Olive-backed Euphonia
Euphonia gouldi
The olive-backed euphonia is 9 to 10 cm (3.5 to 3.9 in) long and weighs about 11 to 16 g (0.39 to 0.56 oz). It is a small euphonia with a thick stubby bill. The species is sexually dimorphic. Adult males of the nominate subspecies have a yellow forehead; the patch extends to the rear of the eye and sometimes has light black flecks. The rest of their crown, and their nape, upperparts, and tail are olive-green. All of them except the uppertail coverts have a bluish gray gloss. Voice: The olive-backed euphonia's song is "a rapid jumble of chatters, buzzes, and harsh whistles". Its calls "include a chi'chi'chi'cheet and a liquid tsip'please-seeee'up!. Another description of its song is "a rambling medley of whistles, chatters and staccato notes, some dry and chaffy, some musical" that may continue for a long time.
ID text from Wikipedia, CC BY-SA 4.0
Orange-bellied Euphonia
Euphonia xanthogaster
The orange-bellied euphonia is 9 to 11 cm (3.5 to 4.3 in) long and weighs 9 to 16 g (0.32 to 0.56 oz). It has a thick stubby bill. The species is sexually dimorphic. Adult males of the nominate subspecies E. x. xanthogaster have a deep yellow forehead; the patch extends to well beyond the eye. The rest of their head and their nape are glossy blackish. Their upperparts, wing coverts, and flight feathers are glossy blue-black. The upper side of their tail is blue-black and the underside gray with white inner webs on the outer two to three pairs of feathers. Their throat is purplish black. Voice: The orange-bellied euphonia's song has some regional differences but their significance has not been studied. In Ecuador it has been described as "a variable, almost random-sounding, series of semimusical phrases given in a leisurely manner" and its calls as "a clear ding-ding-ding, a chee!, an upslurred kueé, and a more gravely cheeur-cheeur".
ID text from Wikipedia, CC BY-SA 4.0
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