Nesting Ruby-throated Hummingbird update

Well she is still sitting on eggs. No surprise that my guesstimate as to the hatch date was off! Checking on it today, she took two short stints off the nest and both times sat back down just as she would if there were eggs there.

Since they have yet to hatch, I thought I would point out a field mark that is useful in separating, especially female, Ruby-throated from their western North American counterpart, the Black-chinned Hummingbird. Their breeding ranges do not overlap, so it is only likely that you would encounter the two of them on migration somewhere in Texas or on their wintering grounds in Mexico. But what if a female or young bird showed up here in the fall? Could you separate these two similar looking species?

Anytime that it is perched one should be able to get a good look at the shape of the wing, and in particular the wing tip or the primaries. On a Ruby-throated Hummingbird, as in the photo below, the wings are narrow with a more pointed wing tip. The last primary P10 being noticeably narrower that the one above it P9. Black-chinned have broad, blunt primaries and P10 (the last one) is about the same width and shape as P9.

It is tough to tell from the photo (as the body has to lay down and the tail is therefore elevated), but another field mark to look for is how much tail projection there is beyond the wing tips. Ruby-throats have a longer tail projection, whereas on a Black-chin the tail only projects very slightly.