Global trends in bird species survival

Since 1988, bird species have faced a steadily increasing risk of extinction in each of the major regions of the world, although the change is more rapid in some regions than others. Between 2008 and 2012, the rate of decline slowed in most regions, although there has been a particularly sharp decline in the Neotropical realm.^{Footnote [1]} In the Nearctic realm, which includes Canada, the status of birds is better than in other regions of the world, but continues to decline.

Red List Index of bird species survival by biogeographic realm,^{Footnote [1]} 1988 to 2012

How this indicator was calculated

Note: The Red List Index (RLI) is currently available for birds, mammals, amphibians and corals, and is under development for other taxa, but the time series of data is longest and richest for birds. RLI values range from 1 (no species at risk of extinction in the near-term) down to zero (all species are extinct). The moderately low sensitivity of the index is balanced by comprehensive geographic coverage and representation of bird species.
Source: BirdLife International and the International Union for Conservation of Nature (IUCN) (2013). Data are current as of end 2012. Terrestrial biogeographic realms from the World Wildlife Federation (WWF) (2001), global generalization from the United Nations Environmental Programme (UNEP).

The Red List Index, based on the IUCN Red List of threatened species, is an indicator of biodiversity trends. It measures the overall extinction risk for a set of species using Red List categories of extinction risk.^{Footnote [2]} Risk is assessed based on standardized criteria, using information and data from a variety of sources. Using categories means the RLI reflects only broad changes in extinction risk. The index is not affected by species that are declining slowly, for example, or by those that have depleted populations but are not near extinction. As a result, any change in the index should be seen as biologically significant.

Declines in the status of birds are seen not only across realms, but also across all habitat types, including terrestrial, freshwater and marine ecosystems. Declines are also seen across most bird species groups, such as waterbirds, game birds, raptors and parrots. Seabirds such as albatrosses and large petrels have experienced particularly rapid deterioration since 1988,^{Footnote [3]} largely due to the expansion of commercial longline fisheries; this contributes to the particularly low Red List Index value in Oceania. In Canada, the group of birds showing the strongest declines are aerial insectivores, that is, birds that eat mainly flying insects, such as swallows; grassland birds and shorebirds are also declining sharply.^{Footnote [4]} In contrast to global trends, however, colonial seabirds such as the Northern Gannet are doing well, and waterfowl and raptors are recovering from past declines.

The most serious threats to bird species worldwide are habitat loss and fragmentation due to agriculture, logging and other types of development.^{Footnote [5]} Invasive species, hunting and trapping, pollution and climate change are also major threats.

Several Canadian bird species have undergone population changes that have resulted in changes to their Red List category of extinction risk during 1988-2012. Kirtland's Warbler has improved in status, while the Greater Prairie Chicken, Black-footed Albatross, Long-tailed Duck, Semipalmated Sandpipier, Kittlitz's Murrelet and Chimney Swift have all declined.^{Footnote [6]} Note that the International Union for Conservation of Nature Red List Index assesses the global status of species, which may differ from their status within particular countries.

Related indicators

• Population status of Canada's migratory birds
• Trends in Canada's bird populations
• Canadian species index
• Changes in the status of wildlife species at risks

Other information

• Birdlife International Datazone: factsheets for the world's birds
• Birdlife International (2013) State of the world's birds: Indicators for our changing world
• Butchart SHM et al. (2004) Measuring Global Trends in the Status of Biodiversity: Red List Indices for Birds. Public Library of Science Biology 2(12):e383. doi:10.1371/journal.pbio.0020383.
• Butchart SHM et al. (2005) Using Red List Indices to measure progress toward the 2010 target and beyond. Philosophical Transactions of the Royal Society B 360(1454):255-268.
• Butchart SHM et al. (2007) Improvements to the Red List Index. Public Library of Science Biology 2(1):e140. doi:10.1371/journal.pone.0000140.
• The IUCN Red List of Threatened Species
• The State of Canada's Birds 2012
• Status of Birds in Canada - 2011