Ted Turner's bison help save historic Texas herd

CAPROCK CANYONS STATE PARK, Texas — Six years ago, inbreeding threatened to destroy the last herd of southern Plains bison. Only 53 were left, and breeders were having trouble getting females to carry their calves to term. Tests showed that unless something was done to increase the diversity of genes in the historic herd, all the animals would be gone within 50 years.