C. Pusapati, M. Manoharakrishnan, A. D. Phillott, K. Shanker
Abstract. The nest environment plays an important role in influencing sea turtle hatchling phenotype. Increasing global temperatures can potentially cause detrimental changes to hatchling size and performance and ultimately influence their recruitment into the adult population. The mass nesting rookeries of olive ridleys in Odisha on the east coast of India are among the largest globally and the only major ones outside Central America. Many nests laid on the east coast of India are translocated to hatcheries as part of hatchery management practices. Therefore, it is imperative to understand the effects of temperature on hatchlings produced in hatcheries as well as site-specific factors in order to undertake appropriate climate-resilient hatchery management measures. This study examined the effect of temperature on the morphology and locomotor performance of hatchlings produced in 2 different hatcheries on the east coast: in Rushikulya, Odisha, and in Chennai, Tamil Nadu, India. We examined various size (body, flipper, and neck length) and performance (crawl speed, righting ability, and righting propensity) parameters for hatchlings at both hatcheries across a range of temperatures. We found that hatchling size and performance were significantly influenced by nest incubation temperature. Higher incubation temperatures resulted in smaller hatchling size, which in turn was correlated with lower performance variables. Incubation temperature also had a direct effect on hatchling performance independent of hatchling size. The effect of nest temperature on morphology and performance of hatchlings could influence their survival and recruitment rates, thus influencing population dynamics and resilience to climate change.
{"title":"Effect of Hatchery Nest Environment on Olive Ridley (Lepidochelys olivacea) Hatchling Performance","authors":"C. Pusapati, M. Manoharakrishnan, A. D. Phillott, K. Shanker","doi":"10.2744/CCB-1450.1","DOIUrl":"https://doi.org/10.2744/CCB-1450.1","url":null,"abstract":"Abstract. The nest environment plays an important role in influencing sea turtle hatchling phenotype. Increasing global temperatures can potentially cause detrimental changes to hatchling size and performance and ultimately influence their recruitment into the adult population. The mass nesting rookeries of olive ridleys in Odisha on the east coast of India are among the largest globally and the only major ones outside Central America. Many nests laid on the east coast of India are translocated to hatcheries as part of hatchery management practices. Therefore, it is imperative to understand the effects of temperature on hatchlings produced in hatcheries as well as site-specific factors in order to undertake appropriate climate-resilient hatchery management measures. This study examined the effect of temperature on the morphology and locomotor performance of hatchlings produced in 2 different hatcheries on the east coast: in Rushikulya, Odisha, and in Chennai, Tamil Nadu, India. We examined various size (body, flipper, and neck length) and performance (crawl speed, righting ability, and righting propensity) parameters for hatchlings at both hatcheries across a range of temperatures. We found that hatchling size and performance were significantly influenced by nest incubation temperature. Higher incubation temperatures resulted in smaller hatchling size, which in turn was correlated with lower performance variables. Incubation temperature also had a direct effect on hatchling performance independent of hatchling size. The effect of nest temperature on morphology and performance of hatchlings could influence their survival and recruitment rates, thus influencing population dynamics and resilience to climate change.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132810285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Pilcher, M. Antonopoulou, C. Rodríguez-Zárate, Thuraya Said Al-Sareeria, R. Baldwin, A. Willson, M. Willson
Abstract. There is limited information on postnesting dispersal of green turtles Chelonia mydas from nesting sites in the Arabian region. Understanding habitat connectivity can promote effective conservation programs across a wider range of critical sea turtle habitats. We present postnesting migration data for 9 green turtles departing from Ras Al Hadd in Oman, one of the largest and most important nesting sites for this species in the northwest Indian Ocean (NWIO). Turtles migrated to Eritrea (n = 1), India (n = 2), Oman (n = 4), and the United Arab Emirates (n = 2), demonstrating connectivity for this species across the NWIO and linkages to known green turtle foraging areas. Turtles used deep international waters of the NWIO, and coastal waters of Eritrea, India, Iran, Oman, Pakistan, Saudi Arabia, and Yemen. Alongside the potential for fisheries bycatch, ghost fishing, entanglement, and direct take in waters near nesting sites and at the dispersal destinations, these movement patterns reveal a need for coordinated efforts to address sea turtle mortality in fisheries at a regional level. These data enhance our knowledge of sea turtle distribution and connectivity in the Arabian region and will contribute to ongoing efforts to conserve sea turtles in the NWIO.
{"title":"Wide-Scale Population Connectivity Revealed by Postnesting Migrations of Green Sea Turtles from Ras Al Hadd, Oman","authors":"N. Pilcher, M. Antonopoulou, C. Rodríguez-Zárate, Thuraya Said Al-Sareeria, R. Baldwin, A. Willson, M. Willson","doi":"10.2744/CCB-1462.1","DOIUrl":"https://doi.org/10.2744/CCB-1462.1","url":null,"abstract":"Abstract. There is limited information on postnesting dispersal of green turtles Chelonia mydas from nesting sites in the Arabian region. Understanding habitat connectivity can promote effective conservation programs across a wider range of critical sea turtle habitats. We present postnesting migration data for 9 green turtles departing from Ras Al Hadd in Oman, one of the largest and most important nesting sites for this species in the northwest Indian Ocean (NWIO). Turtles migrated to Eritrea (n = 1), India (n = 2), Oman (n = 4), and the United Arab Emirates (n = 2), demonstrating connectivity for this species across the NWIO and linkages to known green turtle foraging areas. Turtles used deep international waters of the NWIO, and coastal waters of Eritrea, India, Iran, Oman, Pakistan, Saudi Arabia, and Yemen. Alongside the potential for fisheries bycatch, ghost fishing, entanglement, and direct take in waters near nesting sites and at the dispersal destinations, these movement patterns reveal a need for coordinated efforts to address sea turtle mortality in fisheries at a regional level. These data enhance our knowledge of sea turtle distribution and connectivity in the Arabian region and will contribute to ongoing efforts to conserve sea turtles in the NWIO.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129829540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Turtles have been identified as key dispersers of seeds in many ecosystems; however, seed dispersal by turtles (chelonochory) has received far less attention than seed dispersal by birds or mammals. We assessed the role of gopher tortoises (Gopherus polyphemus)—a keystone species—as potential seed dispersers by analyzing the seed composition of their diet in a globally imperiled ecosystem: the pine rockland ecosystem of South Florida. The pine rocklands contain high numbers of both endemic and invasive plant species that may be dispersed by tortoises. We collected scat samples from wild gopher tortoises living in the pine rockland habitats in the Richmond Tract (Miami-Dade County, Florida, USA) and examined the samples to identify seeds consumed. We extracted 2484 seeds from 53 samples from at least 10 individual tortoises. Of the 2484 individual seeds, we distinguished 33 morphospecies and identified 23 to the species taxonomic level. The 14 most abundant seed species in the scat constituted > 90% of all seeds eaten by the tortoises. Three of the 14 most abundant seeds were from nonnative plants, but none were among the most disruptive invasive species. Tortoises consumed mostly herbaceous ground cover and fibrous grasses. Given that the tortoises were consuming several ground cover plants and contained a high density of those seeds in their scats, they seemed to be consuming the seeds as bycatch rather than selectively feeding on them, therefore supporting Janzen's “foliage is the fruit” hypothesis. The prevalence of many seeds and a variety of seed species in the tortoise scat suggests that gopher tortoises may be serving the ecological role of a seed dispersal agent for some of the plants they consume within the pine rocklands.
{"title":"Seed Consumption by Gopher Tortoises (Gopherus polyphemus) in the Globally Imperiled Pine Rockland Ecosystem of Southern Florida, USA","authors":"Adrian Figueroa, J. Lange, S. Whitfield","doi":"10.2744/CCB-1426.1","DOIUrl":"https://doi.org/10.2744/CCB-1426.1","url":null,"abstract":"Abstract. Turtles have been identified as key dispersers of seeds in many ecosystems; however, seed dispersal by turtles (chelonochory) has received far less attention than seed dispersal by birds or mammals. We assessed the role of gopher tortoises (Gopherus polyphemus)—a keystone species—as potential seed dispersers by analyzing the seed composition of their diet in a globally imperiled ecosystem: the pine rockland ecosystem of South Florida. The pine rocklands contain high numbers of both endemic and invasive plant species that may be dispersed by tortoises. We collected scat samples from wild gopher tortoises living in the pine rockland habitats in the Richmond Tract (Miami-Dade County, Florida, USA) and examined the samples to identify seeds consumed. We extracted 2484 seeds from 53 samples from at least 10 individual tortoises. Of the 2484 individual seeds, we distinguished 33 morphospecies and identified 23 to the species taxonomic level. The 14 most abundant seed species in the scat constituted > 90% of all seeds eaten by the tortoises. Three of the 14 most abundant seeds were from nonnative plants, but none were among the most disruptive invasive species. Tortoises consumed mostly herbaceous ground cover and fibrous grasses. Given that the tortoises were consuming several ground cover plants and contained a high density of those seeds in their scats, they seemed to be consuming the seeds as bycatch rather than selectively feeding on them, therefore supporting Janzen's “foliage is the fruit” hypothesis. The prevalence of many seeds and a variety of seed species in the tortoise scat suggests that gopher tortoises may be serving the ecological role of a seed dispersal agent for some of the plants they consume within the pine rocklands.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123868822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-24DOI: 10.2744/1071-8443-20.1.1
Jeffrey A. Seminoff
{"title":"Introducing Chelonian Conservation and Biology Volume 20: Turtles and Tortoises Can Help Us Through Challenging Times","authors":"Jeffrey A. Seminoff","doi":"10.2744/1071-8443-20.1.1","DOIUrl":"https://doi.org/10.2744/1071-8443-20.1.1","url":null,"abstract":"","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129430690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juliana Gaviria-Hernández, Vivian P. Páez, D. M. Ramírez, Claudia P Ceballos
Abstract. Incubation temperature is a factor that can affect several traits in turtles such as body size, growth, shape, and sex in species with temperature-dependent sex determination. A clear understanding of these effects is particularly important in threatened species such as the red-footed tortoise (Chelonoidis carbonarius), classified in Colombia as Vulnerable mainly due to the capture of wild individuals to be kept as pets. A previous study on the effect of incubation temperature on sex determination concluded that constant temperatures of 31°C and 33°C are lethal to C. carbonarius embryos and that a temperature of 29°C produces 100% females. Although this showed that C. carbonarius has a temperature-based sex determination mechanism, its full reaction norm is still unknown. To fill in the gaps, we incubated 160 eggs from 47 nests at constant temperatures of 24°C, 26°C, and 28°C. The hatching success rates were 55%, 53%, and 60%, respectively, with extremely long incubation periods of 213, 164, and 138 d. Of the 75 neonates obtained, 58 reached 8 mo of age, at which time 45% (n = 26) were sexed. The sexual proportions (% males) obtained were 88.9%, 60%, and 0% from the 24°C, 26°C, and 28°C treatments. From the calculated thermal reaction norm, we estimated that the pivotal temperature is 26.05°C (95% CI = 25.31–26.69) and the transitional temperature range is from 24.34°C to 27.77°C. Incubation temperature also affected incubation period and hatchling body size and growth. Additionally, we found a significant effect of female body size and mass on egg size and mass, supporting a fecundity selection hypothesis of body size. Finally, we inspected hatchlings for sexual shape dimorphism using geometric morphometrics. We found significant differences in anal notch and plastron shape at 7 d of age, but only differences for anal notch at 1 and 2 mo of age. However, the statistical signal was weak and the results varied with age; thus this sexing technique was unreliable. Given the low critical thermal maxima for embryo survivorship (31°C or less), together with a 100% feminizing temperature of 27.9°C, global climate change coupled with deforestation constitute imminent threats to this species due to demographic impacts such as low recruitment rates and skewed primary sex ratios.
{"title":"Embryo Development and Sex Ratios in the Red-Footed Tortoise (Chelonoidis carbonarius) at Masculinizing Temperatures","authors":"Juliana Gaviria-Hernández, Vivian P. Páez, D. M. Ramírez, Claudia P Ceballos","doi":"10.2744/CCB-1441.1","DOIUrl":"https://doi.org/10.2744/CCB-1441.1","url":null,"abstract":"Abstract. Incubation temperature is a factor that can affect several traits in turtles such as body size, growth, shape, and sex in species with temperature-dependent sex determination. A clear understanding of these effects is particularly important in threatened species such as the red-footed tortoise (Chelonoidis carbonarius), classified in Colombia as Vulnerable mainly due to the capture of wild individuals to be kept as pets. A previous study on the effect of incubation temperature on sex determination concluded that constant temperatures of 31°C and 33°C are lethal to C. carbonarius embryos and that a temperature of 29°C produces 100% females. Although this showed that C. carbonarius has a temperature-based sex determination mechanism, its full reaction norm is still unknown. To fill in the gaps, we incubated 160 eggs from 47 nests at constant temperatures of 24°C, 26°C, and 28°C. The hatching success rates were 55%, 53%, and 60%, respectively, with extremely long incubation periods of 213, 164, and 138 d. Of the 75 neonates obtained, 58 reached 8 mo of age, at which time 45% (n = 26) were sexed. The sexual proportions (% males) obtained were 88.9%, 60%, and 0% from the 24°C, 26°C, and 28°C treatments. From the calculated thermal reaction norm, we estimated that the pivotal temperature is 26.05°C (95% CI = 25.31–26.69) and the transitional temperature range is from 24.34°C to 27.77°C. Incubation temperature also affected incubation period and hatchling body size and growth. Additionally, we found a significant effect of female body size and mass on egg size and mass, supporting a fecundity selection hypothesis of body size. Finally, we inspected hatchlings for sexual shape dimorphism using geometric morphometrics. We found significant differences in anal notch and plastron shape at 7 d of age, but only differences for anal notch at 1 and 2 mo of age. However, the statistical signal was weak and the results varied with age; thus this sexing technique was unreliable. Given the low critical thermal maxima for embryo survivorship (31°C or less), together with a 100% feminizing temperature of 27.9°C, global climate change coupled with deforestation constitute imminent threats to this species due to demographic impacts such as low recruitment rates and skewed primary sex ratios.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123695177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ayushi Jain, Francoise Cavada-Blanco, M. Palot, Sandeep Das, V. Deepak, Abhijit Das
Abstract. We review the historical and current distribution for Cantor's giant softshell turtle (Pelochelys cantorii) in India. We report 13 new records from Kerala State. Based on our intensive survey in Kasaragod District, we report a potential breeding population from this region.
{"title":"A Review of Distribution of Cantor's Giant Softshell Turtle in India Along with Multiple Notable New Records from Kerala State","authors":"Ayushi Jain, Francoise Cavada-Blanco, M. Palot, Sandeep Das, V. Deepak, Abhijit Das","doi":"10.2744/CCB-1468.1","DOIUrl":"https://doi.org/10.2744/CCB-1468.1","url":null,"abstract":"Abstract. We review the historical and current distribution for Cantor's giant softshell turtle (Pelochelys cantorii) in India. We report 13 new records from Kerala State. Based on our intensive survey in Kasaragod District, we report a potential breeding population from this region.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"401 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122482073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jichao Wang, Yuxiang Liu, J. Fong, J. F. Parham, H. Shi
Abstract. From 2000 to 2002, the reproductive ecology of the endangered Hainan four eye-spotted turtle (Sacalia insulensis) was studied on Hainan Island, China. A total of 147 adult females were captured, and their reproductive status was evaluated by palpation, X-ray imaging, and ultrasound. Twenty-two gravid females were under observation when they laid their eggs. We observed gravid females and nesting behavior along stream banks between December and April. Nest dimensions ranged from 5 to 6 cm in diameter and from 2 to 3 cm in depth. No females in our study produced more than 1 clutch per season. Clutch size average was 1.9 eggs (range = 1–3 eggs, SD = 0.56, n = 22) with an average egg mass of 16.05 g (range = 11.8–21.0 g, SD = 2.417, n = 21), an average egg width of 2.36 cm (range = 2.1–2.7 cm, SD = 0.135, n = 21), and an average length of 4.65 cm (range = 3.9–5.3 cm, SD = 0.400, n = 21). Hatching success rate was 53%, and hatchlings emerged after an average of 120.9 d (range = 98–148 d, SD = 14.94, n = 21) in late June to early July. The mean nesting site ground temperature was 24.43°C (range = 15.0°C–30.2°C, SD = 2.712, n = 7).
摘要2000 ~ 2002年在海南岛对濒危物种海南四眼斑龟(Sacalia insulensis)的生殖生态进行了研究。共捕获147只成年雌性，通过触诊、x线成像和超声评估其生殖状况。22只怀孕的雌性在产卵时进行了观察。在12月至4月期间，我们观察了雌龟在溪流岸边的怀孕和筑巢行为。巢的直径为5至6厘米，深度为2至3厘米。在我们的研究中，没有一只雌性每一季产超过1窝卵。平均卵数为1.9粒(范围= 1 ~ 3粒，SD = 0.56, n = 22)，平均卵重16.05 g(范围= 11.8 ~ 21.0 g, SD = 2.417, n = 21)，平均卵宽2.36 cm(范围= 2.1 ~ 2.7 cm, SD = 0.135, n = 21)，平均卵长4.65 cm(范围= 3.9 ~ 5.3 cm, SD = 0.400, n = 21)。孵化成功率53%，6月下旬至7月上旬平均孵化120.9 d(范围98 ~ 148 d, SD = 14.94, n = 21)。平均地温为24.43℃(范围15.0℃~ 30.2℃，SD = 2.712, n = 7)。
{"title":"Reproductive Ecology of the Hainan Four Eye-Spotted Turtle (Sacalia insulensis) on Hainan Island, China","authors":"Jichao Wang, Yuxiang Liu, J. Fong, J. F. Parham, H. Shi","doi":"10.2744/CCB-1383.1","DOIUrl":"https://doi.org/10.2744/CCB-1383.1","url":null,"abstract":"Abstract. From 2000 to 2002, the reproductive ecology of the endangered Hainan four eye-spotted turtle (Sacalia insulensis) was studied on Hainan Island, China. A total of 147 adult females were captured, and their reproductive status was evaluated by palpation, X-ray imaging, and ultrasound. Twenty-two gravid females were under observation when they laid their eggs. We observed gravid females and nesting behavior along stream banks between December and April. Nest dimensions ranged from 5 to 6 cm in diameter and from 2 to 3 cm in depth. No females in our study produced more than 1 clutch per season. Clutch size average was 1.9 eggs (range = 1–3 eggs, SD = 0.56, n = 22) with an average egg mass of 16.05 g (range = 11.8–21.0 g, SD = 2.417, n = 21), an average egg width of 2.36 cm (range = 2.1–2.7 cm, SD = 0.135, n = 21), and an average length of 4.65 cm (range = 3.9–5.3 cm, SD = 0.400, n = 21). Hatching success rate was 53%, and hatchlings emerged after an average of 120.9 d (range = 98–148 d, SD = 14.94, n = 21) in late June to early July. The mean nesting site ground temperature was 24.43°C (range = 15.0°C–30.2°C, SD = 2.712, n = 7).","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133675993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-24DOI: 10.2744/1071-8443.20.1.149
S. Dunn
{"title":"The Revolt of the Turtles1","authors":"S. Dunn","doi":"10.2744/1071-8443.20.1.149","DOIUrl":"https://doi.org/10.2744/1071-8443.20.1.149","url":null,"abstract":"","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129235221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eduardo Reyes-Grajales, R. Macip-Ríos, J. Iverson, Wilfredo A. Matamoros
Abstract. The Central Chiapas Mud Turtle (Kinosternon abaxillare) is one of the least-studied turtles in Mexico. It is considered a microendemic, with a limited distribution in the Central Depression of Chiapas. In this article, we summarize its population ecology and provide a new assessment of its morphology from Villa Hidalgo, Chiapas, Mexico. We captured 168 individuals with 64 recaptures (232 total captures), and we report a population size of 231 individuals with a density of 700 turtles/ha (189 kg/ha standing crop biomass). The population showed a female-biased sex ratio (1:1.5) and the population structure was largely composed of adults. Finally, we provide a set of morphological measurements for all size classes and sexes of K. abaxillare for the first time. The plastral formula (relative lengths of midline plastral seams) was identical in all size classes and sexes (Ab > An > Gu > Hu > Fe > Pe). Females and males reached similar carapace length but not body mass. Further studies are needed to determine the overall conservation status of this range-restricted species.
摘要中恰帕斯泥龟(学名Kinosternon abaxillare)是墨西哥研究最少的海龟之一。它被认为是一种微地方性疾病，在恰帕斯中央洼地的分布有限。本文总结了墨西哥恰帕斯州Villa Hidalgo地区的种群生态学，并对其形态进行了新的评价。我们捕获了168只海龟，其中64只被重新捕获(共捕获232只)，我们报告的种群规模为231只，密度为700只/公顷(189公斤/公顷常绿作物生物量)。种群性别比为1:1.5，以成虫为主。最后，我们首次提供了一套对所有大小类和性别的形态学测量。各尺寸类和性别的体型公式(中线体缝的相对长度)相同(Ab > An > Gu > Hu > Fe > Pe)。雌性和雄性的甲壳长度相似，但体重不同。需要进一步的研究来确定这种范围限制物种的整体保护状况。
{"title":"Population Ecology and Morphology of the Central Chiapas Mud Turtle (Kinosternon abaxillare)","authors":"Eduardo Reyes-Grajales, R. Macip-Ríos, J. Iverson, Wilfredo A. Matamoros","doi":"10.2744/CCB-1440.1","DOIUrl":"https://doi.org/10.2744/CCB-1440.1","url":null,"abstract":"Abstract. The Central Chiapas Mud Turtle (Kinosternon abaxillare) is one of the least-studied turtles in Mexico. It is considered a microendemic, with a limited distribution in the Central Depression of Chiapas. In this article, we summarize its population ecology and provide a new assessment of its morphology from Villa Hidalgo, Chiapas, Mexico. We captured 168 individuals with 64 recaptures (232 total captures), and we report a population size of 231 individuals with a density of 700 turtles/ha (189 kg/ha standing crop biomass). The population showed a female-biased sex ratio (1:1.5) and the population structure was largely composed of adults. Finally, we provide a set of morphological measurements for all size classes and sexes of K. abaxillare for the first time. The plastral formula (relative lengths of midline plastral seams) was identical in all size classes and sexes (Ab > An > Gu > Hu > Fe > Pe). Females and males reached similar carapace length but not body mass. Further studies are needed to determine the overall conservation status of this range-restricted species.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116154177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fei Kong, Qin Zhu, F. Xiao, Zhen Hong, Hongxing Zhang, H. Shi
Abstract. A detailed understanding of the spatial ecology and habitat requirements of endangered species is critical for population restoration and conservation. Home ranges and movements of the endangered Chinese softshell turtle (Pelodiscus sinensis) were investigated in the Yellow River, northwestern China, from October 2016 to July 2018. We monitored 9 adult turtles (5 females and 4 males) with radio transmitters. Mean linear range size was 440 ± 161 m SD, mean river channel area was 1.98 ± 0.72 ha SD, the average minimum convex polygon was 1.36 ± 0.65 ha SD, average 95% kernel density estimator measured 0.84 ± 0.51 ha SD, with a core area (50% kernel density estimator) of 0.30 ± 0.20 ha SD. Home range values were not significantly different between the sexes nor were they related to straight-line carapace length or mass. Daily movements of P. sinensis averaged 35 ± 18 m SD for males and 43 ± 18 m SD for females, and there was no significant difference between sexes or significant correlation between movement patterns and body size. However, during the nesting season, there was a significant difference between sexes. Turtle activity was highest in May (average daily movement 59 ± 6 m SD) and lowest in January (0.4 ± 0.6 m SD). Given that P. sinensis individuals have small home ranges and are capable of existing in small rivers, management efforts should protect smaller rivers that may be easily overlooked. Results from this study provide the first assessment of home range requirements for P. sinensis, which may be used in future population modeling efforts and are important for establishing conservation strategies for this vulnerable species.
摘要详细了解濒危物种的空间生态和生境需求对种群恢复和保护至关重要。2016年10月至2018年7月，对中国西北黄河地区濒危中华软壳龟(Pelodiscus sinensis)的活动范围和活动情况进行了调查。我们用无线电发射器监测了9只成年海龟(5雌4雄)。平均线性范围大小为440±161 m SD，平均河道面积为1.98±0.72 ha SD，平均最小凸多边形为1.36±0.65 ha SD，平均95%核密度估估值为0.84±0.51 ha SD，核心区(50%核密度估估值)为0.30±0.20 ha SD。家谱值在两性之间无显著差异，也与甲壳直线长度或质量无关。雄性和雌性的日均移动量分别为35±18 m SD和43±18 m SD，雌雄之间无显著差异，且运动方式与体型之间无显著相关。然而，在筑巢季节，两性之间存在显著差异。海龟活动在5月最高(平均日活动59±6 m SD)， 1月最低(0.4±0.6 m SD)。鉴于中华水蛭个体的活动范围小，能够在小河流中生存，管理工作应该保护容易被忽视的小河流。本研究的结果首次评估了中华白杨对栖息地的需求，可用于未来的种群建模工作，并对建立这一脆弱物种的保护策略具有重要意义。
{"title":"Home Ranges and Movement Patterns of the Chinese Softshell Turtle (Pelodiscus sinensis) in the Yellow River, Northwestern China","authors":"Fei Kong, Qin Zhu, F. Xiao, Zhen Hong, Hongxing Zhang, H. Shi","doi":"10.2744/CCB-1402.1","DOIUrl":"https://doi.org/10.2744/CCB-1402.1","url":null,"abstract":"Abstract. A detailed understanding of the spatial ecology and habitat requirements of endangered species is critical for population restoration and conservation. Home ranges and movements of the endangered Chinese softshell turtle (Pelodiscus sinensis) were investigated in the Yellow River, northwestern China, from October 2016 to July 2018. We monitored 9 adult turtles (5 females and 4 males) with radio transmitters. Mean linear range size was 440 ± 161 m SD, mean river channel area was 1.98 ± 0.72 ha SD, the average minimum convex polygon was 1.36 ± 0.65 ha SD, average 95% kernel density estimator measured 0.84 ± 0.51 ha SD, with a core area (50% kernel density estimator) of 0.30 ± 0.20 ha SD. Home range values were not significantly different between the sexes nor were they related to straight-line carapace length or mass. Daily movements of P. sinensis averaged 35 ± 18 m SD for males and 43 ± 18 m SD for females, and there was no significant difference between sexes or significant correlation between movement patterns and body size. However, during the nesting season, there was a significant difference between sexes. Turtle activity was highest in May (average daily movement 59 ± 6 m SD) and lowest in January (0.4 ± 0.6 m SD). Given that P. sinensis individuals have small home ranges and are capable of existing in small rivers, management efforts should protect smaller rivers that may be easily overlooked. Results from this study provide the first assessment of home range requirements for P. sinensis, which may be used in future population modeling efforts and are important for establishing conservation strategies for this vulnerable species.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114431649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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