Siga este enlace para ver otros tipos de publicaciones sobre el tema: Gender of sexually monomorphic birds.
Artículos de revistas sobre el tema "Gender of sexually monomorphic birds"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 15 mejores artículos de revistas para su investigación sobre el tema "Gender of sexually monomorphic birds".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore artículos de revistas sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
1
Purwaningrum, Medania, Herjuno Ari Nugroho, Machmud Asvan, Karyanti Karyanti, Bertha Alviyanto, Randy Kusuma y Aris Haryanto. "Molecular techniques for sex identification of captive birds". Veterinary World 12, n.º 9 (septiembre de 2019): 1506–13. http://dx.doi.org/10.14202/vetworld.2019.1506-1513.
Texto completoResumen
Background and Aim: Many avian species are considered sexually monomorphic. In monomorphic bird species, especially in young birds, sex is difficult to identify based on an analysis of their external morphology. Accurate sex identification is essential for avian captive breeding and evolutionary studies. Methods with varying degrees of invasiveness such as vent sexing, laparoscopic surgery, steroid sexing, and chromosome inspection (karyotyping) are used for sex identification in monomorphic birds. This study aimed to assess the utility of a non-invasive molecular marker for gender identification in a variety of captive monomorphic birds, as a strategy for conservation. Materials and Methods: DNA was isolated from feather samples from 52 individuals representing 16 species of 11 families indigenous to both Indonesia and elsewhere. We amplified the chromodomain helicase DNA-binding (CHD) gene using polymerase chain reaction with MP, NP, and PF primers to amplify introns with lengths that differ between the CHD-W and the CHD-Z genes, allowing sex discrimination because the W chromosome is exclusively present in females. Results: Molecular bird sexing confirmed 33 females and 19 males with 100% accuracy. We used sequencing followed by alignment on one protected bird species (Probosciger aterrimus). Conclusion: Sex identification may be accomplished noninvasively in birds, because males only have Z sex chromosomes, whereas females have both Z and W chromosomes. Consequently, the presence of a W-unique DNA sequence identifies an individual as female. Sexing of birds is vital for scientific research, and to increase the success rate of conservation breeding programs.
2
Rottenberg, Aaron, Eviatar Nevo y Daniel Zohary. "Genetic variability in sexually dimorphic and monomorphic populations of Populus euphratica (Salicaceae)". Canadian Journal of Forest Research 30, n.º 3 (1 de marzo de 2000): 482–86. http://dx.doi.org/10.1139/x99-230.
Texto completoResumen
The genetic polymorphism of three populations of the dioecious riparian tree Populus euphratica Oliv. in Israel was examined with isozyme tests. Twelve enzyme systems revealed 20 putative loci, of which 13 were polymorphic. A centrally located population (comprising both females and males) was sampled, as well as two small peripheral and isolated stands: one comprised of only females and one containing males only. Genetic diversity values in P. euphratica were usually lower than those reported in other poplars and other species with similar life-history traits. The highest genetic diversity was found in the central, sexually dimorphic population; however, the sexually monomorphic (unisexual) marginal populations also manifested some genetic diversity, with the lowest values in the male population. Each of the unisexual populations could have originated from very few founder individuals of the same gender. The genetic variability detected in the unisexual populations may reflect somatic mutations accumulated in a vegetatively reproducing lineage over a long time span.
3
Schull, Quentin, Vincent A. Viblanc, F. Stephen Dobson, Jean-Patrice Robin, Sandrine Zahn, Robin Cristofari, Pierre Bize y François Criscuolo. "Assortative pairing by telomere length in King Penguins (Aptenodytes patagonicus) and relationships with breeding success". Canadian Journal of Zoology 96, n.º 6 (junio de 2018): 639–47. http://dx.doi.org/10.1139/cjz-2017-0094.
Texto completoResumen
Telomeres are noncoding genetic repeats protecting the ends of linear chromosomes. Long telomeres are often associated with high individual survival, and interindividual variation in telomere length has recently been proposed as a proxy for individual quality. Therefore, one might expect individuals of either sex with long telomeres to be of higher intrinsic quality and to be preferred in the context of mate choice. Thus, in sexually monomorphic species where individuals discriminate mates on the basis of signals of intrinsic quality, mate choice should lead to assortative pairing by telomere length, and it should be associated with breeding performance. We tested these two predictions in the King Penguin (Aptenodytes patagonicus J.F. Miller, 1778), a sexually monomorphic seabird. Over 3 years of study and 73 penguin pairs under contrasting environmental conditions, we found strong assortative pairing by telomere length. Interestingly, only female telomere length was positively associated to chick survival up to fledging, and this relationship was only apparent when foraging conditions at sea were average. The positive link between telomere length and breeding success confirmed that telomere length is somehow related to individual biological state at a given time. The proximate mechanisms by which birds assess individual state related to telomere length remain to be discovered.
4
Dobreva, Mariya P., Joshua G. Lynton-Jenkins, Jaime A. Chaves, Masayoshi Tokita, Camille Bonneaud y Arkhat Abzhanov. "Sex identification in embryos and adults of Darwin’s finches". PLOS ONE 16, n.º 3 (5 de marzo de 2021): e0237687. http://dx.doi.org/10.1371/journal.pone.0237687.
Texto completoResumen
Darwin’s finches are an iconic example of adaptive radiation and evolution under natural selection. Comparative genetic studies using embryos of Darwin’s finches have shed light on the possible evolutionary processes underlying the speciation of this clade. Molecular identification of the sex of embryonic samples is important for such studies, where this information often cannot be inferred otherwise. We tested a fast and simple chicken embryo protocol to extract DNA from Darwin’s finch embryos. In addition, we applied minor modifications to two of the previously reported PCR primer sets for CHD1, a gene used for sexing adult passerine birds. The sex of all 29 tested embryos of six species of Darwin’s finches was determined successfully by PCR, using both primer sets. Next to embryos, hatchlings and fledglings are also impossible to distinguish visually. This extends to juveniles of sexually dimorphic species which are yet to moult in adult-like plumage and beak colouration. Furthermore, four species of Darwin’s finches are monomorphic, males and females looking alike. Therefore, sex assessment in the field can be a source of error, especially with respect to juveniles and mature monomorphic birds outside of the mating season. We caught 567 juveniles and adults belonging to six species of Darwin’s finches and only 44% had unambiguous sex-specific morphology. We sexed 363 birds by PCR: individuals sexed based on marginal sex specific morphological traits; and birds which were impossible to classify in the field. PCR revealed that for birds with marginal sex specific traits, sexing in the field produced a 13% error rate. This demonstrates that PCR based sexing can improve field studies on Darwin’s finches, especially when individuals with unclear sex-related morphology are involved. The protocols used here provide an easy and reliable way to sex Darwin’s finches throughout ontogeny, from embryos to adults.
5
Sogge, Mark K., Thomas J. Koronkiewicz, Charles Van Riper y Scott L. Durst. "Willow Flycatcher Nonbreeding Territory Defense Behavior in Costa Rica". Condor 109, n.º 2 (1 de mayo de 2007): 475–80. http://dx.doi.org/10.1093/condor/109.2.475.
Texto completoResumen
Abstract We studied the intraspecific territorial defense behavior of wintering Willow Flycatchers (Empidonax traillii) in Costa Rica using a randomized playback experiment that exposed male and female birds to recordings of Willow Flycatcher songs and calls, Lesser Ground Cuckoo (Morococcyx erythropygius) vocalizations, and random noise. Flycatchers of both sexes responded most strongly to simulated conspecific territory intrusion, and the agonistic behaviors that we observed were similar to those seen during natural intraspecific encounters in winter. Both males and females engaged in song and aggressive behaviors in defense of territories, and there was no significant difference between the sexes in scored agonistic responses. The similarity between the sexes in intraspecific territorial defense behaviors and aggressiveness may account for both sexes of flycatchers using the same habitats at our study sites in Costa Rica, and wintering females defending territories against males. The Willow Flycatcher, a sexually monomorphic species, differs in this way from a number of sexually dimorphic passerines, in which behaviorally dominant males occur in more optimal winter habitats.
6
A. Weston, M., F. J. L. Kraaijeveld-Smit, R. McIntosh, G. Sofronidis y M. A. Elgar. "A male-biased sex-ratio in non-breeding Hooded Plovers on a salt-lake in Western Australia". Pacific Conservation Biology 9, n.º 4 (2003): 273. http://dx.doi.org/10.1071/pc040273.
Texto completoResumen
The Hooded Plover Thinornis rubricollis is a threatened, sexually monomorphic wading bird that occurs in two allopatric populations in eastern and western Australia. We used a PCR-based molecular sexing technique to sex captured birds from both populations. We found 69% of adults captured at a salt-lake in Western Australia were male. We tested for a sex-bias in our trapping technique by examining the sex-ratio of eastern birds captured under circumstances analogous to the western capture operation. No sex-bias in the trapping technique was apparent although the sample size was low. This suggests that the male-bias at the lake was real. Any spatial or habitat-related segregation of the sexes must be investigated before we can conclude that the bias is a trait of the western population. If the bias occurs in the population as a whole, then the effective size of the breeding population will be less than that indicated by counts. If the sexes segregate to different sites or habitats, then spatially constrained threatening processes may lead to a skewed sex-ratio.
7
Hutchison, R. E., J. B. Hutchison y L. Fusani. "Vocal-Postural Co-Ordination of a Sexually Dimorphic Display in a Monomorphic Species: the Barbary Dove". Behaviour 134, n.º 5-6 (1997): 321–35. http://dx.doi.org/10.1163/156853997x00566.
Texto completoResumen
AbstractIn the Barbary dove (Streptopelia risoria L.), communication involves visual and vocal signals. In this species, behavioural interaction between sexual partners leads to changes in the reproductive hormonal condition of both sexes. At the beginning of courtship, male doves perform the bowing display. This display is composed of a stereotyped movement pattern (bowing) combined with an acoustic pattern (bow-call). In this paper, we studied the individual temporal patterning of bowing and the bow-call and how they are integrated in the display. The co-ordination between bowing movements and bow-call was analysed using a digital system for the synchronous analysis of acoustic-visual signals. Bow-calls differ between individuals in both temporal and frequency characteristics, and in their repetition rate. The bowing movements do not differ between individuals in their temporal structure but the repetition rate is individually different. The repetition rates of the vocal and postural motor patterns are highly correlated. However, the two signals are not synchronised and the phase delay between them is individually different. We suggest that in the bowing display the gender and the identity are signalled respectively by the bowing pattern and the bow-call. The integration of the two signals generates a third signal, the integrated bowing display rate. The role of the three signals during male-male encounters and during courtship behaviour is discussed.
8
Witte, Klaudia, Anne Hörster y Eberhard Curio. "NO SEXUAL IMPRINTING ON A RED BILL AS A NOVEL TRAIT". Behaviour 137, n.º 9 (2000): 1223–39. http://dx.doi.org/10.1163/156853900502619.
Texto completoResumen
AbstractSexual imprinting is one of several known non - genetical, yet social factors which influence mate preferences and might play a role in the evolution of novel traits. We introduced a red bill as a novel trait in a monomorphic estrildid finch, the Javanese mannikin Lonchura leucogastroides. We established three different imprinting groups in which the father only, the mother only or none of the parents had a red bill. After reaching maturity we tested the offspring in double choice tests for a response to birds of the opposite sex with a naturally coloured black bill or with an artificially coloured red bill. Neither males nor females showed a preference for potential mates with a red bill. Males and females raised by a red bill father showed even a strong rejection to conspecifics of the opposite sex with a red bill. This is in contrast to a previous imprinting study in the Javanese mannikin under similar conditions (Witte et al., 2000) in which males and females became sexually imprinted on conspecifics adorned with a red feather on the forehead. It seems that not all kinds of novel traits birds can be sexually imprinted on. We could show in the present study that the red bill is a meaningful trait in female mate choice, i.e. females responded to males with and without a red bill in a similar way as do females imprinted on natural type parents to males with and without other artificial adornments (Witte & Curio, 1999). We could confirm an interaction between the red bill and the natural attractiveness of males as found in a previous study (Witte & Curio, 1999). Our study opens up questions about what traits are really learned and why some traits are not learned during imprinting.
9
Cheviron, Z. A., Shannon J. Hackett y Robb T. Brumfield. "Sequence variation in the coding region of the melanocortin-1 receptor gene ( MC1R ) is not associated with plumage variation in the blue-crowned manakin ( Lepidothrix coronata )". Proceedings of the Royal Society B: Biological Sciences 273, n.º 1594 (4 de abril de 2006): 1613–18. http://dx.doi.org/10.1098/rspb.2006.3499.
Texto completoResumen
Avian plumage traits are the targets of both natural and sexual selection. Consequently, genetic changes resulting in plumage variation among closely related taxa might represent important evolutionary events. The molecular basis of such differences, however, is unknown in most cases. Sequence variation in the melanocortin-1 receptor gene ( MC1R ) is associated with melanistic phenotypes in many vertebrate taxa, including several avian species. The blue-crowned manakin ( Lepidothrix coronata ), a widespread, sexually dichromatic passerine, exhibits striking geographic variation in male plumage colour across its range in southern Central America and western Amazonia. Northern males are black with brilliant blue crowns whereas southern males are green with lighter blue crowns. We sequenced 810 bp of the MC1R coding region in 23 individuals spanning the range of male plumage variation. The only variable sites we detected among L. coronata sequences were four synonymous substitutions, none of which were strictly associated with either plumage type. Similarly, comparative analyses showed that L. coronata sequences were monomorphic at the three amino acid sites hypothesized to be functionally important in other birds. These results demonstrate that genes other than MC1R underlie melanic plumage polymorphism in blue-crowned manakins.
10
Montalti, Diego, Maricel Graña Grilli, René E. Maragliano y Guillermo Cassini. "The reliability of morphometric discriminant functions in determining the sex of Chilean flamingos Phoenicopterus chilensis". Current Zoology 58, n.º 6 (1 de diciembre de 2012): 851–55. http://dx.doi.org/10.1093/czoolo/58.6.851.
Texto completoResumen
Abstract Monomorphic birds cannot be sexed visually and discriminant functions on the basis of external morphological variations are frequently used. Our objective was to evaluate the reliability of sex classification functions created from structural measurements of Chilean flamingos Phoenicopterus chilensis museum skins for the gender assignment of live birds. Five measurements were used to develop four discriminant functions: culmen, bill height and width, tarsus length and middle toe claw. The functions were tested on a sample of live flamingos from a zoo. The best classification for museum flamingos was given by a function using tarsus length, bill width and middle toe claw (97%). However, this function did not give the best classification for the zoo-based flamingos (81%) which had the best sex assignment by a function including measurements of tarsus, culmen and bill height and width (85%). This shows that a function giving good results in the sample from which it originated may not be as good when applied to another group of animals. Our study emphasizes the need for assessing the accuracy of a function by testing it with other methods to ensure its suitability when being applied.
11
Jackson, Louise A. "'Singing Birds as well as Soap Suds': The Salvation Army's Work with Sexually Abused Girls in Edwardian England". Gender History 12, n.º 1 (abril de 2000): 107–26. http://dx.doi.org/10.1111/1468-0424.00173.
Texto completo
12
Bridge, Eli S. y Ian C. T. Nisbet. "Wing Molt and Assortative Mating in Common Terns: A Test of the Molt-Signaling Hypothesis". Condor 106, n.º 2 (1 de mayo de 2004): 336–43. http://dx.doi.org/10.1093/condor/106.2.336.
Texto completoResumen
Abstract Many seabirds are monomorphic and lack obvious ornamentation; thus the mechanisms and signaling systems that mediate mate choice can be elusive. We investigated the possibility that a unique characteristic of wing molt in most species of Sterna terns acts as a sexually selected indicator of fitness. Many terns replace a variable number of primaries and sometimes secondaries twice or occasionally three times each year. Some have suggested that this repeated wing molt may serve as an honest indicator of fitness in mutual mate choice. If this molt-signaling hypothesis is valid, one would expect there to be assortative mating with respect to the extent of repeated wing molt. We tested this prediction by examining 262 breeding pairs of Common Terns (Sterna hirundo) from colonies in Buzzards Bay, Massachusetts. Using banding records and plumage characters, we were often able to distinguish young birds making their first breeding attempt from older birds which may have maintained past pair bonds. We found evidence of assortative mating with respect to repeated wing molt in newly formed pairs, which supports the notion of wing molt as a sexually selected character. Muda del Ala y Apareamento Asociativo en Sterna hirundo: Una Prueba de la Hipótesis de la Muda-Señalización Resumen. Muchas aves marinas son monomórficas y no tienen ornamentaciones obvias; por tanto, los mecanismos y los sistemas de señales que media la selección de pareja son evasivos. Investigamos la posibilidad de que una característica única de la muda en la mayoría de las especies de charranes (Sterna spp.) funcione como un indicador de la aptitud sexualmente seleccionado. Muchos charranes substituyen un número variable de primarias y a veces de secundarias dos veces, u ocasionalmente tres veces, cada año. Algunos autores han sugerido que esta muda repetida podría servir como un indicador honesto de la aptitud durante la selección mutua de las parejas. Si esta hipótesis de la muda-señalización fuera válida, se esperaría que existiera apareamiento asociativo con respecto al grado de la muda repetida de las alas. Para poner a prueba esta predicción, examinamos 262 parejas reproductivas de Sterna hirundo, en colonias en la Bahía Buzzards, Massachusetts. Usando registros de anillamiento y caracteres del plumaje, pudimos distinguir con frecuencia los charranes jóvenes que hacían su primer intento de aparearse de los más viejos que pudieron haber mantenido enlaces con parejas anteriores. Encontramos evidencia de apareamento asociativo con respecto a la muda repetida de las alas en parejas nuevas, lo que apoya la noción de que la muda del ala sería un caracter seleccionado sexualmente.
13
Myers, S. A., J. R. Millam, T. E. Roudybush y C. R. Grau. "Reproductive Success of Hand-Reared vs. Parent-Reared Cockatiels (Nymphicus hollandicus)". Auk 105, n.º 3 (1 de julio de 1988): 536–42. http://dx.doi.org/10.1093/auk/105.3.536.
Texto completoResumen
Abstract We studied the influence of early rearing experience on the reproductive success of Cockatiels (Nymphicus hollandicus) by force-pairing somatically mature birds that had been either hand-reared (H) or parent-reared (P) from hatch to 6 weeks of age. Pairs of H-males and H-females, H-males and P-females, P-males and P-females, or P-males and H-females were encouraged to breed by providing nest-boxes and exposing pairs to a sexually stimulatory environment. Hand-rearing produced gender-specific effects that greatly affected reproductive success. Pairs containing H-females were more likely to lay eggs and laid more eggs than pairs with P-females but often laid them on the cage floor rather than in nest-boxes, reducing hatching success. Pairs containing H-males were less likely than pairs with P-males to produce fertile eggs, inspect nest-boxes, or lay eggs in nest-boxes. Fledging occurred only in pairs containing P-males. Early rearing experience is important for males to learn characteristics of the opposite sex, and for males and females to learn characteristics of nest-sites.
14
Heyligers, Petrus C. "Dispersal and monoecy in Atriplex cinerea (Chenopodiaceae)". Australian Journal of Botany 49, n.º 4 (2001): 501. http://dx.doi.org/10.1071/bt00063.
Texto completoResumen
Atriplex cinerea Poir., indigenous to southern coasts of Australia, has occasionally been found along the shores of Cook Strait, New Zealand. Buoyancy tests have shown that most fruits stay afloat less than 5 weeks. Published data from drift bottle and drift card experiments indicate that it takes at least 300 days for a floating object to cross the Tasman Sea. It is therefore unlikely that A. cinerea fruits have arrived in New Zealand unaided. Transport on rafts of flotsam or by migrating birds are mooted possibilities. Atriplex cinerea is dioecious or monoecious. Monoecious plants are self-compatible and thus one individual could start a new population. Inspection of herbarium specimens and plants in the field showed that there is at least a one in five and possibly a better than a one in three chance that a plant is monoecious. Atriplex cinerea is hexaploid. Some plants of A. canescens (Pursh) Nutt., a polyploid species from North America, change their gender from year to year owing to the sexually labile nature of tetraploid and hexaploid genotypes. Inherent genetic factors as well as seasonal weather conditions have an influence on these changes. It would be interesting to find out whether this also happens in A. cinerea. As A. cinerea is used for saltland rehabilitation, a study of its variability could benefit the selection of better-adapted strains.
15
Xiong, Nanqian, Wei Tang, Tianyu Mu y Chuanyin Dai. "Sex identification of the ashy-throated parrotbill (Paradoxornis alphonsianus): A species heavily hunted for bird fighting in Guizhou Province, China". Avian Biology Research, 3 de mayo de 2021, 175815592110136. http://dx.doi.org/10.1177/17581559211013643.
Texto completoResumen
The ashy-throated parrotbill ( Paradoxornis alphonsianus) is a sexually monomorphic species with high abundance in Southwest China, which has been widely used as a fighting bird across Guizhou Province, leading it to become one of the most coveted and heavily hunted wild birds in the region at present. Information on the sexes is a fundamental requirement for a wide variety of avian studies. From a conservation perspective, knowledge necessary for quick sexing of this species should be important, as the determination of sex contributes to the understanding of which sexes are used for fighting. Our goal was to develop a quick method that can be used to identify sex of the ashy-throated parrotbill in the field. Seven body traits were measured and compared between the sexes among 124 individual ashy-throated parrotbills, with sex determined by molecular techniques. Data revealed that the male is the larger sex, with significantly greater measurements than the female in bill length, wing length, and middle claw length. The univariate discriminant function based on bill length featured the highest identification accuracy (67.7%). The larger body size of males may have evolved by sexual selection, but additional data are needed to test this hypothesis. This study found that male and female ashy-throated parrotbills are divergent in size, although further efforts are required for a discriminant function with more robust accuracy.