In modern times, some of man's domestic animals have been banished from the city for sanitary, health, or other nuisance reasons. An example is the rooster who disturbs householders with news of the dawn. Even dogs and cats have become so numerous in some cities as to constitute a health hazard and a general nuisance. A great many cattle, sheep, goats, even horses, abounded in cities well Into the 1920's. Few cities welcome them today, but horses are used by some city police forces and the mounted police usually are considered the elite among the force. (A six—year waiting period is standard for those seeking duty as mounted policemen In New York City.) One of The few exceptions to the rule against keeping livestock in the city is Phoenix, Arizona. Certain property inside the Phoenix city limits is designated for horse—keeping, and it is not uncommon to see ranch type houses, surrounded by green lawns and split rail fences, with horses grazing in the yard.

Certain animals have been removed from urban ecosystems because they prey on man or on his domestic animals. They have not only been removed from the cities proper but also from the surrounding countryside, which in most cases also is populated by man and his domestic animals. Most of the large wild cats and bears—grizzlies as well as blacks—have been eliminated from areas surrounding cities. Only occasionally, in northern Minnesota or perhaps in Maine, are there reports of black bears wandering into the towns. Grizzly bears can still be seen at the city dump in Cook City, Montana.

Within the cities themselves, a good many animals that are predators of one sort or another—skunks, fox, weasels—also have been removed. It is not certain whether these animals have been systematically extirpated or whether they have disappeared because their habitat has been destroyed or their prey removed.

Many animals have left simply because their living space has been canceled out or altered. When a natural habitat Is destroyed, the animals that occupy the new habitat at the same site may be quite different from the original species. For example, when the water environment of a city is degraded, highly desirable species of fish are replaced by so—called rough fish. Pollution is the most probable cause for elimination from stream courses of other kinds of animals such as muskrat and beaver. Pollution also is the probable cause of the disappearance of wild rice along such rivers as the Potomac. This in turn may have led to the decline in waterfowl along these streams.

The filling of wetlands has been responsible for completely eliminating fish, shellfish, and many fur—bearing animals. Even where the land was not "reclaimed" for city building, drainage has been used to aid in controlling insects, particularly mosquitoes.

It should be noted, however, that in some cities the wetlands have not been drained and many enlightened communities have passed legislation to preserve their wetlands. Even so, on the east coast of the United Slates, the salinity of much of the wetlands has been altered by ditching.

When people choose to live in habitats whose natural conditions are essentially unsuitable for humans, they find themselves at once in conflict with the environment. In many cases, people have employed extreme measures to produce a livable milieu and this has required drastic changes in the natural ecosystems of the area. It does not seem likely that we will abandon these areas since many of our cities are built there, but it is equally certain that at some point we will have to consider a more harmonious relationship with the ecosystems in which we live.

The animals that remain in the city are those that have resisted extermination by man or are compatible with human interests, or which passively occupy niches without interfering with people. In the latter category are squirrels and birds, particularly songbirds. Mankind's desire to make the environment conform to human requirements (lawns and mowed grass, isolated trees, well—trimmed hedges and shrubs), and the desire to live in a healthful environment (one which does not breed disease bearing insects or harbor animals harmful to humans—particularly rodents, poisonous snakes and the like), often puts people into conflict with environmental circumstances. Human ability to achieve all these things and yet to preserve elements of the original ecosystems out of which the city was built, present outstanding opportunities to preserve, conserve, and enjoy nature at the urban doorstep.

Parcels of land that have remained undeveloped end unthreatened from the settlement of the city can be found in the most populous and highly developed cities. On the island of Manhattan can be found places that look like pieces of a city park, but in reality they are bits of the original ecosystem of the island which never have been anything but what they are now.

Most cities have ordinances that require property owners to "clean up" their property—eliminate weeds, wild shrubbery, etc. If the owner fails to treat his vacant lot in this manner, the city will do it and send him the bill. Such activities are in direct conflict with the needs of wildlife. "Cleaning up" for man means destroying the habitat for many quite innocuous animals.

An ordinance in Fairfax, Virginia, a suburb of Washington, DC., required grass to be mowed to a height of six inches. The ordinance was permanently enjoined with the aid of a Smithsonian botanist, who testified as an expert witness in favor of the meadow with its myriad of flowering plants, its grasses and shrubs. How could shrubs and trees get started if by repeated mowing their stems were reduced to six inches or less? Species diversity, both of plants and animals, increases when cut grass goes to meadow. The aesthetic values of added birdlife, honeybees, rabbits and bright flowers more than make up for the less tidy aspect of the meadow as opposed to the formality of the mowed field.

Yet the Virginia householder had to fight the county health department (which had declared his lot a neighborhood "menace"), to defend his honeysuckle, the dandelions used in the family's homemade soups, and wild floribunda roses. In Akron, Ohio, a court ruled in 1976 in favor of a vegetarian who allowed her lawn to grow. It took another court order to allow a Wisconsin wildlife biologist to let his backyard flourish in "native vegetation."

By simplifying the environment with the removal of wild species of shrubs, flowers, grasses, and other kinds of plants normally described as weeds, and by insisting upon a well—ordered, neat environment, people severely limit the number and the kinds of animals that can be accommodated in otherwise unused parts of the city.

Nevertheless, many cities have declared themselves to be sanctuaries of a sort. The signs as one enters a number of South Carolina urban centers proclaim that they are bird sanctuaries, and if they are sanctuaries for birds, they must be so for other kinds of animal life as well. All that is required is to maintain the type of habitat necessary to the resident and migratory birdlife, i.e., nesting sites, adequate food, escape from predatory animals (particularly cats, skunks, weasels, and squirrels). In addition, there must be a general appreciation on the part of the human population that birdlife is desirable and is to be protected. In the early part of this century when more than today seed fruit trees were growing in cities, there was an abundance of food for birds, when city lots were not so neatly trimmed and mowed there was an ample supply of wild seed plants, and most cities were surrounded by meadows, agricultural fields, and river and stream valleys that provided much of the habitat for birds.

In 1977, the National Park Service will test the public's tolerance for urban wildness by allowing 10 of the 120 acres of mowed lawn in D.C's Rock Creak Park to revert to meadow status. The visual beauty of the resulting varieties of clover, black—eyed Susan, Queen Anne's lace, heal—all, blue—curl, sweet everlasting, St. Johnswort, deptford pink, Knapweed and butter and eggs in not the whole story. With the plants will come a whole assortment of associated insects, moths and butterflies, which, in turn, will attract and sustain more song birds, small mammals, hawks and owls. As the new growth is left standing over winter, nesting sites become available for rabbits, and seeds are there for wintering birds.

Before the use of hard pesticides, even some birds of prey such as the peregrine falcon were found in the cities. They nested on high buildings and preyed upon birds whose habitat was below theirs. Their principal prey was the pigeon—a bird considered a pest in many places. Then pesticides entered the food chain of the peregrines, causing faulty calcium metabolism and failure of egg hatches. We might consider reintroducing peregrines into cities. The pigeons certainly are there for them to feed upon (peregrines capture them in flight). The cities, were falcons to be reintroduced, might even become critical habitats, since the peregrine falcon it on the endangered species list. In the case of the peregrine, cities could become the refuge instead of the cemetery.

The steel, concrete, and glass towers that comprise much of the downtown areas of our cities are almost entirely devoid of places where plants can live, thus denying vegetative habitats for birds and other animals. The vast adjacent areas we call suburbia have simplified the natural ecosystems of the surrounding countryside so as to destroy much of the living condition necessary for birds and other animals. Particularly destructive is the removal of trees and their replacement by saplings.

Also damaged by the construction of cities has been migratory bird life. Many cities built along the coasts and the riverways of the continent occupy choice places once used by birds on their long journeys north and south. These sheltered places have been filled and used as platforms for cities. Bottomlands, flatlands, sheltered harbors and bays—they were choice environmental places and they assured the success of the birds' migratory journey. When they filled up as cities, the birds had no choice but to alter their flight plans. Some birds, such as the whooping crane, could not make the adjustment. Apparently successful efforts have been made to induce sandhill cranes to hatch our the whoopers and then introduce them to the migratory route of the sandhill cranes.