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cuckoo from Ping Long, Lam Tsuen

cuckoo from Ping Long, Lam Tsuen

This cuckoo was in Ping Long around 0810 this morning.

Any pointers to specific identity would be welcomed.

Cheers
Mike K

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DSCN1215 O Cuckoo bf.jpg (159.35 KB)

13/04/2010 12:46

DSCN1215 O Cuckoo bf.jpg

Mike KilburnVice Chairman, HKBWSChairman, Conservation Committee

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Mike,

Looks like it might be Common.

Any other photos?

Geoff

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I would say that this is an Oriental/Horsefield's rather than Common.

Not much of the underpart barring is showing (only the sides of the breast), and although this looks a little narrow there is a tendancy for the barring to be slightly narrower on the sides of the breast in most adult cuculus cuckoos.  I spent some time at the British Museum last year looking at specimens of these species (as part of the review of the first record of Common Cuckooon Po Toi) and i was stuck by the differences in the throat.  In Common the throat patch is paler (less blue) and has a lower border which is usually not well defined.  In Horsefields/Oriental the throat patch is darker, slightly bluer and typically has a very defined lower border.

Typical examples of each can be found at:

Horsefield's:

http://orientalbirdimages.org/se ... _ID=&pagesize=1

Common:

http://orientalbirdimages.org/se ... _ID=&pagesize=1

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How useful is iris colour?
I've seen this quoted as a feature for the ID of Indian cuckoo (which supposedly has a dark iris).
Looking through the pictures on OB, it get the impression that adult Common has a yellow iris, similar to the colour of the eye ring. Iris seems to be a bit more variable in Oriental - some are dark (brownish), while others are paler (straw-colour) but still seem to be darker than on Common.

I don't know whether iris colour may be related to season or sex, or maybe individual variation. D
oes anyone know if this is a useful feature to look for?

Incidentally, the iris on the Ping Long bird looks dark, which could support the ID as Oriental/Horsfield's

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Iris colour varies extensively with age, generally getting paler and yellower with age.  Photos of the Po Toi Common Cuckoo (an adult) show an orange-brown iris.

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Many thanks for all these comments.

I would add that the breast band did not look too narrow in the field, so I'll put it down as Horsfield's/Himalayan.

Cheers
Mike
Mike KilburnVice Chairman, HKBWSChairman, Conservation Committee

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Thanks Paul for clarifying the situation with iris colour. I thought maybe it was age-related, as pictures of juvenile Common Cuckoo on OB do all show a dark iris.
It seemed strange to me, though, that all pictures of adult Common showed a yellow iris, but those on Oriental all seemed darker (except perhaps this one http://orientalbirdimages.org/se ... _ID=&pagesize=1). Perhaps just coincidence?

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