Academic literature on the topic 'Frogs – Breeding'
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Journal articles on the topic "Frogs – Breeding"
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Smith, Lora L., Jennifer M. Howze, Jennifer S. Staiger, Eric R. Sievers, Deborah Burr, and Kevin M. Enge. "Added Value: Gopher Tortoise Surveys Provide Estimates of Gopher Frog Abundance in Tortoise Burrows." Journal of Fish and Wildlife Management 12, no. 1 (October 27, 2020): 3–11. http://dx.doi.org/10.3996/jfwm-20-030.
Full textAbstract:
Abstract The gopher frog Lithobates capito is one of the most terrestrial frogs in the southeastern United States and often inhabits gopher tortoise burrows Gopherus polyphemus outside of the breeding season. Gopher frog populations have declined, and the species is under review for listing as threatened or endangered under the U.S. Endangered Species Act. Much of our knowledge on the status of gopher frogs is based on detections of larvae at breeding wetlands, which can be challenging because of environmental variability and provides no information on the terrestrial life stages of the species. Therefore, an alternative method is called for. We recorded observations of gopher frogs during gopher tortoise surveys at four conservation lands in Florida and used line-transect distance sampling to estimate frog abundance. We also recorded burrow size, incidence of frog co-occupancy with tortoises, and distance from frog-occupied burrows to breeding wetlands. We observed 274 gopher frogs in 1,097 tortoise burrows at the four sites. The proportion of burrows occupied by gopher frogs among sites ranged from 0.17 to 0.25. Gopher frog abundance in tortoise burrows was 742 (512–1,076 95% CL) at Etoniah Creek State Forest, 465 (352–615) at Ft. White Wildlife Environmental Area, 411 (283–595) at Mike Roess Gold Head Branch State Park, and 134 (97–186) at Watermelon Pond Wildlife Environmental Area. We observed up to four frogs in a single burrow. The proportion of frogs detected in burrows occupied by a gopher tortoise ranged from 0.46 to 0.79 among sites, and overall, gopher frogs preferred burrows occupied by tortoises over unoccupied burrows (χ2 = 15.875; df = 3; P = 0.001). Gopher frogs used burrows from 7 to 43 cm in width; mean width of frog-occupied burrows did not differ from that of unoccupied burrows (F1,3 = 0.049, P = 0.825). Distance from frog-occupied tortoise burrows to the nearest breeding wetland ranged from 141 to 3,402 m. Our data on gopher frogs collected in conjunction with gopher tortoise monitoring efforts using line-transect distance sampling and burrow cameras provided novel information on frog abundance in their terrestrial habitat and required no additional effort. However, the extent to which frogs use tortoise burrows relative to other available refuges (small mammal burrows, stumps, or other structures) is unknown; thus, our estimates should be considered conservative. We suggest that terrestrial abundance estimates for gopher frogs can complement efforts to monitor breeding activity to provide a more comprehensive means of monitoring population trends in this cryptic species.
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Gordon, Noah. "The effect of supplemental feeding on the territorial behavior of the green frog (Rana clamitans)." Amphibia-Reptilia 25, no. 1 (2004): 55–62. http://dx.doi.org/10.1163/156853804322992832.
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AbstractThe green frog, Rana clamitans, exhibits a resource defense mating strategy whereby males advertise for mates and defend territories along the shoreline of breeding ponds for periods up to several weeks. Because male green frogs may be energy-limited during the breeding season, I tested the predictions that males provided with extra food would 1) have longer tenures on territories, 2) show reduced movement between territories (due to greater site specificity), and 3) expend more energy in calling and territory defense. I tested these predictions by supplementally feeding frogs and by conducting regular surveys of frog location and behavior over the course of the breeding season in a fenced-in pond. My results support the second prediction but do not support the first and third predictions. Supplementally-fed male green frogs moved less than half the distance of sham-fed males. Green frog males reduce foraging but do not increase activities associated with aggression and territorial defense when food resources are more abundant.
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Gillespie, Graeme R., David Lockie, Michael P. Scroggie, and Djoko T. Iskandar. "Habitat use by stream-breeding frogs in south-east Sulawesi, with some preliminary observations on community organization." Journal of Tropical Ecology 20, no. 4 (July 2004): 439–48. http://dx.doi.org/10.1017/s0266467404001361.
Full textAbstract:
The habitat associations of stream-breeding frogs were examined along a series of stream transects on Buton Island in south-east Sulawesi, Indonesia. Of the eight frog species located along streams, four were observed breeding in stream habitats. We examined spatial habitat partitioning among these species. Three of the four species were found to be associated with a non-random selection of the available perch sites. Strong partitioning between species in habitat associations was found; partitioning of the available habitat space was primarily associated with differences in proximity to stream features, and in the height of perch sites. General observations indicated that oviposition sites of most species were associated with the microhabitats in which the adult frogs were found. All four stream-breeding species appear to have synchronous breeding phenologies and the spatial relationships of these species within the habitat space appear to reflect partitioning of calling sites and oviposition sites. The stream-breeding frog community in this region of Sulawesi has much lower species richness and less specialized habitat use compared with other tropical stream-breeding frog communities in the region.
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Matich, Philip, and Christopher M. Schalk. "Move it or lose it: interspecific variation in risk response of pond-breeding anurans." PeerJ 7 (June 7, 2019): e6956. http://dx.doi.org/10.7717/peerj.6956.
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Changes in behavior are often the proximate response of animals to human disturbance, with variability in tolerance levels leading some species to exhibit striking shifts in life history, fitness, and/or survival. Thus, elucidating the effects of disturbance on animal behavior, and how this varies among taxonomically similar species with inherently different behaviors and life histories is of value for management and conservation. We evaluated the risk response of three anuran species—southern leopard frog (Lithobates sphenocephalus), Blanchard’s cricket frog (Acris blanchardi), and green tree frog (Hyla cinerea)—to determine how differences in microhabitat use (arboreal vs ground-dwelling) and body size (small vs medium) may play a role in response to a potential threat within a human-altered subtropical forest. Each species responded to risk with both flight and freeze behaviors, however, behaviors were species- and context-specific. As distance to cover increased, southern leopard frogs increased freezing behavior, green tree frogs decreased freezing behavior, and Blanchard’s cricket frogs increased flight response. The propensity of green tree frogs to use the canopy of vegetation as refugia, and the small body size of Blanchard’s cricket frogs likely led to greater flight response as distance to cover increased, whereas innate reliance on camouflage among southern leopard frogs may place them at greater risk to landscaping, agricultural, and transportation practices in open terrain. As such, arboreal and small-bodied species may inherently be better suited in human altered-landscapes compared to larger, ground-dwelling species. As land-use change continues to modify habitats, understanding how species respond to changes in their environment continues to be of importance, particularly in ecosystems where human-wildlife interactions are expected to increase in frequency.
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Degani, Gad. "Life Cycle of Tree Frogs (Hyla savygnyi) in Semi-Arid Habitats in Northern Israel." International Journal of Biology 8, no. 1 (October 28, 2015): 17. http://dx.doi.org/10.5539/ijb.v8n1p17.
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The life cycle of tree frogs (Hyla savygnyi) in localities of various habitats in northern Israel in the Upper Galilee and Golan Heights (annual rainfall range of 500-1,000 mm) and the Hula Valley, ranging from 212 to 740 m above sea level (ASL), was studied. Tree frogs were observed around winter rain pools, springs and streams. Fifty-one different breeding places were monitored. Only ponds and springs having stable non-flowing water are used by tree frogs for reproduction and are where larvae can metamorphose. The male call in the breeding places attracts the female, who then comes to the male, and breeding occurs underwater. Breeding time in Israel varies according to location and geographical and ecological conditions. It takes place in March-April in northern Israel, the Upper Galilee, the Golan Heights and the Hula Valley. In various breeding places, larvae grow between April and June. Apparently tree frog larvae adapt to breeding places where stable water is found, such as in ponds or springs, but not to breeding places with flowing water such as streams or rivers. Various Anuran and Urodela larvae were found in the same breeding sites where the larvae of H. savygnyi were found, including Pseudepidalea Viridis, Rana bedriagae, Pelobates syriacus, Salamandra infraimmaculata and Triturs vittatus. Following metamorphosis, H. savygnyi adapt to terrestrial life in semi-arid habitats, and is found on plants or in hiding places under rocks and in holes to prevent dehydration particularly during hot and dry weather. The ability to change color helped the frogs to hide in various substrates. The rate of water loss of terrestrial H. savygnyi during dehydration is around 50% of body weight. Plasma osmolality increased from 200 mOsm/kg to about 450 mOsm/kg, which helped the tree frog to survive in semi-arid habitats.
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Dare, O. K., and M. R. Forbes. "Patterns of trematode and nematode lungworm infections in northern leopard frogs and wood frogs from Ontario, Canada." Journal of Helminthology 83, no. 4 (March 26, 2009): 339–43. http://dx.doi.org/10.1017/s0022149x09243495.
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AbstractIn this study we examined trematode and nematode lung helminths commonly found in two species of host ranid frogs for competitive interactions. We examined 147 adult (breeding and non-breeding) and juvenile northern leopard frogs, and 84 breeding male wood frogs in Bishops Mills, Ontario for Haematoloechus spp. (Trematoda) and Rhabdias sp. (Nematoda) infections. A strong negative association between phyla of helminth was observed in breeding and juvenile northern leopard frogs, and also in breeding wood frogs, but not in non-breeding adult northern leopard frogs. Few hosts carried both types of worm concurrently. Thirteen northern leopard frogs carried dual infections, while 77 carried only one phylum of helminth. Twenty-seven wood frogs carried dual infections, while 54 carried only one phylum of helminth. We also observed spatial segregation of the two phyla in host lungs. Our study informs future research on the dynamics of interactions among lung helminths in these two host species.
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Şereflişan, Hülya, and Ahmet Alkaya. "Türkiye’de Eti Yenilebilen Kurbağaların (Ranidae) Biyolojisi, Ekonomisi, Avcılığı ve İhracatına Yönelik Yasal Mevzuatı." Turkish Journal of Agriculture - Food Science and Technology 4, no. 7 (July 15, 2016): 600. http://dx.doi.org/10.24925/turjaf.v4i7.600-604.654.
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The frogs production is done on the basis of fully hunting, an important export product in Turkey. The frogs are almost no domestic consumption. The frogs are exported to France, Italy, Switzerland, Lebanon, Greece and Spain by five companies a processed form as live frog, frozen frog legs and chilled frog legs. In Turkey, some regulations related to hunting frogs and exports are prepared by under the Ministry of Agriculture and Rural Affairs General Directorate of Protection and Control. The hunting frogs is banned by 3/1 the Commercial Fisheries regulating the hunting notification. These prohibitions are designed to be different for each province. The provinces are permitted for frogs hunting by the legislation in Adana, Afyonkarahisar, Balıkesir, Bingöl, Bursa, Edirne, Bursa, Istanbul and Yalova. Frogs were exported in different amounts (kg) with different price in every year during the last ten years. The highest amounts of the frogs with the lowest of price were exported in 2013. Prey weight is shrinking due to overfishing. In this case, the price of export materials has got significantly negative effects. As a result, the ban on hunting and restrictive measures for protection should be taken seriously in some of the provinces. Hunting ban is absolutely necessary in Turkey. In many countries including Turkey, in order to ensure sustainability, it is important to do the frog breeding.
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Iwai, Noriko. "Relationship between chorusing activity and number of oviposition events in the Otton frog." Animal Biology 68, no. 1 (2018): 105–11. http://dx.doi.org/10.1163/15707563-17000143.
Full textAbstract:
Abstract Call surveys are an effective technique for detecting the presence and activity of breeding male frogs. Such surveys have been used to quantify breeding activity at a site under the assumption that male chorusing activity appropriately reflects breeding consequences, such as the number of oviposition events. However, only a few studies have actually examined the relationship between chorusing activity and breeding consequences in the field. In this study, I examined the relationship between chorusing activity (the number of male calls recorded during a five-minute period every night) and the number of oviposition events (number of oviposited egg masses during the night) of the Otton frog, Babina subaspera, with regard to the time lag between calls and oviposition. I constructed nine generalized linear mixed models (GLMMs) to explain the number of oviposition events by chorusing activity on the same night and on nights 1 to 7 days before the oviposition events. The Akaike information criterion (AiC) of the GLMM was lowest when the number of calls from nights 2 days before the oviposition events was used, indicating that breeding consequences in Otton frogs reflect the chorusing activity of 2 days prior. This study shows that frog call surveys can be reliable tools with which to represent breeding activity at a site as long as the time lag between chorusing activity and breeding consequences is considered.
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Pilliod, David S., Charles R. Peterson, and Peter I. Ritson. "Seasonal migration of Columbia spotted frogs (Rana luteiventris) among complementary resources in a high mountain basin." Canadian Journal of Zoology 80, no. 11 (November 1, 2002): 1849–62. http://dx.doi.org/10.1139/z02-175.
Full textAbstract:
Information on how animals partition their activities and travel among complementary resources, such as breeding or overwintering habitats, is needed for species conservation. In a mountain basin at 2500 m elevation in central Idaho, we studied the habitat use and movement patterns of 736 marked and 87 radio-tagged Columbia spotted frogs (Rana luteiventris) from 1995 to 1998. The goals of this study were to (i) identify and characterize R. luteiventris breeding, summer foraging, and overwintering habitats, (ii) describe the movement patterns of juvenile, male, and female R. luteiventris among these resources, and (iii) determine migration routes. Juvenile and adult R. luteiventris occupied a variety of widely distributed wetlands from late June to September. On average, 132% of juvenile, 611% of male, and 1651% of female frogs moved from breeding ponds to summer habitats. Migratory males remained within 200 m of the breeding sites, whereas females traveled up to 1030 m to reach summer habitats. From late August through September, frogs migrated to deep (>3 m) lakes to overwinter. Frog migrations occurred quickly and often followed shortest-distance travel routes through dry, open forest even when stream corridors were available nearby. This study exemplifies the need to protect both complementary resources and the corridors connecting these anuran habitats.
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Seburn, David C., and Kari Gunson. "Has the Western Chorus Frog (Pseudacris triseriata) Declined in Western Ottawa, Ontario?" Canadian Field-Naturalist 125, no. 3 (July 1, 2011): 220. http://dx.doi.org/10.22621/cfn.v125i3.1224.
Full textAbstract:
To determine whether the Western Chorus Frog has declined in western Ottawa, we conducted auditory surveys at historical locations as well as at various other wetlands. Western Chorus Frogs were detected at 12 of 18 historical locations. Wetland habitat remained at all historical locations where the species was not detected. There was no difference in the year of historical records for sites where Western Chorus Frogs were (median 1987.5) and were not (median 1987.5) detected. In the present study, Western Chorus Frogs were also detected at 30 locations where they had not been previously reported. Historical sites where Western Chorus Frogs were not detected were not significantly farther away from known Western Chorus Frog sites (median distance: 2.2 km) than historical sites where Western Chorus Frogs were detected (median distance: 1.4 km). Land use variables for historical sites where Western Chorus Frogs were and were not detected did not vary significantly at any spatial scale from 0.5 to 2.0 km. Western Chorus Frogs were detected in areas with up to 50% forest cover and up to 86% agricultural cover at the 1.0-km radius. The lack of historical data makes it difficult to assess the current status of the Western Chorus Frog in western Ottawa. The species may have declined, remained approximately the same (by shifting to different breeding sites), or even increased its distribution (by colonizing additional sites).
Dissertations / Theses on the topic "Frogs – Breeding"
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Madison, Amanda L. "Effects of male breeding gland in hymenochirus on female reproductive output." Scholarly Commons, 2005. https://scholarlycommons.pacific.edu/uop_etds/610.
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Normal male dwarf African clawed frogs, Hymenochirus sp., possess bilateral, sexually dimorphic, subcutaneous breeding glands just posterior to the forelimbs. Previous studies have shown these glands release pheromones that attract conspecific females. This thesis shows the pheromones also stimulate the reproductive system of conspecific females. Females exposed to normal males prior to mating then allowed to mate with the normal males released a higher number of eggs than females who were not exposed to normal males prior to mating. Microscopic examination of ovarian tissue revealed that females exposed to normal males also produced more highly-developed oocytes than did females not exposed to normal males. These results suggest male Hymenochirus use pheromones not only to attract potential mates, but to increase female receptivity and readiness to mate. Evolutionarily, these pheromonal effects would likely benefit males by increasing their chances of breeding, increasing the number of eggs released by their mates, and thus the number of offspring in the next generation.
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Pearl, Christopher A. "Demonstration of pheromonal activity in the breeding glands of dwarf African clawed frogs (Hymenochirus sp.)." Scholarly Commons, 2000. https://scholarlycommons.pacific.edu/uop_etds/529.
Full textAbstract:
Anurans rely mainly on vocalizations for mate attraction while urodeles rely mainly on pheromones. However, the presence of breeding glands suggests that anurans may also communicate with pheromones during reproduction. Previous studies have shown that male Hymenochirus sp. are able to attract females in a Y-maze, most likely through chemical means, but the source of the attractant has not been identified. By exposing female Hymenochirus sp. to choice tests in a Y -maze it was demonstrated that the breeding glands of male Hymenochirus sp. are the source of a mate-attractant pheromone. This study represents the first experimental evidence for a pheromonal function of breeding glands and further supports the idea that anurans utilize pheromones in reproduction. Evidence is also presented suggesting that the mate attraction is temperature sensitive with an upper limit around 30°C.
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Pearl, Christopher A. "Demonstration of pheromonal activity in the breeding glands of dwarf African clawed frogs (Hymenochirus sp.) : a thesis." Scholarly Commons, 2001. https://scholarlycommons.pacific.edu/uop_etds/529.
Full textAbstract:
Anurans rely mainly on vocalizations for mate attraction while urodeles rely mainly on pheromones. However, the presence of breeding glands suggests that anurans may also communicate with pheromones during reproduction. Previous studies have shown that male Hymenochirus sp. are able to attract females in a Y-maze, most likely through chemical means, but the source of the attractant has not been identified. By exposing female Hymenochirus sp. to choice tests in a Y -maze it was demonstrated that the breeding glands of male Hymenochirus sp. are the source of a mate-attractant pheromone. This study represents the first experimental evidence for a pheromonal function of breeding glands and further supports the idea that anurans utilize pheromones in reproduction. Evidence is also presented suggesting that the mate attraction is temperature sensitive with an upper limit around 30°C.
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Hocking, Daniel J. "Gray treefrog breeding site selection and offspring performance in response to forest management." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5103.
Full textAbstract:
Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 26, 2007) Includes bibliographical references.
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Galeano, Sandra Patricia. "ENZOOTIC PATTERNS OF INFECTION BY BATRACHOCHYTRIUM DENDROBATIDIS IN POND BREEDING ANURANS IN CENTRAL AMERICA." OpenSIUC, 2009. https://opensiuc.lib.siu.edu/theses/62.
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Batrachochytrium dendrobatidis (Bd) has contributed to population declines and extinction of amphibians worldwide. Disease-caused extinction is rare, but may occur where reservoirs exist or where transmission is independent of host density. Because some species persist after Bd epizootic events, they may act as potential reservoirs of the infection. I studied seasonal and elevational patterns of prevalence and intensity of Bd infection in eight pond-breeding species that persisted after an epizootic event at three low- and three mid-elevation ponds in Central America. I visited each pond three times over the rainy season to sample for Bd and to quantify frog density. I recorded air and water temperature at each pond. I analyzed 1,288 samples and detected Bd in all six ponds and in six of the eight species. Elevation and time affected Bd prevalence (F2,7 = 8.90, p = 0.01) and Bd intensity (F2,8 = 9.09, p = 0.008). Frog density was not correlated with Bd prevalence (F1,7= 4.75, p= 0.06), and temperature did not affect prevalence or intensity of the infection. Bd is enzootic at all 6 sites and six pond-breeding species are reservoirs. The presence of abundant reservoirs at enzootic conditions explains the persistence of Bd in areas where other species declined without showing evidence of recovery. Low intensities of infection explain the survivorship of these reservoir species. I suggest that temperature might not be the principal factor molding Bd dynamics in the humid Neotropical forests, and present evidence that ponds are ecosystems where frogs might clean or reduce their infections
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Holloway, Simon, and n/a. "Survey protocols for the stream-breeding frogs of Far East Gippsland : the application of habitat modelling and an assessment of techniques." University of Canberra. Resource, Environmental & Heritage Sciences, 1997. http://erl.canberra.edu.au./public/adt-AUC20060725.150009.
Full textAbstract:
This study developed a heirarchical approach to improve the efficiency and reliability of
surveys for stream-breeding frogs in the montane forests of south-eastern Australia.
Areas with suitable climate for some of these species were first determined by
bioclimatic modelling. Landscape and habitat preferences were then determined for the
four species commonly found in far East Gippsland, along with an assessment of survey
techniques from which effective survey protocols were developed.
The climate of localities at which five stream-breeding species had been previously
found was modelled using BIOCLIM, and maps of the predicted potential distributions
having similar climate were developed. Litoria phyllochroa was found to occur in
coastal to alpine areas from Melbourne to Nowra, and potentially further inland, in areas
with relatively low temperatures and low summer rainfall. Litoria lesueuri had a
slightly larger known and predicted distribution, covering a wide range of values for the
temperature and precipitation parameters. Both species had predicted areas inland from
Melbourne and the Blue Mountains where they had never been recorded, probably
largely due to land clearing. The rare Heleioporus australiacus had a slightly more
northerly distribution, closer to the coast and adjacent ranges from Central Gippsland to
just north of Sydney, with a generally warmer climate and large range of average annual
precipitation values. Litoria citropa occupies an even narrower area along the coast,
extending slightly further north again, with a climatic profile of few extremes but with
relatively high rainfall particularly in summer. The rare Mixophyes balbus had a more
northerly known and predicted narrow range along the NSW coast, just extending into
Victoria and Queensland, characterised by the subtropical influence of higher summer
rainfall. The southern extension into far East Gippsland appears to have an extreme
sub-climate, and is hence considered highly susceptible to climate change. Future
monitoring sites for these species can now be systematically chosen to include their full
climatic range, so that any negative effects of climate change on amphibian populations
may have a greater chance of detection.
Four species were found commonly enough in the far East Gippsland study area for
more detailed study - the three stream-breeding specialist species, L. phyllochroa,
L citropa, and L. lesueuri, along with Crinia signifera which was not restricted to
streams but commonly found along them. Three species, L. phyllochroa, L citropa and
L. lesueuri, were not found at the few higher altitudes sites on the Errinundra Plateau,
however they may have been restricted by habitat requirements other than altitude.
Litoria phyllochroa was otherwise widespread, but preferred larger in-stream pools and
backwaters for breeding with overhanging vegetation for perch and call sites. The other
three species preferred stream reaches characterised by wide bedrock outcrops and
associated wide break in the tree canopy, which may allow their preferred perch sites on
rocky substrates to retain heat after sunset. Litoria lesueuri tadpoles were found in both
unconnected and connected pools, and the common association of this species with
bedrock outcrops may explain its range being largely restricted to granitic substratum
where these outcrops mostly occurred. Litoria citropa preferred reaches with bedrock
and boulder outcrops, although frogs used both rocky and vegetative substrates as perch
sites, with tadpoles caught in both unconnected pools and backwaters. Crinia signifera
tadpoles were mostly restricted to unconnected pools, with frogs generally only detected
within or very close beside these.
Habitat models varied in their predictive ability, from 67.5% for L. phyllochroa frogs to
92.7% for L. lesueuri tadpoles. Models developed from normally-distributed habitat
variables by discriminant function analysis were generally more predictive than those
from logistic regression analysis. The occurrence of frogs and tadpoles of
L. phyllochroa, L. citropa and L. lesueuri can be predicted by the measurement of five
habitat variables along a 50m reach: average width between the banks, average channel
width, an average of the maximum depth of channel cross-sections along the reach,
channel slope, and proportion of the stream length as pools. The occurrence of
C. signifera along reaches can be predicted with the additional measurement of the
proportion of the banks covered in ferns, the maximum cross-sectional channel depth
along the reach, and the number of unconnected pools.
Several different techniques for surveying frogs were compared for the four species
commonly found along the streams. Probability of detection models were derived for
each species for each technique, which allowed calculation of the statistical confidence
of detecting a species that actually occurred at a site for any given number of surveys.
For transect-based techniques, models were also developed which allowed
determination of the minimum number of surveys required without detecting a species
to be 95 percent statistically confident that the species did not occur there, for various
transect lengths. This level of confidence can be obtained for the four common species
by four surveys using the reliable night encounter technique along 500m stream
transects, during the period from Ocotber to March, with air temperatures above 10°C.
The application of habitat models to select favourable 50m reaches for survey also
generally improved the detectability of each species.
Timer-activated tape recorders, which automatically recorded the calls of frogs for many
consecutive nights at a site, were very efficient at detecting all species except the quietcalling
L. lesueuri. Night encounter surveys along stream transects detected all species
from a reasonable effort, and dip-netting for tadpoles was also effective for most
species. Active visual encounter surveys were less reliable, and day encounter surveys
detected few frogs but provided some additional data when other activities were being
performed along the streams.
The findings of this study have important implications for future amphibian surveys and
monitoring undertaken in East Gippsland and the south coast of New South Wales. If
the standardised survey techniques recommended by this study are used in
Environmental Impact Assessments, their results can be objectively assessed and
defended. The use of habitat modelling and improvement in survey reliability can also
be used more efficiently to find sites with populations suitable for monitoring. The
likely amount of effort required by a long-term monitoring program can also be
determined so as to largely overcome daily variations in the detection of each species.
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Donaldson, Chad. "Analyzing Factors Influencing Reproductive Success of the Mountain Chicken : Nordens Ark Captive Breeding Program." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-16623.
Full textAbstract:
Amphibians globally are declining with roughly a third facing extinction due primarily to threats linked to human impacts. One way in which this is being combated is by captive breeding programs. Nordens Ark in Sweden, in collaboration with other organizations, is attempting to breed one of the most threatened frogs for future reintroduction to the wild. The mountain chicken (Leptodactylus fallax) has unique characteristics related to its reproduction which make it challenging to breed successful offspring. Using Nordens Ark’s data on environmental conditions within breeding enclosures, this study attempts to determine which extrinsic factors are having the most influence on reproduction, in order to increase the success of the captive breeding program. Multiple linear regression analysis and model simplification using Stepwise regression and Akaike information criterion (AIC) were performed in order to determine which explanatory variables had the most influence in relation to foam nests. A reduced model with significant values for explanatory variables was deemed the best model based on the dataset. Of the 14 environmental variables tested, minimum temperature after nest construction had the most influence on foam nest length. When compared to wild habitats, temperatures within enclosures may be too high or lack seasonal cyclical patterns. Barometric pressure and humidity also had influence on foam nests, but the relationships between these environmental conditions is difficult to parse. Food supplements were also a significant factor and suggest that lack of vitamins or nutrients can have a negative effect on reproductive success. Ensuring the optimal conditions can be difficult for captive breeding programs, especially as amphibians are under-represented and face biases in conservation and research.
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Gaalema, Diann E. "Sexual conditioning in the dyeing poison dart frog (Dendrobates tinctorius)." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33895.
Full textAbstract:
Amphibian populations worldwide are currently in decline. One approach to preventing extinction of some of the affected species is to create assurance colonies. These sustainable captive populations might some day be used to reestablish wild populations. One issue with creating assurance colonies is successful breeding; often difficulties arise when attempting to breed exotic animals in captivity. Sexual conditioning, a form of Pavlovian conditioning, has been shown to improve breeding behavior. In this project the
efficacy of sexual conditioning to improve breeding behavior in the dyeing dart frog (Dendrobates tinctorius) was tested. The frogs were trained with a stimulus that was either predictive of or independent of exposure to a member of the opposite sex. The group trained with the predictive stimulus showed shorter latencies to a variety of breeding behaviors and produced more eggs than the control groups. The sexual conditioning procedure also increased expression of various breeding behaviors allowing
for careful examination of calls and visual signaling within this species.
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Harper, Elizabeth B. "The role of terrrestrial habitat in the population dynamics and conservation of pond-breeding amphibians." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4693.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 25, 2007) Vita. Includes bibliographical references.
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Vu, Maria. "Time- and Dose-related Effects of a Gonadotropin-releasing Hormone Agonist and Dopamine Antagonist on Reproduction in the Northern Leopard Frog (Lithobates pipiens) and the Western Clawed Frog (Silurana tropicalis)." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36024.
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The recent decline and disappearance of many amphibians around the world is thought to be the sign of an impending sixth mass extinction that is driven by disease, habitat loss and pollution. Reproductive technologies are now required to establish captive colonies followed by reintroduction into suitable habitats. The AMPHIPLEX method is a hormone mixture that has successfully stimulated spawning in several amphibians. However, its extensive application requires further experimentation and knowledge regarding the basic neuroendocrine control of reproduction in amphibians. The role of the catecholamine neurotransmitter dopamine in the regulation of spawning and gonadotropin synthesis was investigated using multiple time- and dose-related approaches in the field and laboratory. These end points were explored in two distantly-related frog species: the Northern leopard frog (Lithobates pipiens) and the Western clawed frog (Silurana tropicalis). Northern leopard frogs were injected during the natural breeding season with three doses of a gonadotropin-releasing hormone agonist (GnRH-A) (0.1 μg/g , 0.2 μg/g and 0.4 μg/g) alone and in combination with two doses of the selective dopamine receptor D2 antagonist metoclopramide (MET) (5 μg/g and 10 μg/g). Injected animals were allowed to breed in mesocosms in an outdoor field. Time to amplexus and oviposition were assessed, and egg mass release, incidences of amplexus, egg mass weight, total egg numbers and fertilization rates were measured. The results revealed no statistically significant interaction between GnRH-A and MET on amplexus and oviposition. A series of GnRH-A dose-response spawning studies were conducted in the Western clawed frog. The current findings indicate that partial ovulation, male sexual behavior and fertilization can be induced by 4 μg/g of GnRH-A alone and in combination with 10 μg/g of MET. This represents a first step towards understanding basic neuroendocrine reproductive mechanisms in this species. These spawning results were paired with a second end point which explored the molecular mechanisms of gonadotropin synthesis in response to GnRH-A and MET alone and in combination. Pituitary gene expression results in the Northern leopard frog indicate a potentiating action of MET when combined with GnRH-A on the mRNA levels of gonadotropin subunits 36 hours following injection. The postulated mechanisms of action are through the upregulation of gonadotropin-releasing hormone receptor 1 and the downregulation of dopamine receptor D2. Such gene expression pathways were similarly explored in the Western clawed frog, however no significant changes in pituitary gonadotropin and receptor gene expression were present at 12 hours post-injection. The hypothesized inhibitory action of dopamine was supported by pituitary gene expression analysis, but not by spawning outcome. The results from this study provide a fundamental framework for future time- and dose-response investigations to improve current spawning methods in amphibians.
Books on the topic "Frogs – Breeding"
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Vosjoli, Philippe De. Care and breeding of popular tree frogs. Santee, CA: Advanced Vivarium Systems, 1996.
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Mattison, Christopher. Keeping and breeding amphibians: Caecilians, newts, salamanders, frogs, and toads. London: Blandford, 1993.
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1949-, Bartlett Patricia Pope, ed. Frogs, toads, and treefrogs: Everything about selection, care, nutrition, breeding, and behavior. Hauppage, NY: Barron's Educational Series, 1996.
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Campbell, Jonathan A. New species of stream-breeding hylid frogs from the northern versant of the highlands of Oaxaca, Mexico. Lawrence, Kan: Natural History Museum, University of Kansas, 2000.
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Kendell, Kris. Northern leopard frog reintroduction: Raven River--year 2 (2000). Edmonton: Alberta Sustainable Resource Development, 2001.
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Drennan, Joseph E. Identifying microclimatic and water flow triggers associated with breeding activities of a foothill yellow-legged frog (Rana boylii) population on the north fork Feather River, California: PIER final project report. Sacramento, Calif.]: California Energy Commission, 2008.
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Foss, Peter J. Hop to it Irish frog survey: A baseline ecological survey conducted by the Irish Peatland Conservation Council on the distribution, habitat preference, breeding date and success of Rana temporaria in Ireland. Dublin: Irish Peatland Conservation Council, 1997.
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Mailloux, Robert, Drew Ready, and Philippe De Vosjoli. Care and Breeding of Popular Tree Frogs: A Practical Manual for the Serious Hobbyist (General Care and Maintenance of Series). Advanced Vivarium Systems, 1997.
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Vanderduys, Eric. Field Guide to the Frogs of Queensland. CSIRO Publishing, 2012. http://dx.doi.org/10.1071/9780643108790.
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Frogs are remarkably variable creatures. Many species adopt different colours or patterns by day or night. In some cases, males are different from females, and many species can change their appearance remarkably when breeding.
Field Guide to the Frogs of Queensland provides a comprehensive photographic guide to the 132 species of frogs in Queensland, Australia’s most species-rich state. It enables identification of all Queensland species and clearly points out pitfalls that may lead to misidentification. Species profiles list common and scientific names, information on size, call and preferred habitat, as well as points of interest for each species. The conservation status of all threatened species is listed and there are special sections devoted to disappearing frogs and the Cane Toad.
Generously illustrated with one or more photographs for each species, the book also includes distribution maps, line illustrations which demonstrate key features, and keys to each family, genus and species.
Book chapters on the topic "Frogs – Breeding"
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Green, Michael, Michael B. Thompson, and Francis L. Lemckert. "The effects of suspended sediments on the tadpoles of two stream-breeding and forest dwelling frogs,Mixophyes balbus andHeleioporus australiacus." In Conservation of Australia's Forest Fauna, 713–20. P.O. Box 20, Mosman NSW 2088: Royal Zoological Society of New South Wales, 2004. http://dx.doi.org/10.7882/fs.2004.042.
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Drent, R., and T. Piersma. "An Exploration of the Energetics of Leap-Frog Migration in Arctic Breeding Waders." In Bird Migration, 399–412. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-74542-3_26.
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Alan Pounds, J. "Amphibians and Reptiles." In Monteverde. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195095609.003.0011.
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Anyone who stood on the bridge over the Río Guacimal at Monteverde on a wet-season night in the early 1980s would understand Archie Carr’s sentiments. Nearly 300 male Fleischmann’s Glass Frogs (Hyalinobatrachium fleischmanni) defended territories along a 120-m section of the stream, and their loud, incessant “peeps” filled the air. In the late 1980s, however, this chorus all but fell silent as the number of glass frogs plummeted. The population has not recovered. In 1998, only a single male could be heard from the bridge. The dramatic reduction in glass frogs was part of a larger decline of Monteverde’s amphibians. A sudden crash of populations in 1987 affected species throughout the area and led to the disappearance of many (Pounds 1990, 1991a, 1997, Crump et al. 1992, Pounds and Crump 1994, Pounds and Fogden 1996, Pounds et al. 1997). The disappearance that has drawn the most attention, however, is that of the Golden Toad (Bufo periglenes). This species, known only from elfin cloud forest high on the ridgetops at Monteverde, is famous for its striking appearance and the colorful spectacle of its breeding congregations (Savage 1966, Jacobson 1983, Fogden and Fogden 1984, Jacobson and Vandenberg 1991; see Savage, “Discovery of the Golden Toad,”. Because the Golden Toad had been locally abundant in seemingly undisturbed habitats for at least 17 consecutive years, its sudden disappearance caused great alarm and dismay (Pounds et al. 1997). Interest in this case has intensified with the suggestion that it is part of a global pattern (Barinaga 1990, Blaustein and Wake 1990, 1995, Phillips 1990, 1994, Wyman 1990, Wake 1991, Wake and Morowitz 1991, Sarkar 1996; see Pounds, “Monteverde Salamanders,”). Many similar declines and disappearances have been reported for highland areas of other continents (Corn and Fogleman 1984, Heyer et al. 1988, Osborne 1989, Weygoldt 1989, Czechura and Ingram 1990, La Marca and Reinthaler 1991, Carey 1993, Fellers and Drost 1993, Kagarise Sherman and Morton 1993, Drost and Fellers 1996, Laurance et al.
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Wheelwright, Nathaniel T. "Conservation Biology." In Monteverde. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195095609.003.0018.
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Each February, when I return to Monteverde to study the reproductive ecology of lauraceous trees, I stay with friends in their farmhouse tucked on the edge of the lower montane moist forest. On my first morning back, I am always eager to listen to the dawn bird chorus. During my most recent visit, I awoke to hear a cacophony of Great-tailed Crackles, a noisy flock of Brown Jays, an exuberant House Wren, and a gang of Bronzed Cowbirds squabbling over spilled grain by the cow barn. Back in 1978, during my first visit, there were no Great-tailed Crackles in Monteverde. Brown Jays had colonized the area, but their flocks were relatively small and restricted to the lower parts of the community. House Wrens, always familiar denizens of Monteverde’s yards and farms, are more abundant today than ever. Once a rarity in Monteverde, Bronzed Cowbirds are now common. Monteverde has changed, and more changes are coming. The rest of Monteverde’s avifauna has undoubtedly felt an impact from the explosive population growth of these bird species. Crackles and jays prey on the eggs, nestlings, and fledglings of other birds; wrens also occasionally destroy other birds’ eggs. Cowbirds are brood parasites. All four species potentially compete with other species for food. Without censuses from earlier years, it is impossible to know how newly colonizing species have affected the fauna and flora of Monteverde. Contributors to this book have provided evidence that various species of animals and plants, especially widespread species of Costa Rica’s lowlands and foothills, have expanded their ranges and increased their population sizes in Monteverde. At the same time, other species are rarer than they used to be only a few decades ago. I used to marvel at the frenzied breeding aggregations of Golden Toads, hold multicolored Harlequin Frogs, and listen to nightly serenades of glass frogs along the Río Guacimal. Most of them no longer exist in Monteverde. In this chapter my goals are to (1) highlight aspects of the biodiversity of Monteverde that are relevant to conservation, (2) give a brief overview of general concepts in conservation biology, (3) discuss conservation problems that are specific to Monteverde and neotropical highland forests, and (4) consider how principles of conservation biology might provide solutions to those problems.