Chestnut-capped Blackbird

Male chestnut-capped blackbirds average 18.5 cm (7.3 in) long and females 17.1 cm (6.7 in). Males weigh an average of 41.3 g (1.5 oz) and females average 32.2 g (1.1 oz). The species is sexually dimorphic. Adult males of the nominate subspecies have a deep dark chestnut forecrown, midcrown, throat, and upper breast. The rest of their plumages is black with a faint bluish gloss. Adult females of the nominate subspecies have a mostly olivaceous brown head with a faint buffish supercilium. Their upperparts are also olivaceous brown with faint dusky streaks. Voice: Male chestnut-capped blackbirds sing two types of songs, though they are highly variable among individuals even within a colony. One type "starts with clicks, warbles or whistles and ends in descending nasal buzz". The other type is "quite musical, either a series of loud, short and tremulous whistles around a sustained pitch...or flute-like notes on ascending scale".