12 Jul
2013

Posted in: Uncategorized
By Hugh    No Comments

Life, Death, and the Odds: Perils of a First Year Bird

At first, I thought the wind was making the glass door rattle. Even the second time I heard the small thud, I didn’t process what was happening. It was a stifling hot day, the air conditioner was running, and there was the oil burner guy who came to do a tune-up to attract my attention. It wasn’t until he was bringing his equipment out to his truck that I figured out what was going on.

As he returned to make a second trip, oil guy said, “You have cats?” “Yup.” “Well, one of them left you a present on your front step.”

Depending on the size and species of the bird, the incubation time of an egg is between two to four weeks. During that period, the parent (or parents, depending on the species) sits on the nest, keeping the eggs at the proper temperature, turning it periodically (to ensure proper development), and of course, protecting it from predators.

Sometimes, predators like fox or raccoons can come looking for the eggs. Other troubles in the nest can come from the brown-headed cowbird, arguably the worst parent in the animal kingdom. This creature lays its eggs in the nests of other, usually smaller birds, and leaves. Once the chick hatches, it is double the size of its nest mates. Therefore, it consumes the lion’s share of the food the parents bring, effectively starving the rest of the chicks.

The story isn’t much better when the birds hatch. Still targets of predators, they may also be attacked by insect parasites, or simply fail to thrive and die. They take weeks to fledge, but the risk isn’t over. There’s the dreaded first flight, the vulnerability of grounded chicks to feline predation, the general klutziness of avian adolescence.

It’s this last immutable fact that led to the death of the Carolina wren on my doorstep. My cats are indoor animals, so they could not be the culprits behind the death (cats are responsible for hundreds of millions of bird deaths each year, according to http://allaboutbirds.org , Cornell University’s excellent birding site). The tiny rust colored bird laying on my step was simply the victim of inexperience, flying into the glass door of my home after mistaking it for more open territory.

The likelihood that a bird will die during the first year of its life is around 83%. The odds are long, and the challenges are nonstop. Mind that step, guys.