Efeitos da Urbanização populações de Bothrops jararaca no Município de São Paulo, Brasil
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Data
2016-03-28
Autores
Siqueira, Lucas Henrique Carvalho [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Neste trabalho investigamos a existência de diferenças no tamanho corporal, disponibilidade de presas e pressão de predadores em duas populações de Bothrops jararaca de dois parques do Município de São Paulo sujeitos a diferentes graus de urbanização. As serpentes não apresentaram diferenças de comprimento e robustez entre as duas populações, entretanto houve uma tendência de uma maior proporção de fêmeas maiores no parque com maior influência urbana. A oferta de recursos e a pressão de predadores foram significativamente maiores no ambiente com menor influência da cidade. Os resultados sugerem que a menor oferta de presas no parque urbano não diminui significativamente o crescimento de B. jararaca, porém a menor incidência de predadores pode resultar em um maior tempo de vida das serpentes e consequentemente maior proporção de serpentes com tamanho corporal superior.
Maintenance of suitable habitat is essential for animal population persistence. Quantitative and qualitative alterations in the environment may generate serious ecological consequences. One of the most common causes of alterations in quality, habitable area decrease and isolation is the forest fragmentation carried by urbanization. Forest remnants can function as oceanic islands, and the resident animal species may show morphological variation like dwarfism or gigantism, caused generally by the modification of diet and/or predator incidence. Here, we investigate the body size, prey availability and predation pressure in populations of Bothrops jararaca in two parks subject to different urbanization degree. We found no differences in snakes length, neither stoutness between the two populations. However the prey availability and predator incidence was significantly higher in the park with less urban influence. The results suggest that smaller food availability offer in the isolated urban park did not decrease significantly B. jararaca growth rate, but the lesser predators incidence can result in longer lifetime and consequently higher proportion of snakes with superior body length.
Maintenance of suitable habitat is essential for animal population persistence. Quantitative and qualitative alterations in the environment may generate serious ecological consequences. One of the most common causes of alterations in quality, habitable area decrease and isolation is the forest fragmentation carried by urbanization. Forest remnants can function as oceanic islands, and the resident animal species may show morphological variation like dwarfism or gigantism, caused generally by the modification of diet and/or predator incidence. Here, we investigate the body size, prey availability and predation pressure in populations of Bothrops jararaca in two parks subject to different urbanization degree. We found no differences in snakes length, neither stoutness between the two populations. However the prey availability and predator incidence was significantly higher in the park with less urban influence. The results suggest that smaller food availability offer in the isolated urban park did not decrease significantly B. jararaca growth rate, but the lesser predators incidence can result in longer lifetime and consequently higher proportion of snakes with superior body length.
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Palavras-chave
Urbanização, Fragmentação florestal, Serpentes, Presas, Predação, Urbanization, Forest fragmentation, Snake, Prey, Predation