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Saturday, September 17, 2011

Is it a Black-chinned?

Ruby-throated and Black-chinned Hummingbirds are very close relatives and very difficult to tell apart in the wild.  Well, I'd better qualify that.  If you happen to get an adult male Ruby-throat and an adult male Black-chinned side by side in just the right light, then you would have no trouble telling them apart.  The Black-chinned's throat is actually purple if you see it with the light shining on it, and the Ruby-throat's is, well, ruby-red.  But it is not often that you will have such an ideal situation in which to identify your hummers.  It is more likely that you will have the situation I was faced with today.

There was a flock of the little birds darting around me as I walked into my backyard.  As best I could count, there were about ten.  The rule of thumb for birders in our area is that every hummingbird that we see is a Ruby-throat until proved otherwise, but it has been an unusual migration season so far and I know I've had at least one Rufous Hummingbird in my yard which I reported on here last week.  I know that Black-chinned Hummingbirds have also been reported in the area, although I'm always suspicious of such reports simply because it is so difficult to distinguish them from Ruby-throats.  Nevertheless, I have been on the lookout for a Black-chinned in my yard.  Today I think I might have found one.

Again, as with the Rufous, rather than the distinctively colored male, I have the more ambiguously colored female.  The thing which drew my attention to her was not her coloring but her behavior.  She acted different than the other birds.  Specifically, I noticed that she was often pumping her tail as she flew about, and even after she perched, in a way that is not common with Ruby-throats.  Then I took a closer look at her as she perched and began to notice some subtle differences.

For one thing, the length and curve of the wings.  The Black-chinned's wings are broad and curved whereas the Ruby-throat's are narrow and straight.

Also, the bill of the BCH is slightly longer than the RTH.  It's hard to judge without another bird sitting next to it for comparison, I know, but this bird's bill seemed longer to me.

This shows the shape of the wing a little better and it also shows the back which in the BCH is a duller green than the more iridescent RTH.

Here, you see her with her wings folded and they look pretty straight, but she's also giving that little tail pump which she was doing pretty constantly.

A somewhat better view of that curved wing which reaches just about to the tip of the tail and of the long beak.

 Again, she's pumping her tail.

The voice of the bird is no help in identifying her as the voices of the BCH and RTH are virtually identical.

So, do I have a Black-chinned Hummingbird in my yard?  I'd be a lot happier and a lot more definite if I had an unmistakable adult male, but yes, I think I do.  She's a female and the differences between her and the Ruby-throats in the yard are subtle, but when you see them together they are noticeable.

On the other hand, it wouldn't be the first time I tried to see something that wasn't there.

6 comments:

  1. It is very difficult for me to distinguish between a female Red Ruby throat and a female Black chin. I have a two females hanging around my feeder and after reading your post, I'm sure one is a female Red Ruby Throat. I have a male RRT that only allows the female RRT to approach the feeder. I have yet to see a Rufous. I'm still hoping one will stop by.

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  2. The two really are almost indistinguishable, Rambling Wren. The Rufous, on the other hand, is quite distinct - even the female. If you see one, you'll know it!

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  3. I posted on an earlier blog...but I'm glad to have found you again. Did the newspaper paychecks start bouncing?

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  4. Hey, Elkhartjim! Welcome! I'm so glad you found me. Yes, the Chronicle decided to "go in a different direction" and axed the Houston Grows pages. I think their new direction sucks, but perhaps I'm prejudiced. Anyway, I'm delighted when any of my old Chronicle readers turn up at this site and I look forward to hearing more from you.

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  5. I had wondered if perhaps some of our hummingbirds were black chinned, but I really don't know. Now that you mention it, I've seen quite a bit of tail pumping, so I may have some. Whichever they are, they're entertaining and I will miss them when they head south.

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  6. The two species are VERY difficult to tell apart, Jayne, especially the young or the females, unless you can catch them in exactly the right light, but I'm convinced that I've had some Black-chinneds in the yard this fall.

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