DEAR JOAN: Several times I have observed house sparrows being followed by their young. The young bird cheeps and the adult bird finds seeds on the ground and puts them in the young bird's mouth.
This year I observed the same behavior under my bird feeder at home, but it was an adult junco feeding a young bird, which was quite a bit bigger, maybe a house sparrow or towhee. Why would a junco feed another bird's young? Do either sparrows or towhees lay eggs in other birds' nests?
DEAR BARBARA: Those aren't sparrows or towhees you're seeing. They are young cowbirds.
Cowbirds are classified as "brood parasites," which means they lay their eggs in other bird nests and hope the foster moms will hatch the eggs and raise the birds until they fledge.
They often choose the nests of juncos.
It was believed that the cowbird developed this trait many generations ago. They followed herds of bison, eating the insects that were stirred up by the movement of the massive animals, and in order to stay mobile, they couldn't sit on nests. More recent research casts doubt on this theory. The species developed in an area where there were no bison. Instead, it may simply be descended from a line of nomadic type birds, and while the modern cowbird isn't all that mobile, it still follows its instincts.
You may wonder why the juncos, and other birds, put up with this. The nesting mother may not realize the new egg isn't hers, or she may be trying to protect her brood.
After laying her egg, the cowbird will continue to watch the nest. If the foster mom shoves the new egg out of the nest, the cowbird often will return and destroy all of the remaining eggs.
DEAR JOAN: As an avid hiker, I've not only seen but have heard of more rattlesnake sightings than in recent years. I usually hike the Walnut Creek open space near the west side of Shell Ridge. Can you explain and or verify an increase in rattlesnakes?
DEAR EILEEN: From what I hear, there are not necessarily more rattlesnakes out there, but there are more sightings, probably due to the drought.
The snakes are looking for water, plus the wildlife they feed on also is coming in closer to civilization in search of food and water, too.
So we've likely got a typical number of snakes out there; they are just in areas where we're more likely to bump into them.
Keep an eye out when walking, and give them a wide berth. Wear over-the-ankle hiking boots and long pants, and stick to the trails. Rattlesnakes are aggressive only if threatened, but accidentally stepping on one could result in a bite. Never step or put your hands where you can't see where they are going.
If someone is bitten, follow the advice of the California Poison Control Center:
Don't cut the wound and try to suck out the venom. It doesn't work and it causes further injury to the victim.