Saturday, August 2, 2008
I'm a pretty happy boy today. After several fits and starts I have finally had some success in catching Sedge Wrens, Cistothorus platensis, in order to gather some life history data. I was able to draw in a few individuals with a tape call even though the breeding season is coming to an end and the wrens will be leaving soon. They were pretty wary and not as vocal as they are in the spring. What was really fun was watching them sneak up through the grasses. Often they will walk along the ground rather than fly.
These photos are of hatch year birds. It was interesting that young birds were drawn to the tape call. I did get one adult also. The young birds were easy to tell because of the plumage texture and the fact that their skulls are not yet ossified. The adult had a nice complete skull.
This photo shows the tail of the first young bird I caught today. It is molting in new tail feathers before it's fall migration and the molt appears to be asymmetrical. Molt timing is one of the things I hope to get a handle on with this study.
Sedge Wrens are a species of concern here in North America due to population declines. Their habitat choice is sedge meadows and grassy fields as opposed to Marsh Wrens, Cistothorus palustris, which prefer cattail marshes. If you have Sedge Wrens near you consider yourself very lucky.
Now get outside and BIRD!