|
Since 1985, private zoos at seven locations in the United States and Canada, including the Henry Doorly Zoo in Omaha, have established captive breeding populations, thus minimizing the potential for disease or other disaster to eliminate the entire species. The captive breeding program has been successful, with the first captive-raised animals reintroduced back to the wild in Wyoming in 1991. Additional animals were released at the same Wyoming site in 1992, 1993 and 1994, with sites in South Dakota and Montana also receiving ferrets in 1994.
Although the reintroductions are encouraging, problems are still being encountered. Fewer animals have been released at each site than biologists would like, and survival of released animals has been low.
Funding is also a problem for ferret recovery. The Sybille facility has produced about 75 percent of the young ferrets since 1987, but production has been expensive. The Wyoming Game and Fish Department is facing budget problems and likely will scale back captive breeding activities. Federal funds for endangered species recovery have always been limited, and budget cuts are likely. Future captive breeding activities might have to rely more on the zoos and other private funding sources.
Black-footed ferret recovery efforts in Nebraska since the mid-1970s have centered on the investigation of ferret reports in the wild and the monitoring of prairie dog colonies. Prairie dogs have been surveyed to identify areas where ferrets might still occur in the wild and to determine potential ferret reintroduction sites. For a site to be considered, a complex of prairie dog colonies must occur that includes at least 1,000 acres of prairie dogs. Prairie dogs can occur in one or more colonies, but colonies cannot be separated by more than about 4.3 miles, the maximum distance ferrets were found to travel in one night.
Although several potential complexes were identified in Nebraska, recent prairie dog control efforts have reduced colony acreage considerably, significantly affecting their suitability for ferrets. Potential prairie dog complexes must be monitored routinely to assess any changes in their suitability as ferret reintroduction sites. Sites in Nebraska would then be compared with sites in other states to determine the best sites for reintroduction.
Fortunately, in 1995, the Nebraska Legislature repealed a law in force since the 1930s that required annual extermination of prairie dogs on all private and state-owned land. This action eliminated a large obstacle to the reintroduction of the ferret. Another possible problem for ferret recovery in Nebraska is one of land ownership. Unlike most states within the historic range of the ferret that contain large amounts of federal land, most land in Nebraska is in private ownership. It will require the cooperation of a large number of landowners before ferrets can be released.
|
|
