The cases of dead polar bears at the Buffalo Zoo made U.S. inspectors fault care given to the animals and conditions in their enclosures. One bear died after apparently falling into an empty pool, while the others had swallowed pieces of stone and plastic.
The Department of Agriculture's recent inspection report, which also cited the death of a hyena found pinned under a boulder, moved the animal rights group People for the Ethical Treatment of Animals to seek revocation of the zoo's national accreditation.
"The zoo's most recent ... inspection reports reveal an appalling pattern of carelessness, negligence and incompetence that has resulted in a great deal of animal suffering as well as numerous animals' deaths," a letter from PETA to the national Association of Zoos and Aquariums said.
Zoo officials declined Wednesday to comment on specifics of the August report, but said in a statement the incidents were under review. The zoo, the third oldest in the United States, accused PETA of "gross misrepresentation of facts."
The first polar bear death was on Aug. 21, 2006, when Danny, an adult male, was found dead in the bottom of an empty pool about 6 feet (1.8 meters) deep. The bear had been anesthetized for treatment of fly bites to his ears and died after a keeper left the holding area for two hours, the report said.
"A safe environment needs to be provided when animals are anesthetized to prevent injury during this period. Correct immediately," an inspector wrote.
The report went on to note "several instances of garbage bags and plastic items observed in the polar bear exhibit as well as an incident of rat poison bait observed in the exhibit."
Such debris was cited in the deaths of polar bears Kelly in November 2006 and Becky in February 2007.
Kelly's stomach contained "a fair amount of stone material and a chunk of plastic `toy"' while Becky died a day after undergoing stomach and bowel surgery to remove "plastic rims" from her stomach, the report said. Keepers suspected she swallowed a garbage bag.
The report said a fourth polar bear, Kinapak, may have eaten parts of a plastic garbage bag and rat bait found in his exhibit in January.
The hyena was found suffocated in its enclosure May 18. The zoo was instructed to ensure the structural soundness of its outdoor enclosures.
A spokesman for the Association of Zoos and Aquariums was unavailable for comment Wednesday, but told The Buffalo News the zoo had responded quickly to issues raised by the association last year.
"We have a lot of confidence in the expertise of the veterinarians and staff at the Buffalo Zoo," spokesman Steve Feldman said.
The USDA report also cited a series of attempts to introduce a pair of Amur tigers that resulted in fights and injuries to both animals, and an attempt to introduce a male maned wolf to a pup that resulted in the pup being hurt by the aggressive adult.
"Animals must be compatibly housed for their safety and well being," the report said.
The USDA conducts annual inspections of zoos and animal parks and returns to follow up when they find problems, spokeswoman Jessica Milteer said. She said the agency is working with the zoo on the issues raised in the report.
Established in 1875, the Buffalo Zoo is five years into a 15-year, $75 million (50 million EUR) renovation plan under the direction of president Donna Fernandes.
"The health and welfare of the 1,200 animals in our care is, as always, the top priority and driving principle in everything we do at the Buffalo Zoo," Fernandes' statement said. "That will never change."