This study aimed to describe the reproductive biology of populations of Thamnodynastes hypoconia in subtemperate wetlands based on macroscopic analyses of their gonads. We analyzed 101 specimens from the southernmost regions of Brazil. The males had a greater snout-vent length, but the females reached sexual maturity with a greater body size. The reproductive cycle of the females was seasonal, with secondary vitellogenesis occurring between the winter and spring (May-October). Based on macroscopic analysis of gonads, data suggests that males have a continuous reproductive cycle. Parturition occurs between the late summer and early fall (January-April). The clutch size ranged between 4 and 16 embryos and showed no relationship with the female's body size. The recorded reproductive frequency of T. hypoconia is low (38 %) compared to other phylogenetically related species. Conversely, the studied populations appear to have a high reproductive success because it is an abundant species in the study site.
Apresentamos o segundo registro do caburé-acanelado (Aegolius harrisii) para o Bioma Pampa no sul do Brasil. No dia 17 de janeiro de 2010, um macho adulto de A. harrisii foi encontrado morto no acostamento da rodovia BR-290, município de São Gabriel, centro-oeste do Estado do Rio Grande do Sul. O indivíduo provavelmente colidiu com um veículo quando usava a rodovia como área de forrageamento. Esse registro indica que A. harrisii pode utilizar áreas abertas e degradadas.
Species richness and abundance, as well as trophic relationships, are affected by habitat configuration. Smaller habitat patches suffer greater external interference, being more susceptible to diversity loss and could also receive more trophic subsidies from outside or matrix, which can favour the maintenance of populations even in small patches. Natural mosaics of forest patches in a grassland matrix in southern Brazil are good places to analyse such a process. Our objective was to analyse the effect of habitat patching on trophic relationships based on the evaluation of two forest amphibian species (Physalaemus lisei and P. carrizorum) and compare those from habitat patches versus core/contiguous habitat. We compared isotopic carbon (d 13 C) and nitrogen ratios (d 15 N) in two anuran species as well the variation in their diet at different forest patch sizes. We chose carbon isotopes since they act as a proxy for inferences on the original habitat from which the matter flows towards the anurans, while nitrogen reveals their tropic level. Our results revealed that trophic sources for these amphibians derives predominantly from primary forest productivity. However, Physalaemus lisei d 13 C values indicated that the contribution of grassland trophic sources in the diet was higher in frogs from forests patches (<100 ha) than in those from core forest habitat. In smaller patches, P. lisei consumed predominantly ants, which was the most abundant prey on habitat. On the other hand, in the core forest, where isopods were the most abundant prey, most of its consumption was beetles, spiders and ants. In contrast, P. carrizorum showed no significant changes in isotopic ratios or diet across habitats. Isotopic data suggested that both species occupied lower trophic levels in smaller forests than in core forests. Our data showed a tendency towards the increase of grassland contribution and decrease of amphibian trophic position in patched habitats in comparison to continuous habitat.
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