Tree cavities and associated vertebrate fauna in a coniferous forest of Dhirkot, Azad Jammu and Kashmir part of Pakistan

Tree cavities are a globally important structural element of forest ecosystems that host numerous cavity-dwelling vertebrates, but they have received little research in Pakistan. We investigated cavity-bearing trees, the attributes of their cavities, and their associated vertebrate fauna in a coniferous forest of Pakistan. We recorded 1140 trees in a 2-km2 sampled area. We found 211 cavities (64% decay-formed and 36% excavated cavities) in 83 trees (41% live and 59% snags). Of the cavities found, 74% were recorded in trunks and 26% were in branches. Only 28% of the cavities showed signs of recent use by any vertebrate species. We observed 19 vertebrate species using cavities: 2 mammals, 13 birds (including 5 woodpecker species as primary excavators), and 4 reptiles. Height from the ground, entrance diameter, and depth of the cavities used by mammals were greater than those measurements of the cavities occupied by birds and reptiles. Our study shows that tree cavities have a critical role in providing nesting sites to many vertebrate species of Pakistan that require tree cavities in order to breed. We recommend such research be done in other forests of the country to investigate cavity availability and requirements of cavity users. We suggest that certain minimum populations of cavity-bearing trees should be maintained during silviculture practices to support populations of tree-dwelling vertebrates in the coniferous forests of Pakistan