Artificialcanopy bridge use by primates and other arboreal mammals in a fragmented tropical forest of northeast Bangladesh

Abstract

Forest fragmentation has resulted in a breakdown in connectivity for arboreal species. Effects of fragmentation are particularly acute in forest patches in densely populated countries, resulting in high mortality in many species attempting to cross roads to travel between forest patches. We evaluated the use of three, single-line artificial canopy bridges made of polypropylene ropes in a forest patch in northeastern Bangladesh. Camera traps were used to determine the extent of bridge use by different species. A total of 1060 events of bridge use by mammals were observed using our artificial canopy bridges over the 157 camera trap days. Eight mammal species, including five primate species, two squirrel species and one palm civet species were recorded using the bridges at varying levels of frequency. The location of the bridge and season influenced bridge use. We did not observe mortality of mammals from road accidents or electrocution during the study period. We suggest that artificial canopy bridges increased connectivity between forest patches and reduced mortality from road accidents and electrocution. We strongly recommend the use of this and other, simple canopy bridges to prevent mortality of arboreal mammals.