Vail Daily column: Real estate for the birds
If Slifer, Smith and Frampton were to open a new division catering to birds, then their market research would quickly narrow the client base. Potential customers would not include birds who construct their own homes. Off the list go all the birds who scrape minimal nests in the dirt and sand. Gone are the crafters and weavers of intricate basket-like structures. The sculptors of mud and twig homes are of no interest. Who is left? Eighty-five of the approximately 914 bird species native to North America. These are the cavity nesters — birds who like wooden walls and roofs. A few cavity nesters do their own construction, but most are in the market for natural or previously inhabited spaces.
The birds that hollow out their own spaces in dead trees or in the decaying parts of live trees are called primary cavity nesters. Tiny chickadees and nuthatches chip out their own homes, but woodpeckers, armed with their strong necks, sharply pointed beaks and incessant drive to hammer away at wood, are the quintessential cavity builders. On average, they speed through their construction in about two weeks and use the holes for only one season. One species, though, the endangered red-cockaded woodpecker, though, is a finicky builder, working on his hole for two years and re-using it for decades.
Primary cavity nesters, particularly woodpeckers, carve multiple homes in the same dead trees, producing kind of a bird condominium community. Many of these units are occupied by secondary cavity nesters such as swallows, bluebirds and wrens. Mother Nature also scoops out a variety of different sized cavities in decaying wood of living and dead trees, providing the homes preferred by owls and some ducks and mergansers, and by masses of chickadees huddling together on cold winter nights.
Cavity sizes and shapes vary widely, and chamber dimensions and entry hole sizes depend on the size of the bird. Cavity placement reflects the need for protection against predators and environment, and for proximity to food supply. Cavity nesters need proper construction sites and materials. Old growth forests are ideal because of large tree trunk sizes, but logging has taken a toll on primal forest acreage. Prior to the late 1970s, forest management did not include specific rules about retaining enough downed logs and the standing dead trees called snags that provide the neighborhoods for cavity nesters. Progressive clearing of swamplands and shorelines decreased available territory even more.
With declines in available housing stock, cavity nester numbers drop. Since most cavity nesters are insectivores, their loss means that bugs thrive. This upset in nature’s balance of power causes cascading side effects for forests and waterways.
However, cavity nesters readily accept human atonement and often move into the boxes we provide to replace their natural homes. The wood duck, in particular, has been brought back from the brink by all those long houses you see on posts near ponds and lakes. The bluebird similarly takes to an appropriately constructed box in its natural habitat.
In a real win-win situation, you can attract cavity nesters to your yard by correctly choosing and placing a box built to the specifications of the bird you would most like to watch produce and fledge a bunch of little birds, as long as they are able to get to their chosen food. Information on building, placing and maintaining nesting boxes abounds in books and on the Internet.
Once they did their research on the bird housing, Slifer Smith and Frampton would realize that the paying market is the bird loving and environmentally conscious human population.
They help increase the cavity housing stock by scouting out suitable locations and subsidizing the construction of box nests. In this unnatural end of the market, the houses are prefabricated and easily de-cluttered and cleaned for repeat use. Their entrances are not sticky with snake-repelling resin from wells drilled into sapwood, though some tenants do smear foul smelling insects around the doorways to discourage visitors. But the tenants reliably leave at the end of their breeding season. And there probably will not be a bird box housing bubble.
Betsy Holter is a volunteer at Walking Mountains Science Center.