Effectiveness of crossings as wildlife passages for mammals in the Yungas of Argentina

BAECHLI JOHAN; ALBANESI, SEBASTIAN; BELLIS, LAURA M

JOURNAL FOR NATURE CONSERVATION

ELSEVIER GMBH

Año: 2021

1617-1381

Irrigationcanals are an important cause of wild mammal mortality in the Piedmont forestof the Argentine Yungas. To improve the permeability of this infrastructure,specific wildlife crossings were added to the existing non-wildlife crossings builtfor other purposes. However, the effectiveness of these wildlife-specific crossingshas still not been evaluated. Here, we identified the mammalian species that usethe crossings, determined the global frequency of use of each crossing through ause index, and evaluated the possible predilection of a species for a particularcrossing type using species-specific models. We found that 50% of species in thestudy area used the crossings. The highest percentages of use corresponded to tapeti(Sylvilagus brasiliensis, 25.4%), lowland tapir (Tapirus terrestris, 21.5%),agouti (Dasyprocta punctata, 20.7%), crab-eating fox (Cerdocyon thous,9.1%) and tayra (Eira barbara, 6.3%).Theglobal model shows that crossing type, openness and vegetation verticalstructure were the best predictors of crossing use. Species-specific modelsshow in general that variables related to the structure of the crossings were betterable to explain animal movement. The dry season increased the use of thecrossings. We concluded that the presence of both wildlife-specific and non-wildlife-specificcrossings would contribute to reducing the barrier effect and, therefore, tomammal conservation. In this connection we recommend that simple, low-cost wildlife-specificcrossings be taken into account.