Dados do Trabalho

TÍTULO

ASSESSING HABITAT USE WITH OCCUPANCY MODELLING FOR PUMAS (PUMA CONCOLOR) AND MANED WOLVES (CHRYSOCYON BRACHYURUS) IN INTENSIVE AGRICULTURE LANDSCAPES

Resumo

Large mammals from the order Carnivora have specific ecological characteristics, such as high food requirements, huge home ranges, long life cycles, and slow reproductive rates. Additionally, habitat loss and fragmentation, land conversion and depletion of preys are factors that explain the massive declines in carnivores’ populations around the world. Yet, pumas and maned wolves still survive in the Cerrado of São Paulo state, despite the fact that this native vegetation type was reduced to only 8.5% of its original extent. Given this, our aim was to understand how different land use covers in highly modified landscapes affect habitat use by these two carnivores. We recorded mammals with camera traps in 205 sampling stations distributed in three landscapes having contrasting land use covers in the northeast part of São Paulo state ("Jataí", "Cara Preta" and "Cajuru"). We then extracted environmental and anthropogenic variables from 200 ha buffers around sampling stations and used single-season, single-species occupancy models to assess predictors of occupancy (ψ) and detection (p) parameters. Overall, results show low detection but high occupancy which we interpret, respectively, as frequency of use and probability of use. Both species were relatively more detected on unpaved roads, but presented idiosyncratic responses to other factors. Pumas visited more frequently Jataí (p=0.072±0.017), the landscape encompassing the largest protected area in our study region, the Jataí Ecological Station, than the two other landscapes (Cara Preta and Cajuru; p=0.041±0.011). Contrastingly, the maned wolf was less frequent in Jataí (p=0.072±0.019) than in the other two study landscapes (p=0.157±0.028). Different factors modulated the use probability in the two species. The maned wolf used highly and rather similarly all three landscapes (ψ=0.720±0.098) but was negatively affected (β=-0.016±0.007) by native forests (wooded cerrado). Pumas used the landscapes a bit differently (ψ=0.85±0.093 in Jatai and ψ=0.687±0.162 in Cara Preta and Cajuru) and were negatively affected by sugar cane plantations. Further and rather importantly, the negative impact of this crop was much lower in Jataí (β=-0,009±0,008), than in the two landscapes having lower proportion of native forests and protected areas (Cara Preta and Cajuru; β=-0.041±0.019). Our results corroborate other studies reporting frequent use of unpaved roads by large carnivores. This, taken together with the high occupancy estimates, indicate that both pumas and maned wolves are not restricted to protected areas and are using the agricultural matrix. However, given that sampling stations were revisited rarely overall, our findings suggest that both carnivores are foraging extensively and exhibiting low site fidelity.  The dispersal potential of these carnivores through landscapes modified into biofuel production zones seem therefore to be high, corroborating existing metapopulations.  However, since they seem to range extensively, these two carnivores expose themselves to hazards and conflicts with humans, which may explain why they are frequent victims of o vehicle collisions, for example. We also conclude that the presence of relatively large and strictly protected areas lessen the negative effect of sugar cane for pumas in ethanol producing landscapes.

Palavras-chave

Carnivores, Cerrado, Predators, occurrence, sugar cane

Financiamento

FAPESP (Auxilios regulares: 2011/22449-4 e 2016/19106-1 e bolsa de mestrado 2013/12914-7); CNPq e CAPES (bolsas de mestrado)