Follow the natural resources team as we restore Saint Paul's natural areas with the help of generous grants, project partners, and volunteers.
Thursday, April 26, 2012
Como Park Bluebird Trail Update: April 26th
Post contributed by Sharon--Volunteer Como Park Bluebird Trail monitor:
Example of a cowbird egg that was laid in a bluebird nest.
To learn more about cowbirds check out this web article.
April 26, 2012: The bluebird nest with 5 eggs, one smaller than the rest, is likely a failed attempt and out of an abundance of caution I will wait until next week to remove it. Then I can be certain the nest has failed as by then those eggs, if viable, should have hatched. One chickadee nest has 8 eggs, another, 7 eggs, and a third is covered completely in fur. Another box has a carpet of moss, a chickadee nest in progress. A medium-sized speckled egg has been deposited in an unoccupied nest, probably made by bluebirds but abandoned. House sparrows and cowbirds lay speckled eggs of that size. I believe it is a cowbird egg, because the next box on the trail, one containing a thriving bluebird nest, now also has two speckled eggs in it, in addition to the 5 blue eggs. Cowbirds lay their eggs in the nests of other birds. They are a protected native species so I may not interfere, though it may make it difficult for the bluebird parents. A tree swallow emerged from one nest box, but hasn't yet begun to build a nest in it. A nearby box had one feather, one long pine needle, and one empty gum wrapper inside. The gum wrapper points to a house sparrow, the feather could mean a tree swallow. I removed the wrapper and will check again next week. The final box has only a small amount of grass inside.