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1.
Zoologia (Curitiba) ; 35: 1-8, 2018. tab, ilus
Artigo em Inglês | VETINDEX | ID: vti-733987

Resumo

Identification of the predators of bird nests is essential to test ecological and evolutionary hypotheses and to make practical management decisions. A variety of nest monitoring devices have been proposed but many remain difficult to set up in the field. The aim of this study was to test camera traps as a potential tool to study predation of natural nests in a tropical rainforest environment. Specifically, we registered the predators, assessed their size range, and we compared the use of one and two cameras per nest. Of 122 nests from 24 bird species, 45 (37%) were depredated, and the cameras recorded the predator species in 29 of the total of depredated nests (64%). We identified predators in eight of 16 depredated nests (50%) in which we used one camera trap per nest, and we identified predators in 21 of 29 depredated nests (72%) when we used two camera traps per nest. The predators included six species of birds and six species of mammals, with body masses varying from 20 g to 16.5 kg. Causes for 10 of the 16 detection failures were identified and are discussed. These results suggest that camera traps are viable tools to investigate nest predation in a tropical rainforest area.(AU)


Assuntos
Animais , Aves , COMPORTAMENTO PREDATَ , Fotografia/instrumentação , Floresta Úmida , Brasil
2.
Zoologia (Curitiba, Impr.) ; 35: 1-8, 2018. tab, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1504514

Resumo

Identification of the predators of bird nests is essential to test ecological and evolutionary hypotheses and to make practical management decisions. A variety of nest monitoring devices have been proposed but many remain difficult to set up in the field. The aim of this study was to test camera traps as a potential tool to study predation of natural nests in a tropical rainforest environment. Specifically, we registered the predators, assessed their size range, and we compared the use of one and two cameras per nest. Of 122 nests from 24 bird species, 45 (37%) were depredated, and the cameras recorded the predator species in 29 of the total of depredated nests (64%). We identified predators in eight of 16 depredated nests (50%) in which we used one camera trap per nest, and we identified predators in 21 of 29 depredated nests (72%) when we used two camera traps per nest. The predators included six species of birds and six species of mammals, with body masses varying from 20 g to 16.5 kg. Causes for 10 of the 16 detection failures were identified and are discussed. These results suggest that camera traps are viable tools to investigate nest predation in a tropical rainforest area.


Assuntos
Animais , Aves , Fotografia/instrumentação , Brasil , Floresta Úmida
3.
Zoologia (Curitiba, Impr.) ; 32(6): 438-444, Nov.-Dec. 2015. map, graf
Artigo em Inglês | VETINDEX | ID: biblio-1504360

Resumo

The flight initiation distance has been used either to understand the cost-benefit trade-offs related to the risk of predation or as an important tool for wildlife managers. Although this variable is well-discussed for temperate regions, it is still poorly known in the Neotropics. Here we analyze the escape behavior of birds from southeastern Brazil, comparing an urban to a non-urban area. We tested for the influence of sites (urban vs. non-urban area), approaching (by one vs. two people), daytime (morning vs. afternoon), seasons (breeding vs. non-breeding) and body mass on the determination of the initial (FID) and final (FFD) flight distances across different bird species. We predict that FID will be greater in rural areas and under a greater threat (higher number of predators approaching) in the afternoon and in the non-breeding season. We also expect a direct relationship between body mass and FID and between FID and FFD. We sampled 11 species after measuring 331 escape behaviors, and we confirmed our predictions for sites (five species), daytime (one species) and rejected our premise about seasons for one species. Mean FID was strongly affected by body mass, and directly affected FFD. Adjustments in FID are, most likely, an important adaptive trait in urban habitats and may partially explain the predominance of species with higher ecological plasticity in cities.


Assuntos
Animais , Aves/fisiologia , Comportamento Animal , Reação de Fuga , Voo Animal
4.
Zoologia (Curitiba) ; 32(6): 438-444, Nov.-Dec. 2015. mapas, graf
Artigo em Inglês | VETINDEX | ID: vti-30442

Resumo

The flight initiation distance has been used either to understand the cost-benefit trade-offs related to the risk of predation or as an important tool for wildlife managers. Although this variable is well-discussed for temperate regions, it is still poorly known in the Neotropics. Here we analyze the escape behavior of birds from southeastern Brazil, comparing an urban to a non-urban area. We tested for the influence of sites (urban vs. non-urban area), approaching (by one vs. two people), daytime (morning vs. afternoon), seasons (breeding vs. non-breeding) and body mass on the determination of the initial (FID) and final (FFD) flight distances across different bird species. We predict that FID will be greater in rural areas and under a greater threat (higher number of predators approaching) in the afternoon and in the non-breeding season. We also expect a direct relationship between body mass and FID and between FID and FFD. We sampled 11 species after measuring 331 escape behaviors, and we confirmed our predictions for sites (five species), daytime (one species) and rejected our premise about seasons for one species. Mean FID was strongly affected by body mass, and directly affected FFD. Adjustments in FID are, most likely, an important adaptive trait in urban habitats and may partially explain the predominance of species with higher ecological plasticity in cities.(AU)


Assuntos
Animais , Aves/fisiologia , Reação de Fuga , Comportamento Animal , Voo Animal
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