Smilodonfatalis
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- May 5, 2013
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Ice Age-Influenced Avian Speciation in North America | GeorgiaBeforePeople
During the Miocene forested environments existed over most of North America. When Ice Ages began to occur, about 5 million years ago, the climate became drier. This resulted in a desert grassland habitat, unsuitable for forest birds, across the middle of the continent, isolating eastern birds from western birds. This explains why there are 22 species of eastern birds with similar but distinct western counterparts such as eastern and western bluebirds, scarlet and western tanagers, eastern and western peewees, etc.
Glaciers also provided a barrier that caused north-south speciation between northern shrikes and loggerhead shrikes, boreal owls and saw-whet owls, and 5 other pairs of similar but distinct species.
During the Miocene forested environments existed over most of North America. When Ice Ages began to occur, about 5 million years ago, the climate became drier. This resulted in a desert grassland habitat, unsuitable for forest birds, across the middle of the continent, isolating eastern birds from western birds. This explains why there are 22 species of eastern birds with similar but distinct western counterparts such as eastern and western bluebirds, scarlet and western tanagers, eastern and western peewees, etc.
Glaciers also provided a barrier that caused north-south speciation between northern shrikes and loggerhead shrikes, boreal owls and saw-whet owls, and 5 other pairs of similar but distinct species.
