The science behind the Zoo
Animal habitats in zoos weren't always designed to address their biological and behavioural needs but that is changing, writes CLAIRE O'CONNELL
WHEN YOU think of an elephant, what springs to mind? Beasts of burden hauling logs? Circus animals putting on a show? Our relationship with Earth’s largest land mammals has had its less-than-stellar moments, but an initiative at Dublin Zoo is putting biology first to ensure that its elephants can live and behave as naturally – and happily – as possible.
“The whole philosophy behind the house was the biology,” says Gerry Creighton, Dublin Zoo’s operations manager.
He explains how the Asian elephants, two sisters who arrived over from Rotterdam, pregnant, in 2006, and their offspring interact with the zoo team through a “protected contact” system that allows the animals to function as a matriarchal society, but still lets the zoo team care for them, from giving them pedicures to tracking their hormone cycles.
“In the old days when they designed houses here, nothing about the animal would be taken into consideration,” he says.
“Now the inspiration for the design comes from the animal itself. We looked at elephants and biologically how they are programmed, what behaviours we wanted to maximise and what they do in the wild – and we created an environment where they could do all those in the zoo situation.”
So how does it work in practice? One of the key areas is feeding, because elephants in the wild spend around 18 hours a day searching for food or eating, explains Creighton.
The habitat in the zoo makes the animals think and work for their grub – hay dangles in cargo nets overhead, and the elephants are encouraged to put their trunks through holes in a special wall to find a feast.
“We also bury food up to a metre deep [in sand], turnips, apples, and they come in and use their trunks like a mine detector,” says Creighton. “They might have to displace a ton of sand to find an apple and they love this, this is naturally what they do in the wild. And we know we have increased their feeding to up to 70 to 80 per cent of waking hours.” But while the sand gives the elephants a workout, their feet still need further care. “In the wild [elephants] can travel 60 or 70km in search of food, but in this environment they don’t have the opportunity, so you have to monitor and check their feet, file them, wear them down,” says Creighton
The elephants learn to take part in the process when they are rewarded with fruit, he explains. “We get them to present their feet out through a specially constructed wall and we can pedicure.”
As well as tending to the toes, the team also tracks the animals’ hormone levels from samples of their dung, and they have come up with a clever way to identify the owners – by putting colour-coded glitter in each animal’s concentrated feed, thus creating a sparkly end product.
“The keeper puts on gloves and breaks open a piece, they see the [coloured] glitter and they know who it belongs to. Then you can check hormone cycles of elephants from their faeces. It works and we know they are synchronised in their cycle.”
The plan is to bring over a bull elephant from the UK next year and extend the family, according to Creighton, who explains how zoo programmes can help protect elephant species in the wild.
“They are in big trouble and without international breeding programmes like what the Zoo is doing here they wouldn’t have a future.”
The zoo also links in with an international breeding programme for Sumatran tigers and positive reinforcement training has helped keep stress levels down, says Creighton.
One cub, Wanita, had a problem with her heart and needed frequent monitoring, but because sedatives can alter blood flow she needed to be checked while awake, so Creighton worked with her to ease her into that situation.
“I got her to recognise a target and when she touched it she got a piece of meat,” he recalls, describing how eventually she would stretch up high to touch the target, and her heart could be checked. “It’s a positive way of training them for what would be a stressful situation.”
Wanita’s training also helped to ease her relocation to France as part of a breeding programme, says Creighton. And it fed into a larger study of positive reinforcement training of zoo tigers, published in the journal Animal Welfare.
Other at-risk species are also getting a helping hand at the zoo – keeper Yvonne McCann has been looking at the breeding behaviour of the Waldrapp ibis.
“They are critically endangered,” she says of the birds. “They used to be found all over Europe but now there are 300 in Morocco in one national park, in Turkey there are about 40 – and in Syria there is one breeding pair.”
McCann has been keeping a close eye on the ibis colony in Dublin Zoo, which sees the birds tucked away in a cliff-face habitat, particularly since they stopped breeding in 2004.
“We didn’t know why that happened,” she recalls, citing possible reasons such as wet summers and being gathered up for vaccination programmes.
Or maybe it was their diet: “We were feeding them a lot of fish and that can affect their liver so we cut that out.”
Changing the nesting material seems to have been a good move, as McCann describes: “It used to be twigs but we found that wasn’t very pliable so they couldn’t make their nests properly. So we started giving them fresh grass every day, and you would see them in the summer bringing the grass to the pool, washing it and bringing it back to the nest. That increases the humidity so it is a perfect little incubator for them.”
The breeding started again, and the zoo is currently home to 19 ibis, including six chicks that have survived in the last three years, according to McCann, who is now studying the behaviour of these newest additions to the group.
Unfortunately the mortality rate for chicks is still high. “This year they had 19 eggs and reared two chicks,” she says. “But even though we have only had six [chicks] in the last few years, it’s still six we wouldn’t have had if we hadn’t tried.”
The secret to finding the sex of a flamingo? It's all in the legs
HELLO BOYS! Or should that be girls? When it comes to flamingos, assessing the sex is not that straightforward, and can require a blood sample or DNA test to be sure.
But a study at Dublin Zoo has highlighted a tell-tale sign that could cut down on the need for expensive and time-consuming tests when determining the breakdown of adults in a flock – it’s in the length of the legs.
Dublin Zoo’s Chilean flamingos (Phoenicopterus chilensis) provided good subjects for such a study because their sex breakdown was already known from tests carried out when the birds were gathered up for vaccinations, explains keeper Louise McDermott.
For this study 68 adult birds were gathered up and had their wings, weight and legs measured.
“Then we looked at all the males and all the females to see if there was a correlation,” says McDermott, who carried out the study with Peter Phillips.
“There was quite a bit of overlap between weights and between wing lengths but there was minimal overlap between leg lengths – there were only four that overlapped out of 68, which is a very small proportion.”
The finding that males tend to be leggier could help other zoos to determine the gender balance of flamingo groups – which can inform breeding programmes – without incurring the sometimes prohibitive expense of gathering up and testing all of the birds, according to McDermott. “Some zoos can’t afford [that],” she says.