Nearly three billion fewer birds in North America since 1970

September 19, 2019

North America has lost nearly three billion birds since 1970, according to a new report, which also details widespread population declines among hundreds of North American bird species, including those once considered abundant. The results signal a long-developing yet largely overlooked biodiversity crisis occurring in avifaunal habitats across North America. Human impacts have contributed to an increase in global extinctions. Research focused on understanding extinction is underway, but much of it fails to recognize ongoing declines in "abundance" within still-common species, even as such declines can have significant ecological, evolutionary and economic impacts. "Given the current pace of global environmental change, quantifying change in species abundances is essential to assess ecosystem impacts," Kenneth V. Rosenberg and colleagues say. Evaluating these declines requires large and long-term datasets, which do not exist for most animals. However, long-term, detailed records do exist for bird populations. Using multiple standardized bird-monitoring datasets, Rosenberg et al. analyzed the net change over recent decades in numbers of birds for 529 species in the continental United States and Canada. Their results show a loss of nearly one in four birds since 1970 - a net loss of 2.9 billion birds. According to the authors, more than 90% of this loss can be attributed to 12 bird families, including songbird species like sparrows and warblers. However, not all species are on the decline; some bird species, including raptors and waterfowl, showed population gains - likely due to focused conservation efforts and Endangered Species legislation. Similar strategies for other species could avert the potential collapse of North American avifauna, the authors say. To expand their analysis, the authors used migration data from the NEXRAD radar network to estimate long-term changes in nocturnal migratory passage. The results, similar to those from the ground-based bird-monitoring datasets, reveal a steep decline for migrating birds over a recent 10-year period, particularly in the eastern U.S.
-end-


American Association for the Advancement of Science

Related Bird Species Articles from Brightsurf:

Abundance of prey species is key to bird diversity in cities
A team of scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) and the Technische Universität Berlin (TUB) collaborated to analyse breeding bird data from the Senate of Berlin gathered by citizen scientists.

Shifts seen in breeding times and duration for 73 boreal bird species over 40 years
In a new study out this week, a team including forest ecologist Malcolm Itter at the University of Massachusetts Amherst reports finding ''clear evidence of a contraction of the breeding period'' among boreal birds in Finland over a 43-year span for which good quality data were available.

Two new species of parasite discovered in crabs -- discovery will help prevent infection of other marine species
Two new species of parasite, previously unknown to science, have been discovered in crabs in Swansea Bay, Wales, during a study on disease in the Celtic and Irish Seas.

Marine species are outpacing terrestrial species in the race against global warming
Global warming is causing species to search for more temperate environments in which to migrate to, but it is marine species -- according to the latest results of a Franco-American study mainly involving scientists from the CNRS, Ifremer, the Université Toulouse III-Paul Sabatier and the University of Picardy Jules Verne -- that are leading the way by moving up to six times faster towards the poles than their terrestrial congeners.

Analysis of bird species reveals how wings adapted to their environment and behavior
Bird wings adapted for long-distance flight are linked to their environment and behavior, according to new research on an extensive database of wing measurements, led by the University of Bristol.

Discovery of smallest known mesozoic dinosaur reveals new species in bird evolution
The discovery of a small, bird-like skull, described in an article in Nature, reveals a new species, Oculudentavis khaungraae, that could represent the smallest known Mesozoic dinosaur in the fossil record.

One species to four: New analysis documents new bird diversity in the Pacific
New findings from UMBC researchers and colleagues suggest several island bird populations in the Pacific that were previously designated as a single species actually comprise up to four distinct species.

APS tip sheet: Using bird song to determine bird size
An analysis of a bird species' unique rasps shows how sound fluctuations in birds' songs might reveal details about birds' body sizes.

Directed species loss from species-rich forests strongly decreases productivity
At high species richness, directed loss, but not random loss, of tree species strongly decreases forest productivity.

How bird flocks with multiple species behave like K-pop groups
Peer into a forest canopy, and you will likely spot multiple bird species flying and feeding together.

Read More: Bird Species News and Bird Species Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.