Foam lake Birding No. 2





Foam Lake Birding
No. 2

Last week, I ended by cautioning people to look very carefully before identifying black and white stripe-headed sparrows as there are two of them – the White Throated and White Crowned. In this article I am featuring the latter and attempting to point out the similarities and differences between them.
The behavior and habits of the two are exactly the same. Both are usually seen scratching about in leaf litter and hopping across lawns and gardens. Much of the time they are in mixed groups; which makes identification much easier. Why? It is easier to distinguish between two birds when they are side by side than if viewed separately at different times and places.
To an experienced birder the physical differences between the two are quite pronounced, but to beginners they are quite subtle. Here are the differences as I have experienced them;
First, the colours are slightly different. Both have striped heads, but the White Throat has a white throat (no surprise) and yellow lores (the space between the eyes and the beak) which the White Crown does not. Overall, the White Crowned is grayer.
Second, the beak of the White Throat is dark, while the beak of the White Crown is a “candy corn” colour.
Third, the birds have a slightly different physical shape. The White Throated looks somewhat flat headed, while the White Crowned is very round headed giving it the effect that it is wearing a bicycle helmet. The White Crowned appears to be long necked. If anxious, it looks like a deer on alert.
Four, the songs are entirely different. The White Crowned, much like the White Throated, starts with two whistles (usually) followed by a series of low whistles and ending in a buzzy sound. The song is not nearly as memorable as the White Throat’s.
Both birds migrate to the southern US and northern Mexico; however, the White Crown will winter farther north even spending winters in Canada along the west coast. In summer, the White Throated nests in the boreal forests of Canada as nearby as Greenwater Lake. On the other hand, the White Crowned nests in the Tundra and at high mountain elevations above the tree line.
As confusing as the birds can be to identify in the spring, it is far more difficult in the fall. The problem actually starts with the White Throated. Even though I described it as having black and white head stripes (which it usually does) there is, also, a buffy-headed version. This one has tan and dark brown head stripes and a dirty white throat patch making it look like an entirely different bird. They are quite common and one should look for them -in the spring. In the fall, juvenile White Crowns, also, have the same buffy head stripes and some even sport a pale white throat patch making them look very similar to the buffy White Throats. How does one tell them apart? The White Throated has yellow lores; the White Crowned does not. The White Throated has a dark beak; the White Crowned has a ‘candy corn” coloured beak. These field marks are definitive.
I was hoping to deal with a few more transient species, but most of them are on their way north to their nesting grounds. Therefore, for the rest of the summer, I will write about our summer migrants. Until then, enjoy the transients.