ML148169551

Age and sex

Juvenile, Unknown sex - X

Observation details

Juvenile bird, sex unknown. Cream colored head typical of all juvenile frigate bird species. Brown allar bars on upper wing. Triangular chest and abdominal white patch (rounded tip pointing rearwards) with straight vertical demarcation relative to wings and bordering the black chest band, which is characteristic of Lesser and not the "egg-shaped" or oval white patch of the Greater, which shows a rounded edge into the chest and towards the head. A few of the shots, I believe show very good evidence of the spurs advancing into the auxiliaries and the wings, another characteristic of Lesser. The spurs form from the front edge of the triangular patch forming a straight line into the auxiliaries and also originate roughly mid-wing. These spurs also angle slightly forward. All these spur characteristics are typical of Lesser. Combining all this evidence, I believe this bird is a straight-forward candidate for Juvenile Lesser Frigatebird. I used The Field Guide to the Birds of Australia by Pizzy and Knight as well as "Identification of Christmas Island, Great and Lesser Frigatebirds" published in Birding Asia 1 (2004): 22-38 by David J. James. (http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.691.6104&rep=rep1&type=pdf).

Technical information

Original file size

5.8 MB