Reuters, March 19, 2006 DALLAS (Reuters) -  The stranding deaths of about 60 bottlenose dolphins on Texas beaches over the past three weeks has puzzled researchers and is a cause for concern during the calving season, a senior scientist said on Monday. "This is the calving season so we often have strandings at this time of the year. It's tough to be an air-breather born in the water," said Dr. Daniel F. Cowan, professor of pathology at the University of Texas Medical Branch at Galveston and director of the Texas Marine Mammal Stranding Network. "But over the last few weeks we have had about 3 to 4 times the usual mortality," he told Reuters. (This story has been widely published throughout the nation and internationally.)