RAN
URI permanente desta comunidadehttps://bdc.icmbio.gov.br/handle/cecav/1401
Centro Nacional de Pesquisa e Conservação de Répteis e Anfíbios
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Resultados da Pesquisa
Item Growth of Caiman crocodilus yacare in the Brazilian Pantanal.(Plos One, 2014-02-28) Campos, Zilca; Moura, Guilherme; Coutinho, Marcos; Magnusson, William E.; Sean Rogers, University of Calgary, Canada2013.We recaptured 647 of 7769 C. c. yacare initially marked in an area of 50 km2, in two ranches. We were able to determine size at age accurately for 24 male and17 female caimans that had been marked at hatching or less than 1 year old, and recaptured over periods of 5 to 24 years. The other 606 caimans were used to evaluate short-term growth rates. Age-size relationships were estimated using growth models from the Richards family of curves (full model, von Bertalanffy and monomolecular). The form of the relationships differed between analyses based on caimans of known age and analyses based on integration of growth rate on size relationships for caimans whose ages were not known. Individuals showed large variation in short-term growth rates, but data on known-age animals indicated little between-individual variability in long term growth rates. There was evidence of a small effect of rainfall, but not temperature, on short-term growth of small caimans, but most variation in growth rates was unexplained by variables other than age and sex. Data on known-age individuals indicated that female C. c. yacare generally reach sexual maturity between 10 and 15 years of age. Because of the asymptotic relationship between age and size, deviations of observations from the model for age are larger than for size, and estimates of age at a given size have greater errors than estimates of size at a given age. Integration of growth rate on size relationships may be adequate for estimating size from age in many cases, but accurate estimates of age from size require data on known-age individuals over the size range of the species.Item Distance sampling surveys reveal 17 million vertebrates directly killed by the 2020’s wildfres in the Pantanal, Brazil.(Scientifc Reports, 2021-12) Tomas, Walfrido Moraes; Berlinck, Christian Niel; Chiaravalloti, Rafael Morais; Faggioni, Gabriel Paganini; Strüssmann, Christine; Libonati, Renata; Abrahão, Carlos Roberto; Alvarenga, Gabriela do Valle; Bacellar, Ana Elisa de Faria; Batista, Flávia Regina de Queiroz; Bornato, Thainan Silva; Camilo, André Restel; Castedo, Judite; Fernando, Adriana Maria Espinóza; Freitas, Gabriel Oliveira de; Garcia, Carolina Martins; Gonçalves2, Henrique Santos; Guilherme, Mariella Butti de Freitas; Layme, Viviane Maria Guedes; Lustosa, Ana Paula Gomes; Oliveira, Ailton Carneiro De; Oliveira, Maxwell da Rosa; Pereira, Alexandre de Matos Martins; Rodrigues, Julia Abrantes; Semedo, Thiago Borges Fernandes; Souza, Rafael Augusto Ducel de; Tortato, Fernando Rodrigo; Viana, Diego Francis Passos; Vicente‑Silva, Luciana; Morato, RonaldoAnthropogenic factors have significantly influenced the frequency, duration, and intensity of meteorological drought in many regions of the globe, and the increased frequency of wildfires is among the most visible consequences of human-induced climate change. Despite the fire role in determining biodiversity outcomes in different ecosystems, wildfires can cause negative impacts on wildlife. We conducted ground surveys along line transects to estimate the first-order impact of the 2020 wildfires on vertebrates in the Pantanal wetland, Brazil. We adopted the distance sampling technique to estimate the densities and the number of dead vertebrates in the 39,030 square kilometers affected by fire. Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fires in the Pantanal, demonstrating the impact of such an event in wet savanna ecosystems. The Pantanal case also reminds us that the cumulative impact of widespread burning would be catastrophic, as fire recurrence may lead to the impoverishment of ecosystems and the disruption of their functioning. To overcome this unsustainable scenario, it is necessary to establish proper biomass fuel management to avoid cumulative impacts caused by fire over biodiversity and ecosystem services.