Bicolored Hawk

At 34–45 centimetres (13–18 in) in length and 200–450 grams (7.1–15.9 oz) in weight, it is significantly smaller than the northern goshawk of Eurasia and North America, and somewhat smaller than the Cooper's hawk of North America, but it is among the largest hawks in Central and South America (only the rare grey-bellied hawk is larger). As in other hawks, the female is far larger than the male. Adults are grey above with darker wings and crown, and a banded tail. The underparts typically vary from dark grey to very pale grey, but the southern subspecies can sometimes be rufescent below. Voice: Its vocalisations are mainly subdued and unnoticeable. Males have been heard to give a soft, clear whistle and females can emit a loud "cac cac cac" when around the nest and young. A barking "kra-kra-kra-kr-kr-kr-ka" may also be heard from both sexes. During incubation, males give a sharp "kek" vocalisation upon arrival to the nest with food, to which the female replies with a nasal "wreh".