Breeding biology and nest site characteristics of the Bicolored Hawk in Guatemala

We studied the breeding biology of the Bicolored Hawk (Accipiter bicolor) i n the forest of Tikal National Park of northeastern Guatemala from 1991 to 1994. Bicolored Hawks are year-round residents and establish nesting territ ories during the breeding season, which coincides with the late dry season and bt ginning of the wet season. Nest building and courtship spanned 92 da ys. We documented 17 nesting attempts from February to July 1991-1994. Egg- laying began in April and May, with 36 eggs laid in 15 nests for an average clutch size of 2.4 (range 1-3 eggs). We documented one renesting after fai lure of the first clutch. Incubation was approximately 35 days (n = 5 clutc hes). Young hatched asynchronously with a light pinkish natal down. Of 36 e ggs laid, 64% hatched. Nearly all hatching occurred during May except one r enesting, from which one young hatched on 26 June 1994. Young departed from the nest tree at 30-36 days of age and 100% of the nestlings fledged: thus a total of 1.4 young fledged per breeding attempt and overall nest success was 76%. Most reproductive losses occurred during the incubation period. W e found addled eggs in 2 nests and egg predation and nestling predation at 1 nest each. Bicolored Hawk nests averaged 22 m above the ground in living trees 75 cm in diameter. All nests were stick nests, averaging 51 x 44 cm e xterior diameter, 26 cm exterior depth, and 3.6 cm interior depth. The Bico lored Hawk diet of 173 identified prey was composed almost exclusively of b irds (95%) with relatively few mammals (3%) or reptiles (2%) taken.