BIRDS OF COSTA RICA

PHOTO LIBRARY

Gray-headed Tanager / Tangara Cabecigris (Eucometis penicillata)

Ageing and sexing overview:

Spring:

AHY - U
Sexes identical; ageing criteria unknown.  

Ageing and sexing details:

SPRING:  AHY-U (after-hatch-year, sex unknown)

Adult Gray-headed Tanagers have identical plumage. Differences in the extent of moult by HY/SY and AHY/ASY individuals may exist, but are unknown, and even if present might have limited visibility on perched birds. However, the presence of some green over the eye in the second photo below suggests the retention of some juvenile feathers, indicating that bird is likely SY.


Photo by Marcel Gahbauer, Las Caletas (CR), April 2008


Photo by Marcel Gahbauer, Las Caletas (CR), April 2008


As with many species, the open wing may provide information to assist with the ageing of individual Gray-headed Tanagers.  There are no moult limits apparent on the first photo below, but on the second, it appears that the first six primaries have been replaced, as they are darker and fresher than the outer primaries; there is also a noticeable contrast between the second and third secondaries, with s1 and s2 having much darker shafts, suggesting that s3 and s4 may be retained juvenile feathers, and that the bird may be SY.


Photo by Marcel Gahbauer, Las Caletas (CR), April 2008


Photo by Marcel Gahbauer, Las Caletas (CR), April 2008


It is unknown whether the shape and condition of rectrices provides any information about the age of Gray-headed Tanagers.


Photo by Marcel Gahbauer, Las Caletas (CR), April 2008

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2002- The Migration Research Foundation Inc.