Birds are critical to ecosystems. They are the most studied and most attractive group of animal species. As the future of birds gets more at risk, its conservation becomes more urgent.
The larger number of observers, researchers, and legislation that protects the birds confirms a great interest in these animals, for aesthetic, scientific or economic reasons.
Birds are ancient symbols of freedom, strength, wisdom and death. Many bird-watchers around the world seek the pleasure that its proximity provides. Much of our current knowledge was obtained by studying birds. Darwin’s theory of natural selection was formulated after observing the finches of the Galapagos. Birds are also good bioindicators of environmental changes. The decline of some species is a reminder of the damage that we are causing to the environment.
Birds also have economic importance. Large sums of money are spent, both in their observation and in hunting. It is estimated that between the 80s and 90s the number of U.S. observers has tripled, and they spend now about 20 billion dollars a year in this activity. But the economic value of birds is also due to its impact as pollinators, insect predators and rodent controllers. They destroy 98% of the larvae of a major pest of apple trees. Its importance as insect predators was estimated in 2000 dollars/year/km2. The costs of conservation of endangered species are also high. By 1995 there were already $ 18.5 million spent in the recovery of a North American owl.
There are about 11,000 species of birds in the world. There are migratory species - living in an area in winter, in spring or passing there in the course of migration - and residents who remain in a territory throughout the year. Hunting species are the most protected group in the world because of the interest in hunting them.
All birds require specific conditions to breed and survive. They need a suitable habitat for feeding and nesting, and many species also need appropriate places to stop during migration. Among the features that a habitat should possess are its size and configuration. For a species to live in a given area, this must be large enough to meet the species needs for food and shelter. Furthermore, if the habitat is fragmented, the edge effect increases, promoting changes in temperature, humidity and predation pressure in this environment. Migratory species need several habitats for the different stages of their annual cycle. The common crane, for example, uses wetlands to nest and uses agricultural areas to withstand the winter. A quality habitat provides good nesting sites, abundant food and appropriate shelter. If a habitat is large, but not appropriate, the bird does not stay there. Its quality depends on physical and biotic factors.
Other causes of the decline of birds are pollution, construction of human structures and invasive species.
We have to understand why the species are endangered and how can we avoid this endangerment. Genetics and the impacts of population size led to the emergence of conservation biology, which aims to support efforts of species recoveries.
Legislation is essential to protect birds. For example, the Ramsar Convention on Wetlands, the Bonn Convention on Migratory Species and the Birds Directive, about the wild birds in Europe. Under the latter, the European countries have created special protection areas to preserve species in need of strict measures.
Habitat management is the most powerful way to protect birds. The increase of habitat areas, their connection with corridors, hunting management and proper special planning are critical to the conservation of birds.
But to save them we must first investigate the requirements of the species, its threats and possible conservation measures. Population monitoring, often performed by volunteers, is also crucial. The Atlas’ are also important instruments for conservation, containing information on the distribution of species.
In addition to recovering endangered species, it is also necessary to maintain the common species, protecting their habitat and meeting their needs, to prevent declines in the future.