As I write, two Golden-crowned sparrows are pecking at the grass. Above them, a male mockingbird is perched, singing from his routine of songs defiantly, letting the world know he has claims on this territory. Meanwhile, around them the rain falls constantly, soaking their winter world, and it would appear that they hardly notice. I have been asked a couple of questions recently related to our birds and winter. What is the effect of the rain and other winter phenomenon on local birds? What effect do humans have on birds by feeding them?

The birds that do not migrate away from our valley in winter have to adapt to numerous changes. It is colder and wetter, and there are major shifts in food sources and supply. Some birds find these conditions intolerable, and they migrate to warmer areas or otherwise to where the food that suits them is in greater supply. Several species of local swallows are an example of such migrants. Other birds migrate here in winter specifically because the area suits them. This winter, shorebirds and waterfowl have good reason to be here.

Other birds are not so lucky. Continuous days of rain are particularly challenging because foraging for food is more difficult. I asked a renown bird biologist, Dr. Louis Baptista of the California Academy of Sciences, about whether these birds get wet. Birds have protective feathers covered with a fine layer of water repellent oil, and I assumed these feathers can only keep them dry for so long. His simple answer was, "Yes".

He also explained some of their strategies for winter survival. When it is very wet, they find a place to hide and stay dry, and come out only when necessary to feed. Given their extremely high "metabolism", the rate at which an organism carries out its life functions and uses energy, birds must eat often. Thus, most birds will come out to feed even in the rain after a couple of days of wet weather. Some other birds including hummingbirds and swifts can actually regulate their metabolism, slowing their heart and lowering their body temperature by as many as twenty degrees. They can remain in this state of "torpor" for a longer period until conditions improve. Eventually, though, all birds need food, and Dr. Baptista sees no problem with augmenting their food supply with a feeder providing sanitary conditions are maintained. There are many diseases that affect wild birds. If you feed them it is important to be responsible about it.

Bird feeding experts include Wildlife Center volunteers Barbara and Doug Murray of Oakmont. They have been avidly feeding and monitoring birds for a number of years and have helpful advice from their experience. They prefer sunflower seeds for hanging feeders, where finches and other birds congregate in numbers that can empty a feeder in a day. To protect the birds from disease, clean the feeders every week or two. Soak it in a solution including warm water and a small amount of chlorine bleach to sterilize. Rinse the feeder thoroughly to avoid passing on any residual chemicals to the birds. A univeristy publication suggests making sure that feeders are plentiful enough or otherwise designed to prevent overcrowding which can also pass on disease.

The Murrays use a wild bird seed mix for ground feeding birds like juncos. This seed should be raked up every two weeks or so, though, to keep the seed from becoming moldy. Increasing natural habitat for ground feeders is good, too, and a simple way to accomplish this is to let oak leaves collect in an area in the yard. Birds will turn over the leaves looking for grubs. You can provide all birds with cover from predators by having shrubs. There are many benefits from maintaining habitat to attract birds, including that birds work for your garden, keeping insects such as earwigs and aphids under control. There are no earwig problems in the Murray's garden anymore.

Hummingbirds are famous for their love of feeders. Special precautions need to be taken to make sure that these feeders are kept clean. Mrs. Murray recommends cleaning them often by washing them well, letting them soak, and thoroughly rinsing them without soap or chemicals due to the sensitive nature of hummingbirds. Clean the feeding holes with a pipe cleaner. A male will tend to control a feeder as part of his territory, and the Murrays like to provide a second or third feeder at a distance from the first to allow for more males. Mr. Murray will take a feeder inside at night when there are several cold nights in a row so the feeder mix doesn't freeze. When he steps out early in the morning with the feeder, a hummingbird is often there waiting for him.

Birds are among the most cherished wild animals, numerous and large enough to remind us to stop and see the wonders of nature at work all around us, even in the rain.