Beggars

The incessant chirps of newly fledged chicks fill my backyard with noise in the mornings and evenings.  Poor little Chipping Sparrows flit about the yard collecting food for their enormous and ever-hungry Cowbird chicks whose parents happily deposited their eggs in the sparrow nest (see my earlier post on this).

cowbird-chick-being-fed by Chipping Sparrow

Fledgling Cowbirds look to be twice the size of their foster parent. Adult Cowbirds are nest parasites, (depositing their eggs in the nests of host species), a strategy that worked well for the nomadic behavior that evolved while the birds followdc buffalo herds through the temperate grasslands.

Lately, it’s the Blue Jay chicks that have dominated the backyard, as they follow their parents around begging for scraps. It must give the fledglings plenty of practice flying around obstacles and landing in tight spaces, as their parents fly from tree to tree to lawn, and back again.  They must have to wean those big chicks of their dependence on adults for food soon.

blue jay fledglings-

Five Blue Jay fledglings crowd around while one of the parents (top right) forages in the grass.

blue jay fledglings-

Still in its cute stage — this one followed a parent into the middle of the tree, and immediately started into begging mode as it watched the parent forage.  Its wings and tail are a bit shorter than the adult’s, but soon they will be indistinguishable.

blue jay fledglings-

Parent moves on…baby still begging with wings fluttering and making sharp jay noises.

Red-winged Blackbird males typically have more than one mate — the average is about five females per male territory, but some males have been observed to have as many as 15 females nesting in their territory.  As you might expect, with all those active nests with 4-5 youngsters in each, the females take care of almost all of the feeding chores (males might help feed the first nest in his territory, but usually none beyond that).  However, that doesn’t prevent youngsters from flying right up to dad to beg a bit of food.

red-winged blackbird male and fledgling

Nonchalant male ignores begging youngster — his job is to guard the nest, not feed the chicks.

Bird brains

Despite what we might think, birds do have personalities, and can be quite different  from one another even within the same species.  Take the case of two House Wrens who happen to be nesting quite close to one another in cute little wren boxes in this lovely garden (of a friend).

Diamond-shaped boxes  with just the right-sized holes attract House Wrens.

Diamond-shaped boxes with just the right-sized holes attract House Wrens.

My presence (along with that of a friendly cat) immediately set the wrens to chattering and scolding.  I could see that they were busy feeding their broods in the nest box, so I stood quietly and watched.

One wren was quite perturbed by my presence and flew from perch to perch, trying to decide whether it was safe to enter her nest box or not.  She had a juicy caterpillar to feed her chicks.

I assume this is a female because she still has a bare abdominal area where her brood patch was.  First she sat in a tree and scolded me.

I assume this is a female because she still has a bare abdominal area where her brood patch was.  First she sat in a tree and scolded me.

Then she sat on a tomato cage and scolded me, quite loudly considering that she kept her beak closed around that caterpillar.

Then she sat on a tomato cage and scolded me, quite loudly considering that she kept her beak closed around that caterpillar.

Then she moved to within about 6 feet of the nest box, but still hesitated to enter.  That caterpillar is starting to look dehydrated.

Then she moved to within about 6 feet of the nest box, but still hesitated to enter. That caterpillar is starting to look dehydrated.

Oops, what happened to the caterpillar -- did she drop it or eat it?  She is sitting right opposite the nest box and giving me a piece of her mind.

Oops, what happened to the caterpillar — did she drop it or eat it? She is sitting right opposite the nest box and giving me a piece of her mind.

Contrast this behavior with that of another wren (couldn’t tell if it was male or female) feeding its offspring in the box next door.

"I have something to feed my babies -- don't look while I approach."  This wren made two short hops in a bush next to the nest box and then popped inside.

I have something to feed my babies — don’t look while I approach.” This wren made two short hops in a bush next to the nest box and then popped inside with a big, juicy fly.

Task completed -- off to find another meal.

In and out, task completed — off to find another meal.

You can see how natural selection might act here, depending on the type of threat.  Wren A’s chicks might not get fed as well and perhaps not all of them would fledge but she doesn’t give away the location of the nest. Wren B’s chicks might get lots of food, but could be easily discovered by a predator, since the bird made no attempt to disguise where it was headed with its prey.  Good thing there is such variation in behavior among individuals, insuring that some will exhibit the appropriate response and survive.