Enten skal de kunne tilpasse sig de ændrede forhold, ellers også forsvinder de – og mange arter er standfugle, som ikke bevæger sig særlig langt, konkluderer videnskabelig undersøgelse.
Up to 900 species of tropical land birds around the world could become extinct by 2100, researchers say, according to BBC online Monday.
The finding is modelled on the effects of a 3,5 Centigrade Earth surface temperature rise, the Biological Conservation Journal paper “Elsevier” shows.
Species may struggle to adapt to habitat loss (tab af levesteder) and extreme weather events, author Cagan Sekercioglu says.
Mountain, coastal and species unable to get to higher elevations could be the worst affected.
Depending on future habitat loss, each degree of surface warming could affect between 100-500 species, says Mr Sekercioglu, assistant professor of biology at the University of Utah.
“The problem is most species in the world are highly sedentary (standfugle)… the public perception is most birds are migratory (trækker) and so climate change is not a problem for them,” he says.
Mr Sekercioglu says tropical mountain species are among the most vulnerable. He says bird species will need to be able to adapt physiologically to changes in temperature and be able to move to higher altitudes if they are to survive.
He says cooler, more humid forests could recede (trække sig) higher up mountains and combined with human settlements at higher altitudes, forest habitat could “get pushed off the mountain”.
This would create “an escalator to extinction” he says.
“Coastal species are also vulnerable – as coastal forest can be sensitive to salinity (tilsaltning), and these forests can get hit harder by hurricanes and typhoons, and these events are also expected to increase.”
Birds in extensive lowland forests with few mountains in places such as the Amazon and Congo basins – may have trouble relocating, while tropical birds in open habitats such as savanna, grasslands, scrub and desert face shrinking habitats.
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http://www.sciencedirect.com/science/article/pii/S0006320711003880
