Bad weather has been linked to a 57pc increase in animal deaths at Dublin Zoo, where a number of endangered species were among 83 creatures that died in 2018.
They included two of the zoo's five eastern bongos - critically endangered antelopes that are native to Africa - and a female ring-tailed lemur, of which there are thought to be only 2,000 left in the wild.
Three grey wolves also died at the zoo during the 12-month period, along with a female ostrich, three slender-tailed meerkats and three okapis, an endangered species also known as a zebra giraffe.
Two endangered white-naped mangabeys were also among the losses, one of which died within 30 days of its birth, along with a male Rodrigues flying fox, which is an endangered species of bat.
The most high-profile death at Dublin Zoo in 2018 was that of Lena, one of its five western lowland gorillas, who was reported to have died from an unknown illness.
She was 35-years-old and had given birth seven times since her arrival at the zoo in 1988.
A Humboldt penguin, which has a "vulnerable" conservation status, also died, along with one of two little egrets, a type of small heron.
Fifty-three animals died at the zoo in 2017.
A spokesman said 40 of the deaths in 2018 were of neo-natal or pre-fledge age, 34 of which were pre-fledgling birds. In 2017, 17 of the 53 deaths related to animals of neo-natal or pre-fledge age.
"Therefore, the increase in deaths between 2017 and 2018 was due to an increase in deaths of pre-fledgling birds," the spokesman said.
"This increase could have been the result of adverse weather conditions in the peri- od shortly after hatching, a phenomenon that also occurs in the wild.
"The physical and psychological well-being of the animals in our care is paramount to Dublin Zoo. However, as in the wild, animals also die in human care.
"We mourn the loss of every animal."