Sunday, May 3, 2015

Indian Pond Heron(s?)

A visit to Suan Rot Fai yesterday produced a few migrants including single Dark-sided Flycatcher and Forest Wagtail, plus two Thick-billed Warblers.

Pride of place however went to an Indian Pond Heron which was present in the same place as the previous weekend's bird.  When reviewing photos in the field I had a suspicion that it may be a different individual even though it was feeding in exactly the same place, however initial examination of the images once I got home made me think that these was just one bird involved.   Now though, after spending a bit more time looking at the images I rather think that two birds are indeed involved.

2nd May
25th April
Allowing for the very different photographic conditions, lighting, distance from the bird and consequent quality of the images, there is a significant difference in the colour of the forewing. My initial thinking was that this was due simply to the position of the feathers, but perhaps it is actually due to the degree of growth of the scapulars? If so, I don't think the scapulars could grow so much in just one week, though I stand to be corrected...

2nd May - not grey at top of mantle
25th April - no grey at top of manlte

More interestingly perhaps, from the rear view I interpret that the 25th April bird is more advanced in attaining breeding plumage due to the lack of grey at the top of the mantle (Indian PH has a wholly maroon mantle in full breeding plumage).

Either way, securing these new images means that I have good quality shots of all three Pond Heron species from the patch, in breeding plumage:

Chinese Pond Heron

Javan Pond Heron

Javan Pond Heron
Indian Pond Heron
variant Javan, or possible hybrid...

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