Bird Populations Plummet in North America
By: Alina Dang
The overall bird population in North America has dropped 29% since 1970, decreasing by around three billion. Due to the stories told by bird watchers and guesses by scientists, researchers were sure that the population was declining. Now, they have the evidence.
The loss was particularly extreme for grassland birds including more common species such as sparrows and finches. The grassland birds’ population fell by 53%. The decline of these birds surprised researchers due to their well-known ability to adapt to human landscapes.
Researchers tracked population changes for 529 bird species in the continental U.S. and Canada using the data from a span of around five decades. Of the tracked species, 419 had a population decrease, while only 100 experienced small increases. Researchers used bird-monitoring data sets and 143 total weather radars to track the birds.
The discoveries show a new and unexpected evaluation of the bird population across the continent which has been described as unprecedented by researchers and scientists. The research also is a warning of the general health of the environment, reflecting what may be happening in other less closely observed animal populations, said Ken Rosenberg, a conservation scientist at the Cornell Lab of Ornithology who was the study’s lead author., “Birds are literally the canary in the coal mine.” He said.
The reasons for the decrease in the population are hard to figure out due to the many causes that differ from one species to another. “There is no Holy Grail,” said Nicole Michel, senior quantitative ecologist at the National Audubon Society, a nonprofit conservation group. However, researchers credit the drop to the broader impact of climate change, deforestation, and shifts in agricultural practices. Meanwhile, habitat loss and the use of pesticides has had an impact on the grassland birds’ decrease in North America.
The studies said the findings in North America reflect similar declines in bird populations globally, like those of farmland birds in Europe.
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