A Cowbird, but not as we Know it!

Don’t you just hate it when a bird pops up and gives you a headache because it just does not fit the norm? It happened to me (again!) when I came across this cowbird on the Goat Man’s drive at Daniel’s Head, Cape Sable Island. Normally you don’t spend a lot of time enjoying crippling views of cowbirds, mostly because, whether you like it or not, they are trash birds and don’t command your attention the same way something making more effort to be interesting would. I’d better start at the very beginning, a very good place to start.

Every time I pass the Goat Man’s place I scan his drive. He scatters corn for his goats and chickens and the corn attracts birds. So far my luck has been restricted to two Dickcissels (at the same time) and the odd sparrow that wasn’t a Song or Savannah. On this occasion the floor was dominated by Mourning Doves but, right at the back (of course) was this smaller body that hinted at Rusty Blackbird. Once it stuck its head up it clearly wasn’t. Suddenly the Goat Man appeared, probably on some goat-related duty, and the doves and guest flew along the drive towards me.

The light was not terrible but the wind was and so everything was being teased around and kept low. I had another look at the cowbird and thought it looked a bit odd, the body plumage of a male and a female-type head with a pale supercilium. So I heaved to with the camera and blasted a few shots off before the whole lot flew off and away, then thought no more about it and went about my birding business. Later I downloaded the photos to the PC and was surprised to see how different the bird looked, as to how I expect a Brown-headed Cowbird to look.

Just to reiterate, the back, tail and wings of the bird were the iridescent blueyness we all know and love about cowbirds. From the breast/neck up it was brown, as was the throat, which was supposed to be white, or at least whitish. The bill too looked a bit different, longer and more pointed, well maybe. So I Googled some images and found nothing similar. I checked some books and found nothing similar so I started thinking it might be something more glamorous and perhaps shinier.

To put things in context, Brown-headed Cowbird is reasonably common in Nova Scotia and so the odds were stacked against being anything but, still you have to be thorough. I pulled my ‘New World Blackbird – The Icterids’ by Jaramillo and Burke (Helm, 1999) from the shelf, it was reduced in price so who could resist? I read up on both possibilities. Now take a look at the doc shots before I proceed.

img_7579

In cowbird circles this would be a looker! Is it a male Brown-headed in moult, if so why the pale supercilium, more obvious head-on? Is the bill big enough for a Brown-headed? What of the wings? To me they look the wrong shape for Shiny, p8 is longer than p9 in Shiny, meaning the outermost wing feather is longer in Brown-headed, but it is not clear from the images, just suggestive of Brown-headed Cowbird.

img_7576

This image shows the pale supercilium, present on both sides of the head, so actually there and not an artefact of the light.

img_7587

This one has been lightened and sharpened. The originals are at ISO 1000 so grainy. Here there is a suggestion of eye-arcs but the eye is hardly ‘beady’ as in Brown-headed Cowbird. The light doesn’t help when assessing the bill colour but it does look heftier here.

img_7574

This equates to my original view, is it slim-chunky or chunky-slim! I think you can just about make out the primary structure here, although the angle suggests p9 curves inward a little.

img_7583

This is the most confusing image, purely because the bill looks so small, putting the bird back in the Shiny camp. Meanwhile, back in ‘the book’…

The icterids guide states that female Shiny Cowbird can have an iridescent body, a feature Brown-headed does not have – whoa, read on. Brown-headed Cowbird has a paler lower mandible than Shiny, which always has a black bill. So what was I looking at? I think, still think, that it is a Brown-headed Cowbird. I don’t know why it has a supercilium, or ‘glossy’ body. I don’t know why one view makes it look good for Shiny and another in the same sequence of frames makes it good for Brown-headed.

There are three things to take from this experience. First is that even common birds can look different from the field guides and even the family specific guide, not all plumages are covered or even, surprisingly, well described. Secondly, identification from photographs can be subjective. In the field the bird looked different, I already mentioned the similarity to Rusty Blackbird in shape and some plumage colouration, this perceived similarity can cloud your thinking. Third, only look at adult male cowbirds in summer plumage and you’ll sleep better!

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s