Ecological crisis: One-fourth of birds in U.S., Canada lost in last 50 years

(CN) – Wild bird populations in the United States and Canada have shrunk by 2.9 billion, or one in four, in the last 50 years, according to a new study published Thursday.

The study, published in the academic journal Science, documented how a team of scientists collected and analyzed environmental data from weather radar stations going all the way back to the early 1970s in the hopes to better understand the state and health of bird populations around North America. What they discovered was that wild bird populations have in recent decades undergone a massive and troubling reduction in size.

The study reports that since the 1970s, bird populations have reduced in size by roughly 29% in the United States and Canada alone, meaning one in four birds have been lost in a mere half-century.

Researchers such as Ken Rosenberg, lead author of the study and a senior scientist at the Cornell Lab of Ornithology and American Bird Conservancy, contend that because bird populations are often used as living indicators of general environmental health, this kind of unparalleled decimation of bird populations could signal the start of an ecological crisis.

The study reports that the kinds of bird populations being decimated over the last 50 years come from a wide variety of different species.  From small house sparrows to old world finches, to yellow-breasted meadowlarks and even common barn swallows, birds of all kinds have found their populations drastically cut short. Grassland birds in particular, the study points out, have been hit the hardest, losing just over half of their population in recent decades.

While the study does not fully determine the cause of this reduction, it points to the hands of humankind as a likely factor. The study says that as human activity continues to negatively affect wildlife and wild habitats continue to shrink, it is only inevitable that wild animals find it more difficult to a sustain healthy, growing populations.

Researchers note that as other bird populations around the world are experiencing similar population drop-offs, such a widespread problem must kickstart larger talks on bird conservation efforts. The study reports that with conservation efforts of the past showing signs of success, such as the population bounce-back of the bald eagle that took place after harmful pesticides were banned, new efforts may have the potential to be successful as well.

Rosenberg was unavailable for an interview by press time.