Informations about the population dynamic of Trachemys dorbigni were collected from February 2006 to January 2007, in the Santa Barbara stream, Pelotas, Brazil. It was collected 377 individuals in the traps, 160 females, 146 males and 71 juveniles. The sex ratio was not different from 1:1. Males of T. dorbigni reached sexual maturity at 127 mm length. The smallest reproductive female presented 176 mm length. The females were heavier and larger than males in all morphometric measures, except to the CPD. The CPUE of females and juveniles was higher in February and March and in males in February and April. The RELEASE software did not indicated significant violations in premises of equal capture and survival probability. The population size estimated by Jolly-Seber was 3.145 adults and 544 juveniles. The week survival was constant to adults (97%) and to juveniles (94%). The weekly capture probability ranged from 0.3% to 13% to adults and it was constant to juveniles (4%). 122 nests were found. They present the smallest egg average already registered (8.2). Eggs had the smallest average size already reported to the species, 37.3 x 20.2 mm. The smallest reproductive female presented 176 mm in length. Egg width was positively dependent to their length. Clutch size had no relationship with their dimensions. Egg length and egg width also not depended on the female size. However, clutch size increased with female body size. Nesting occurred between October 22 and January 4. Only 35.3% of females in the population nested in evaluated year and 11.9% deposited two nests in the reproductive period. The species nested preferably in soils with more than 88% of sandy and higher frequency of nesting behavior occurred in the morning. Higher abundance of nests were found in areas between 25 m and 50 m away from the water and in flatter areas, between 0 ° and 10 ° of declivity. The incubation temperature ranged from 16.1 °C to 35.5 °C. It was registered 18.1% of predation in the nests. The nests were deposited on an aggregate form and the nests closest of stream, between 20 m and 30 m, had a higher rate of predation (52.4%). Higher survival recorded for the species can be linked to the relatively short period sampled. Besides exposition to human wastes, the turtles of the Santa Barbara stream are subject to high road mortality and to the wild animals trafficking. Only the analyses of the annual fluctuation of the populational parameters will demonstrate if the population is impacted by these effects. Due to the longevity of the turtles, some impacts can be assessed only in long term. / Informações a respeito da dinâmica populacional de Trachemys dorbigni foram coletadas entre os meses de fevereiro de 2006 e janeiro de 2007, no arroio Santa Bárbara, Pelotas, Brasil. Foram coletados 377 indivíduos, 160 fêmeas, 146 machos e 71 juvenis. A razão sexual não foi diferente de 1:1. A maturidade sexual dos machos foi alcançada a partir de 127 mm de comprimento. A menor fêmea reprodutiva apresentou 176 mm de comprimento. As fêmeas foram mais pesadas e maiores que os machos em todas as medidas morfométricas, exceto para o CPD. A CPUE das fêmeas e dos juvenis foi maior nos meses de fevereiro e março e dos machos nos meses de fevereiro e abril. O Software RELEASE não indicou violações significantes nas premissas de igual captura e sobrevivência e o tamanho populacional estimado por Jolly-Seber foi de 3145 adultos e 544 juvenis. A sobrevivência foi constante para os adultos (97%) e para os juvenis (94%) entre as ocasiões semanais de amostragem. Já a probabilidade semanal de captura variou de 0,3% a 13% para os adultos e foi constante para os juvenis (4%). Foram encontrados 122 ninhos, com a menor média de ovos já registrada (8,2). Os ovos, por sua vez, tiveram a menor média de tamanho já reportada para a espécie, 37,3 x 20,2 mm. A largura dos ovos esteve relacionada positivamente com o seu comprimento. Porém, o número de ovos de cada postura não teve relação com as suas dimensões. O comprimento e a largura dos ovos também não dependeram do tamanho das fêmeas. No entanto, o número de ovos esteve relacionado ao comprimento das fêmeas. Foram observadas desovas entre 22 de outubro e quatro de janeiro. Somente 35,3% das fêmeas se reproduziram e 11,9% depositaram dois ninhos na mesma temporada reprodutiva. A espécie desovou preferencialmente em solos com mais de 88% de areia e os comportamentos de desovas ocorreram com maior freqüência na parte da manhã. Foi encontrada maior abundância de ninhos em locais entre 25 m e 50 m de distância da água e em áreas mais planas, entre 0º e 10° de declividade. A temperatura de incubação variou de 16,1°C a 35,5°C. Predação foi registrada em 18,1% dos ninhos. Os ninhos foram depositados de forma agregada, onde os mais próximos do arroio, entre 20 m e 30 m, tiveram maior taxa de predação (52,4%). A alta sobrevivência registrada para a espécie pode estar associada ao período amostral relativamente curto. Além da exposição aos resíduos humanos, as tartarugas do arroio Santa Bárbara estão sujeitas à atropelamentos e ao comércio ilegal de animais silvestres. Assim, é necessário que a flutuação anual dos parâmetros populacionais seja avaliada para demonstrar se a população está sendo impactada por estes efeitos. Devido à longevidade dos quelônios, alguns impactos podem ser notados somente em longo prazo.

Made available in DSpace on 2015-03-05T16:20:42Z (GMT). No. of bitstreams: 0 Previous issue date: 9 / Nenhuma / No presente trabalho foi estimado o tamanho populacional, a estrutura da população, a biomassa e a razão sexual (devido ao dimorfismo sexual dos indivíduos) da população de Trachemys dorbigni do lago urbano, “Lago dos Pedalinhos”, no Parque Farroupilha, Porto Alegre, Rio Grande do Sul. Entre Maio e Dezembro de 2009 no mencionado lago, 113 espécimes de T. dorbigni foram capturados, pesados, sexados e marcados com um número de identificação. Além disso, foram realizadas nove medidas corporais nos espécimes capturados. Após o término dos procedimentos todos os espécimes foram liberados no mesmo local onde foram coletados. A partir dos resultados observados no presente estudo sugere-se a implementação de programas de conscientização voltados para os frequentadores do parque, a fim de promover o conhecimento das espécies que habitam o lago e evitar os maus tratos e o abandono dos espécimes. / This study presents data about abundance and population structure as well sexual dimorphism to the population of Trachemys dorbigni from “Lago dos Pedalinhos”, an urban lake from the city of Porto Alegre – Brazil. The captures and data collection were conduced weekly, between May and December 2009. All the captured specimens were weighed, sexed (whenever was possible) and marked with a number of identification. In order to evaluate the differences in size between sexes nine body measurements were taken from adult males and females. After completed the procedure, all individuals captured were released in the same place that they were caught. The sex ratio was calculated by the division between the total number of males and females.

Abstract (Summary) Wood turtles ( Glyptemys insculpta ) are of conservation interest rangewide. Anecdotal accounts demonstrate that some populations have been decimated since 1850, and recent studies demonstrate that declines are still underway. From 2004-2008 I investigated the ecology of wood turtles in Massachusetts and New Hampshire. I obtained between one and five years of annual home range data for 150 turtles, and evaluated population structure at 31 sites in five major watersheds. Seasonal floods displaced 7% of wood turtles annually in one watershed, and accounted for elevated mortality. Twelve wood turtles were displaced < 16.8 km, and two were displaced over a 65-foot dam. Several turtles overwintered at their displacement site and two returned successfully, indicating that floods are a mechanism of population connectivity. Several homing turtles ended up in new areas. Turtles occupied stream segments with gradient < 1%, lower than generally available. Agricultural machinery accounted for most observed mortality, followed by automobiles and mammals. Female turtles exhibit smaller home ranges in agricultural areas. Older turtles move farther from the river than do young turtles, possibly reflecting their familiarity with a former landscape. Population density ranged from 0-40.4 turtles/river-kilometer. The highest densities occur in central New Hampshire and lower densities occur in the Housatonic watershed. Population density is negatively correlated with agriculture at both riparian and watershed scales, and responds unimodally to forest cover. Wood turtle populations in western Massachusetts are declining by 6.6-11.2% annually. I estimated ages of turtles by assessing shell-wear rates from photographs. Wood turtles regularly achieve ages over 80 years, and like related species, do not exhibit clear signs of senescence. Old wood turtles are reproductively dominant, and their survival rates are twice as high as young turtles. Carapace scutes appear to require 80 years to become worn. Population modeling indicates that wood turtle populations are declining in New England due to anthropogenic and natural factors. Conservation efforts must address the effects of agriculture on adult survival. Climate change may negatively affect northeastern wood turtles through increased flooding. Populations in mountainous areas may be likely candidates for conservation because they don't occupy prime agricultural land, but may be more susceptible to floods.