On mountain lion patrol in the California wilds
by Nadia Drake, Santa Cruz mountains, California
IT IS after dark, and I'm 2 metres away from a snarling mountain lion. We are in the mountains above Santa Cruz, California, across the road from a prison work camp. The lion - a young male - pauses in his pacing only to hiss at us. Filling the air is the powerful aroma of the half-eaten deer carcass that lured him into captivity.
"It's creepy out here," observes my guide, wildlife ecologist Chris Wilmers from the University of California, Santa Cruz. We retreat a short distance to let the animal calm down.Since 2008, Wilmers and his team of wranglers have been capturing the elusive animals (otherwise known as pumas, cougars and panthers, or more formally Puma concolor). They fit them with collars equipped with GPS transmitters that relay their location, and other instruments that record what they are up to, moment by moment - then let them go.
The data should reveal how pumas adapt to life in a habitat fragmented by roads, dotted with houses, and surrounded by water and concrete. This information can later be put to use by conservationists planning open spaces for the animals, or wildlife corridors they can use to travel safely. Though California's mountain lions are not endangered, the population is small enough that geographic barriers could lead to reductions in genetic diversity and ultimately population decline.
"The long-term prognosis is not very good if they're not interbreeding with other populations," Wilmers says. He points to the Florida panther as a classic case of inbreeding's harmful effects. "They've got a population of 80 or so individuals, and they are starting to have all these genetic defects like single testicles and infertile animals." Using DNA from captured mountain lions, he plans to analyse gene flow in the population.
The techno-blinged collars are essential to understanding the lives of these nocturnal and notoriously shy animals. "They're professionally secretive. They kill by being able to sneak up on things," says Paul Houghtaling, the team's primary field biologist. "Right now, biologists are limited to knowing where animals are, but they don't know what they're doing," Wilmers says. Successful conservation efforts depend on understanding the connection between an animal's behaviours and its habitats. The collars contain magnetometers, which act like tiny magnetic compasses and so reveal which direction a mountain lion is facing. They also carry accelerometers - similar to the devices in iPhones - which record speed and movement in three dimensions 64 times each second. This generates distinct signatures for different kinds of activities. "If the animal is walking, every time the foot hits the ground it's going to send a little jolt through the skeleton, and that will show itself in the data," Wilmers says. "If the animal is running, every time it hits the ground, it's going to really spike. If it turns its head, we'll know which direction it is looking."
Earlier that day, Houghtaling and I were on the trail of three pumas: a female called 2F and her two male cubs. At nearly 2 years old, 2F's cubs are ready to leave their mother. The fact that they haven't done so intrigues the team, but it gives them a chance to collar the youngsters before they disperse. We download 2F's location data, and searching in the woods stumble across a freshly killed, half-eaten deer. A fresh kill means the lions will likely return in the evening. We use the carcass to bait two 2-metre-long cage traps which we camouflage, then go home to wait. At 8.30 pm I get a call saying we have a catch. Inside the cage is one of 2F's cubs, called 9M. He is wearing the green ear tag he acquired when he was caught as a kitten. Field personnel sedate him and get to work measuring vital signs and taking blood, and measuring details such as paw width and tooth length. Finally, the collar goes on. In another hour, 9M will be up and stumbling around. Though he weighs 45 kilograms, "he's got a lot of bulking up to do before he's big and savvy enough to play king of the hill with a resident male", Houghtaling says. A team member will stay with him till he is fully alert, to make sure he doesn't wander onto a road. After that it's up to him. The puma project has another participant.
There's a postscript to my night in the mountains. Two weeks later, 9M does the adolescent thing and leaves his mother. He has recently killed a deer, a raccoon and a snake. "Not sure what he was doing with the snake," Houghtaling says.
"It's creepy out here," observes my guide, wildlife ecologist Chris Wilmers from the University of California, Santa Cruz. We retreat a short distance to let the animal calm down.Since 2008, Wilmers and his team of wranglers have been capturing the elusive animals (otherwise known as pumas, cougars and panthers, or more formally Puma concolor). They fit them with collars equipped with GPS transmitters that relay their location, and other instruments that record what they are up to, moment by moment - then let them go.
The data should reveal how pumas adapt to life in a habitat fragmented by roads, dotted with houses, and surrounded by water and concrete. This information can later be put to use by conservationists planning open spaces for the animals, or wildlife corridors they can use to travel safely. Though California's mountain lions are not endangered, the population is small enough that geographic barriers could lead to reductions in genetic diversity and ultimately population decline.
"The long-term prognosis is not very good if they're not interbreeding with other populations," Wilmers says. He points to the Florida panther as a classic case of inbreeding's harmful effects. "They've got a population of 80 or so individuals, and they are starting to have all these genetic defects like single testicles and infertile animals." Using DNA from captured mountain lions, he plans to analyse gene flow in the population.
The techno-blinged collars are essential to understanding the lives of these nocturnal and notoriously shy animals. "They're professionally secretive. They kill by being able to sneak up on things," says Paul Houghtaling, the team's primary field biologist. "Right now, biologists are limited to knowing where animals are, but they don't know what they're doing," Wilmers says. Successful conservation efforts depend on understanding the connection between an animal's behaviours and its habitats. The collars contain magnetometers, which act like tiny magnetic compasses and so reveal which direction a mountain lion is facing. They also carry accelerometers - similar to the devices in iPhones - which record speed and movement in three dimensions 64 times each second. This generates distinct signatures for different kinds of activities. "If the animal is walking, every time the foot hits the ground it's going to send a little jolt through the skeleton, and that will show itself in the data," Wilmers says. "If the animal is running, every time it hits the ground, it's going to really spike. If it turns its head, we'll know which direction it is looking."
Earlier that day, Houghtaling and I were on the trail of three pumas: a female called 2F and her two male cubs. At nearly 2 years old, 2F's cubs are ready to leave their mother. The fact that they haven't done so intrigues the team, but it gives them a chance to collar the youngsters before they disperse. We download 2F's location data, and searching in the woods stumble across a freshly killed, half-eaten deer. A fresh kill means the lions will likely return in the evening. We use the carcass to bait two 2-metre-long cage traps which we camouflage, then go home to wait. At 8.30 pm I get a call saying we have a catch. Inside the cage is one of 2F's cubs, called 9M. He is wearing the green ear tag he acquired when he was caught as a kitten. Field personnel sedate him and get to work measuring vital signs and taking blood, and measuring details such as paw width and tooth length. Finally, the collar goes on. In another hour, 9M will be up and stumbling around. Though he weighs 45 kilograms, "he's got a lot of bulking up to do before he's big and savvy enough to play king of the hill with a resident male", Houghtaling says. A team member will stay with him till he is fully alert, to make sure he doesn't wander onto a road. After that it's up to him. The puma project has another participant.
There's a postscript to my night in the mountains. Two weeks later, 9M does the adolescent thing and leaves his mother. He has recently killed a deer, a raccoon and a snake. "Not sure what he was doing with the snake," Houghtaling says.
Posts
No comments:
Post a Comment