Endangered in the wild, and in the zoo
A special panel will be set up by Congress to investigate the growing number of animal deaths at America's prestigious national zoo in Washington.
Officials from the zoo appeared before a Congressional committee to explain why up to 70 animals - some of them endangered species - have died over the last three years.
Two rare red pandas have been among the casualties, along with a hippopotamus, giraffes, a lion, zebras, an orang-utan and an elephant.
Animal rights groups have argued that many of the deaths were due to lack of care.
Congressman John Larson of Connecticut said that the zoo was a national treasure, and that it was his children who were demanding answers on what has been happening to the animals.
Inquiry to be set up
But the head of the Smithsonian Institution, Lawrence Small, which has ultimate responsibility for the zoo, said that only a few of the deaths were due to human error.
He admitted that rat poison had been buried in animal enclosures - "a bad decision, bad judgement, poorly implemented" - causing the death of two red pandas who ate it.
But he said most of the other deaths were due to "professional judgements" about animals that were old or sick or both.
And he appeared to diffuse some of the public criticism by agreeing with the Congress to set up a blue-ribbon panel of scientists from the National Academy of Scientists to investigate the deaths.
He also agreed to submit the zoo to surprise inspections from the US Department of Agriculture, which has supervisory power over all zoos in the United States except the National Zoo.
Food cut back
The zoo's director, Lucy Spellman, also appeared at the hearing.
She said that the zoo's procedures had been at fault, and that she would now personally authorise any use of chemicals at the zoo.
And she said that "any animal death affects me the most" of anyone at the zoo.
Two of the employees who had been at fault at the zoo had retired, and the third was reassigned.
But she said that many other deaths reflected the fact that the zoo had an ageing collection of animals who sometimes were difficult to treat.
Representative John Mica of Florida said that Ms Spellman was a dedicated professional who had been unfairly attacked in the press, and wondered whether there was a personal vendetta at work.
But Congresswoman Juanita Millender-McDonald of California wanted to know whether there had been more zoo deaths during Ms Spellman's tenure of office than in previous years.
Among the concerns at the zoo in past years were the deaths of two zebras, whose food was reduced until they had too little body fat to survive the winter.
Animal rights campaigners have also cited the case of a Persian onager, a relative of the horse, that died of salmonella at the zoo's conservation and research centre.
And further complaints have been made about a number of deer killed by dogs which got into their enclosure at the conservation centre.