Helping Animals Feel at Home : Environment: People who like to look out for other species can easily attract birds, squirrels and other interesting creatures to their back yards.

Birds of a feather not only flock together, they flock to people, too. And with a little encouragement, so do bats, butterflies, squirrels and other denizens of the wild.

With the growth of environmental consciousness, more and more people are spending more and more time and money to accommodate their fellow residents in nature.

Bird-watching and the home feeding of wild birds now are, taken together, the second most popular leisure activities in the country, behind only gardening. Americans spend roughly $1 billion a year on seed and other wild bird foods.

“I find it fascinating. It has a lot to do with urbanization and the desire of parents to teach their children about the world, and with an agrarian nature we all have inside. It’s in our nature to want to take care of other species,” maintains George Petrides, a former Peace Corps worker who in 1985 opened the Wild Bird Center in Montgomery County, Md.

“It seems to be becoming more popular, for sure. People are looking for things they can do to help (the environment), and this is a relatively easy one to do in their own back yards,” says Robert Mardiney, education director of the Irvine Natural Sciences Center near Baltimore.

So how can you begin to reach out to wild creatures? And what kind of animals are likely to respond?

* Landscaping: Many people make their choice of trees, shrubs and other landscaping flora with an eye toward attracting and sheltering birds and other creatures, says Graham Egerton of the Maryland Ornithological Society.

“I have a string of cypress trees, for example. The birds line up in the trees and wait their turn to get at the feeder,” he says.

“The habitat has to be right,” says Mardiney of the Irvine Center. The facility maintains a garden of such native flora and offers a pamphlet on how to plant with wildlife attraction in mind.

For example, holly trees, bayberry shrubs and other bushes with berries offer some birds a food supply, and dogwood trees provide good roosting. Milkweed and a ground cover called butterfly weed can attract beautiful flying insects.

Homeowners should even consider leaving dead trees standing as bird habitats, Mardiney says. Insects that thrive in the dead wood can be food for birds, and the trees provide nests for woodpeckers and other hole-dwelling species.

* Birds: The most popular of wildlife relationships can be as simple as regularly tossing out sunflower seeds into your yard or, better, erecting a simple feeder.

Birdbaths (heated or unheated) and progressively larger and more expensive feeding devices attract more varieties. And nesting boxes and houses offer a more permanent abode to many bird species.

Finches, nuthatches, thrushes and, of course, sparrows are among the small birds that flock to feeders. Bluebirds, jays, waxwings, mockingbirds and cardinals are larger species that take advantage of feeders and birdbaths. In shore areas, ducks and gulls can benefit from human contact.

Some people can even attract small owls, says Mardiney.

* Bats: Who wants to attract bats anyway? And don’t they fly into your hair and cause disease?

“All that folklore is nonsense. They’re perfectly harmless,” says Mardiney. While bats can contract rabies like any mammal, they usually pose a far less serious threat than the ubiquitous raccoon.

Bats are helpful, too, consuming mosquitoes and other nettlesome insects.

A bat box looks like a birdhouse, but is open on the bottom. The nocturnal mammals roost inside during the day, hanging from slats.

* Squirrels: The bushy-tailed rodents common in many parts of the United States split bird-feeding enthusiasts into two camps: those who make war and those who make friends.

“I certainly try to discourage squirrels,” Egerton says.

The rodents, he explains, steal seed intended for birds, and a variety of ingenious bird-feeding devices are designed to thwart marauding squirrels, such as baffles built around the food supply.

“They are very destructive, no two ways about that. But we find them entertaining,” says Ray Lane of the Wild Bird Center in Baltimore. “Some people tell us their squirrels sit up on the front step waiting for them to come home.”

In his store, customers can buy devices to attract and feed squirrels, ranging from simple chains for hanging out an ear of dried corn to nesting houses similar to birdhouses. The goal is mutual satisfaction: to establish a squirrel dining area in one corner of your yard some distance from where the birds eat.