Clear skies + cooler morning + north winds = lots of birds. Not today, though. Despite what seemed like ideal conditions, we only banded 18 new birds with 6 recaptures of 11 different species. Empidonax flycatchers appear to be on the move with 3 of them banded today - 2 "Traill's" and 1 Acadian. This is only the 2nd Acadian Flycatcher ever banded at KIBS and the first this season. At a later date, I will put together a post explaining how banders are able to separate the incredibly similar Empidonax flycatchers.
|Acadian Flycatcher (hatch-year, sex unknown)|
We have been banding a lot of Northern Waterthrushes lately, so I thought I would explain how banders can distinguish between young (hatch-year) and adults (after hatch-year). The key is to look at the tertials. The tertials are the last 3 secondaries on the wing closest to the body.
|Tertials on a Northern Waterthrush|
Hatch-year birds will have buffy edging on the tertials while adults will lack the buffy edging.However, late in the fall there is a chance that the buffy edging can wear away and they will look adult, so it's always a good idea to check the primary coverts for shape and wear. In the following photo, the bird on the left is an adult and the bird on the right is a juvenile. Notice the buffy edging on the tertials on the hatch-year bird on the right. This trick also works for determining the age of Ovenbirds except the egding on the tertials is more of a rusty color.