Bird Conservation

There are approximately 85 species of birds in North America to nest in cavities. Some, such as woodpeckers, excavate their own holes. Non-shovels like the nest in cavities Purple Martin already dug by other birds or animals. Then there are birds such as ducks that nest in natural tree cavities that form in several trees. Many of these birds also nest in nest boxes provided by humans.
If you could travel to a time before the Europeans started coming to the New World, we could see the birds that live in abundance, each occupies a niche in the ecosystem. Birds eat bugs that could become a scourge on forests. In turn, their number would be kept in check by hawks, owls, snakes and other predators. It was a beautiful balance.
In the case of people living within their natural balance, the Indians in parts of the country has long ago discovered they could attract swallows to nest in hollowed gourds. In this case, the swifts eat many bugs that have been considered harmful to people and animals. Thus, the nest was first Purple Martin was created. (It is important to note here that, contrary to numerous requests, the mosquitoes are not favored by insects among the swallows.)
A more common human interaction with nature over the last two centuries at least, may be considered in a discussion on "introductions." Humans have often brought all kinds of plants and animals from their native place on foreign soil. Sometimes it happens accidentally, but there have been many intentional introductions as well. Many times, the new species becomes extinct, because they were taken from their natural niche and inserted where there was no place for them. From time to time a species to survive, to carve a new niche. When this happens, it usually has devastating effects on native species.
In the world of birds, two excellent examples of successfully introduced species are the English sparrows and starlings. The house sparrow was introduced in North America in the 1850s in an attempt to reduce insect populations in human communities. Unfortunately, this proved wise. As the number of sparrows has increased, they began to consume huge quantities of grain and vegetable growing, and they competed with native birds nest in cavities. The intentions were good, but the experience was simply poorly designed. The sparrows aggressively defend a nest site she claims, and these sites are often preferred by birds such as bluebirds and swallows.
If the introduction of the English house sparrows in the United States was ill-conceived, the case of the starling was downright ridiculous. In the 1890s, a man named Eugene Schieffelin wanted to bring to our shores all the birds mentioned in the works of William Shakespeare. This comedy of errors ultimately led to the continental distribution of starlings. They now reside from coast to coast. Very aggressive, they actually "evict" other birds nest in cavities of their homes. This, combined with the ever-increasing pace of land by man, puts a lot of pressure on our native bird populations.
Preservation
Conservation is not new or recent. Conservation, or living in a sort of balance with nature, had been the norm for successful crops for millennia. Many ancient societies were very respectful and respectable, agricultural policies. Some have been easier not to over-kill, and using all parts of the animal for food, clothing and shelter. Some early techniques were quite complex, as terracing land crop rotation, and irrigation.
Then came the Flag