Indonesian Serin Chrysocorythus estherae Scientific name definitions

A scarce (or at least rarely observed) species confined to alpine meadows and montane forests in Indonesia (Sumatra, Java, and Sulawesi), the Indonesian Serin is a distinctive finch (unrelated to the Serinus serins, despite its English name) with a stout, arched bill, and a yellow forecrown, rump, and wingbars. Its populations are widely scattered, with much variation in the plumage and bill size of its four recognized subspecies. A fifth, currently undescribed, taxon from Central Sulawesi is, somewhat ironically, one of the most frequently observed by birders, and differs from all other subspecies in having all golden-yellow plumage replaced by orange-red. A sixth taxon found on Mindanao, in the southern Philippines, is also rather distinct, with more extensive yellow underparts and a blunter bill—it is now treated as a separate species herein, Mindanao Serin (Chrysocorythus mindanensis), as it was by its describers. Given its elusiveness and confinement to remote areas (it was only discovered on Sulawesi as recently as 1980), there are no available breeding, behavioral, or diet data for the Indonesian Serin, and additional populations in other areas of Sulawesi may remain to be discovered.