Press release. Seattle, 6/26/2019
Snow leopards remain one of the least well understood big cat species. In the wild, very little is known about their reproductive cycle, birth and survival rates and other key demographic parameters that will determine their chances at survival against a growing number of threats.
But through the Snow Leopard Conservation Foundation and Snow Leopard Trust’s long-term study in Mongolia, scientists are slowly finding answers to some of the most pressing questions.
“The opportunity to document and observe wild cubs in their den and later as they grow up is invaluable to science. It provides first-hand information on litter size and cub survival, but also the reproductive cycle of adult female snow leopards – data that is extremely scarce to date”, says Charu Mishra, the Snow Leopard Trust’s Science & Conservation Director.
Watch: Snow Leopard Trust researcher Örjan Johansson explains why we locate and visit den sites and what happens during the process
This spring, using data from a GPS tracking collar researchers were able to pinpoint the den site of a female snow leopard named Dagina. When the mother was out on a hunt, the team quickly examined and chip-tagged her three cubs to record their health and ensure they can be identified later, once they’ve grown up.
“This is only the fifth time ever that researchers have been able to record wild cubs in their den, so it greatly enhances what we know about these cats. And it’s particularly valuable data because we know Dagina, the cubs’ mother, so well”, Charu Mishra says.
Dagina is one of the most thoroughly studied wild snow leopards – and the oldest snow leopard that has ever been recorded to have given birth.
“Thanks to our long-term research with both GPS collars and camera traps, we’ve been able to document most of Dagina’s life in these mountains”, says Snow Leopard Conservation Foundation researcher Puji Lkhagvajav, who has observed and studied Dagina since she was a little cub.
A Snow Leopard’s Life Story
Born in 2009, Dagina was first photographed by one of our camera traps in August 2009 as a tiny fur ball, following her mom, a cat we had named Agnes. Dagina left her mother’s side in 2011 and inherited part of her territory – a phenomenon referred to as philopatry, which is fairly common in large carnivores.
In 2012, while she was wearing a GPS tracking collar for the first time, three-year-old Dagina gave birth to one cub – her first offspring. Our team found the den site she had used after she and her cub had left it. Two years later, she had her next litter of 3 cubs, all of whom survived at least until autumn 2015 according to our camera trapping data.
The next time we saw Dagina, in 2016, she was traveling alone. We don’t know if she had another litter of cubs that did not survive, or if she took a break from the two-year reproductive cycle we assume to be the norm for wild snow leopards. In either case, she had two more cubs the following year (2017) – and our camera traps show both of them surviving at least until fall 2018.
Now, she again had cubs at age 10, making her the oldest snow leopard confirmed to have given birth in the wild. “These three new cubs are at least her fourth litter”, Puji says. “And she used the same den this year that she had used in 2012 for her first cub.”
An Ideal Den Site
Even with the latest technology, locating a wild snow leopard den site is no easy feat. The tracking collars we use emit both a GPS and a radio signal – the latter can be picked up with an antenna from within a mile or so, while the former sends the cat’s locations to a secure server via satellite every five hours.
“When the snow leopard mother is inside the den, we don’t get a satellite signal from her collar, so the only GPS locations we have are from around the den site, when she leaves to get food, for instance. At best, these gives you an idea of the area to look in. But it takes a mix of knowledge, educated guesswork, stamina and a bit of luck to pinpoint the exact location of the den and identify it”, says Justine Shanti Alexander, one of the researchers who found and examined the cubs.
“For a few days, we searched the area where we suspected Dagina’s den to be. From her collar’s radio signals, we could her that she was relatively close by. But then, one day, there was no signal coming from the usual direction, a strong indication that Dagina was away on a hunt. So we decided to take our chance and look for her den in the vicinity of the 2012 site. We moved in closer, and after a few minutes spotted the small crack in a rock face, and scrambled down a steep cliff to reach it. We looked inside, and through the tiniest of openings in the rock face, we saw three snow leopard cubs curled up and sleeping in this little hollow space where perhaps a large dog could fit”, Justine recalls.
“It’s a very good den, located in a narrow ravine, rather high up on a mountainside. The opening is really just a small crack in the rock, 5-7 m above the ravine floor. All of this makes it very protected and hard to access. To make things even better, there is a waterhole about 50 m from it, which is probably particularly important to female snow leopards when they are lactating.”
After examining and tagging the cubs, which took less than 10 minutes, the team left the den site. Radio telemetry signals showed that Dagina was still about 2 km away.
The next day, the researchers went back to the area and picked up a radio signal from Dagina’s collar, confirming that she was with her cubs inside the den. They set up 4 camera traps about 2 km from the den site, hoping to capture photos of her and the three cubs throughout the summer.
Pioneering Long-Term Ecological Study
Since 2008, the Snow Leopard Trust and Snow Leopard Conservation Foundation Mongolia in collaboration with the Swedish University of Agricultural Sciences (SLU), the Mongolian Ministry of Environment & Tourism, and the Mongolia Academy of Science, have been conducting the world’s first and only ongoing long-term ecological study of snow leopards and their mountain habitat in Mongolia’s Tost Mountains.
During this study, researchers have tracked a total of 30 individual snow leopards with GPS collars, producing the world’s most comprehensive data set about the spatial behavior of wild snow leopards. They’ve discovered five wild snow leopard den sites, allowing them to gather unprecedented information about litter size and survival rates of cubs.
The international research team has also monitored Tost’s snow leopard population with camera traps for ten consecutive years, collected data on snow leopard exposure to pathogens, prey species abundance and other ecological parameters.
Over 70 foundations, zoos, and corporate partners, and hundreds of individual donors, have made it possible to run our long-term study and collar snow leopards over the past decade—for a full list please visit www.snowleopard.org/decade.
Article Source: Snow Leopard Trust