Nest site characterization of Oriental Pied Hornbill and Grey Hornbill in tropical dry forests of the Western Himalayas
Ces, Ii Sc, Bangalore
Hornbills are key seed dispersal agents in tropical forests. Hornbill feeding and breeding behaviour in dry tropical forests is poorly understood. Given their specialised breeding requirements, availability of suitable trees for nesting play an important role in the persistence of hornbill populations. This study characterized nesting sites of Oriental Pied (OPH) and Indian Grey hornbills (IGH) in a tropical dry forest landscape in the Western Himalayas
Forty-two hornbill nest sites were characterised in Chilla range, Rajaji National Park. These sites were measured for nest characteristics (length, width, height, depth), characteristics of the nesting tree (height of tree, species, DBH).
Nests of OPH and IGH were very similar. OPH chose trees with wider girth at nest height, while IGH displayed greater variation in nest site characteristics. OPH appear to select nest sites slightly away from human habitation compared to IGH. This could also be due to availability of larger trees in the interior of forest.
Our study provides detailed nest site characterization in a seasonally tropical forest. Hornbills are patchily distributed in the Himalayan foot hills, and are threatened by habitat degradation and hunting. This study could potentially aid in assessment of suitable habitats for hornbills, as well in designing nest boxes for hornbills.