Mosaic Monday: June 14, 2010

This is a Mosaic Monday post (see more over at the Little Red House Blog).

I love house finches. They are very beautiful and illustrate the attentiveness of good parents. I was very excited when they returned to my porch this year to raise a batch of babies.

Their first nest was blown asunder when a big thunderstorm whipped through the area, but as they are diligent birds, they quickly rebuilt. The nest wasn't far from our front door, and at night we would often scare mama bird from her perch where she was keeping the eggs warm, which wasn't ideal by any means.  We tried to do as little disturbing as possible.

After about a week, I stood on a chair and took pictures to understand how many eggs were in the nest. The pictures were too blurry to post here, but showed something I didn't like. To my dismay, I found five beautiful blue house finch eggs and one speckled brown egg. Evidently a brown headed cowbird played a dirty trick and did what has earned it categorization as a brood parasite - it laid an egg in the house finches' nest.

Through research, I found that the cowbird baby would most likely hatch first, then potentially kill the other birds by destroying their eggs prior to their hatching or by out begging the parent birds. However, there was information stating that a cowbird cannot exist on a house finch diet and would most likely die anyways, but that both species are protected enough that you are not suppose to mess with their nests. These were from forums and blogs, so I am not sure how reliable the information was. I will have to figure out what is allowed in Michigan for the next time I run into this problem.

Knowing that I wanted the house finches to live, but not wanting to kill the other bird, I decided in this case to let nature do what nature does. I snapped pictures after one bird hatched. I believe this was the cowbird. A couple days later, I found a broken blue egg on the ground. A day or two later, I found a baby bird corpse on the ground. I think this was the cowbird baby. I checked the nest and it was empty. The parent birds haven't been seen since.

I think the whole nest perished because I didn't make a choice which would have saved at least one bird. I was at a moral crossroads though because although it is not believed that cowbirds can survive on a diet of seeds only, it is not an absolute and I didn't feel good about either decision. So, I let nature take over. I don't like the results though.

What would you have done in this situation?