Claudia Cabrera Guerra, Julia Azanza Ricardo, Ryan Betancourt Ávila, F. Bretos, Pedro Pérez Álvarez
Abstract. Vegetation has been shown to influence nest environment (temperature, humidity), affecting hatchling's development as well as emergence success, and has also been used as a cue during the selection of a nesting site. For green turtles, Chelonia mydas, nest density is typically higher in the vegetated zones. This study evaluated the influence of vegetation presence and percent cover on the nesting success and embryonic development of green turtles in Guanahacabibes Peninsula, Cuba. The vegetation cover had a positive and significant relationship with the number of nests (r = 0.56, p = 0.01, n = 17). Two vegetation patches are identified with different vegetation cover values: 29% for the first (closer to the high tide line) and 37% for the second. We found the highest nesting success (70%) and nest relative frequency (15% of total nesting) around the first patch of vegetation. Median hatchling emergence success was 88% (40%–96%, n = 54) in the first patch and 93% (78%–100%, n = 40) in the second. The incubation period was lower in the first patch (mean = 51 d, range = 48–60 d, n = 44) and higher in the second (mean = 54 d, range = 45–67 d, n = 39). This is the first study that reveals the positive impact of sandy coast vegetation on Guanahacabibes' green turtle nesting and will be useful in conservation actions such as native vegetation restoration plans and temperature control using shade management with vegetation.
{"title":"Influence of Sandy Coast Vegetation on the Reproductive Success of Green Turtles at Cuban Nesting Beaches","authors":"Claudia Cabrera Guerra, Julia Azanza Ricardo, Ryan Betancourt Ávila, F. Bretos, Pedro Pérez Álvarez","doi":"10.2744/CCB-1460.1","DOIUrl":"https://doi.org/10.2744/CCB-1460.1","url":null,"abstract":"Abstract. Vegetation has been shown to influence nest environment (temperature, humidity), affecting hatchling's development as well as emergence success, and has also been used as a cue during the selection of a nesting site. For green turtles, Chelonia mydas, nest density is typically higher in the vegetated zones. This study evaluated the influence of vegetation presence and percent cover on the nesting success and embryonic development of green turtles in Guanahacabibes Peninsula, Cuba. The vegetation cover had a positive and significant relationship with the number of nests (r = 0.56, p = 0.01, n = 17). Two vegetation patches are identified with different vegetation cover values: 29% for the first (closer to the high tide line) and 37% for the second. We found the highest nesting success (70%) and nest relative frequency (15% of total nesting) around the first patch of vegetation. Median hatchling emergence success was 88% (40%–96%, n = 54) in the first patch and 93% (78%–100%, n = 40) in the second. The incubation period was lower in the first patch (mean = 51 d, range = 48–60 d, n = 44) and higher in the second (mean = 54 d, range = 45–67 d, n = 39). This is the first study that reveals the positive impact of sandy coast vegetation on Guanahacabibes' green turtle nesting and will be useful in conservation actions such as native vegetation restoration plans and temperature control using shade management with vegetation.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128528014","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}
Joshua G. Otten, Austin C. Hulbert, S. Berg, J. Tamplin
Abstract. Wood turtles (Glyptemys insculpta) are considered rare or threatened throughout their range. Populations in Iowa occur at the western periphery of the species' range and may be particularly vulnerable to extirpation due to low population density, geographic isolation with restricted opportunities for gene flow, a small range, and a high percentage of land that has been converted for agriculture. To improve our understanding of the ecological needs of the species and to provide targeted conservation of required habitat, determining home range size, site fidelity, and movement patterns is needed. We conducted a 2-yr radiotelemetry study on wood turtles in Iowa to provide baseline data on movement patterns (including estimated total distance moved in an active season and mean daily movement) and home range size and site fidelity between years of survey. Home range size of adult male and female wood turtles differed significantly for 100%, 95%, and 50% minimum convex polygon home range, with male mean home range being nearly 3 times the mean size of female home range. Stream home range length also differed significantly between males and females, with males utilizing a larger portion of lotic habitat. Both sexes showed a high degree of site fidelity to annual home ranges but not to specific overwintering locations. Our study provides important data on home range size, degree of site fidelity, and movement patterns of wood turtles from an isolated population in Iowa at the southwest periphery of the species' range. These data will inform conservation agencies on relevant habitat protection and management strategies of riparian areas that are necessary for the continued survival and protection of the species in the state.
{"title":"Home Range, Site Fidelity, and Movement Patterns of the Wood Turtle (Glyptemys insculpta) at the Southwestern Edge of Its Range","authors":"Joshua G. Otten, Austin C. Hulbert, S. Berg, J. Tamplin","doi":"10.2744/CCB-1463.1","DOIUrl":"https://doi.org/10.2744/CCB-1463.1","url":null,"abstract":"Abstract. Wood turtles (Glyptemys insculpta) are considered rare or threatened throughout their range. Populations in Iowa occur at the western periphery of the species' range and may be particularly vulnerable to extirpation due to low population density, geographic isolation with restricted opportunities for gene flow, a small range, and a high percentage of land that has been converted for agriculture. To improve our understanding of the ecological needs of the species and to provide targeted conservation of required habitat, determining home range size, site fidelity, and movement patterns is needed. We conducted a 2-yr radiotelemetry study on wood turtles in Iowa to provide baseline data on movement patterns (including estimated total distance moved in an active season and mean daily movement) and home range size and site fidelity between years of survey. Home range size of adult male and female wood turtles differed significantly for 100%, 95%, and 50% minimum convex polygon home range, with male mean home range being nearly 3 times the mean size of female home range. Stream home range length also differed significantly between males and females, with males utilizing a larger portion of lotic habitat. Both sexes showed a high degree of site fidelity to annual home ranges but not to specific overwintering locations. Our study provides important data on home range size, degree of site fidelity, and movement patterns of wood turtles from an isolated population in Iowa at the southwest periphery of the species' range. These data will inform conservation agencies on relevant habitat protection and management strategies of riparian areas that are necessary for the continued survival and protection of the species in the state.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126636589","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}
Andrews Agyekumhene, Prince Yankson, Leyna R. Stemle, P. Allman
Abstract. The recovery of depleted sea turtle populations will require careful documentation of sea turtle reproduction sites and anthropogenic mortality risks throughout their known ranges. Although sea turtle nesting is well documented in many locations, there remains a paucity of data on the species and nesting ecology in western Africa. Here we provide the first longitudinal study of sea turtle nesting activity in Ghana. In decreasing order of abundance, we observed nesting olive ridley (Lepidochelys olivacea) (60 nests/yr), leatherback (Dermochelys coriacea) (17 nests/yr), and green (Chelonia mydas) sea turtles (2 nests/yr) along 3.7 km of beach. The primary nesting season for all species is September through January; however, olive ridley turtles sporadically nest throughout the year. Olive ridley nesting activity significantly declined during the study period (R2 = 0.53, p = 0.04). The primary risk factors for these animals are fishery bycatch, direct harvest of nesting females, and egg poaching.
摘要减少的海龟数量的恢复将需要仔细记录海龟的繁殖地点和在其已知范围内的人为死亡风险。虽然海龟筑巢在许多地方都有很好的记录，但关于西非的物种和筑巢生态的数据仍然缺乏。在这里，我们提供了加纳海龟筑巢活动的第一个纵向研究。在3.7 km的海滩上，我们观察到橄榄蠵龟(Lepidochelys olivacea)筑巢(60个/年)、棱皮龟(Dermochelys coriacea)筑巢(17个/年)和绿海龟(Chelonia mydas)筑巢(2个/年)。所有物种的主要筑巢季节是9月到1月;然而，橄榄蠵龟全年都会偶尔筑巢。研究期间，绿蠵龟筑巢活动显著下降(R2 = 0.53, p = 0.04)。这些动物的主要危险因素是渔业副渔获、直接捕获筑巢的雌性和偷猎卵子。
{"title":"Sea Turtle Nesting Activity in Ghana, West Africa","authors":"Andrews Agyekumhene, Prince Yankson, Leyna R. Stemle, P. Allman","doi":"10.2744/CCB-1487.1","DOIUrl":"https://doi.org/10.2744/CCB-1487.1","url":null,"abstract":"Abstract. The recovery of depleted sea turtle populations will require careful documentation of sea turtle reproduction sites and anthropogenic mortality risks throughout their known ranges. Although sea turtle nesting is well documented in many locations, there remains a paucity of data on the species and nesting ecology in western Africa. Here we provide the first longitudinal study of sea turtle nesting activity in Ghana. In decreasing order of abundance, we observed nesting olive ridley (Lepidochelys olivacea) (60 nests/yr), leatherback (Dermochelys coriacea) (17 nests/yr), and green (Chelonia mydas) sea turtles (2 nests/yr) along 3.7 km of beach. The primary nesting season for all species is September through January; however, olive ridley turtles sporadically nest throughout the year. Olive ridley nesting activity significantly declined during the study period (R2 = 0.53, p = 0.04). The primary risk factors for these animals are fishery bycatch, direct harvest of nesting females, and egg poaching.","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":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125381217","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}
D. Ayaz, Yusuf Bayrakcı, K. Çiçek, F. Ihlow, C. V. Tok, U. Fritz
Abstract. Eiselt's pond turtle (Emys orbicularis eiselti) was described in 1998, based on only 4 museum specimens collected in the 1960s and 1970s. Its distribution range has been massively reduced by large-scale drainage measures and only little suitable habitat remains near the Turkish–Syrian border. During 20-yr-long fieldwork we could locate only 18 individuals of this subspecies. We estimate the number of surviving Eiselt's pond turtles to be less than 100 mature individuals in the wild. The distribution range (area of occupancy) in the Amik Maraş Rift Valley shrank from originally 11,612 km2 to only 206 km2 at present (approx. 2%), qualifying E. o. eiselti as a Critically Endangered taxon. Without immediate conservation measures and the strict protection of the remaining habitat, the subspecies will soon be extinct.
摘要1998年，根据20世纪60年代和70年代收集的4个博物馆标本，人们描述了艾瑟尔塘龟(Emys orbicularis eiselti)。由于大规模的排水措施，它的分布范围大大缩小，在土耳其-叙利亚边境附近只有很少的合适栖息地。在长达20年的野外调查中，我们只找到了18个亚种个体。我们估计在野外存活的艾瑟尔池塘龟的数量不到100只。Amik maraku裂谷的分布范围(占用面积)从最初的11,612平方公里缩小到目前的仅206平方公里(约为4800平方公里)。(2%)，认定E. o. eiselti为极危分类单元。如果不立即采取保护措施和严格保护剩余的栖息地，亚种将很快灭绝。
{"title":"On the Brink of Extinction: Results of a 20-Year Quest for Eiselt's Pond Turtle (Emys orbicularis eiselti) in Southeastern Turkey","authors":"D. Ayaz, Yusuf Bayrakcı, K. Çiçek, F. Ihlow, C. V. Tok, U. Fritz","doi":"10.2744/CCB-1505.1","DOIUrl":"https://doi.org/10.2744/CCB-1505.1","url":null,"abstract":"Abstract. Eiselt's pond turtle (Emys orbicularis eiselti) was described in 1998, based on only 4 museum specimens collected in the 1960s and 1970s. Its distribution range has been massively reduced by large-scale drainage measures and only little suitable habitat remains near the Turkish–Syrian border. During 20-yr-long fieldwork we could locate only 18 individuals of this subspecies. We estimate the number of surviving Eiselt's pond turtles to be less than 100 mature individuals in the wild. The distribution range (area of occupancy) in the Amik Maraş Rift Valley shrank from originally 11,612 km2 to only 206 km2 at present (approx. 2%), qualifying E. o. eiselti as a Critically Endangered taxon. Without immediate conservation measures and the strict protection of the remaining habitat, the subspecies will soon be extinct.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132935635","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. The goal of this study was to determine whether marine turtle (loggerhead) embryos communicate with one another using mechanical cues detected through the flexible egg shell. In the process, the embryos might develop faster and hatch with greater synchrony (as occurs in some freshwater turtles). To find out, we performed experiments under controlled laboratory conditions to determine how changes in the embryonic social environment affected both the rate of development and the temporal pattern of hatching when temperature, moisture, and substrate composition were controlled. We found that developmental periods were significantly shortened and hatching synchrony was increased when 1) a critical number of eggs were in contact with one another, facilitating the possibilities for embryos to communicate, and when 2) a threshold number of those eggs remained viable and completed development at about the same time. We used this information, in combination with field studies done by others, to clarify temporal relationships between hatching and emergence from the nest that occurs several days later.
{"title":"Evidence for Synchronous Hatching in Marine Turtle (Caretta caretta) Embryos and Its Influence on the Timing of Nest Emergence","authors":"Angela Field, Jessica K. McGlashan, M. Salmon","doi":"10.2744/CCB-1489.1","DOIUrl":"https://doi.org/10.2744/CCB-1489.1","url":null,"abstract":"Abstract. The goal of this study was to determine whether marine turtle (loggerhead) embryos communicate with one another using mechanical cues detected through the flexible egg shell. In the process, the embryos might develop faster and hatch with greater synchrony (as occurs in some freshwater turtles). To find out, we performed experiments under controlled laboratory conditions to determine how changes in the embryonic social environment affected both the rate of development and the temporal pattern of hatching when temperature, moisture, and substrate composition were controlled. We found that developmental periods were significantly shortened and hatching synchrony was increased when 1) a critical number of eggs were in contact with one another, facilitating the possibilities for embryos to communicate, and when 2) a threshold number of those eggs remained viable and completed development at about the same time. We used this information, in combination with field studies done by others, to clarify temporal relationships between hatching and emergence from the nest that occurs several days later.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"58 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114119545","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. We present 4 observations of hawksbill turtles Eretmochelys imbricata found in anchialine ponds on 3 islands in The Bahamas. These ponds had no surface connection to the ocean, but they were connected by subterranean conduits that, in at least one instance, extended over 1.5 km in length. It is possible that the turtles were placed in these ponds by humans; however, it appears more likely that they accessed these habitats via the subterranean conduits suggesting that anchialine ponds may function as either novel habitat or a potential ecological trap.
{"title":"Novel Use of Anchialine Ponds by Hawksbill Turtles in The Bahamas","authors":"N. Robinson, R. Ditter, John Campion, E. Cole","doi":"10.2744/CCB-1499.1","DOIUrl":"https://doi.org/10.2744/CCB-1499.1","url":null,"abstract":"Abstract. We present 4 observations of hawksbill turtles Eretmochelys imbricata found in anchialine ponds on 3 islands in The Bahamas. These ponds had no surface connection to the ocean, but they were connected by subterranean conduits that, in at least one instance, extended over 1.5 km in length. It is possible that the turtles were placed in these ponds by humans; however, it appears more likely that they accessed these habitats via the subterranean conduits suggesting that anchialine ponds may function as either novel habitat or a potential ecological trap.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"14 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123045216","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}
Kevin M. Enge, Dirk J. Stevenson, Travis M. Thomas, Gerald R. Johnston, J. Jensen, Benjamin S. Stegenga, Houston C Chandler, P. Moler
Abstract. The Suwannee alligator snapping turtle (Macrochelys suwanniensis) was first described in 2014. The species is thought to occur in blackwater and spring-fed streams of sufficient size throughout the Suwannee River drainage, but we have limited detailed information regarding its range. To clarify the distribution of M. suwanniensis, we compiled 111 museum, 16 literature, and 40 other credible records and trapped streams throughout the Suwannee drainage in Georgia and Florida, plus 8 streams in the Big Bend region of Florida (total of 1893 trap nights). We documented the first records from the Willacoochee River and Okapilco, Piscola, Warrior, Jones, and Toms creeks in Georgia and from Rocky and Olustee creeks in Florida. Relative abundance based on catch per unit effort (CPUE) varied among streams (0.00–0.50) and sections of the same stream. Macrochelys suwanniensis is apparently scarce in the Okefenokee Swamp and in the Suwannee River upstream of White Springs, Florida (none trapped), but it occurs in small blackwater tributaries in this section of the river in both states. In the Suwannee River between White Springs and the estuary, we had a mean CPUE of 0.25, and the highest trapping success in Florida was in downstream reaches of the Suwannee River and in its major tributaries, the Santa Fe and New rivers. The species is widely distributed in Georgia, but relative abundance in most streams appears lower than in Florida. In Georgia, we had the highest trapping success in the Alapaha drainage and in sections of the Little River and Okapilco Creek in the Withlacoochee drainage. In Florida, we failed to trap Macrochelys in the purported distribution gap between the Suwannee and Ochlockonee drainages and in the Wacasassa River to the south, indicating that this species is restricted to the Suwannee drainage.
{"title":"Distribution and Relative Abundance of the Suwannee Alligator Snapping Turtle (Macrochelys suwanniensis)","authors":"Kevin M. Enge, Dirk J. Stevenson, Travis M. Thomas, Gerald R. Johnston, J. Jensen, Benjamin S. Stegenga, Houston C Chandler, P. Moler","doi":"10.2744/CCB-1488.1","DOIUrl":"https://doi.org/10.2744/CCB-1488.1","url":null,"abstract":"Abstract. The Suwannee alligator snapping turtle (Macrochelys suwanniensis) was first described in 2014. The species is thought to occur in blackwater and spring-fed streams of sufficient size throughout the Suwannee River drainage, but we have limited detailed information regarding its range. To clarify the distribution of M. suwanniensis, we compiled 111 museum, 16 literature, and 40 other credible records and trapped streams throughout the Suwannee drainage in Georgia and Florida, plus 8 streams in the Big Bend region of Florida (total of 1893 trap nights). We documented the first records from the Willacoochee River and Okapilco, Piscola, Warrior, Jones, and Toms creeks in Georgia and from Rocky and Olustee creeks in Florida. Relative abundance based on catch per unit effort (CPUE) varied among streams (0.00–0.50) and sections of the same stream. Macrochelys suwanniensis is apparently scarce in the Okefenokee Swamp and in the Suwannee River upstream of White Springs, Florida (none trapped), but it occurs in small blackwater tributaries in this section of the river in both states. In the Suwannee River between White Springs and the estuary, we had a mean CPUE of 0.25, and the highest trapping success in Florida was in downstream reaches of the Suwannee River and in its major tributaries, the Santa Fe and New rivers. The species is widely distributed in Georgia, but relative abundance in most streams appears lower than in Florida. In Georgia, we had the highest trapping success in the Alapaha drainage and in sections of the Little River and Okapilco Creek in the Withlacoochee drainage. In Florida, we failed to trap Macrochelys in the purported distribution gap between the Suwannee and Ochlockonee drainages and in the Wacasassa River to the south, indicating that this species is restricted to the Suwannee drainage.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134599887","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}
Alexander R. Gaos, C. E. Johnson, Don B. McLeish, Cheryl S. King, J. Senko
Abstract. Social behaviors represent a central tenet of ecology and evolutionary biology, but remain widely undocumented in reptiles. Although marine turtles have been studied for decades, the prevalence, importance, and potential role of social behaviors have been largely overlooked. Consequently, marine turtles have predominantly been characterized as nonsocial animals in the literature. Here we report on visual observations of hawksbill turtles (Eretmochelys imbricata) inhabiting a nearshore coral reef in Hawai‘i that reveal a complex array of social behaviors. Combined with recent evidence for social behaviors in other marine turtle species, our results confirm that traditional views of nonsocial life histories are incomplete and that social behaviors are likely prevalent in many marine turtle species. Our findings have important implications for marine turtle management and suggest increased research into social behaviors is warranted across the taxon.
{"title":"Interactions Among Hawaiian Hawksbills Suggest Prevalence of Social Behaviors in Marine Turtles","authors":"Alexander R. Gaos, C. E. Johnson, Don B. McLeish, Cheryl S. King, J. Senko","doi":"10.2744/CCB-1481.1","DOIUrl":"https://doi.org/10.2744/CCB-1481.1","url":null,"abstract":"Abstract. Social behaviors represent a central tenet of ecology and evolutionary biology, but remain widely undocumented in reptiles. Although marine turtles have been studied for decades, the prevalence, importance, and potential role of social behaviors have been largely overlooked. Consequently, marine turtles have predominantly been characterized as nonsocial animals in the literature. Here we report on visual observations of hawksbill turtles (Eretmochelys imbricata) inhabiting a nearshore coral reef in Hawai‘i that reveal a complex array of social behaviors. Combined with recent evidence for social behaviors in other marine turtle species, our results confirm that traditional views of nonsocial life histories are incomplete and that social behaviors are likely prevalent in many marine turtle species. Our findings have important implications for marine turtle management and suggest increased research into social behaviors is warranted across the taxon.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114226750","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}
E. Suarez, Travis M. Thomas, W. Turner, Ryan Gandy, Kevin M. Enge, Steve A. Johnson
Abstract. Management decisions for species are often based on estimates of abundance, which can be difficult to obtain for species that are a challenge to survey, as are some reptiles. Information on abundance and population status are lacking for the diamondback terrapin (Malaclemys terrapin), a coastal species that inhabits brackish waters and plays an important trophic role in the saltmarsh ecosystem. Population declines are suspected throughout the species' range, and its population status is unknown in Florida. Of the 5 subspecies that inhabit Florida's coastline, the most understudied subspecies may be the ornate diamondback terrapin (M. t. macrospilota). We conducted a capture–mark–recapture study of M. t. macrospilota during the summer of 2013 on 3 adjacent coastal islands in the eastern panhandle of Florida that provided information on population size and demography. We captured 334 individuals; modeling estimated a population size of 1282 (867–1905 95% CI) and a density of 150 terrapins/ha. Population size decreased throughout the study, suggesting that this population is an aggregation that seasonally emigrates from the islands. This emigration trend was more evident for females. Males outnumbered females 4:1, and females were larger than males. Our study is the first to report on M. t. macrospilota populations in the Florida panhandle. We recommend collaborative, long-term population monitoring at our sites to estimate population trends that will be crucial for managing this subspecies.
{"title":"Population Size and Structure of the Ornate Diamondback Terrapin (Malaclemys terrapin macrospilota) on Small Gulf Coast Islands in Florida","authors":"E. Suarez, Travis M. Thomas, W. Turner, Ryan Gandy, Kevin M. Enge, Steve A. Johnson","doi":"10.2744/CCB-1485.1","DOIUrl":"https://doi.org/10.2744/CCB-1485.1","url":null,"abstract":"Abstract. Management decisions for species are often based on estimates of abundance, which can be difficult to obtain for species that are a challenge to survey, as are some reptiles. Information on abundance and population status are lacking for the diamondback terrapin (Malaclemys terrapin), a coastal species that inhabits brackish waters and plays an important trophic role in the saltmarsh ecosystem. Population declines are suspected throughout the species' range, and its population status is unknown in Florida. Of the 5 subspecies that inhabit Florida's coastline, the most understudied subspecies may be the ornate diamondback terrapin (M. t. macrospilota). We conducted a capture–mark–recapture study of M. t. macrospilota during the summer of 2013 on 3 adjacent coastal islands in the eastern panhandle of Florida that provided information on population size and demography. We captured 334 individuals; modeling estimated a population size of 1282 (867–1905 95% CI) and a density of 150 terrapins/ha. Population size decreased throughout the study, suggesting that this population is an aggregation that seasonally emigrates from the islands. This emigration trend was more evident for females. Males outnumbered females 4:1, and females were larger than males. Our study is the first to report on M. t. macrospilota populations in the Florida panhandle. We recommend collaborative, long-term population monitoring at our sites to estimate population trends that will be crucial for managing this subspecies.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120943920","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}
Kayhan Ostovar, Gabriel Wolff, D. Dockery, Ulrich A Hoensch, M. Ruggles, A. Massey, Reece Robinett, Earl Radonski
Abstract. To conserve or restore riverine turtles, managers need baseline information on subpopulation structure and abundance in multiple rivers across large geographic areas. Assessing the demographics and morphological characteristics of different subpopulations can increase our understanding of how anthropogenic factors influence mortality and reproduction. We examined spiny softshell turtles (Apalone spinifera) in 5 rivers at the western edge of the species' range in southcentral Montana, where no commercial harvest is allowed. Over 4 yrs, we captured 637 spiny softshell turtles with fish-baited hoop traps. Our objective was to compare the subpopulation demographics in the Yellowstone River—considered one of the most intact rivers in the conterminous United States—to 3 Yellowstone River tributaries (Bighorn and Clarks Fork rivers and Pryor Creek) and the adjacent Musselshell River. Subpopulations differed significantly based on the demographic metrics we examined (e.g., mean sizes and sex ratios), and we documented limited numbers of males (4%–15%). Reproductive potential and mortality of adults among rivers appeared distinct based on juvenile and size class distribution of length-frequency histograms. This information from unharvested populations illustrates the variability in subpopulation demographics of riverine turtles.
{"title":"Population Structure of the Spiny Softshell Turtle (Apalone spinifera) in Five Montana Rivers","authors":"Kayhan Ostovar, Gabriel Wolff, D. Dockery, Ulrich A Hoensch, M. Ruggles, A. Massey, Reece Robinett, Earl Radonski","doi":"10.2744/CCB-1466.1","DOIUrl":"https://doi.org/10.2744/CCB-1466.1","url":null,"abstract":"Abstract. To conserve or restore riverine turtles, managers need baseline information on subpopulation structure and abundance in multiple rivers across large geographic areas. Assessing the demographics and morphological characteristics of different subpopulations can increase our understanding of how anthropogenic factors influence mortality and reproduction. We examined spiny softshell turtles (Apalone spinifera) in 5 rivers at the western edge of the species' range in southcentral Montana, where no commercial harvest is allowed. Over 4 yrs, we captured 637 spiny softshell turtles with fish-baited hoop traps. Our objective was to compare the subpopulation demographics in the Yellowstone River—considered one of the most intact rivers in the conterminous United States—to 3 Yellowstone River tributaries (Bighorn and Clarks Fork rivers and Pryor Creek) and the adjacent Musselshell River. Subpopulations differed significantly based on the demographic metrics we examined (e.g., mean sizes and sex ratios), and we documented limited numbers of males (4%–15%). Reproductive potential and mortality of adults among rivers appeared distinct based on juvenile and size class distribution of length-frequency histograms. This information from unharvested populations illustrates the variability in subpopulation demographics of riverine turtles.","PeriodicalId":126915,"journal":{"name":"Chelonian Conservation and Biology: Celebrating 25 Years as the World's Turtle and Tortoise Journal","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131244645","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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