Did we just permanently scare off a mama bird?

We just got back to our house after a week away on vacation. Tonight I was putting my son to bed in his room when I noticed some large critter parked in his windowsill. (There’s currently no screen in the window, and the window only opens about 6 inches because we have one of those window guards installed.) I pulled back the curtain and discovered that it was a pigeon, sitting there nonchalantly in its nest on the sill. Weirdly, or so I thought, it didn’t fly off when I pulled the curtain back. So I called in MrWhatsit to confer, and MrWhatsit kind of gave it a little shove, which finally made it fly off… only to reveal two tiny white eggs in the nest.

I feel terrible. I know, it’s just a pigeon, but I feel bad anyway. We closed the window, which had no effect on the nest, as it was built kind of hanging out on the windowsill a little. I’ve been watching for the last half hour or so, but there have been no signs of mama bird. Did I scare her off permanently or will she come back? I know nothing about bird behavior.

Ugh.

I would not assume that she won’t be back.

Last year, a bird had built a nest inside a small box in our backyard that my husband uses for tool storage. He didn’t konw about the nest, and when he reached into the box, the mother bird flew out, disappearing into the trees. Several hours went by, with no sign of the mother bird. We worried about this situation, but the next day the mama was back, and everything turned out fine. It’s amazing how quickly eggs turn into little birdies, and how soon they are fully fledged and out on their own.

I wouldn’t worry about it if she’s just been gone a half-hour. She’ll probably come back, and the eggs probably won’t be hurt much by not being incubated for a short time.

But even if she doesn’t, I wouldn’t feel too guilty. If birds lose a clutch of eggs, or even all their nestlings, early enough in the season they will often re-lay. This is pretty normal. It’s possible she may decide to build another nest in a safer spot.

I had birds build a nest in a hanging planter on my front porch. The adults would fly off to the safety of a nearby tree whenever I went out on the porch — which I did as seldom as possible while they had taken up temporary residence — but they always came back.

On a related note, earlier this year, a pair of robins set up housekeeping in a very low tree in my backyard. My sister took a lot of pictures of the chicks after they had hatched. The next day the nest was empty, not only of the chicks (which we assume the robins had moved) but also of the egg shells. Not real sure what happened with those. Anybody have any guesses?

Birds remove the eggshells after eggs have hatched in order not to give predators clues that a nest is nearby.

As for what happened to the chicks, I hate to be the bearer of bad tidings, but if they disappeared from the nest before they were ready to fly something probably ate them. (Maybe another bird, like a jay or crow.) Songbirds generally aren’t capable of moving small nestlings before they can fly.

Parent birds can be remarkably persistant.

Draw the drapes, lower the blind - basically, put a visual barrier between the room inside and the sill outside - and mama will be most likely be back to finish the job.

Update: I drew back the curtain this morning to check, and mama bird was back! Except, the act of drawing back the curtain startled her off again. Argh.

I’m not touching those curtains again until I hear baby birds cheeping out there.