Shocking Decline In North American Bird Population

Since 1970 the bird populations of North America have suffered a net loss of approximately 2.9 billion individuals. That's a 30% decline in less than 50 years!

These numbers are not wildly different from the decline in worldwide insect biomass measured in a study from earlier in 2019. But lead author Ken Rosenberg of the Cornell Lab of Ornithology and American Bird Conservancy found the scope of species and total number of individuals lost unexpected. This, I think, shows that even scientists working in areas affected by climate change aren't fully aware of it's impact. It's also interesting that these kinds of comprehensive studies of wildlife populations are only just happening in the second decade of the 21st century.

Photo by Laitche [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)

This study is the first comprehensive attempt to understand the change in North American bird populations in the decades since 1970. Rosenberg's team compiled data from a number of sources; including USGS and Canadian Wildlife Service bird surveys, citizen-science data, and even weather radar station data collected over a recent 10-year period. The 143 NEXRAD weather radar stations are able to measure the entire biomass of bird migrations in the spring and fall. 

The researchers found broad decreases across both threatened and common species, and across all habitats. Certain categories of birds were hit especially hard; including grassland birds (53% decline), forest birds, and shore birds. If there is a positive side to this story, it's that waterfowl (for example, geese, ducks, swans) have increased over 50% across the period of the study. According to study co-author Michael Parr, president of the American Bird Conservancy, it's that the reason for the increase in waterfowl populations is directly related to the actions of recreational duck hunters. They noticed a decline in duck populations and they called for and supported legislation to help protect the wetlands that supported those birds.   

In current times, we must take similar action; including calling for legislation to ban the use of neonicotinoid pesticides - which will help protect insects as well as birds. 

Action:
The Environmental Protection Agency banned 12 neonicotinoid pesticides earlier in 2019, but that still leaves 47 other pesticides that contain neonicotinoids on the market. There is a bill (H.R. 1337) in the House to "to cancel the registrations of any pesticides containing imidacloprid, clothianidin, thiamethoxam, dinotefuran, acetamiprid, sulfoxaflor, flupyradifurone, or fipronil until the board has made a determination that such insecticide will not cause unreasonable adverse effects on pollinators based on findings that include results of studies of neonicotinoids and the effects of residues, repeated applications, and multiple chemical exposures." Please take a few moments to urge your elected representatives to take action on neonicotinoid pesticides today: https://www.usa.gov/elected-officials/

Sources:
https://science.sciencemag.org/content/365/6459/1228/   
https://www.scientificamerican.com/article/silent-skies-billions-of-north-american-birds-have-vanished/
https://www.sierraclub.org/sierra/3-billion-birds-across-many-species-have-disappeared-north-america/
https://www.usnews.com/news/top-news/articles/2019-09-19/bird-numbers-plunge-in-us-and-canada-with-people-to-blame/
https://www.the-scientist.com/news-opinion/north-american-bird-populations-decline-66454/
http://www.startribune.com/where-have-the-wild-birds-gone-3-billion-fewer-than-1970/
https://www.congress.gov/bill/116th-congress/house-bill/1337/