Movimentação e uso do espaço por adultos de Podocnemis unifilis Troschel, 1848, na reserva biológica do rio Trombetas, Pará, Brasil

Adults of Podocnemis unifilis were monitored using VHF radiotelemetry from September 2013 to September 2014 in the Rio Trombetas Biological Reserve, Pará, Brazil. Our principal aim was to analyze movements and use of space by this species, near the Tabuleiro base, by describing movements, size and shape of the estimated home ranges. Twenty transmitters were attached to 10 males and 10 females. We never found the signal of one female during the study. Mean movements around 9.6 km and a rate of 65 meters per day were found. The home range calculated through the fixed kernel (KF) method with 95% of the locations averaged 79.28 ± 77.08 ha (0.56 – 215.07; N = 13). There was a relation found by multiple regression between female home ranges and weight (F1,3 = 16.98; R2 = 0.85; p<0.05; N = 5). The mean of overlapping areas with the KF95% was 14.07%. The comparison related to the environment use was statistically significant between sexes (χ2 = 110.63; df = 6; p<0,0001). Males stayed more often in open flooded forest areas (IAM), besides females were frequently at lake. For conservation purposes it is necessary to continue the protection of the nesting sand beaches and increase that effort throughout the campinas inside the lake where the species nest in the dry season. The flooded forest areas as zones of intense use at the wet season and the linkage lake canals, as the bridge between the environments trough the seasons should be preserved.Adultos de Podocnemis unifilis foram monitorados entre setembro de 2013 e setembro de 2014 recorrendo a radiotelemetria VHF na Reserva Biológica do Rio Trombetas (REBIO Trombetas), Pará, Brasil. O objetivo principal do estudo foi analisar a movimentação e o uso do espaço pelos indivíduos do entorno da base do Tabuleiro, procurando descrever a sua movimentação, o tamanho e forma de suas áreas de uso. Equiparam-se 10 machos e 10 fêmeas com radiotransmissores. O sinal de uma fêmea não foi detectado durante todo o período de monitoramento. Verificaram-se deslocamentos anuais de cerca de 9,6 km e taxas de deslocamento com valores médios de 65 m/dia. A área pelo Kernel Fixo com 95% das localizações (KF95%) variou de 0,56 a 215,07 ha com média de 79,28 ± 77,08 ha (N = 13). Foi encontrada relação por meio de regressão múltipla, entre a área das fêmeas e a sua massa corpórea (F1,3 = 16,98; R2 = 0,85; p<0,05; N = 5). Verificaram-se sobreposições frequentes com proporção média de 14,07% nas áreas pelo KF95%. O uso dos ambientes foi significativamente diferente entre machos e fêmeas (χ2 = 110,63; gl = 6; p<0,0001). Machos usaram habitualmente o ambiente de igapó aberto misto, enquanto que fêmeas se situaram mais em ambiente de lago. Visando a conservação da espécie, para além da proteção efetiva verificada nas praias de areia grossa, propõe-se a proteção das áreas de desova, como as campinas de areia branca, em ambiente de lago durante a estação seca. No período de cheia, as florestas de igapó são os locais de maior intensidade de uso, sendo necessário preservá-las juntamente com os canais de lago que efetuam a ponte entre as áreas utilizadas nas estações do ano

Home Range of Yellow-Spotted Amazon River Turtles (Podocnemis unifilis) (Testudines: Podocnemididae) in the Trombetas River Biological Reserve, Pará, Brazil

Adult Podocnemis unifilis were monitored using VHF radio tracking from September 2013 to September 2014 in the Rio Trombetas Biological Reserve, Pará, Brazil. Our aim was to analyze the use of space by this species near the nesting beach base by describing size and overlap of estimated home ranges. Transmitters were attached to 10 males and 10 females. The mean home range size calculated through the fixed-kernel (FK) method with 95% of the fixes was 79.28 ± 77.08 ha (0.56-215.07 ha; n = 13). The mean of overlapping areas was 14% with FK95% (0.02%-81%; n = 13) and 5% with FK50% (0.1%-23%; n = 9). There was a significant difference in the mean overlapping areas between females and males. The analysis of the overlap of activity centers estimated by FK50% is extremely important for the establishment of conservation strategies in the management plan for this species in the reserve. We were able to identify 2 critical areas for the maintenance of this population where there was a frequent overlap of activity centers: the first, identified during the dry season, was composed of small overlaps among 7 turtles and was near the nesting areas on the clay banks within the Lago Jacaré; the second, identified during the rainy season, was composed of a concentration of overlap areas of larger size among 6 turtles and was an open area in the flooded forest. It is important not only to protect the nesting areas during the dry season but also to protect flooded forest areas with the major intensity of use along with the canals that link the flooded forests to the lakes in the rainy season. For conservation purposes, it is necessary to continue the protection of the nesting beaches throughout the savannas inside the lake where the species nests in the dry season. The flooded forest areas that are zones of intense use during the rainy season, and the canals where the turtles can move between lakes must be protected throughout the year. © 2019 Chelonian Research Foundation