Navegando por Assunto "reptile"

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Artigo
Population assessment of a novel island invasive: tegu (Salvator merianae) of Fernando de Noronha. In: C.R. Veitch, M.N. Clout, A.R. Martin, J.C. Russell and C.J. West (eds.) (2019). Island invasives
(Occasional Paper SSC no. 62. Gland, Switzerland: IUCN., 2019) Abrahão, Carlos R.; Russell, James Charles; Silva, Jean Carlos Ramos; Ferreira, F. E. Rodrigues; Dias, Ricardo Augusto
Fernando de Noronha is an oceanic archipelago in the Atlantic Ocean, 345 km o൵shore from the Brazilian coast. It comprises 21 islands and islets, of which the main island (FN) is 17 km2 with a rapidly growing tourism industry in the last decades. Despite being a protected area and bearing Ramsar and UNESCO World Heritage site status, it is threatened by multiple terrestrial invasive species since its colonisation in the early 16th century. Invasive species and the increasing tourism contributes to a list of at least 15 endangered or critically endangered species according to IUCN criteria. The black and white tegu (Salvator merianae) is the largest lizard in South America, occurring in most of the Brazilian territory and reaching up to 8 kg and 1.6 m from head to tail. As an omnivorous and opportunistic lizard, it feeds on a variety of available items, including smaller vertebrates and eggs. The introduction of the tegu to FN as well as its immediate impact on local fauna were not recorded; however, its ongoing impact is expected to be high. We captured and marked 103 tegu in FN during the months of February and November of 2015 and 2016. We also counted animals by line-transect census in a sparsely inhabited and an uninhabited area of FN. Body size a൵ected the capture probabilities, while season and sex had little or no e൵ect. Densities estimated by capture-recapture in the sparsely inhabited area varied from 2.29 to 8.28 animals/ha according to sampling season. Line transect census in the same area revealed a density of 3.98 (±1.1) animals/ha and in the uninhabited area 13.83 (±3.9) animals/ha. Home range was 10.54 ha, ranging from 7.36 to 15.33 hectares. Tegu activity decreased in the months of July and August of 2015. Results from this study can assist conservation managers and decision makers to implement a science-based tegu management programme in the future.
Artigo
Reproductive indices in natural nests of giant Amazon river turtles Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae) in the Environmental Protection Area Meanders of the Araguaia River.
(Brazilian Journal of Biology, 2012-02) Alves-Júnior, JRF; Lustosa, APG; Bosso, , ACS; Balestra, RAM; Bastos, LF; Miranda, LB; Santos, ALQ
A count was made of unhatched eggs and hatchling live and dead Podocnemis expansa turtles in 327 natural nests located on the beaches of the Environmental Protection Area (EPA) Meanders of the Araguaia River, to determine the percentage of hatching (94.63%), non-hatching (5.37%), survival (94.24%) and hatchling mortality (5.76%), and the average percentage of dead hatchlings during the 15 days in the nursery (0.97%). The mean number of hatchlings per nest was determined from the sum of the number of live and dead hatchlings divided by the total number of nests, while the mean number of eggs per nest was determined from the sum of live and dead hatchlings and unhatched eggs divided by the number of nests. These calculations yielded the following mean values: live hatchlings (88.98 ± 23.94), dead hatchlings (0.37 ± 0.93), unhatched eggs (5.07 ± 9.57), and total number of eggs (94.42 ± 21.30). The reproductive efficiency of the wild population of P. expansa can be affected by many environmental factors such as temperature, humidity and rainfall. In addition, man-made factors like the presence of chemicals in the water and the potential for infectious disease also have significant impact. The reproductive indices data obtained from this study are indispensable for future investigations of hatching anomalies.