Because of urbanization and environmental changes, species rotate; more and more hawks, caranchos and chimangos are observed; also the population of parrots increased; goodbye to the goldfinches and the chingolos. In the city there are more and more birds of prey, parrots and pigeons, and less sparrows and goldfinches. While there are no censuses that accurately quantify populations, changes are noted by bird watchers. And the neighbors also notice, at first sight, the frequent passage of caranchos and hawks through the skies of Buenos Aires. Urbanization, the presence of plant and animal species that they feed on or that are their predators, as well as other changes in habitat are among the causes that promote the decline or the growth of species.
From Aves Argentinas, an association that since 1916 promotes the conservation of birds and their environments, confirmed to the NATION that more and more pigeons are sighted, especially of the common and pigeon pigeon.
"Anthropisation has associated risks for bird survival, mortality rates for many species are high, but there are some generalists who can adapt, such as pigeons. of food in the environment and even the man tends to feed them, which favors their establishment and permanence, "explained the doctor in biology and researcher of the Institute of Research in Biodiversity and Environment Ente del Conicet, Sergio Lambertucci.
The proliferation of pigeons brought in the abundance of raptors, who are their "biological controllers." Some years ago, when the Buenosairean government analyzed the release of hawks to combat the problems caused by the pigeons, worried the neighbors about the possible presence of these little-known but feared birds. And the initiative was archived.It is not strange to see them flying over their wings spread over groups of pigeons or between buildings and, of course, in large green spaces of the city, such as the forests of Palermo or Sarmiento Park in Saavedra. In the social networks, many share, surprisingly, photos of specimens momentarily detained in antennas and trees.
In the Capital, over a year, there are more than 250 species of birds, according to Aves Argentinas
Parrots from the north-east and north-west of the country also increased their presence in Buenos Aires. Aires. For example, the ñanday, the quiteri chirirí and the talkative parrot. Alexis Cerezo, a biologist and scientific director of Aves Argentinas, recalled that both the warming caused by climate change and the process of afforestation of the Pampas plain promotes that the city be colonized by parrots and parrots typical of warmer and more wooded environments.
"They are granivores who have available in the cities the plant species they need," agreed Lambertucci.
The starling pinto - a species exotic invasive, which competes for food and nesting sites - is also more visible in Buenos Aires. In other countries, it became a scourge, a destroyer of crops and an expulsion of native birds.
Among the species less and less seen in the capital are the friendly sparrows, goldfinches, chingolos and cardinals . The first are an exotic group, introduced from Europe, while the remaining three are native."The causes are still unknown and may be linked to changes in the degree and type of urbanization, as well as the increase in natural predators. These factors could also be affecting local sparrow populations: the city recorded changes in urbanization and vegetation, and there are conflicting views, "said Cerezo.
In the same vein, Lambertucci recalled that the infrastructure of large cities is inimical to birds. "Not only do they lose their natural habitat, buildings, cabling, vehicles are constant threats and cause of mortality, but the expansion of carnivores, cats and domestic dogs, attacks birds." No ecosystem could be sustained by the density of carnivores that cities have, "he concluded.