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Tuesday, April 3, 2012

Another early migrant: Whooping Cranes

U.S. Fish and Wildlife Service photo of Whooping Cranes


You can add yet another species to the list of birds that are heading north earlier than usual this year. The endangered Whooping Cranes are leaving their winter home on the Texas coast at least a month earlier than usual. Some of the birds have already made their way as far north as South Dakota, on their way to their summer home in Canada.

It was an unusual winter all way around for the cranes. First, the flock that arrived in Texas was larger than it had been in the memory of living observers. Second, when they got here, they found a landscape, including their habitat, that had been devastated by drought and wildfires. That was a bad combination that did not bode well for a successful winter, but the cranes proved themselves adaptable. They responded by expanding their ranges to areas where they had not been seen before in winter. Mostly, they moved out into areas adjoining their usual ranges at Aransas Wildlife Refuge, but nine of the big birds - six adults and three chicks - even spent the winter in Central Texas near Granger Lake!

This winter's experience of the cranes is just more evidence for my theory about why birds are among the most successful animals on earth: They are adaptable. Even more importantly, they can fly. If things are not working out for them in one location, they move on in search of a more amenable spot. And they can readily respond to changing climate conditions.

So, now we've heard from the smallest North American birds, the hummingbirds, and the largest, the cranes, both of which started their migration earlier than usual this year. Moreover, birds up and down the size spectrum in between those two extremes are also on the move. It will be interesting to see what effects this might have on the breeding season, as well as whether this represents a new trend in migration.  

2 comments:

  1. So interesting! We had such a mild winter and an early spring. I wonder what this summer will be like?

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    1. We hit the high 80s in March, so that doesn't bode well for August, Steph!

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