Saturday, May 8, 2010

A Mother's Day Lesson from Birds

Every year I get two large ferns to hang from our front porch. After about a week my husband noticed a bird flying out of one of the ferns whenever he opened the front door. Upon further inspection when watering the ferns, we found a bird's nest already built. Within a day or two there were eggs. And imagine my surprise to see two different sizes and types of eggs in this nest!

I wondered how this could happen so I did a google search and learned about "brood parasites" What this means is that a mother bird (frequently a cowbird) will find a nest that another mother bird has built (the host bird), then lay her eggs there and she may or may not ever return. In some species of birds, they aren't capable of building a nest so they just find one already built for them. In most cases, the host bird will come back and lay her eggs with the others. She may abandon her eggs when she notices there are other eggs in her nest. Or the brood parasite bird may come back and remove the eggs that are not hers from the host nest.

As you can see from the photo that I took, the speckled eggs are much larger and they tend to be the ones to hatch first. I really had to wonder how 7 babies could even fit in this tiny nest. It is probably about 3" wide.

Unfortunately, I read that when all the babies have hatched, the host mother will feed the babies that are the biggest and have their mouths open first. She may not even realize that the babies are a different species. This endangers the life of her own babies, and she is feeding birds that aren't even hers. Her smaller babies may end up starving because of the competition for food. Or they may get thrown out of the nest by the larger babies. I have read that this practice has possibly reduced the number of songbirds, while increasing the number of (brood parasite) cowbirds.

For days I struggled with getting involved in this circle of life. It didn't seem fair that a "squatter" bird's eggs should jeopardize the 5 blue eggs that were laid by the mom that built the nest in the first place. I considered removing the cowbird eggs myself. But I decided not to interfere with nature and see how this plays out. I hope that all these babies will have a chance at life.

Last night we checked and the 7 eggs were still there. Today I checked and the two speckled eggs have hatched! I hope this new mama can take care of all 7 of her babies. I only see 4 blue eggs now, but hope that the 5th one is under the new hatchlings.

More pics to come in the days ahead, if mama allows it.

Happy Mother's Day!


kelleysbeads said...

Thanks for sharing pics! Now I have new ideas for making more egg beads :)

I hope the Mama feeds them all and all the bebes survive!!

Anonymous said...

Kim, isn't it great to watch this happen! I'd never heard of taking over or "sharing" a nest. I did have some finches and parrotlets once, and when those babies hatched, they were so ugly! Teri

ChezChani said...

Wow, that's really interesting. Looking forward to pics...

dentedhalo said...

What great pics! What is it about a nest of robin's eggs that is so darn sweet? :) I hope all the birdies make it. I saw on a nature show not too long ago that sometimes the parasite birds knock the original babies out of the nest once hatched! Cycle of nature for sure. Can't wait to see more pics!