Saturday, October 3, 2009

Madison migrants

The last few weeks in Madison have been dreary and wet. Not the best weather to go birding. But the migrating birds are definitely flowing through right now.

A few weeks ago I was able to do some banding at Biocore Prairie again. The fall colors were just beautiful because of all the late blooming prairie plants.

We got quite a few migrants and young birds like this juvenile Red-eyed Vireo. It was neat to see the difference in eye color with the young vireos. Their eyes are dark brown and will turn red next year.

We caught this little guy, a Tennessee Warbler which can be very easily confused with another bird that we catch a lot of. Below is a picture of a female Common Yellowthroat. You can see how the Tennessee and the Yellowthroat both have whitish to buffy eyerings and yellow bellies! The biggest difference here though is size. The Tennessee Warbler is a very tiny warbler whereas the Yellowthroat is a bit more robust. It's too bad we didn't catch these two at the same time so I could have gotten a side-by-side comparison. But you'll also notice that the Tennessee has yellow all the way down its breast while the Yellowthroat has more yellow on the throat (surprise!) and is whiteish below.

Female Common Yellowthroat

Oh yes, we got another confusing Empidonax Flycatcher, similar to all the ones we were catching in Texas. Based on our many measurements, this guy ended up being a Traill's Flycatcher. The Traill's Flycatcher does not count as its own species, but it refers to both the Willow and the Alder Flycatcher. Apparently, there is just not enough information out there to completely tell the difference between these two in the hand. It is kind of scary how similar this guy looked to the Least Flycatchers I had banded before. There were differences in size though, with this one being a little bit too big to be a Least. Also this empidonax flycatcher had a less visible eyering, which is something to look for in the Traill's flycatcher.

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