Flycatchers Galore!

Yesterday was all about quality, not quantity. We caught 19 total birds, but 12 different species, which made things interesting. The singletons: Nashville warbler, Black-throated green warbler, Wilson's warbler, Black-throated blue warbler, House Wren, Veery, Least Flycatcher, and a Gray Catbird. We caught a trio of doubles: Magnolia warblers, Yellow-bellied Flycatchers, and American Robins. We had one triple: Common Yellowthroat, plus 2 Common Yellowthroat recaptures.

By far the most time-consuming birds are the Empidonax flycatchers, two of which are pictured here (Least Flycatcher on the left, and Yellow-bellied on the right). In order to identify them, we have to take a series of measurements, including bill width, length of the bill from nostril to tip, wing length, tail length, and lengths of 3 primary feathers (the longest ones on each wing, also called flight feathers). Then, we look at the eye-ring shape and color, leg color, and lower mandible color. If it's still a bit fuzzy after all that (which it usually is, as the measurements for each species overlap quite a bit) we can use a series of equations to find more numbers to compare (finding the differences between the flight feather lengths). Usually by that point we've got a pretty good idea of what the bird is, though sometimes it can take quite a while. Normally, we can process a bird (put a band on, measure wing length and weight, determine how much fat it has, look for and remove any ticks) in about 2 minutes (longer if removing ticks, which is a delicate operation). Empidonax flycatchers, on a good day, take at least 10-15 minutes each just to figure out the species. This can be a problem when we have a lot of birds to process, but has not been an issue for us yet this season, where 19 birds in a 4 or 5 hr netting session is a "big" day. We're eagerly awaiting the big waves of migrants coming through, enough of these catbirds and robins!

Now it's time to put your Empidonax id skills to the test! 

Can you tell which flycatcher is which?

Come visit us at the banding station sometime soon!

Happy Birding!