About the longevity of birds there are no exact data. Such facts can be treated only as incomplete or sketchy. They are based only on the information about the birds living in bondage or the banded individuals. It is reliable to establish age on appearance and the structure of a bird it is quite difficult. It is only possible to claim old she or young, but it is impossible to tell its exact age.
The birds living in bondage
Data on age of birds which contain in bondage completely cannot reflect the valid picture about the actual duration of their life since they live in the conditions very very different from their native habitat. There are all problems connected with accommodation, the person undertakes. He protects birds from hunger, enemies and cold weather.
At the same time in the conditions of bondage in particular birds of the large sizes are limited in swimming, flight or run. Besides, food which they eat does not correspond to the food got by them in the environment of dwelling. And the climate in bondage often strongly differs from habitual climatic conditions. All these factors cause in birds various diseases — tuberculosis, avitaminosis, heart obesity that leads of them to premature death.
The banded birds
Data on longevity of the banded birds cannot be considered completely reliable too. The caught and banded bird is released, but nobody knows when she is caught next time to register age. Besides, not always baby birds fall into hands of ornithologists for ringing. Quite often it is adult individuals whose age is not established. But contrary to it by means of mass ringing by the scientist it was succeeded to learn approximate age for several bird species. It was found out that from 10 thousand banded ducks up to twenty years only one lives. In the majority the trade bird species perish at young age. Among the general causes of death of game birds the large role is played by a human factor.
Official long-livers among birds
Today there are data on life expectancy about 70 bird species. It is so authentically known that the African ostrich lived 40 years, a silvery seagull 44 years, an albatross 46, a sea eagle-belokhvost of 48 years. The fifth ten life exchanged a royal signature stamp - 52 years, a raven - 51 year, an eagle owl - 53. Advanced bird's years were reached a goose of gray 65 years, scare the macaw - 64 years. The most for certain known to ornithologists the case of longevity of birds belongs to a large predator — the condor living in the South American Andes. In 1892 it was brought to the Moscow zoo already rather adult. It is registered that the condor male fell in 1961, having lived nearly 70 years in Moscow Zoo and if to consider that predators receive adult plumage only by fourth year of life, then for certain the condor long-liver lived not less than 75 years.