This may sound like a stupid question, but will a wild bird, such as a sparrow, pigeon or songbird lay an egg if it hasn’t mated?
Hubby and I started wondering about this when we found a bird sitting quietly in the dirt. I wondered why it didn’t move, and approached it to see if it was injured. It took off. Hubby said, “Maybe she was about to lay her egg.”
“No,” I replied. “That kind of bird doesn’t lay on the ground, and no bird lays its eggs in the open.”
“But what if she didn’t get her nest built?” he asked.
I considered this, and offered that perhaps birds delayed mating until the nest was built. “But don’t birds produce eggs even if they’re not fertilized?” he wondered. Chickens, of course, lay every day, regardless of whether there’s a rooster in the coop, but they’ve been artificially selected to do so by man for a thousand years. I hesitantly said that I didn’t think a “wild” chicken in its natural state (if such a thing can be said to exist) would lay every day because it would be a waste of resources.
But, I digress. Will a small bird lay an egg even if she hasn’t mated? Does she build a nest for this egg? I haven’t a clue, and don’t know quite where to look for the answer.
This may not help much, but mallards are the same species as domesticated ducks and I’m pretty sure they lay infertile eggs. (not in a nest) Also, I’ve heard of pet (wild) birds doing the same thing if they have no mate. I think the answer is that some birds do, and others don’t.
Yes, wild birds do sometimes lay infertile eggs. This can be due to intrinsic problems with the gametes produced by either the male or the female; or maybe the copulation didn’t pass along enough sperm; or other factors.
However, this is probably not the case in the scenario you describe above. It’s unlikely the bird was sitting in the dirt in order to lay an egg. Most female birds will not become stimulated enough to develop eggs to the laying stage unless they have gone through nest building an courtship already (there may be occasional exceptions). It’s possible a gravid female with an egg ready to lay could be “caught short” if her nest was destroyed, but I expect she would at least try to find a better place to deposit it than open dirt.
I suspect the bird may have been engaged in either dust-bathing or anting. Birds will often “bathe” in dust, not just water, in order to keep their feathers in good condition and get rid of parasites. They also sometimes engage in a behavior known as “anting.” They will either sit on an anthill, and allow ants to walk through their feathers and over their skin; or pick up ants in the beak and rub them on the feathers. It’s thought that the formic acid secreted by the ants may help to control parasites. If the bird was just sitting still on dirt it may have been letting ants crawl over it.
Not so; many nighthawks and nightjars nest in the ground in the open.
I don’t think either of these solutions applies. The bird was sitting very still on a small pile of dirt/sand in the cul-de-sac in front of my house. My first thought was that it must have been ill or injured due to how still it was. After it flew away, I glanced at where it had been sitting, but didn’t see any ants. (But then again, I wasn’t specifically looking for them.) I don’t think there were any ants, because that would be a pretty bad place to build a hill, with all of the traffic. I actually first spotted the bird when I drove home. I saw it in time to avoid running over it, and later, on our evening walk, we saw that the bird was still sitting there, which led to the discussion in my OP.
some ground nesting birds move awaw from the nest when a predator approaches (the nest being well camouflaged and the eggs virtually indisctinguishable from pebbles; the birds then put on this wonderfully convincing ‘broken wing’ act, hobbling away from the nest just a little faster than the predator can keep up.
Then when they have led it away a sufficient distance they return to the nest by a more circuitous route.
The eggs are blotched with brown and extremely well camouflaged. The birds are nocturnal; during the day they are sitting on the eggs, and they themselves are so well camouflaged they are almost invisible.
As far as your particular bird, if it was a sparrow type I’m a bit stumped as to what it might have been doing, particularly if it returned to the same site repeatedly.
I’ve seen that! My granfather used to have a hay field which harbored a kind of bird which did this. As a kid, the act endlessly facsinated me. I drove those poor birds insane, approaching the nest just to see it. (I was kind enough, though, never to disturb the eggs.)
Colibri, I don’t know if the bird returned. When I drove by, it didn’t move. About an hour later, when we walked, it was still sitting in the same spot. It only flew away when I got within a few feet of it. It wasn’t there the next morning, so I don’t think it returned.
