In September, the American Audubon Society released a disturbing report which attempted to describe how the birds of North America could be impacted by climate change over the next 65 years.
Some people may already be aware that birds are facing huge challenges to find appropriate areas where they can continue to thrive despite increasing loss of habitat and pesticide use. A variety of studies indicate that global warming could result in a two to four degree temperature rise by the end of this century accompanied by a 0.2-0.6 metre increase in sea level.
The Audubon study, summarized on their website (www.audubon.org), shows the impacts of global warming on birds could be profound. Of a total of 588 bird species which spend both their winters and summers in North America, 314 are expected to lose over half of their habitat by 2080. One of the reasons why so many birds will be affected by global warming is that most species of birds have evolved to be habitat specialists. Thus, they rely on finding a certain type of habitat and food. Their needs often put them in conflict with people who have tended to cut down forests, drain wetlands and convert grasslands into agricultural fields.
In addition, many birds are migratory, which means they must rely on finding suitable habitat along lengthy migration corridors. Climate change is altering many of the areas upon which birds rely.
Take, for example, whooping cranes. These elegant birds were once hunted almost to the point of extinction. They were known to congregate along the Texas coast each winter but, for many years, the area where they nested remained a mystery. In 1937, when only 21 birds remained in the flock, the American government initiated a huge effort to protect and restore their population. The first step taken was to protect their winter habitat as the Aransas National Wildlife Refuge. When, in 1954, their summer nesting area was fortuitously discovered to be in the wetlands of Wood Buffalo National Park on the northern boundary of Alberta, the Canadian Wildlife Service also got involved.
While this flock of whooping cranes now numbers about 350, climate change is threatening their habitat. For example, recent severe droughts in Texas have reduced fresh water inflow in the Aransas Refuge, which is reducing their vital winter food supply. A severe hurricane along the Gulf coast in Texas could also damage their habitat. During migration these cranes rely on wetland habitat along their migration corridor. One important area lies along the Platte River in Nebraska where the irrigation needs of farmers is reducing the amount of suitable river habitat for cranes.
These cranes also migrate over the tar sands of Alberta which increases the risk that storms might force some birds to the ground in areas of polluted tar sand pools. While it is not known if global warming could affect their wetland habitat in Wood Buffalo National Park, it is clear that climate change is already altering some of their critical habitat.
To inform people about the dangers of a rapidly warming world and actions we should be taking to reduce fossil fuel emissions, the Tri-Cities LeadNow group is hosting an upcoming presentation by UBC professor Bill Rees. Ben West from ForestEthics Advocacy will also take part in the event. The presentation will be held on Tuesday, Oct. 21 at the Evergreen Cultural Centre (1205 Pinetree Way, Coquitlam). Doors open at 6:30 pm and the presentation will begin at 7 pm. Tickets ($10) are available through evergreenculturalcentre.ca/buy-tickets.
