The Cowbird Invasion Has Begun in the Westrich Backyard
One of those "teaching moments" just occurred this past weekend. While out playing basketball with my son and daughter, the ball happened to roll to a particular bush. While retrieving the ball, I spied a bird's nest inside the bush. After looking a little more closely, I realized that the eggs inside the nest were not the same. One of the eggs was small and blue, while the other was larger and white with brown speckles. I realized what had recently transpired inside that bush, so I called Emily and Elliot over to look at the eggs.
"This is a teaching moment!" I thought to myself. I explained to them how cowbirds will lay eggs in other birds' nests, so the other mama bird will end up raising the cowbird along with its own. As you may know, however, two problems will likely take place with this scenario. The cowbird will hatch first, giving it the opportunity to eat the other egg(s) in the nest. If that doesn't happen, then the cowbird, being larger, will muscle out the other baby birds and get the food from the mama bird, allowing the mama's offspring to starve to death.
So after pondering what I should do about the situation...whether to allow nature to run its course or to intervene by eliminating the cowbird egg, I finally made a decision. With a small stick, I carefully removed the cowbird egg from the nest of whichever bird made it (to prevent my scent from rubbing off onto the nest), and I threw the egg away. Consider it heartless, if you want, but considering the facts about cowbirds, I'm sure they'll more than make up for losing one of their eggs to an intervening human.
Watch the video below and see a female cowbird in action, laying its egg in a cardinal nest. It removes one of the cardinal eggs from the nest, placing it on the rim and possible damages the other cardinal egg.