Asian Koels, age & sex? Iran, Hormozgan, Feb. 2023 (1 Viewer)

[Pedrambirder]

Hi all,
We observed these two birds in one place, nice to know if it's possible to identify their age and sex.
I think the black one could be an immature male.

 

[MJB]

Hi all,
We observed these two birds in one place, nice to know if it's possible to identify their age and sex.
I think the black one could be an immature male.

Are these birds near Chalabar, Sistan & Baluchestan Province?
MJB

 

[Pedrambirder]

Are these birds near Chalabar, Sistan & Baluchestan Province?
MJB

No, they were in a place near Bandar-e-Jask in Hormozgan Province, named Kahouti.
I think the place you are mentioning is Tiss Natural Garden near Chabahar in Sistan & Baluchestan Province, I visited there in March 2022 and I think there were two adults, one male and one female.

 

[johnallcock]

Sexing koels is easy - they can be sexed when they fledge (and presumably in the nest). In your birds, the spotty bird in the first picture is a female, the black bird is a male.

To age them, it's useful to know that adults will moult completely at the end of the summer, but birds in their first year usually retain some juvenile flight feathers and wing coverts. Adults also usually have a bright red eye, but in my experience (in Hong Kong), the red eye develops over the first winter and many first year birds have red eyes by the spring.

The age for your male (2nd bird) is fairly straight-forward. An adult would be pure glossy black. The white edges to wing coverts show these to be juvenile feathers. You can also see a contrast between brownish (worn) flight feathers and glossy black lesser coverts. So this bird is a first winter with retained juvenile wing feathers.

Females are trickier to age because the juvenile and adult plumages are similar, although the spots tend to be more buff on juvenile and whiter on adult. On your bird (first picture) the secondaries look worn, but at least one primary looks fresh (black & white not dark brown & buff). There also seems to be similar contrast in the wing coverts between worn juvenile feathers (with buff spots) and fresh adult feathers (with whiter spots). The eye doesn't look particularly bright red, it has a slight grey tone. So I would say that this bird is also a first winter with some retained juvenile feathers.

 

[Pedrambirder]

Sexing koels is easy - they can be sexed when they fledge (and presumably in the nest). In your birds, the spotty bird in the first picture is a female, the black bird is a male.

To age them, it's useful to know that adults will moult completely at the end of the summer, but birds in their first year usually retain some juvenile flight feathers and wing coverts. Adults also usually have a bright red eye, but in my experience (in Hong Kong), the red eye develops over the first winter and many first year birds have red eyes by the spring.

The age for your male (2nd bird) is fairly straight-forward. An adult would be pure glossy black. The white edges to wing coverts show these to be juvenile feathers. You can also see a contrast between brownish (worn) flight feathers and glossy black lesser coverts. So this bird is a first winter with retained juvenile wing feathers.

Females are trickier to age because the juvenile and adult plumages are similar, although the spots tend to be more buff on juvenile and whiter on adult. On your bird (first picture) the secondaries look worn, but at least one primary looks fresh (black & white not dark brown & buff). There also seems to be similar contrast in the wing coverts between worn juvenile feathers (with buff spots) and fresh adult feathers (with whiter spots). The eye doesn't look particularly bright red, it has a slight grey tone. So I would say that this bird is also a first winter with some retained juvenile feathers.

Thank you very much for your complete answer and your time, it was very helpful and informative.

 

[MJB]

No, they were in a place near Bandar-e-Jask in Hormozgan Province, named Kahouti.
I think the place you are mentioning is Tiss Natural Garden near Chabahar in Sistan & Baluchestan Province, I visited there in March 2022 and I think there were two adults, one male and one female.

Thanks for the swift reply!
MJB