el ERA para cuatro colonias de Petrochelidon pyrrhonota que habitan puentes en el este-central de Texas desde 1982 hasta 1985 (n = 1805 nidos) y comparamos nuestros cálculos de ERA con aquellos reportados para otras regiones. Analizamos las diferencias en el número de pichones por hembra para estimar variaciones en el ERA entre años y entre puentes. En el este-central de Texas el ERA varió significativamente entre años y entre puentes. Atribuimos la variación en el ERA a depredación y factores abióticos. El informe consistente de valores de ERA facilitaría la comparación entre poblaciones y especies a través de múltiples escalas.
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Gandini, Patricia, Esteban Frere und P. Dee Boersma. „Status and conservation of Magellanic PenguinsSpheniscus magellanicusin Patagonia, Argentina“. Bird Conservation International 6, Nr. 4 (Dezember 1996): 307–16. http://dx.doi.org/10.1017/s0959270900001787.
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SummaryThere are 36 breeding colonies of Magellanic PenguinsSpheniscus magellanicusalong the coast of mainland Argentina. During the breeding period we counted the number of active nests and estimated the breeding population was approximately 652,000 pairs. Development of coastal areas is diminishing the quality of Magellanic Penguin breeding habitat and reducing penguin reproductive success. Adult mortality rates are increasing because of human activities. Maritime petroleum traffic and petroleum operations are known to cause mortality. Fishing activities cause incidental mortality and may negatively affect penguin foraging and reproductive success. In some areas, offal is increasing gull populations with a corresponding increase in predation on penguin eggs and chicks, thereby lowering reproductive success. These sources of mortality are relatively recent and are human caused. We found three areas where human activities are of particular concern: Península Valdés, Golfo San Jorge and Estrecho de Magallanes. Human impacts on Magellanic Penguin populations could be reduced, benefiting the tourist industry where yearly tens of thousands of people come to the provinces of Chubut and Santa Cruz to visit penguin colonies.Existen 36 colonias de pingüino de MagallanesSpheniscus magellanicusa lo largo de la costa Argentina. La población reproductiva se estimó en 652,000 parejas realizando un conteo de nidos activos durante la estación reproductiva. El desarrollo de las áreas costeras está reduciendo la calidad del hábitat de reproducción y el éxito reproductivo del pingüino de Magallanes. El tráfico de petróleo y las actividades relacionadas son conocidas causas de mortalidad. Las actividades pesqueras están causando mortalidad incidental y pueden estar afectando negativamente el éxito de alimentatión y reproductivo. En algunas áreas la basura está contribuyendo al aumento de la población de gaviotas, incrementándose la predación sobre huevos y pichones de pingüino reduciendo su éxito reproductivo. Estas fuentes de mortalidad son relativamente recientes y provocadas por el hombre. Hemos detectado tres áreas donde la mortalidad relacionada con actividades humanas es preocupante: Península Valdés, Golfo San Jorge y Estrecho de Magallanes. El impacto humano sobre la población de pingüino de Magallanes podría reducirse y beneficiar la industria turística de las provincias de Chubut y Santa Cruz, donde anualmente decenas de miles de personas visitan las colonias reproductivas del pingüino.
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Barve, Sahas, Christina Riehl, Eric L. Walters, Joseph Haydock, Hannah L. Dugdale und Walter D. Koenig. „Lifetime reproductive benefits of cooperative polygamy vary for males and females in the acorn woodpecker ( Melanerpes formicivorus )“. Proceedings of the Royal Society B: Biological Sciences 288, Nr. 1957 (18.08.2021): 20210579. http://dx.doi.org/10.1098/rspb.2021.0579.
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Cooperative breeding strategies lead to short-term direct fitness losses when individuals forfeit or share reproduction. The direct fitness benefits of cooperative strategies are often delayed and difficult to quantify, requiring data on lifetime reproduction. Here, we use a longitudinal dataset to examine the lifetime reproductive success of cooperative polygamy in acorn woodpeckers ( Melanerpes formicivorus ), which nest as lone pairs or share reproduction with same-sex cobreeders. We found that males and females produced fewer young per successful nesting attempt when sharing reproduction. However, males nesting in duos and trios had longer reproductive lifespans, more lifetime nesting attempts and higher lifetime reproductive success than those breeding alone. For females, cobreeding in duos increased reproductive lifespan so the lifetime reproductive success of females nesting in duos was comparable to those nesting alone and higher than those nesting in trios. These results suggest that for male duos and trios, reproductive success alone may provide sufficient fitness benefits to explain the presence of cooperative polygamy, and the benefits of cobreeding as a duo in females are higher than previously assumed. Lifetime individual fitness data are crucial to reveal the full costs and benefits of cooperative polygamy.
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Morin, A., M. Rughetti, S. Rioux-Paquette und M. Festa-Bianchet. „Older conservatives: reproduction in female Alpine chamois (Rupicapra rupicapra) is increasingly risk-averse with age“. Canadian Journal of Zoology 94, Nr. 5 (Mai 2016): 311–21. http://dx.doi.org/10.1139/cjz-2015-0153.
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In long-lived mammals, costs of reproduction may vary with age. The terminal investment hypothesis predicts greater reproductive effort as females approach the end of their life expectancy. We monitored 97 individually marked female Alpine chamois (Rupicapra rupicapra (L., 1758)) between 2007 and 2013 to determine how age-specific reproduction affected body mass and subsequent reproductive success. We captured and weighed females between April and August and monitored reproductive success from April to October through mother–kid associations. Reproductive success was strongly age-dependent and peaked at 70% for prime-aged females (4–7 years). Reproductive senescence began at 8 years, earlier than reported by other studies of ungulates. There was no clear evidence of reproductive costs in any age class. Reproductive success was very heterogeneous for old females, suggesting variability in the onset of senescence. Old females were less likely to reproduce in poor years despite being heavier than prime-aged females, suggesting reproductive restraint in late life rather than terminal investment. Female mass remained stable from May to August with no effect of lactation. Our results suggest that chamois reproductive strategy becomes increasingly conservative with age, resulting in no detectable costs of reproduction.
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Dumas, Pascale, und Lucie Maillette. „Rapport des sexes, effort et succès de reproduction chez Rubus chamaemorus, plante herbacée vivace dioïque de distribution subarctique“. Canadian Journal of Botany 65, Nr. 12 (01.12.1987): 2628–39. http://dx.doi.org/10.1139/b87-354.
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Studies published on the reproductive success of dioecious species concentrate on the role of sex ratios and pollinator behaviour. In the case of Rubus chamaemorus L., a circumboreal dioecious species, we hypothesized that flower survival and biomass allocation to reproductive tissues, which are climate dependent, also influence fruit production. Only 0.05% of total biomass is allocated to reproduction, whereas 94% goes to underground organs responsible for vegetative propagation. Many male (28 – 51%) and female flower buds (35 – 54%) and young fruits (24–51%) die prematurely mainly because of the climate; fruit production then becomes independent from initial female flower density. The scarcity of female flowers at most sites (except near open water) limits fruit production. The limited sexual reproduction would allow cloudberry to maintain somatic resources, thereby increasing the longevity of individuals and their chance of encountering the climatic conditions required for reproductive success. Such a strategy is adaptive in a variable climate like that of the subarctic. Furthermore, the reduced importance of sexual reproduction would diminish the need to optimize sex ratios. Other selective pressures (e.g., competition) would then favour male clones in most sites, in spite of the unproductive pollen excess.
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Peters, Kathleen, Debra Jackson und Trudy Rudge. „Failures of reproduction: problematising ?success? in assisted reproductive technology“. Nursing Inquiry 14, Nr. 2 (Juni 2007): 125–31. http://dx.doi.org/10.1111/j.1440-1800.2007.00363.x.
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Weibel, Chelsea J., Jenny Tung, Susan C. Alberts und Elizabeth A. Archie. „Accelerated reproduction is not an adaptive response to early-life adversity in wild baboons“. Proceedings of the National Academy of Sciences 117, Nr. 40 (21.09.2020): 24909–19. http://dx.doi.org/10.1073/pnas.2004018117.
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In humans and other long-lived species, harsh conditions in early life often lead to profound differences in adult life expectancy. In response, natural selection is expected to accelerate the timing and pace of reproduction in individuals who experience some forms of early-life adversity. However, the adaptive benefits of reproductive acceleration following early adversity remain untested. Here, we test a recent version of this theory, the internal predictive adaptive response (iPAR) model, by assessing whether accelerating reproduction following early-life adversity leads to higher lifetime reproductive success. We do so by leveraging 48 y of continuous, individual-based data from wild female baboons in the Amboseli ecosystem in Kenya, including prospective, longitudinal data on multiple sources of nutritional and psychosocial adversity in early life; reproductive pace; and lifetime reproductive success. We find that while early-life adversity led to dramatically shorter lifespans, individuals who experienced early adversity did not accelerate their reproduction compared with those who did not experience early adversity. Further, while accelerated reproduction predicted increased lifetime reproductive success overall, these benefits were not specific to females who experienced early-life adversity. Instead, females only benefited from reproductive acceleration if they also led long lives. Our results call into question the theory that accelerated reproduction is an adaptive response to both nutritional and psychosocial sources of early-life adversity in baboons and other long-lived species.
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Ludwiczak, Agnieszka, und Marek Stanisz. „The Reproductive Success of Farmed American Mink (Neovison Vison) – A Review“. Annals of Animal Science 19, Nr. 2 (01.04.2019): 273–89. http://dx.doi.org/10.2478/aoas-2018-0061.
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AbstractThe aim of this review was to define the most important factors that affect the reproductive success of farmed mink. The biology of mink reproduction is unique when comparing it with other farmed fur animals. The article emphasizes the importance of optimal environmental conditions in prevention of reproductive disorders. The novel attempts to the mating schedule, optimal diet and body condition of dams, kits transfer between dams, these are only examples of advantageous procedures used in mink farming to increase the effectiveness of reproduction.
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Rotella, Jay J., Robert G. Clark und Alan D. Afton. „Survival of Female Lesser Scaup: Effects of Body Size, Age, and Reproductive Effort“. Condor 105, Nr. 2 (01.05.2003): 336–47. http://dx.doi.org/10.1093/condor/105.2.336.
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AbstractIn birds, larger females generally have greater breeding propensity, reproductive investment, and success than do smaller females. However, optimal female body size also depends on how natural selection acts during other parts of the life cycle. Larger female Lesser Scaup (Aythya affinis) produce larger eggs than do smaller females, and ducklings from larger eggs survive better than those hatching from smaller eggs. Accordingly, we examined patterns of apparent annual survival for female scaup and tested whether natural selection on female body size primarily was stabilizing, a frequent assumption in studies of sexually dimorphic species in which males are the larger sex, or was directional, counteracting reproductive advantages of large size. We estimated survival using mark-recapture methods for individually marked females from two study sites in Canada (Erickson, Manitoba; St. Denis, Saskatchewan). Structurally larger (adults) and heavier (ducklings) females had lower survival than did smaller individuals in Manitoba; no relationship was detected in adults from Saskatchewan. Survival of adult females declined with indices of increasing reproductive effort at both sites; consequently, the cost of reproduction could explain age-related patterns of breeding propensity in scaup. Furthermore, if larger females are more likely to breed than are smaller females, then cost of reproduction also may help explain why survival was lower for larger females. Overall, we found that advantages of large body size of female scaup during breeding or as young ducklings apparently were counteracted by natural selection favoring lightweight juveniles and structurally smaller adult females through higher annual survival.Sobrevivencia de Aythya affinis: Efectos del Tamaño Corporal, Edad y Esfuerzo ReproductivoResumen. En las aves, las hembras de mayor tamaño generalmente presentan una mayor predisposición a la reproducción, mayor inversión reproductiva y mayor éxito que las hembras de menor tamaño. Sin embargo, el tamaño óptimo de la hembra también depende de cómo la selección natural opera durante otras etapas del ciclo de vida. Hembras de Aythya affinis más grandes producen huevos de mayor tamaño que hembras más pequeñas, y los polluelos provenientes de huevos más grandes sobreviven mejor que aquellos que eclosionan de huevos más pequeños. Consiguientemente, examinamos los patrones de sobrevivencia anual aparente para hembras de A. affinis y probamos si la selección natural sobre el tamaño del cuerpo de las hembras era principalmente estabilizadora (una suposición frecuente en estudios de especies sexualmente dimórficas en que los machos son el sexo mayor), o era direccional, contrarrestando las ventajas reproductivas de un tamaño mayor. Estimamos la sobrevivencia de hembras utilizando métodos de marcaje y recaptura en dos sitios de estudio (Erickson, Manitoba; St. Denis, Saskatchewan). Hembras estructuralmente más grandes (adultas) y más pesadas (polluelos) tuvieron una menor sobrevivencia que individuos más pequeños en Manitoba; no se detectó una relación entre adultos de Saskatchewan. En ambos sitios la sobrevivencia de hembras adultas decreció con los índices de incremento de esfuerzo reproductivo; consecuentemente el costo reproductivo podría explicar los patrones de predisposición reproductiva relacionados a la edad en A. affinis. Además, si las hembras de mayor tamaño presentan mayor probabilidad de reproducirse que las hembras pequeñas, entonces el costo reproductivo también podría ayudar a explicar porqué la sobrevivencia fue menor para hembras más grandes. En general encontramos que en las hembras de A. affinis las ventajas de un tamaño corporal grande durante la cría o como juveniles fueron aparentemente contrarestadas por la selección natural que favorece juveniles de peso liviano y hembras adultas estructuralmente más pequeñas a través de una mayor sobrevivencia anual.
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ZYLBERBERG, M., E. P. DERRYBERRY, C. W. BREUNER, E. A. MACDOUGALL-SHACKLETON, J. M. CORNELIUS und T. P. HAHN. „Haemoproteusinfected birds have increased lifetime reproductive success“. Parasitology 142, Nr. 8 (24.03.2015): 1033–43. http://dx.doi.org/10.1017/s0031182015000256.
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SUMMARYThe impact of haematozoan infection on host fitness has received substantial attention since Hamilton and Zuk posited that parasites are important drivers of sexual selection. However, short-term studies testing the assumption that these parasites consistently reduce host fitness in the wild have produced contradictory results. To address this complex issue, we conducted a long-term study examining the relationship between naturally occurring infection withHaemoproteusandPlasmodium, and lifetime reproductive success and survival of Mountain White-crowned Sparrows. Specifically, we tested the hypothesis that birds infected with haematozoan parasites have reduced survival (as determined by overwinter return rates) and reproductive success. Contrary to expectation, there was no relationship betweenHaemoproteusandPlasmodiuminfection and reproduction or survival in males, nor was there a relationship betweenPlasmodiuminfection and reproduction in females. Interestingly,Haemoproteus-infected females had significantly higher overwinter return rates and these females fledged more than twice as many chicks during their lifetimes as did uninfected females. We discuss the impact of parasitic infections on host fitness in light of these findings and suggest that, in the case of less virulent pathogens, investment in excessive immune defence may decrease lifetime reproduction.
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Gaskins, Audrey J., Myriam C. Afeiche, Diane L. Wright, Thomas L. Toth, Paige L. Williams, Matthew W. Gillman, Russ Hauser und Jorge E. Chavarro. „Dietary Folate and Reproductive Success Among Women Undergoing Assisted Reproduction“. Obstetrics & Gynecology 124, Nr. 4 (Oktober 2014): 801–9. http://dx.doi.org/10.1097/aog.0000000000000477.
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Solomon-Lane, Tessa K., Madelyne C. Willis, Devaleena S. Pradhan und Matthew S. Grober. „Female, but not male, agonistic behaviour is associated with male reproductive success in stable bluebanded goby (Lythrypnus dalli) hierarchies“. Behaviour 151, Nr. 10 (2014): 1367–87. http://dx.doi.org/10.1163/1568539x-00003188.
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In many social species, there are important connections between social behaviour and reproduction that provide critical insights into the evolution of sociality. In this study, we describe associations between agonistic behaviour and male reproductive success in stable social groups of bluebanded gobies (Lythrypnus dalli). This highly social, sex-changing species forms linear hierarchies of a dominant male and multiple subordinate females. Males reproduce with each female in the harem and care for the eggs. Since aggression tends to be associated with reduced reproduction in social hierarchies, we hypothesized that males in groups with high rates of aggression would fertilise fewer eggs. We also hypothesized that a male’s agonistic behaviour would be associated with his reproductive success. Dominants often exert substantial control over their harem, including control over subordinate reproduction. To address these hypotheses, we quantified egg laying/fertilisation over 13 days and observed agonistic behaviour. We show that there was a significant, negative association between male reproductive success and the total rate agonistic interactions by a group. While no male behaviours were associated with the quantity of eggs fertilised, female agonistic behaviour may be central to male reproductive success. We identified a set of models approximating male reproductive success that included three female behaviours: aggression by the highest-ranking female and approaches by the lowest-ranking female were negatively associated with the quantity of eggs fertilised by males in their groups, but the efficiency with which the middle-ranking female displaced others was positively associated with this measure. These data provide a first step in elucidating the behavioural mechanisms that are associated with L. dalli reproductive success.
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Bailey, James A. „Reproductive success in female mountain goats“. Canadian Journal of Zoology 69, Nr. 12 (01.12.1991): 2956–61. http://dx.doi.org/10.1139/z91-416.
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Kid production by marked females, age ratios from a 24-year study, and the literature are used to evaluate hypotheses that three intrinsic and three extrinsic factors affect reproduction by female Rocky Mountain goats (Oreamnos americanus). On Sheep Mountain – Gladstone Ridge, Colorado, mountain goat age ratios declined while the herd grew during 1966–1979, and continued to decline with population stability during 1980–1989, suggesting a continued increase in ecological density of goats 39 years after they were introduced in 1950. Among intrinsic factors, age and persisting individual characteristics have influenced reproductive success of females. Reproductive success in any year has not limited success in the following year, except in 4-year-olds. Among extrinsic factors, reproductive success of female mountain goats has been negatively influenced by density or ecological density and by snowpack during gestation. Reproductive success of females may have been positively influenced by snowpack that enhanced forage conditions prior to breeding. The relative importance of these six factors in determining reproductive success of females may vary among and (temporally) within herds. Most hypotheses regarding reproductive success in female mountain goats remain poorly tested. Short-term observational studies hold little promise for testing hypotheses, owing to large among-years variation in reproductive success. Long-term, intensive observational studies, or manipulative experiments, are suggested.
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Hayward, Adam D., Ilona Nenko und Virpi Lummaa. „Early-life reproduction is associated with increased mortality risk but enhanced lifetime fitness in pre-industrial humans“. Proceedings of the Royal Society B: Biological Sciences 282, Nr. 1804 (07.04.2015): 20143053. http://dx.doi.org/10.1098/rspb.2014.3053.
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The physiology of reproductive senescence in women is well understood, but the drivers of variation in senescence rates are less so. Evolutionary theory predicts that early-life investment in reproduction should be favoured by selection at the cost of reduced survival and faster reproductive senescence. We tested this hypothesis using data collected from preindustrial Finnish church records. Reproductive success increased up to age 25 and was relatively stable until a decline from age 41. Women with higher early-life fecundity (ELF; producing more children before age 25) subsequently had higher mortality risk, but high ELF was not associated with accelerated senescence in annual breeding success. However, women with higher ELF experienced faster senescence in offspring survival. Despite these apparent costs, ELF was under positive selection: individuals with higher ELF had higher lifetime reproductive success. These results are consistent with previous observations in both humans and wild vertebrates that more births and earlier onset of reproduction are associated with reduced survival, and with evolutionary theory predicting trade-offs between early reproduction and later-life survival. The results are particularly significant given recent increases in maternal ages in many societies and the potential consequences for offspring health and fitness.
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Lynch, Robert F., und Emily C. Lynch. „The impact of parental investment on lifetime reproductive success in Iceland“. PeerJ 5 (19.01.2017): e2904. http://dx.doi.org/10.7717/peerj.2904.
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BackgroundDemonstrating the impact that parents have on the fitness of their children is a crucial step towards understanding how parental investment has affected human evolution. Parents not only transfer genes to their children, they also influence their environments. By analyzing reproductive patterns within and between different categories of close relatives, this study provides insight into the genetic and environmental effects that parents have on the fitness of their offspring.MethodsWe use data spanning over two centuries from an exceptionally accurate Icelandic genealogy, Íslendingabók, to analyze the relationship between the fertility rates of close relatives. Also, using genetic data, we determine narrow sense heritability estimates (h2) to further explore the genetic impact on lifetime reproductive success. Finally, we construct four simulations to model the expected contribution of genes and resources on reproductive success.ResultsThe relationship between the reproduction of all full sibling pairs was significant and positive across all birth decades (r = 0.19) while the reproductive relationship between parents and offspring was often negative across many decades and undetectable overall (r = 0.00) (Fig. 1 and Table 1). Meanwhile, genetic data among 8,456 pairs of full siblings revealed a narrow sense heritability estimate (h2) of 0.00 for lifetime reproductive success. A resources model (following the rule that resources are transmitted from parents to children, distributed equally among siblings, and are the only factor affecting reproductive success) revealed a similar trend: a negative relationship between parent and offspring reproduction (r = − 0.35) but a positive relationship among full siblings (r = 0.28). The relationship between parent and offspring lifetime reproductive success (LRS) and full sibling LRS was strongly and positively correlated across time (r = 0.799,p < 0.001). Similarly, the LRS among full siblings was positively correlated with both the LRS among half siblings (r = 0.532,p = 0.011) and the relationship between the LRS of aunts and uncles with their nieces and nephews (r = 0.438,p = 0.042).DiscussionWe show that an individual’s lifetime reproductive success is best predicted by the reproduction of their full and half siblings, but not their parents, grandparents or aunts and uncles. Because all siblings share at least one parent, we believe parental investment has had an important impact on fitness. Overall, these results indicate that direct parental investment, but not genes, is likely to have had an important and persistent impact on lifetime reproductive success across more than two centuries of Icelandic history.
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Rox, Astrid, Sophie Waasdorp, Elisabeth H. M. Sterck, Jan A. M. Langermans und Annet L. Louwerse. „Multigenerational Social Housing and Group-Rearing Enhance Female Reproductive Success in Captive Rhesus Macaques (Macaca mulatta)“. Biology 11, Nr. 7 (27.06.2022): 970. http://dx.doi.org/10.3390/biology11070970.
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To optimize costs and reproductive success, rhesus macaques in biomedical primate research facilities are often peer-reared. Older, dependent infants are typically removed from their natal group to enhance female reproduction. The minimal husbandry age-norm of infant removal is ten months. These practices deviate from species-specific behavior and may reduce welfare, suggesting a trade-off between female reproduction and welfare. However, the effect of breeding group type and rearing history on female reproductive success (i.e., birth rate; inter-birth interval (IBI); offspring survival) is unclear. This retrospective study investigated whether group type (i.e., peer groups versus multigenerational groups) and rearing history (i.e., peer- or hand-reared; group-reared with peer- or hand-reared mother; group-reared) affected female reproductive success in captive rhesus macaques. Data on female reproduction between 1996 and 2019 were collected at the Biomedical Primate Research Centre, Rijswijk. Birth rates were higher in multigenerational breeding groups than in peer groups. Moreover, group-reared females had higher offspring survival than peer- or hand-reared females. IBI was not affected by breeding group type or female rearing history. However, females in both peer and multigenerational breeding groups typically conceived earlier after giving birth than the husbandry infant removal age-norm of ten months. Thus, infant removal at an age of ten months does not enhance a female’s reproduction. Altogether, female reproduction and non-human primate welfare can simultaneously be optimized through multigenerational breeding groups and group-rearing.
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Halstead, Jennifer E., und Lisa E. Schwanz. „Impacts of thermal limitation on thermoregulatory behaviour and reproductive success in a lizard“. Australian Journal of Zoology 63, Nr. 4 (2015): 225. http://dx.doi.org/10.1071/zo15012.
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Climatic variation can impact populations of ectotherms by altering reproduction, development, and survival. While a warm climate can provide additional thermal opportunities for ectotherms, excessively warm conditions can restrict activity in avoidance of lethal temperatures. However, ectotherms are not necessarily passive to thermal conditions, and often employ flexible thermoregulatory behaviour to accommodate environmental variation. Here, we examine whether the Australian jacky dragon lizard, Amphibolurus muricatus, can compensate for reduced basking opportunity by basking with greater intensity, and how the thermal environment influences reproductive success in females. Overall, there was no compelling evidence for compensatory thermoregulatory behaviour in response to reduced basking opportunity. Moreover, females with reduced thermal opportunities did not produce eggs, although reproductive success was quite low for both groups, so additional factors may have limited reproduction in the colony. This study allows insight into the links between climate and population persistence in wild animals by providing crucial and rare data on how thermal environment impacts reproduction in an egg-laying lizard.
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Murphy, Michael T. „Lifetime Reproductive Success of Female Eastern Kingbirds (Tyrannus Tyrannus): Influence of Lifespan, Nest Predation, and Body Size“. Auk 124, Nr. 3 (01.07.2007): 1010–22. http://dx.doi.org/10.1093/auk/124.3.1010.
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AbstractI report on the lifetime reproductive success (LRS) of female Eastern Kingbirds (Tyrannus tyrannus) in central New York. I investigated the major correlates of LRS and specifically tested the hypothesis that small body size yields reproductive benefits. Lifetime reproductive success varied widely: 15–20% of females failed to fledge young over their life, whereas 50% of young were fledged by 20% of females. Female lifespan varied between one and eight years, and females that died after one breeding season tended to be smaller-bodied than long-lived females (≥2 seasons). I therefore conducted analyses of LRS for the entire sample and for longer-lived females separately. As in other species, lifespan was the strongest predictor of LRS, followed by the proportion of eggs laid that resulted in fledged young (P). Lifetime reproductive success varied positively with clutch size and, as predicted, inversely with body size (i.e., tarsus length) of females. However, variance partitioning indicated that most variation in LRS was attributable to the effects of lifespan and P, but that a substantial negative covariance existed between lifespan and P. The latter result was consistent with experimental evidence of a cost of reproduction in Eastern Kingbirds. Analysis of the correlates of lifespan, P, and clutch size showed that over a female's lifetime, (1) the longest-lived birds fledged an intermediate proportion of the eggs that they laid, (2) the most productive birds were of intermediate wing length, and (3) females with small tarsi produced the largest clutches and lost the fewest nests to predators. Hence, although lifespan was the dominant influence on LRS, negative effects of large female size appeared to be expressed through the influence of body size on other demographic parameters that contribute to LRS.Éxito Reproductivo Completo de Vida de Hembras de Tyrannus tyrannus: Influencia de la Duración de la Vida, la Depredación de Nidos y el Tamaño Corporal
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Festa-Bianchet, Marco. „The cost of trying: weak interspecific correlations among life-history components in male ungulates“. Canadian Journal of Zoology 90, Nr. 9 (September 2012): 1072–85. http://dx.doi.org/10.1139/z2012-080.
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Life-history trade-offs are well known in female mammals, but have seldom been quantified for males in polygynous species. I compared age-specific mass, weapon size, survival, and reproductive success of males in eight species of ungulates, and found weak interspecific correlations among life-history traits. Young males tended to have higher reproductive success in rapidly-growing than in slow-growing species, and in species where horns or antlers reached near-asymptotic size over the first few years of life. There was no clear interspecific trade-off between early reproduction and early survival. Reproductive senescence was evident in most species. Generation length, calculated as the mean age of fathers, was negatively correlated with the reproductive success of young males and positively with life expectancy of 3-year-olds, but not with early mortality. The main determinant of male reproductive success in polygynous ungulates is the ability to prevail against competing males. Consequently, the number and age structure of competitors should strongly affect an individual’s ability to reproduce, making classic trade-offs among life-history traits very context-dependent. Most fitness costs of reproduction in male ungulates likely arise from energy expenditure and injuries sustained while attempting to mate. Individual costs may be weakly correlated with fitness returns.
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Vasilieva, N. A., und A. V. Tchabovsky. „Timing is the only thing: reproduction in female yellow ground squirrels (Spermophilus fulvus)“. Canadian Journal of Zoology 92, Nr. 8 (August 2014): 737–47. http://dx.doi.org/10.1139/cjz-2014-0084.
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Based on 4-year field observations of yellow ground squirrels (Spermophilus fulvus (Lichtenstein, 1823)), we determined whether female reproductive effort, annual reproductive success, and survival were dependent on age, body condition, time of emergence from hibernation, and previous reproduction. The probability of weaning a litter did not vary with female age, body condition, time of emergence, or previous reproduction. Litter size, litter mass, and offspring survival did not vary with age, whereas individual offspring mass was lower in yearlings than in older females. Body condition upon emergence had no effect on litter size, litter mass, offspring mass, and survival. Reproduction did not influence female survival, physical condition upon emergence next spring, or subsequent reproductive efforts. The only factor that affected the extent of reproductive effort and offspring survival was the date of emergence: the later a female emerged, the lower the total and mean offspring mass, and fewer offspring survived. The modulation of reproduction in female S. fulvus by only the timing of vernal emergence and independent of other individual characteristics can be explained by the high costs of missed reproductive opportunity because of short longevity combined with low costs of reproduction when resources are abundant enough to meet both somatic and reproductive needs.
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Međedović, Janko. „Intelligence and Fitness: The Mediating Role of Educational Level“. Evolutionary Psychology 15, Nr. 2 (01.04.2017): 147470491770693. http://dx.doi.org/10.1177/1474704917706936.
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The evolutionary status of intelligence is not clear: It is positively related to various indicators of fitness but negatively to reproductive success as the most important fitness marker. In the present research, we explored the links between intelligence and three fitness indicators: number of children (short-term reproductive success), number of grandchildren (long-term reproductive success), and age at first birth. Participants were individuals in a postreproductive stage ( N = 191; mean age = 66.5 years). Intelligence had a positive correlation with short-term reproductive success and age at first birth but a negative correlation with long-term reproductive success. Participants’ education turned out to be a significant mediator of the link between intelligence and criterion measures. The results showed that intelligence can elevate short-term reproductive success. Furthermore, individuals with higher intellectual abilities tended to delay reproduction, which negatively affected their long-term reproductive success. Education was revealed as a very important resource which affects the link between cognitive abilities and fitness, thus proving its evolutionary role in contemporary populations.
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Fusani, Leonida, Daniele Della Seta, Francesco Dessì-Fulgheri und Francesca Farabollini. „Altered reproductive success in rat pairs after environmental-like exposure to xenoestrogen“. Proceedings of the Royal Society B: Biological Sciences 274, Nr. 1618 (24.04.2007): 1631–36. http://dx.doi.org/10.1098/rspb.2007.0064.
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Endocrine-disrupting compounds (EDCs) have the capacity of altering the normal function of the endocrine system. EDCs have shown dramatic effects on the reproductive biology of aquatic wildlife and may affect human reproduction as well. Studies on EDCs in mammalian species have often investigated the effects of short-term, high doses on male and female reproductive physiology. However, it is difficult to predict from such studies the effects of EDC on populations that are exposed to very low doses throughout their life via contaminated food and water. We studied the effects of EDC on mammalian reproduction with an environmental-like protocol where the endpoint is the reproductive success of exposed pairs. We focused on a subclass of EDC, the xenoestrogens, which mimic the action of natural oestrogen hormones. Male and female rats were exposed to low doses of the pure oestrogen, ethynyloestradiol, during development, by oral administration to their mothers during pregnancy and lactation, and to them until puberty. We evaluated the effects of the exposure on development and reproductive physiology of individuals, and on fertility and fecundity of pairs in which both members had been exposed to the same treatment. We found that low doses caused major reproductive deficits in the experimental animals. Very low, environmentally relevant doses did not have evident effects on exposed animals; however, the fecundity of exposed pairs was substantially altered. Environmentally relevant doses of xenoestrogens which have no evident physiological effects can alter the reproductive success of exposed pairs in natural populations.
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Quiroz-Pacheco, Enya N., Francisco Mora, Karina Boege, César A. Domínguez und Ek del-Val. „Effects of herbivory and its timing on reproductive success of a tropical deciduous tree“. Annals of Botany 126, Nr. 5 (15.08.2020): 957–69. http://dx.doi.org/10.1093/aob/mcaa117.
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Abstract Background and Aims The implications of herbivory for plant reproduction have been widely studied; however, the relationship of defoliation and reproductive success is not linear, as there are many interacting factors that may influence reproductive responses to herbivore damage. In this study we aimed to disentangle how the timing of foliar damage impacts both male and female components of fitness, and to assess when it has greater impacts on plant reproductive success. Methods We measured herbivore damage and its effects on floral production, male and female floral attributes as well as fruit yield in three different phenological phases of Casearia nitida (Salicaceae) over the course of two consecutive years. Then we tested two models of multiple causal links among herbivory and reproductive success using piecewise structural equation models. Key Results The effects of leaf damage differed between reproductive seasons and between male and female components of fitness. Moreover, the impact of herbivory extended beyond the year when it was exerted. The previous season’s cumulated foliar damage had the largest impact on reproductive characters, in particular a negative effect on the numbers of inflorescences, flowers and pollen grains, indirectly affecting the numbers of infructescences and fruits, and a positive one on the amount of foliar damage during flowering. Conclusions For perennial and proleptic species, the dynamics of resource acquisition and allocation patterns for reproduction promote and extend the effects of herbivore damage to longer periods than a single reproductive event and growing season, through the interactions among different components of female and male fitness.
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Casarini, Livio, Daniele Santi und Marco Marino. „Impact of gene polymorphisms of gonadotropins and their receptors on human reproductive success“. REPRODUCTION 150, Nr. 6 (Dezember 2015): R175—R184. http://dx.doi.org/10.1530/rep-15-0251.
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Gonadotropins and their receptors' genes carry several single-nucleotide polymorphisms resulting in endocrine genotypes modulating reproductive parameters, diseases, and lifespan leading to important implications for reproductive success and potential relevance during human evolution. Here we illustrate common genotypes of the gonadotropins and gonadotropin receptors' genes and their clinical implications in phenotypes relevant for reproduction such as ovarian cycle length, age of menopause, testosterone levels, polycystic ovary syndrome, and cancer. We then discuss their possible role in human reproduction and adaptation to the environment. Gonadotropins and their receptors' variants are differently distributed among human populations. Some hints suggest that they may be the result of natural selection that occurred in ancient times, increasing the individual chance of successful mating, pregnancy, and effective post-natal parental cares. The gender-related differences in the regulation of the reproductive endocrine systems imply that many of these genotypes may lead to sex-dependent effects, increasing the chance of mating and reproductive success in one sex at the expenses of the other sex. Also, we suggest that sexual conflicts within the FSH and LH–choriogonadotropin receptor genes contributed to maintain genotypes linked to subfertility among humans. Because the distribution of polymorphic markers results in a defined geographical pattern due to human migrations rather than natural selection, these polymorphisms may have had only a weak impact on reproductive success. On the contrary, such genotypes could acquire relevant consequences in the modern, developed societies in which parenthood attempts often occur at a later age, during a short, suboptimal reproductive window, making clinical fertility treatments necessary.
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Setiawan, Alvin N., Melanie Massaro, John T. Darby und Lloyd S. Davis. „Mate and Territory Retention in Yellow-Eyed Penguins“. Condor 107, Nr. 3 (01.08.2005): 703–9. http://dx.doi.org/10.1093/condor/107.3.703.
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AbstractUsing nest and banding data collected from 1991 to 2002, we investigated mate and territory retention rates of Yellow-eyed Penguins (Megadyptes antipodes), and the effects of reproductive success. Annual mate retention rate was 63%, and territory retention for males and females were 52% and 46% respectively. The majority of pair dissolutions were due to death of a partner, with only 6% of bonds ending in separation. Previous reproductive success was a good predictor of mate or territory retention as pairs that failed to fledge a single chick were significantly more likely to separate or move their territories than those that were successful at fledging chicks. Reproductive success of birds that changed their mates or moved territories was not higher than those that retained their mates or territories. However, birds that moved territories were less likely to have reduced fledging success relative to their previous breeding attempt. Birds that did not retain their mates, particularly males, were significantly more likely to skip breeding for at least one year. This suggests that the costs of mate or territory changes are not accrued at the end of the breeding attempt (as reflected by the number of fledged chicks), but are associated with the costs of pair formation and establishment of territories at the beginning of the breeding season.Retención de Parejas y Territorios en Pingüinos Megadyptes antipodesResumen. Investigamos las tasas de retención de parejas y de territorios por parte de pingüinos Megadyptes antipodes y el efecto del éxito reproductivo sobre estas tasas con base en datos de nidificación y anillamiento recolectados entre 1991 y 2002. La tasa anual de retención de parejas fue del 63% y las de retención de territorios del 52% y 46% para machos y hembras, respectivamente. La mayoría de las disoluciones de parejas se debieron a la muerte de una de las aves y sólo el 6% de las parejas terminaron separándose. El éxito reproductivo previo predijo acertadamente la retención de compañeros y de territorios, ya que las parejas que no lograron emplumar ningún pichón tuvieron una probablilidad de disolverse o de cambiar de territorio significativamente mayor que las que criaron exitosamente. El éxito reproductivo de las aves que cambiaron de pareja o de territorio no fue mayor que el de aquellas que no lo hicieron. Sin embargo, los individuos que cambiaron de territorio fueron más propensos a presentar un éxito de emplumamiento reducido con respecto a su intento reproductivo previo. Las aves que no retuvieron sus parejas, particularmente los machos, presentaron una probabilidad mayor de no reproducirse durante al menos un año. Esto sugiere que los costos que implica cambiar de pareja o de territorio no se hacen evidentes al final del intento reproductivo (como lo indica el número de volantones producidos), sino que están asociados con los costos de la formación de parejas y el establecimiento de territorios al comienzo de la época reproductiva.
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Crockford, Catherine, Liran Samuni, Linda Vigilant und Roman M. Wittig. „Postweaning maternal care increases male chimpanzee reproductive success“. Science Advances 6, Nr. 38 (September 2020): eaaz5746. http://dx.doi.org/10.1126/sciadv.aaz5746.
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Humans are unusual among animals for continuing to provision and care for their offspring until adulthood. This “prolonged dependency” is considered key for the evolution of other notable human traits, such as large brains, complex societies, and extended postreproductive lifespans. Prolonged dependency must therefore have evolved under conditions in which reproductive success is gained with parental investment and diminished with early parental loss. We tested this idea using data from wild chimpanzees, which have similarly extended immature years as humans and prolonged mother-offspring associations. Males who lost their mothers after weaning but before maturity began reproducing later and had lower average reproductive success. Thus, persistent mother-immature son associations seem vital for enhancing male reproductive success, although mothers barely provision sons after weaning. We posit that these associations lead to social gains, crucial for successful reproduction in complex social societies, and offer insights into the evolution of prolonged dependency.
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Michel, Eric S., Stephen Demarais, Bronson K. Strickland, Jerrold L. Belant und Larry E. Castle. „Body mass influences maternal allocation more than parity status for a long-lived cervid mother“. Journal of Mammalogy 100, Nr. 5 (26.07.2019): 1459–65. http://dx.doi.org/10.1093/jmammal/gyz107.
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Abstract Mothers should balance the risk and reward of allocating resources to offspring to optimize the reproductive value of both offspring and mother while maximizing lifetime reproductive success by producing high-quality litters. The reproductive restraint hypothesis suggests maternal allocation should peak for prime-aged mothers and be less for younger mothers such that body condition is not diminished to a level that would jeopardize their survival or future reproductive events. We assessed if reproductive tactics varied by maternal body mass and parity status in captive female white-tailed deer (Odocoileus virginianus) to determine if prime-aged mothers allocate relatively more resources to reproduction than primiparous mothers. Maternal body mass, not parity status, positively affected maternal allocation, with heavier mothers producing both heavy litters and heavy individual offspring. Conversely, maternal body mass alone did not affect litter size, rather the interaction between maternal body mass and parity status positively affected litter size such that maternal body mass displayed a greater effect on litter size for primiparous than multiparous mothers. Our results suggest that heavy white-tailed deer mothers allocate additional resources to current year reproduction, which may be an adaptation allowing mothers to produce high-quality litters and increase their annual reproductive success because survival to the next reproductive attempt is not certain.
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Garcia-Garcia, R. M. „Integrative Control of Energy Balance and Reproduction in Females“. ISRN Veterinary Science 2012 (26.09.2012): 1–13. http://dx.doi.org/10.5402/2012/121389.
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There is a strong association between nutrition and reproduction. Chronic dietary energy deficits as well as energy surpluses can impair reproductive capacity. Metabolic status impacts reproductive function at systemic level, modulating the hypothalamic GnRH neuronal network and/or the pituitary gonadotropin secretion through several hormones and neuropeptides, and at the ovarian level, acting through the regulation of follicle growth and steroidogenesis by means of the growth hormone-IGF-insulin system and local ovarian mediators. In the past years, several hormones and neuropeptides have been emerging as important mediators between energy balance and reproduction. The present review goes over the main sites implicated in the control of energy balance linked to reproductive success and summarizes the most important metabolic and neuroendocrine signals that participate in reproductive events with special emphasis on the role of recently discovered neuroendocrine peptides. Also, a little overview about the effects of maternal nutrition, affecting offspring reproduction, has been presented.
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Pericoli, Ralph V., Emma L. Karsten, Allen M. Fish und Christopher W. Briggs. „Nesting Biology of Urban Cooper’s Hawks in Alameda County, California“. Western Birds 51, Nr. 4 (31.10.2020): 307–17. http://dx.doi.org/10.21199/wb51.4.3.
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In recent decades Cooper’s Hawks have successfully colonized urban landscapes, where there may be ample prey but also a greater prevalence of disease in their prey. We searched for nesting Cooper’s Hawks in and around Berkeley, California, from 2002 to 2010, locating 95 nests, 89 of which successfully fledged at least one nestling. On average, each nest produced 3.6 fledglings. We evaluated the possible effects of the protozoan parasite Trichomonas gallinae on Cooper’s Hawk reproduction from the proportion of potential prey items brought to Lindsay Wildlife Experience that tested positive for the parasitic disease. We did not find a correlation between T. gallinae in potential prey species and nest success (i.e., if the nest fledged any offspring) or reproductive success (i.e., number of fledglings produced). Similarly, we did not find a relationship between reproductive success and distance to parks or percent of impervious surface within 500 m of the nest. The high reported rates of reproduction and high densities of Cooper’s Hawk in Berkeley and neighboring Albany suggest a robust population, and we did not find evidence that T. gallinae influences its reproductive success.
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Međedović, Janko. „The Position of Body Mass in a Network of Human Life History Indicator“. Psihologijske teme 31, Nr. 2 (17.07.2022): 403–25. http://dx.doi.org/10.31820/pt.31.2.10.
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Body mass is widely recognized as a morphological trait which is important for fitness optimization both in humans and other animals. Here, we propose that body mass is a part of fast life history trajectory – the fitness optimization pattern which emerges from harsh environment with a function to maximize reproductive output. To test this prediction, we measured body mass index (BMI) and a set of life history indicators in a large sample of reproductive individuals (N = 1,504; 32% males; Mage = 27.20; SD = 9.2). The data were collected via an online survey. Bivariate correlations showed that BMI was positively related to reproductive success, childhood poverty, and short-term mating success; furthermore, it was negatively associated to physical health, age of the first menarche, and economic reasons against reproduction. The Network Analysis confirmed that BMI is positively related to short-term mating success and reproductive success, and negatively to physical health and economic reasons against reproduction. Furthermore, centrality metrics showed that BMI has relatively low centrality indices, and thus represents a peripheral node in the network. The present data confirm that body mass is a morphological trait which participates in the fast life history trajectory of fitness optimization. A body mass which is slightly higher than population mean (but below obesity levels) probably represents an adaptive response to depriving economic conditions in childhood and contributes to the maximization of reproductive fitness. Finally, we highlight that the relations between body mass and life history may differ between and within species.
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Bell, M. B. V., H. J. Nichols, J. S. Gilchrist, M. A. Cant und S. J. Hodge. „The cost of dominance: suppressing subordinate reproduction affects the reproductive success of dominant female banded mongooses“. Proceedings of the Royal Society B: Biological Sciences 279, Nr. 1728 (13.07.2011): 619–24. http://dx.doi.org/10.1098/rspb.2011.1093.
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Social species show considerable variation in the extent to which dominant females suppress subordinate reproduction. Much of this variation may be influenced by the cost of active suppression to dominants, who may be selected to balance the need to maximize the resources available for their own offspring against the costs of interfering with subordinate reproduction. To date, the cost of reproductive suppression has received little attention, despite its potential to influence the outcome of conflict over the distribution of reproduction in social species. Here, we investigate possible costs of reproductive suppression in banded mongooses, where dominant females evict subordinates from their groups, thereby inducing subordinate abortion. We show that evicting subordinate females is associated with substantial costs to dominant females: pups born to females who evicted subordinates while pregnant were lighter than those born after undisturbed gestations; pups whose dependent period was disrupted by an eviction attained a lower weight at independence; and the proportion of a litter that survived to independence was reduced if there was an eviction during the dependent period. To our knowledge, this is the first empirical study indicating a possible cost to dominants in attempting to suppress subordinate breeding, and we argue that much of the variation in reproductive skew both within and between social species may be influenced by adaptive variation in the effort invested in suppression by dominants.
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DuVal, Emily H. „Variation in annual and lifetime reproductive success of lance-tailed manakins: alpha experience mitigates effects of senescence on siring success“. Proceedings of the Royal Society B: Biological Sciences 279, Nr. 1733 (16.11.2011): 1551–59. http://dx.doi.org/10.1098/rspb.2011.1840.
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The causes of variation in individual reproductive success over a lifetime are not well understood. In long-lived vertebrates, reproductive output usually increases during early adulthood, but it is difficult to disentangle the roles of development and learning on this gain of reproductive success. Lekking lance-tailed manakins provide an opportunity to separate these processes, as the vast majority of male reproduction occurs after a bird obtains alpha status and maintains a display area in the lek, but the age at which males achieve alpha status varies widely. Using 11 years of longitudinal data on age, social status and genetic siring success, I assessed the factors influencing variation in siring success by individuals over their lifetimes. The data show increases in annual reproductive success with both age and alpha experience. At advanced ages, these gains were offset by senescence in fecundity. Individual ontogeny, rather than compositional change of the population, generated a nonlinear relationship of breeding tenure with lifetime success; age of assuming alpha status was unrelated to tenure as a breeder, or success in the alpha role. Importantly, these findings suggest that social experience can mitigate the negative effects of senescence in older breeders.
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Pike, D. A., und J. C. Stiner. „Fluctuating reproductive output and environmental stochasticity: do years with more reproducing females result in more offspring?“ Canadian Journal of Zoology 85, Nr. 6 (Juni 2007): 737–42. http://dx.doi.org/10.1139/z07-055.
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Reproduction is a key life-history process often constrained by abiotic conditions, which affect resource availability and influence reproductive output, including the number of females in a population that reproduce within a given year. We investigated whether population-level fluctuations in reproductive effort (i.e., the number of nesting females) result in fluctuations in the number of offspring produced under environmentally stochastic conditions. Here we show that timing and frequency of tropical storms constrain reproductive success in green sea turtles ( Chelonia mydas (L., 1758)); in years when storms arrive early or when multiple storms occur most green sea turtle nests are inundated by seawater and fail to hatch. Although equal proportions of the nests were destroyed by tropical storms in peak and non-peak nesting years, significantly more hatchlings emerged from nests during peak nesting years. Thus, the cyclic patterns of green sea turtle reproduction result in cyclic patterns of hatchling emergence under high levels of nest failure owing to seawater inundation. Ultimately, green sea turtle reproductive success is constrained by the timing of tropical storms in relation to the nesting season. Continuing increases in the severity of tropical storms from changing global climates could contribute to a higher proportion of nesting seasons with low reproductive success, such that population growth rates are slowed, which may have long-term negative effects on the ability of this species to recover to historical levels.
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Ebbing, Alexander P. J., Gregory S. Fivash, Nuria B. Martin, Ronald Pierik, Tjeerd J. Bouma, Jacco C. Kromkamp und Klaas Timmermans. „In-Culture Selection and the Potential Effects of Changing Sex Ratios on the Reproductive Success of Multiannual Delayed Gametophytes of Saccharina latissima and Alaria esculenta“. Journal of Marine Science and Engineering 9, Nr. 11 (11.11.2021): 1250. http://dx.doi.org/10.3390/jmse9111250.
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Multiannual delayed gametophyte cultures can stay vegetative for years, while also having the ability to grow. This study aims to investigate whether male and female multiannual delayed gametophyte strains of the species Saccharina latissima and Alaria esculenta grow at different rates in culture. We furthermore assessed how changing sex ratios can affect the reproductive yields of these cultures. The results indicate that the reproductive yield of cultures declines with decreasing male:female ratios, a correlation that becomes especially apparent at higher culture densities for both species. Female gametophyte densities in particular affected the observed reproductive yield of the cultures, with S. latissima cultures showing a clear reproductive optimum (sporophytes·mL−1) at 0.013 mg·mL−1 DW female gametophyte biomass, while the reproductive success of A. esculenta peaked at a density of 0.025 mg·mL−1 DW of female gametophyte biomass, after which the reproductive yield started to decline in both species. The results show that the sex ratio of a gametophyte culture is an important biotic life cycle control, with higher amounts of female gametophyte biomass halting gametophyte reproduction. Understanding how these changing sex ratios in gametophyte cultures affect reproduction is especially important in the aquaculture of kelp, where reliable preforming cultures are key to long-term success.
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Rodríguez Gabilondo, Adrian, Liz Hernández Pérez und Rebeca Martínez Rodríguez. „Hormonal and neuroendocrine control of reproductive function in teleost fish.“ Bionatura 3, Nr. 3 (15.08.2021): 2122–33. http://dx.doi.org/10.21931/rb/2021.06.02.35.
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Reproduction is one of the important physiological events for the maintenance of the species. Hormonal and neuroendocrine regulation of teleost requires multiple and complex interactions along the hypothalamic-pituitary-gonad (HPG) axis. Within this axis, gonadotropin-releasing hormone (GnRH) regulates the synthesis and release of gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Steroidogenesis drives reproduction function in which the development and differentiation of gonads. In recent years, new neuropeptides have become the focus of reproductive physiology research as they are involved in the different regulatory mechanisms of these species' growth, metabolism, and reproduction. However, especially in fish, the role of these neuropeptides in the control of reproductive function is not well studied. The study of hormonal and neuroendocrine events that regulate reproduction is crucial for the development and success of aquaculture.
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Nicolai, A., J. Filser, V. Briand und M. Charrier. „Seasonally contrasting life-history strategies in the land snail Cornu aspersum: physiological and ecological implications“. Canadian Journal of Zoology 88, Nr. 10 (Oktober 2010): 995–1002. http://dx.doi.org/10.1139/z10-066.
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When a life history is characterized by both seasonality in reproduction and seasonality in offspring fitness, trade-offs in reproductive traits might be adjustments to seasonal time constraints to optimize reproductive success. Therefore, we compared in the laboratory the trade-offs in reproductive traits between early (after maturity) and delayed (after dormancy) reproduction in young land snails Cornu aspersum (Müller, 1774) (syn. Helix aspersa ), depending on food energy content. We also investigated the maternal investment in reproductive output in both breeding periods. After attaining maturity, snails produced single clutches with many small eggs, which resulted, in contrast to previous studies, in large offspring with a low hatching rate owing to high within-clutch cannibalism. The young cannibals may have a higher survival probability in the following hibernation. Snails starting to reproduce after hibernation had smaller clutches of larger eggs, resulting in high quantity of lighter offspring. The clutch mass was positively correlated with maternal mass in snails reproducing after having attained maturity and negatively correlated in snails reproducing after hibernation. Multiple oviposition occurred only after hibernation, thereby enhancing reproductive success. An energy-rich diet did not affect reproductive strategies. Further studies should focus on seasonal plasticity of reproductive strategies in natural populations of C. aspersum and investigate survival probabilities of breeders and juveniles in an evolutionary context.
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Bercovitch, Fred B. „Reproductive success“. Ethology and Sociobiology 11, Nr. 2 (März 1990): 141–43. http://dx.doi.org/10.1016/0162-3095(90)90034-4.
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Sinsch, Ulrich, Katharina Hecht, Silvia Kost, Pablo R. Grenat und Adolfo L. Martino. „Asymmetric Male Mating Success in Lek-Breeding Rhinella arenarum“. Animals 12, Nr. 23 (24.11.2022): 3268. http://dx.doi.org/10.3390/ani12233268.
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Mate choice is the attempt of an individual to gain higher reproductive fitness by preferring to mate with some individuals and not with others. We studied the role of mate choice in the mating system of the neotropical toad Rhinella arenarum by assessing male reproductive tactics for mate acquisition and the contribution of female choice for pair formation. In a shallow pond in central Argentina, we estimated male mating success and the corresponding reproductive tactics by focal observation. The variation of phenotypic and genotypic traits (size and shape, longevity, vocalization features, heterozygosity) was related to the observed mating success in 110 males. The phonotactic response of 21 reproductive females to conspecific advertisement call features was tested in arena experiments. Mating success was limited to 32 males, pair formation was size-assortative. The dominant reproductive tactics were advertising from call positions near suitable breeding sites and pre-mating fights with intruding males, whereas the interception of amplectant pairs and the displacement of mated males were never observed. Female phonotaxis was directed to conspecific choruses but complex and simple call structures were not distinguished. We conclude that the mating system is a lek combining pre-mating fights among males and female choice of slightly smaller males. Fights interfere with female choice, undermining size-assortative mating. This is a unique system in the R. marina species group, in which interception behavior dominates reproduction.
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Dorn, Nathan J., und Gary G. Mittelbach. „Effects of a native crayfish (Orconectes virilis) on the reproductive success and nesting behavior of sunfish (Lepomis spp.)“. Canadian Journal of Fisheries and Aquatic Sciences 61, Nr. 11 (01.11.2004): 2135–43. http://dx.doi.org/10.1139/f04-158.
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While crayfish are traditionally considered fish prey, they are capable of feeding on substrate-bound fish eggs and their introductions have been blamed for the decline in fish populations in Europe and North America. To investigate their potential effects on fish reproductive success we measured the effects of a native crayfish (Orconectes virilis) on the reproductive success of two substrate-nesting sunfish, pumpkinseed (Lepomis gibbosus) and bluegill (Lepomis macrochirus), in replicated pond experiments. Crayfish were observed feeding on eggs in both experiments. Crayfish presence delayed successful reproduction by pumpkinseeds in densely vegetated ponds, resulting in lower young-of-the-year biomass in ponds with crayfish. In the second experiment, with bluegills in less-vegetated ponds, crayfish prevented successful reproduction entirely. However, when we added crayfish-proof exclosures to the crayfish ponds late in the summer, bluegills located the crayfish-free habitat and successfully reproduced inside the exclosures (1 month after first successful reproduction in control ponds). The results of these experiments demonstrate the potential strong negative effects of crayfish on sunfish reproduction and suggest that the spatial distribution of crayfish and other egg predators may influence fish nesting behaviors and habitat choices. Further studies are needed to determine the magnitude of crayfish effects in natural lakes and ponds where sunfish and crayfish co-occur.
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Jahren, Torfinn, Torstein Storaas, Tomas Willebrand, Pål Fossland Moa und Bjørn-Roar Hagen. „Declining reproductive output in capercaillie and black grouse – 16 countries and 80 years“. Animal Biology 66, Nr. 3-4 (2016): 363–400. http://dx.doi.org/10.1163/15707563-00002514.
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Declines in populations of capercaillie (Tetrao urogallus) and black grouse (Lyrurus tetrix) have been reported from both Central Europe and the continuous boreal forests of Fennoscandia. While intensified land-use is assumed to be the underlying cause of these declines, the mechanisms are not yet understood. Predation is the proximate cause of mortality of eggs, chicks and adults throughout capercaillie and black grouse ranges, but the link between predation and habitat and/or climate change remains unclear. To investigate temporal trends in reproductive output of woodland grouse, we collated previously published and unpublished data of reproduction in capercaillie and black grouse throughout their ranges from 1930 to 2012. We show that, overall, reproductive success has decreased and stabilized at low levels in most regions whilst capercaillie reproductive output in Scotland is still declining. With today’s net reproduction, capercaillie and black grouse adult survival is too low to compensate for reproduction declines. Consequently, populations are expected to further decline unless reproductive performances improve. We put our findings in the context of changes in land use, climate and generalist predator numbers. By critically reviewing how these factors limit reproductive success in capercaillie and black grouse, we hope to shed light on the underlying mechanisms causing the decline. Our results imply that measures should be undertaken to reduce mortality of capercaillie and black grouse chicks and eggs. We suggest that future studies should aim to better understand which predators limit capercaillie and black grouse populations and how predation rates are mediated by continuously changing habitat and climate.
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Millar, John S., Elissa M. Derrickson und S. T. P. Sharpe. „Effects of reproduction on maternal survival and subsequent reproduction in northern Peromyscus maniculatus“. Canadian Journal of Zoology 70, Nr. 6 (01.06.1992): 1129–34. http://dx.doi.org/10.1139/z92-158.
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Female survival, number of young weaned, and offspring survival were documented for 130 individual Peromyscus maniculatus in the Kananaskis Valley, southwestern Alberta. Reproductive success was highly variable, ranging from 0 to 19 young per female at weaning and from 0 to 12 young per female at the end of the breeding season. Breeding success was not related to body size of the female prior to breeding, and the commitment to reproductive processes had no negative effects on female survival or the survival of the offspring. Most of the variation in reproductive success was attributable to female survival. Females that survived the entire breeding season weaned, on average, twice as many young as females that did not survive the breeding season. We suggest that physiological and behavior compensation and local habitat effects mask potential costs of reproduction during the breeding season. We speculate that any negative effects of high reproductive success may be evident during the nonbreeding season, or prior to breeding in the spring.
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Anderson, Sydni, Elizabeth Sipes, Megan Franke und Dena Hammond-Weinberger. „Spawning Conditions Affect Clutch Probability and Size in Laboratory-Housed Zebrafish (Danio rerio)“. American Journal of Undergraduate Research 20, Nr. 1 (30.06.2023): 47–58. http://dx.doi.org/10.33697/ajur.2023.079.
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Zebrafish are common experimental models used in biological studies that are bred and raised in laboratory settings. Published studies, anecdotal evidence, and industry practices are variable and offer conflicting suggestions on maximizing reproductive success, particularly regarding sex ratios and segregating males and females before spawning. This study identified conditions that promote maximum reproductive success (clutch probability and average clutch size) in zebrafish. Clutch probability was higher when females were seven to ten months old and bred in groups with equal sex ratios and an artificial spawning substrate in the winter or spring. Clutch size was significantly larger when females were seven to ten months old, outnumbered by males, and bred with an artificial spawning substrate. Optional spawning substrates (marbles and plants) improved reproductive success, whereas other parameters had no impact. These data support the implementation of simple steps that reliably maximize reproductive success of laboratory zebrafish. KEYWORDS: Reproduction; Breeding; Seasonality; Behavior; Substrate; Sex Ratios; Captivity; Eggs
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Ramírez, Francisco, Isabel Afán, Giacomo Tavecchia, Ignacio A. Catalán, Daniel Oro und Ana Sanz-Aguilar. „Oceanographic drivers and mistiming processes shape breeding success in a seabird“. Proceedings of the Royal Society B: Biological Sciences 283, Nr. 1826 (16.03.2016): 20152287. http://dx.doi.org/10.1098/rspb.2015.2287.
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Understanding the processes driving seabirds' reproductive performance through trophic interactions requires the identification of seasonal pulses in marine productivity. We investigated the sequence of environmental and biological processes driving the reproductive phenology and performance of the storm petrel ( Hydrobates pelagicus ) in the Western Mediterranean. The enhanced light and nutrient availability at the onset of water stratification (late winter/early spring) resulted in annual consecutive peaks in relative abundance of phytoplankton, zooplankton and ichthyoplankton. The high energy-demanding period of egg production and chick rearing coincided with these successive pulses in food availability, pointing to a phenological adjustment to such seasonal patterns with important fitness consequences. Indeed, delayed reproduction with respect to the onset of water stratification resulted in both hatching and breeding failure. This pattern was observed at the population level, but also when confounding factors such as individuals' age or experience were also accounted for. We provide the first evidence of oceanographic drivers leading to the optimal time-window for reproduction in an inshore seabird at southern European latitudes, along with a suitable framework for assessing the impact of environmentally driven changes in marine productivity patterns in seabird performance.
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Larson, Douglas L., Jacob G. Kimmel, Joseph J. Riedy, Jonathan Hegna, Edward A. Baker und Kim T. Scribner. „Male lake sturgeon (Acipenser fulvescens) migratory and spawning behaviors are associated with sperm quality and reproductive success“. Canadian Journal of Fisheries and Aquatic Sciences 77, Nr. 12 (Dezember 2020): 1943–59. http://dx.doi.org/10.1139/cjfas-2020-0124.
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Intra-annual reproductive investments may not be predictive of male reproductive success because of the effects of intra- and intersexual interactions on sperm depletion. For long-lived iteroparous fish species such as lake sturgeon (Acipenser fulvescens), reproductive effort may affect lifetime reproductive success. Radio frequency identification antennas were placed at the mouth of the Upper Black River, Michigan, and downstream of spawning locations to quantify male migratory and mating behaviors, including upstream migration time (UT), river residence time (RT), number of intra-annual spawning migrations (IM), interannual spawning interval, and operational sex ratio during 2017–2018. Computer assisted sperm analysis was used to quantify sperm quality. RT had a strong negative influence on sperm concentration and with measures of sperm quality. RT and the number of females encountered were positively associated with male reproductive success (number of offspring sired) across years. RT, IM, and UT were negatively associated with sperm quality, indicating sperm depletion is a reliable measure of sexual activity. Results demonstrate trade-offs between benefits and costs associated with current reproductive effort on future reproduction.
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Velando, Alberto, Hugh Drummond und Roxana Torres. „Senescent birds redouble reproductive effort when ill: confirmation of the terminal investment hypothesis“. Proceedings of the Royal Society B: Biological Sciences 273, Nr. 1593 (21.03.2006): 1443–48. http://dx.doi.org/10.1098/rspb.2006.3480.
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This study reports an experimental confirmation of the terminal investment hypothesis, a longstanding theoretical idea that animals should increase their reproductive effort as they age and their prospects for survival and reproduction decline. Previous correlational and experimental attempts to test this hypothesis have yielded contradictory results. In the blue-footed booby, Sula nebouxii , a long-lived bird, after initial increase, male reproductive success declines progressively with age. Before laying, males of two age classes were challenged with lipopolysaccharide to elicit an immune response, which induced symptoms of declining survival prospects. Reproductive success of immune-challenged mature males fell, while that of immune-challenged old males showed a 98% increase. These results demonstrate that senescent males with poor reproductive prospects increase their effort when those prospects are threatened, whereas younger males with good reproductive prospects do not.