The size of bird populations in Canada, on average reduced by 12% since the beginning of the seventies, according to a report released Thursday, "Birds of Canada 2012."
According to ornithologists, only lives in Canada 451 species of birds that nest in the country, and winter in some other countries. While 66 species of birds in some degree threatened with extinction. In its report, ornithologists analyzed data on birds in eight major regions of Canada. The main reasons for the reduction of scientists believe human activities: deforestation, use of pesticides in agriculture, construction landscape.
"With the general decline of populations of birds, 44% of the number of birds has decreased, almost a third of the representatives has increased, the remaining 23% of the species showed no significant change in numbers. Most significant population decline affected meadow and insectivorous birds. Meanwhile, advances in the preservation of species, such as birds of prey, were related to the ban on the use of pesticides in agriculture. Due to this, the number of peregrine falcon, osprey and bald eagles. also increased populations of sea birds and waterfowl, "- says the report.
As explained by the authors of the report, almost on the verge of extinction in the early 20th century it was the white heron feathers which were used to decorate women's hats. Reduction of its strength was stopped only after the birds in the list of protected species.
In addition, ornithologists say complicated state populations of waterbirds, such as waders. Their number fell by almost 50%. According to the report, make a huge water birds flying from wintering sites to breeding grounds, while they are necessary stopover on the road trip. People often destroys the natural habitat of birds near rivers, lakes and wetlands, besides birds are shot by poachers.
"Only 22% of Canadian birds spend all year in the country, so the need for international efforts to preserve the species," — the report says.
The paper also clarify that the 33% of Canadian birds are sent to winter in the U.S., 23% of departures on time in Central America, Mexico and the Caribbean islands, 15% — to South America. However, about 7% migrated to Europe and Asia.