Chestnut-sided Warbler

18 September 2014. Burlington ON. Through an organization to which I belong, I recently offered to lead birding trips for anyone interested. I know there are many who’d like to learn more about birds, but getting started seems to be daunting.

Today I had just one person join me on a pleasant walk around; we had a very rewarding three hours. The splendour of a male Northern Cardinal or Wood Duck never lessens but it’s nice to share the appreciation with someone who’s really seeing it for the first time. I suspect my discussions on the finer points of Trumpeter Swans (versus Tundra and Mute Swans) and the key identification points on a Gray Catbird or Green-winged Teal in eclipse plumage (as against nearby Mallards) may need revisiting; but never mind, we both enjoyed it. I noted that we saw about thirty species including a pair of adult Bald Eagles passing overhead and a Green Heron stalking minnows.

We stopped along a boardwalk where birds suddenly started popping up. I have to admit that many of those fleeting glimpses left me mumbling ‘Not sure.” But I captured a lucky and actually very nice photo of one, which had caused me quite a bit of head-scratching. I’m not ashamed to acknowledge that my first quick-glance impression was that it was a Ruby-crowned Kinglet; except that the overall colour was wrong and it’s a little early to see them on their fall migration, October is a better time.

Chestnut-sided Warbler (juv. female)
Chestnut-sided Warbler (juv. female)

But my lucky photo (above) was a dignity-saver. It is a hatch-year, female Chestnut-sided Warbler. The vivid yellow-green on its back is diagnostic and if you compare it to the youngish male below, photographed in May 2012, it’s a bit of a stretch to tie the two together as the same species.  (The male was probably in its first spring, the chestnut extends further down the flanks in older birds.)

Chestnut-sided Warbler. (adult male photographed in May 2012)
Chestnut-sided Warbler. (adult male photographed in May 2012)

I remember seeing and being puzzled by a young female Chestnut-sided some years ago, but while there’s always something to learn, it’s also too easily forgotten.