A swift parrot photographed on Bruny Island. (Wikimedia Commons File/JJ Harrison/HO)

Animal rights group PETA has offered a $1,000 reward to help catch the intruders who decapitated birds and released other animals, some of them rare, at a zoo in Australia.

Nine birds were mutilated at the Tasmania Zoo last week, and another 60 animals were reported missing, reports 9News.

The locks on more than 30 animal enclosures were cut and the doors flung open. A kangaroo is missing after the fence of its pen was cut.

Among the birds that had their heads torn off was a swift parrot, which is listed as endangered. Also released were a population of quolls - a rare indigenous mammal the zoo was trying to breed.

The privately-owned zoo bills itself as the largest collection of native and exotic animals in Tasmania, with more than 80 species of birds, Tasmanian devils, penguins, wombats, and monkeys in addition to kangaroos and quolls.

The zoo is now accepting donations to help repair the damage and replace the missing animals.