Monday, March 31, 2008

Greater White-fronted Goose on the increase


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As discussed on the Wisconsin Birding List this week, the Greater White-fronted Goose is most definitely on the increase. See the graphic above, which represents birds-per-party-hour for CBC records for this species over the past 30 years. White-fronts, like Snow Geese and Ross's Geese are sometimes collectively described as "light geese", and they all have been increasing due to a number of factors: increasing winter temperatures, good feeding conditions in the southern Great Plains and Gulf states due to changes in agricultural practices, increased number of refuges compared with a half-century ago --- all of which create the conditions for better over-winter survival. In turn, when birds in better body condition arrive on a warming low Arctic tundra habitat, they over-eat the vegetation there, and are in fact damaging their habitat due to their increasing numbers. Damage to their breeding grounds is in some cases so severe it can be seen from satellite images.

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