Hidden from the public, the Dallas Zoo’s newest antelope spends his days nesting under thick brush inside one of about a half-dozen indoor stalls dedicated to his rare species.
At 10 days old, the calf is barely bigger than a size-7 tennis shoe and weighs less than a pound — a passerby could easily miss the newborn curled up behind the leaves and hay.
His mother, Cupcake, herself only a foot tall and less than 10 pounds, occupies the stall with him. She spends her days roaming the stall and occasionally bringing him food and checking on him, just as she would in the wild.
A team of caretakers quietly helped Cupcake deliver the calf, who is unnamed for now, on June 1. He’s the newest member of the zoo’s group of blue duikers (pronounced dye-ker), one of the smallest species of antelope in the world.
With the addition of the calf, the zoo has 10 blue duikers in its care — a significant accomplishment as the team leads an effort with zoos across the country to increase the species’ population.
“Some zoos weren’t really heavily invested in them, and we kind of decided that we needed to step up and make sure that somebody is going to continue creating this sustainable population,” said Matt James, the zoo’s senior director of animal care.
After two years of efforts to bolster the species, there are about 50 blue duikers at zoos in the United States, he said.
James is one of the leaders of the taxonomic advisory group for the species, which uses a species survival plan created by the Association of Zoos and Aquariums to select pairs of blue duikers that would breed well based on their genetics.
With 10 blue duikers, the Dallas Zoo has a fourth of the blue duikers living in zoos accredited by the Association of Zoos and Aquariums.
Careful matchmaking
Two years ago, the Dallas Zoo began with two calves, Walter and Soksi, who eventually gave birth to Viazi, the new calf’s father.
Because the Dallas Zoo’s population is so small, the team has been able to pair the animals based on pedigree, or relatedness to one another. With a larger group, caretakers would have to take a blood sample to get a more detailed breakdown of the population’s genetics.
“We know that we started with these unrelated animals, and then this one is a mix of animal one and four, and this one’s three and five,” James said. “Based on that, we can figure out relatedness between every single animal in the population. Then we find animals that are the least related and have the best genetic match.”
Blue duikers are not monogamous, and each female gives birth to one calf at a time. Every time a new calf is born, the team re-evaluates the group and chooses a new pair, he said.
The ninth and 10th members of the herd, Thumper and Kaiju, are waiting out a quarantine period before they’ll be introduced. They came from the Montgomery Zoo in Alabama and will help increase the genetic diversity of the Dallas herd.
Behind-the-scenes work
The name duiker comes from the Afrikaan word for “diver,” James said. As prey animals, the blue duikers’ main form of protection is running from predators. They primarily live in forested areas of western Africa and are named for the way they dive into and under bushes, he said.
To encourage breeding, the team has set up four outdoor runs that each hold a pair of antelope. Each run is separated by a chain-link fence and filled with plants and tunnels that allow the animals to hide.
“The best thing that we can do is promote species-typical behavior,” Senior Zoologist Jenny Roath said. “We want them to be hiding because that is something that they’re naturally born to do. That’s kind of how we know that they’re feeling comfortable, when they’re breeding with each other and we’re having calves, you know that something is right.”
There are only two blue duiker paired for breeding now, Walter and Peridot, Roath said. Cupcake remains indoors with her newborn, and the two will stay together for nine to 12 months until the calf is ready to breed with a female in the group or is sent to another zoo.
To ensure the animals are in the best condition to breed, the team also carefully monitors their stress. Three times a week, a fecal sample is taken from each antelope to check their cortisol levels, a hormone that is connected to stress.
To further reduce the animals’ anxiety, caretakers train with the animals for hours every week to make them more comfortable in their presence.
As the caretakers walk by the runs, some of the antelope are still skittish and dive into their hideouts, while others, like Viazi, have started to look forward to the company of humans.
“When ... [Cupcake] originally got here, she would not come near a trainer, and she is now comfortably eating out of my hand and allowing me to touch her,” Roath said. “It gives them some portion of choice and control over their day and it helps them participate in their own care, so when the vets come down and need to work on their hooves or need to give them a vaccination, it’s way less stressful.”
Growing the herd
As the herd expands, the team is prepared to add outdoor runs to accommodate more breeding pairs, James said.
Although James said he’d like to build the zoo’s herd to 20, sometimes calves born are needed elsewhere.
About nine months ago, Soksi and another animal, Daisy, each had a calf. Those two calves have since moved to other zoos because they were good breeding matches there.
It may seem strange to send a young calf to a zoo on its own, but that’s like what would happen if they were in the wild, Roath said.
“It works so well when we do ship them to other facilities because once they’re weaned and they’re kind of on their own, that’s just something that would naturally happen,” she said. “It’s literally at exactly the time that that would be happening and they’re going somewhere else to kind of start their own herd, do their own thing.”
As the group grows and individual antelope are no longer good matches to breed with others at the zoo, the team will move the animals into a public exhibit, James said. That could happen within the next year.
Although blue duiker haven’t been studied extensively enough to determine whether they’re an endangered species, James said it’s important to build their population in zoos because their natural habitats are at risk.
“This is kind of where we’re heading at least at the Dallas Zoo, but also in AZA, is trying to create these bigger breeding hubs of each species so that we can create the sustainable populations,” he said. “When the forest in the Congo is all extinct and their habitats are destroyed, we still have them in the United States in case we can ever restore habitats and put them back in the wild.”
