DEAR JOAN: I have a question about a dove that seems to be overwintering in a neighbor's tree.

I hear his or her familiar call every so often, usually in the mornings, and I wonder what has brought about this atypical situation of a dove in residence so late in the year.

Is the bird perhaps injured and cannot fly? An anti-social avian who is flouting conventional behavior? Any ideas?

Chris Rackowski

San Jose

DEAR CHRIS: I'm guessing from your question that you think this dove should have migrated south for the winter. In our area, most of the mourning doves are year-round residents. The mildness of our winters combined with a supply of food from various backyard feeders sustain them.

A pair of mourning doves searching for nest-building materials
A pair of mourning doves searching for nest-building materials (Courtesy Joe Oliver)

While they are ground feeders, they nest on horizontal branches in trees and shrubs.

Doves have a large range. They are found throughout the United States and southern Canada, Mexico, the Greater Antilles and Central America. They even have been spotted in Alaska, the Azores and Iceland.

Doves also are among the most hunted birds, with 20 million to 70 million being killed each year by sportsmen. And yet the population of doves remains strong. In warmer climates, the birds will produce up to six broods a year. In California, it's usually two or three.

While I'm on the topic, I had a question from a reader about the whistling sound doves make when they take off. It's not a vocalization, it's a sound made by their wings.

DEAR JOAN: I have been putting out a hummingbird feeder for a little while now. When it's empty, I bring it in and wash it thoroughly with hot water and brushes, not wanting to use any soap or bleach because of a possible residue.

Lately, when I bring it in the tray and a little in the bottle is covered with mold. I clean out all the mold, but have been wondering if it's a problem for the birds. Should I be using something more than just hot water and brushes?

Marcia Citta

Saratoga

DEAR MARCIA: You are right to be concerned. The mold can prove fatal to our little feathery flying friends. Fortunately, you can do a lot of things to prevent it.

Mold, or mildew, is always a threat when you have sugar and water, or water and anything really. It occurs naturally, so it probably is not that you aren't cleaning your feeders properly. If you want to be doubly sure, you can try a mixture of one part vinegar and four parts water. I reader recently told me that she pours boiling water over her feeders and hasn't had a mold issue again.

Probably the best thing you can do is to change the feeders frequently, whether they are empty or not. Birders recommend every three days, but if you're still getting mold, then try every other day. In the summer, you may need to clean them every day.

You also can move the feeders into the shade. That will slow the growth of mold and prevent the solution from fermenting. Just make sure that you don't relocate the feeder to a spot that will give cats and other predators easier access to the birds.

Lastly, if you do all these things and you're still getting mold, check your formula. Always use cane sugar -- no other types of sweeteners -- and use the ratio of a quarter cup of sugar to 1 cup of water.

Contact Joan Morris at jmorris@bayareanewsgroup.com. Read the Animal Life blog at blogs.mercurynews.com/pets.