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Whoopers work to survive

By Victoria Advocate
March 17, 2010 at midnight
Updated March 16, 2010 at 10:17 p.m.

A mated pair of whooping cranes search for food in the marsh at Aransas National Wildlife Refuge.  Theylook for roots, tubers, fiddler crabs, small mammals and reptiles to supplement their diet of blue crabs. This helps them make it through the winter and prepares them for their migration to Canada starting this month.

By Ray Kirkwood

The whooping crane has been a symbol of Texans' love of the wild for many years.

This magnificent bird nearly vanished from the earth during the 1930s and '40s.

But, due to good fortune and much hard work by Texans and Canadians, the whooping crane has recovered to a record 270 birds in the fall of 2008.

However, in the winter months of 2008 and 2009, things went very wrong in South Texas, and it hasn't been much better this winter.

The whooping crane is an omnivore - it can and will eat nearly anything. But in order to thrive, it needs an abundance of blue crabs, which are found in the waters along the coast during the winter.

And not just any blue crab. Size matters and silver-dollar size is about right.

Now, at that stage of the blue crab's life, it needs water that has some salt in it, but is not nearly as salty as the waters of the Gulf of Mexico.

Also, when the water is at the right salinity level, the whooping crane can drink it. What happens when the water gets too salty?

The crabs disappear, and the cranes must fly inland to find a fresh water pond to drink from.

The whooping crane is deprived of the staple in its diet, the blue crab, and the whooper must expend extra energy just to get a drink of water. Of course, it is around these freshwater ponds that the bobcats and alligators hang out.

If you were in South Texas last winter, you know that it was one of the worst droughts in history. We did not have any significant rainfall in nearly two years.

This fact alone would have made the waters of the whooping cranes' habitat saltier. But this situation has happened before, and the cranes survived the dry spell.

But the drought was not the major reason for the whoopers' problems. The nearly dry Guadalupe River was. Never before has this spring-fed river been so low. It's the flow from this river that keeps the salinity level of the water stable for the crabs and cranes.

Last winter, coastal waters were much saltier than the Gulf of Mexico because of a combination of the drought and low water flow from the Guadalupe.

The blue crabs disappeared and the whooping cranes got hungry and thirsty. Twenty-three whoopers died in all.

The migration brought 270 whooping cranes in the fall of 2008 and only 247 left here last spring.

This winter, the rains came too late. The blue crabs have not had time to reproduce, so the whooping cranes are searching elsewhere for food.

The current amount of rainfall has enabled the cranes to drink the water. While none have starved, one baby died.

As these most famous of winter Texans get ready to make their long trip back to their summer home in Canada, they are not as strong and healthy as they should be.

Ray Kirkwood is a certified Texas Master Naturalist and whooping crane specialist. He is a colleague of Master Naturalists Paul and Mary Meredith. Contact them at paulmary0211@sbcglobal.net.

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