Friday, December 19, 2008

Species at risk from climate change


A recent article from the New Scientist reports on a new study released by the World Conservation Union on species susceptible to climate change impacts. The highlights are not pleasant.

Of 17,000 assessed species, over 7000 could become threatened with extinction because of climate change.

Ninety "life history traits" - essential elements of a species' behaviour or lifestyle - were identified that were likely to be affected by a change in a species' local climate. These included:

* Requirements for a specialised habitat: some amphibians depend on a stream or pond, so if that dries out there is no way they can survive;
* Specific environmental tolerances: many corals cannot survive if the water temperature or pH exceeds a certain threshold;
* Dependence on environmental cues: many species depend on changes in day length or rainfall to start breeding;
* Dependence on interactions with other species: without prey a specialised predator cannot survive; lichen depend on trees, and many plants on their pollinators;
* Ability to disperse: as their historical habitats become increasingly hostile, species will need to move to new territories but may not be able to do so if there is something - a body of water, perhaps - in their way.

Half of all amphibians, one-third of all birds and over two-thirds of assessed corals are susceptible to climate change.

Within each group, some species are more likely to suffer. Among the birds, all albatross and penguin species were deemed susceptible. Herons, egrets, ospreys, kites, hawks and eagles, on the other hand, are less so.

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