Diet and hunting behavior of the Crane Hawk in Tikal National Park, Guatemala

We studied the breeding diet and hunting behavior of Crane Hawks (Geranospi za caerulescens) in Tikal National Park, Peten, Guatemala in 1994 and 1995. We observed 227 prey items while conducting observations at six nesting at tempts, and during opportunistic sightings in the breeding season. Among 18 1 identified prey items, rodents comprised 47.5%, lizards 19.9%. frogs 16.0 %. bats 6.6%, birds 6.1%. and snakes 2.8%; a juvenile skunk also was repres ented. Rodents accounted for 77% of estimated biomass, including at least e ight species representing terrestrial, cursorial, and arboreal habits. More than half of all prey items weighed <20 g, but 40% weighed >50 g: many wer e nocturnal species presumably taken from daytime hiding places. We observe d hunting attempts in all strata of the forest and in several forest types. Hunting behavior included still-hunting from a perch and probing with head or feet in holes, bromeliads and other epiphytes, palm leaf axils, crotche s of branches, behind bark in living and dead trees, and in puddles. Compar ed to other raptors studied at Tikal, the Crane Hawk had a moderately broad food niche that overlapped most with other raptors deemed dietary generali sts. However, the Crane Hawk's unique anatomical features and hunting behav ior enabled it to capture diurnally reclusive prey presumably unavailable t o many other raptors, thus facilitating relatively low dietary overlap.