ID pointers, Asian and Pacific koels (1 Viewer)

[THE_FERN]

Could someone with access to BoW or similar summarise what the morphological differences are meant to be. Not obvious to me given extensive sspp variation.

Ta

 

[MacNara]

Essentially morphological variation seems to be bill colour.

I think this is fair use (BoW):

[Asian Koel] Male is glossy black, whereas female has predominantly dark brown upperparts with pale streaks and spots varying with populations. It is often treated as conspecific with Black-billed Koel (Eudynamys melanorhynchus) and Pacific Koel (E. orientalis) under the name Common Koel (6, 7). It differs from both congeners in female plumages and having pale bills in all sexes and age-classes. Further taxonomic study is needed to clarify species-limits. Asian Koel (E. scolopaceus), potentially wanders into Pacific Koel’s range, [but] has broad vertical streaks on throat and upper-breast in female plumage.

Pacific Koel is an arboreal, frugivorous cuckoo. It is brood-parasitic; laying eggs in nests of medium-sized passerines generally smaller than those of Asian Koel (E. scolopaceus)... Unlike its western counterpart Asian Koel (Eudynamys scolopaceus), Pacific Koel nestling often evicts host chicks like do most parasitic cuckoos... Males are all-black with bluish gloss. Females have pale malar stripe, dark brown upperparts with pale spots and heavily barred tail. Underparts rufous or buff, with thin blackish barrings. Juveniles are similar to female, but crown paler and upperparts appearing barred rather than spotted.

HTH

If it's not fair use, then feel free to delete.

 

[THE_FERN]

Essentially morphological variation seems to be bill colour.

I think this is fair use (BoW):




HTH

If it's not fair use, then feel free to delete.

Thanks for that. Alas, I remain a bit confused. Female plumages are probably separable, but I see no material difference in male bill colour, at least judging by ebird headline photos.

(Asian is said to have a greenish bill, Australian/Pacific a bluish bill—at least in some subspecies: Eaton says that bill is black in Pacific subspecies orientalis)

Wikipedia and other net refs say there are differences in bare part colour (suggesting other parts of the birds differ) but if so they're not obvious to me. Arlott's "checklist" images suggest Asian has a greenish gloss and pacific a bluish one but again I can't see this in ebird photos. I wondered if there was a slight difference in head shape, with Asian having a flatter, less rounded profile but it's clear this isn't consistently different.

In summary, I suspect that non-calling males aren't separable in the field but would love to hear from someone who knows better.