Keepers at a Queensland zoo are heartbroken after the death and euthanasia of Australia's last remaining lion-tailed macaques on the weekend.
The Rockhampton Zoo's director and curator, Liz Bellward, said Lhasa, 29, died in her sleep and the decision was made to euthanase her companion Dana, 21, as a result.
"If we had decided to keep Dana alive, to keep her on display because she's the last lion-tailed macaque in Australia, we'd be doing the wrong thing by her," she said.
In a statement, the Zoo and Aquarium Association (ZAA) said considering the circumstances, euthanasia "seemed appropriate".
It is believed Lhasa died from natural causes.
"The keepers found her curled up in the sleeping position on her heated platform in the morning when they came in," Ms Bellward said.
"We're still waiting on the results from the vets to confirm that but we're pretty confident that's what happened at 29, she was a very old girl.
"In the wild they normally only live to about 20."
Dana and Lhasa shared an enclosure with otters at the council-owned zoo.
"For Dana to be living on her own, would cause severe psychological stress and we didn't want to put her through that, so we made the decision to euthanase her that day," Ms Bellward said.
"To house a monkey on their own is a major welfare concern because they're a highly social species.
Rehoming not an option
Ms Bellward said the zoo had discussed the possibility of rehoming Dana in Australia or overseas, but ultimately it was not a viable option.
She said no other lion-tailed macaques lived in Australian zoos because they were classified by ZAA "as a phase-out species" and introducing Dana to different monkeys would put her in danger.
"They interact differently, they communicate differently," Ms Bellward said.
"Which would mean not only would she have mental distress but she'd have physical distress and even a high chance that they may kill her.
"We'd rather she passed in a peaceful way rather than put her through all that trauma."
A series of unfortunate events
The loss of the duo was another devastating blow to the zoo after the euthanasia of 40 birds due to a salmonella outbreak in March and a second chimpanzee miscarriage in April.
"It has been a very tough year, we all have our moments," Ms Bellward said. "Different keepers obviously have different relationships with the animals they work with."
While keepers were devastated, Ms Bellward said they understood the realities of working in the industry.
"They both were very old girls at 21 and 29, we knew this was coming, we had discussed this for the last couple of years, of what we would do when we were faced with this situation.
"It doesn't make it easier when you let them go but you are semi-prepared for it."
Decision 'seems appropriate'
ZAA executive director Nicole Craddock said the decision to euthanase an animal was not taken lightly.
"ZAA considers euthanasia as a necessary practice when expert zoo staff determine an animal is suffering from disease, ailments, detrimental psychological state or severe pain/stress which cannot be adequately alleviated."
Ms Craddock said the zoo had been in discussions with ZAA regarding the situation.
"Rockhampton Zoo is accredited for positive animal welfare under the ZAA Accreditation Program and has demonstrated their commitment to the wellbeing of animals under their care," she said.
"Based on the information we were provided, (signs of distress, solitary animal, likelihood of re-socialising an aged animal, likelihood of finding a companion in the region) the decision to euthanase seems appropriate."
