Some general information on climate change and birds

Recent regional changes in climate, particularly increases in temperature, have already affected terrestrial and marine ecosystems in many parts of the world. [Source: IPCC Synthesis Report 2001] For example:

• Between 1971 and 1995 the laying date for many species of British birds has shifted earlier by an average of nine days. [Source: Nature 388: 526]
   
• Adelie penguin breeding numbers have declined over the last 40 years. This decline is thought to be tied to a reduction in the frequency of years with extensive heavy winter sea ice in the Antarctic making suitable feeding sites too scarce or distant. At the same time, Chin-strap Penguin numbers have increased. [Source: Polar Biology 11: 525-531]
   
• Meta-analyses on 143 previously published studies reveal a consistent temperature-related shift, or 'fingerprint' in a number of species from around the globe. More than 80% of the 1,400 plant and animal species studied show changes in the direction expected on the basis of known physiological constraints of species. Of those species showing a change in spring phenology (earlier arrival, for example), the average rate of change has been approximately 5 days earlier per decade with an average study length of three decades. One of the biggest changes was in the breeding of the Common Murre which has advanced by 24 days per decade. [Source: Nature 421: 57-60].
   
• Biodiversity will be affected by climate change and sea-level rise, with an increased risk of extinction of some species. Significant disruptions to ecosystems from disturbances (e.g., fire, insect outbreaks) are expected to increase and changes in climate could also increase the probability of abrupt, non-linear changes in many ecosystems. [Source: IPCC Synthesis Report 2001] For example:
   
• In the Prairie Pothole region of the United States, increasing temperatures will likely result in increased drought conditions and loss of wetlands. This could lead to an almost 50% reduction in breeding waterfowl numbers. While these ducks may be able to move farther north to breed, wetlands in those areas may also be adversely affected by climate change. [Source: Climatic Change 40: 343-369]
   
• The ranges of most North American grassland birds will likely shift northward into areas currently containing forests. Unless all species (birds and plants) shift at the same rate, an unlikely prospect, then habitat may be limiting for these species in the future.  Models suggest that at least two grassland birds (Sprague's Pipit and McCown's Longspur) may face extinction. [Source: Price, J.T. In press. Potential impacts of climate change on North American grassland birds. U.S.G.S. Tech. Publication]. Current research is looking at how much habitat may be available for these species to move into.
   
• Parts of northern Minnesota and southwestern Ontario may end up with 14 fewer species of warblers than are currently found there. This could lead to increased outbreaks of some forest pests like spruce budworms. [Source: Transactions of the 66th North American Wildlife and Natural Resources Conference 371-379; Managing for Healthy Ecosystems 465-469]
   
• The range of the Baltimore Oriole may shift north until it is no longer found around Baltimore. [Source: The Birdwatcher's Guide to Global Warming]