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Meet the professional Les

Mountain Lions:
General Info
Diet
Habitat
Reproduction
Research
Human Interactions
Questions

Name: Leslie Chow
Title: Research Wildlife Biologist
Organization/Department: US Geological Survey
Field of study/research: Terrestrial Vertebrate Ecologist

CAREER INFO
How long have you been doing this?
23 years total. I used to work in Sequoia for 5 years and then worked in Hawaii. I have worked in Yosemite National Park for 17 years. I worked here on Bighorn sheep from 1986-1991, forest carnivores (rare mammals) from 1991-1994, and the past eight years on mountain lions.

How did you get interested/involved in your field of study? What was your degree in and where did you study?
I came to the Sierras in 1974 and just never left. I fell in love with the place. I started as a climber and ended up running into a wildlife biologist. He convinced me to go back to school to get an education that would let me work outdoors. Once you learn about it, the world becomes a much more interesting place. I get to work outdoors, study animals, and live here.

I went back to school at UC Berkeley and got my Bachelor’s degree in Conservation and Resource Studies and my Master’s degree in Wildland Resource Science.

For those out there who may have an interest in the study of animals or something of that sort; is there anything you can tell them about what you do and how to get there? What colleges to go to? What to study? Steps to take to put you in the right direction?
Volunteer. Try it out, see if you like it. Get a feel for what they really do. That will tell you what you need to know. I think you should take basic biology courses, ecology course work, and statistics.

Do you like your job? What are some positive and negative aspects of what you do?
It’s really frustrating. In the four year period that I spent researching the forest carnivores, only one was detected out of 295 stations. Most of the time when we catch lions to put radio collars on them, they die. We caught 7 lions and 3 of them lived. They’re just really big house cats. And the younger cats are more likely to try new things.

We did a study on how often mountain lions were in Yosemite Valley and what they did. We had a hard time finding them, and with little data, it was hard to rationalize continuing requests for the funding of that study.

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GENERAL INFORMATION
Why does the mountain lion carry so many other names (cougar, mountain lion, puma, catamount)?
It’s regional. If you live in California they’re called Mountain Lions. If you’re in the Southwest they call them Puma. If you’re in Montana they’re called Cougars. And if you’re back East they’re called Panthers.

They are all the same species and all can successfully breed. The Florida Panther is sometimes referred to as a sub-species because its populations have been isolated for so long that individuals are showing signs of inbreeding. To combat problems of inbreeding, scientists have introduced pumas from Texas to the area.

How many mountain lions have you seen? What’s it like to see a mountain lion?
A dozen or more. The first thing you notice is that they’re really big. Their body is about 6 to 7 feet long. Their tail is about 3 feet long, about as big as your arm. They’re really muscular; most of their weight is in muscle. Only about 15% of their weight is skeletal.

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DIET
What do mountain lions eat?
Mountain lions are carnivores. In Yosemite they eat primarily deer, but also feed on smaller animals such as coyotes and raccoons. They are opportunistic hunters, meaning that they take the foods that are available to them.

They prefer their meat cool and fresh, and will leave old meat for other animals. Mountain lions typically will kill about one deer per week. They may eat 10-15 pounds of meat right away and then cover the carcass with leaves and twigs to hide it from other animals. They also may pull the carcass into the shade to keep it cooler.

How do mountain lions hunt (sight/sound/scent?)
They mostly use sight and sound. They don’t really have a good sense of smell. They tend to meander back and forth. They’re crepuscular, so they hunt during dawn and dusk. They have reasonable eyesight, they know their territory. They’re lay and wait predators; good at stalking. They usually jump on the back of their prey and split the spinal cord with one bite.

To identify and characterize the diets of individual lions do you need to examine the feces when it’s fresh? Can it have been there for days or weeks and still be good?
It can be pretty old. We usually collect scat and pick through it. We wash away the yucky stuff and then we’re left with hair and bones

With the possibility that mountain lions may be attracted into the Valley because access to human food has created artificially high populations of raccoons, coyotes, and mule deer do you believe that mountain lions will soon go after human food and possibly encounter humans more often like the black bears have a tendency to do?
Nobody knows, they’re specialist – they only eat meat. They don’t experiment much for fear of injury. If the mother takes the kittens into Yosemite Valley for 3 months or so, the kittens might get used to humans. Even in the foothills where there is a lot of activity, there is no evidence that mountain lions act accustomed to human presence.

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HABITAT
What kind of environment/habitat does the animal depend on? Does it change throughout the year?
Pumas depend on covered areas like brush or talus, rocky areas. They sometimes migrate with the deer, going to higher elevations in the summer and lower ones in the winter.

How much territory does the animal need?
Males have a larger home range (about 100 square miles) than females (35 square miles). The males mark their territories for breeding purposes. It depends totally on food availability.

Where have mountain lions been seen in Yosemite Valley?
The ones we found were mostly located in the more developed, Eastern end of the valley where human garbage and food have supported raccoon populations.

Do you think we are moving in on mountain lion territory?
Yes, as people spread into the foothills people will encounter mountain lions more often, especially if we have dogs and livestock or plants that deer feed off. With continual expansion into the foothills, we are definitely moving into their habitat.

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REPRODUCTION
When do mountain lions reproduce? What’s mating season like? Do they have a mating call? How long does mating season last?
They can mate at any time of the year, but they typically mate in the spring. That’s just for the Sierra Nevada’s though.

Are there any mating rituals that the mountain lions do?
They’re very secretive, there’s only been one mating couple taped. The females usually mark their areas by urinating on trees and such and also let the males know they’re ready by roaring. Males compete for females by marking their territory with urine and feces. Mountain lions are very strong, but their bones are actually quite fragile so fighting other males for territory rarely happens.

Who does the post-natal care? For how long?
The female. The kittens stay with the mother for about 14 to 18 months. Their mothers leave them at a kill site to feed, and they understand not to follow her.

What is the life expectance of a cub after birth? Are they in danger of being hunted by other predators?
Pretty high. Male mountain lions will eat them to get to the female back into estrous (ready for breeding). They’re also attractive prey for bears and coyotes. The kittens are defenseless for the first few weeks, but if they last for 6 to 8 months then they’ll probably live to see they’re second or third year. The females live to be about 10 or 12 years old. The males live to be about 8 or 10 years old.

Do you ever come across orphaned mountain lions?
No.

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RESEARCH
Is there a limit (a boundary) to the area you’re allowed to research or work in? If so, will you get in trouble for going out of that area?
Because mountain lions do not stay within boundaries that humans have drawn on maps, I have had to work with many agencies including the National Park Service, The National Forest Service and the California Department of Fish and Game. I try to keep everyone informed of what I am doing and get permits for my research. Anything in the National Park is federal property and they have sovereign jurisdiction to manage wildlife as they see fit.

I was once observed for about 3-4 hours by two rangers that thought I was a poacher. As I was leaving the site, they approached me and didn’t know that I had obtained a permit to work in the area. I didn’t get in trouble because I had permission, but they were pretty upset at first.

Do you believe that it is a good idea to capture and install radio transmitters on mountain lions? How does this affect the mountain lion and its way of living? Does it hurt the mountain lion? How do you install the transmitters?
To capture a mountain lion is an intensive and potentially traumatizing process. Snares and traps are best, but not the most common ways of capturing a mountain lion. We use hounds to chase the mountain lions up a tree. The researcher tracks the dogs (also radio collared) to the site and then shoots the lion with a dart. The medicine takes 3-5 minutes to take effect, in which time the researcher must attempt to climb the tree and safely tie a noose around the mountain lion’s paw so that it doesn’t fall out of the tree when it falls asleep. Mountain lions have fragile bones that are easily broken.

The researcher should have a good reason to use collars and they much follow up on them. The collars themselves normally don’t seem to bother mountain lions. I made the decision to not re-capture a lion after the battery went dead on his collar. I thought the trauma of getting re-captured just to replace the battery or remove the collar wasn’t worth it, and the collar still helps us identify the animal when it is seen in the wild.

Are there other ways that you track and research the animals?
It depends on the objectives of the study.

Scat shows what they’re eating, and mitochondrial DNA analysis can help identify individual lions. We had a study that tracked the gene flow of mountain lions from the Western to the Eastern Sierras. The researcher in the project, using DNA analysis, found 9 more lions than we hadn’t tracked. We also collect hair to identify and see how many lions are in the area.

Because the can cover such large distances in one day, we use cars a lot to follow the cats around, sometimes driving over 100 miles a day.

How can you determine a mountain lions age?
By their teeth, the patterns of tooth wear. Kittens tend to have erupted teeth. With adults we look at the gums above the tooth and their canines.

I read that you were spearheading a four-year study of the puma in the Yosemite Valley region, where you would capture and collar several cats to determine the mountain lions role and niche in its natural environment. Did you find any interesting information and how well did the research go? Were any of your hypothese confirmed?
Not well: we were able to capture the lions but it was hard to keep them alive. Mountain lions don’t go to Yosemite Valley very often, but when they do they are there for extended periods of time, they go to hunt.

How do you teach a dog to hunt out mountain lions? How do you keep them from scaring the mountain lions away? What kind of dogs do you use?
We use walker-treeing hounds. Most of them come from Texas and are English bread. They start with small stuff like chasing raccoons up trees, etc. We send the younger dogs out with the older dogs for more experience. They are scolded with shock collars and other things when they learn to hunt for mountain lions to help them keep focus, to stay away from other animals. The dogs are worth $10,000. They can’t be afraid; they’ve got to be feisty, but obedient. Some of the more experienced dogs are considered to be “cold trackers” and can pick up a scent that’s 3 to 5 hours old. The hunters use the cold trackers to detect the scent, and then may send out younger dogs to do the chase one the scent is picked up by them.

What can a paw print tell you? What does its size say about that specific animal?
We can measure the track sizes to determine if they’re male or female and can actually determine who they might be.

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HUMAN INTERACTIONS
Are humans contributing to apparent changes in mountain lion behavior? How so?
Yes. In Yosemite Valley we see populations of raccoons that survive on human food and garbage. We have noticed a 2-3 year interval of mountain lion sightings in the Valley that corresponds with the rise in raccoon populations. Most alarming is the atypical behavior we have seen, such as mountain lions seen on trails and in parking lots whereas they normally are pretty discreet animals.

People also are moving into mountain lion territory in the foothills, perhaps changing the way the animals have to hunt for food. Ranchette owners with pets and livestock as well as those that grow plants that deer like to eat help attract mountain lions to these residential areas.

Some black bears are “put down” because of their re-occurring interaction with humans, have there been any cases with mountain lions being “put down” for the same reasons? And why?
Rarely, because there are so few incidents that involve mountain lion predation. One time in El Portal, there was a sick juvenile lion that was obviously underfed and hungry. It hung around the hotels and was a threat to humans. The Department of Fish and Game was called to come and remove her. We don’t relocate mountain lions.

Because younger lions have less experience and are sometimes forced to move into marginal territory they tend to mistake pets as prey, do you believe that most of the attacks on humans are from younger lions who have been forced out of their home with little experience? Or are the attacks from older, more mature lions?
I don’t know. Luckily, not enough people have been attacked. Typically, younger inexperienced cats are more likely to experiment with and chase after new food items, but there is no study that I know of that proves younger cats attack humans more often.

If I were to have my dog with me, would I be more likely to encounter a mountain lion?
Depends on where you are. It might be more attracted to the dog.

I was told if you came across a mountain lion that you should never cower down, always make yourself look bigger and made a lot of noise, possibly throw rocks or something, is this true? Does this work?
Yes, DON’T RUN! They like to chase things. Mountain lions are a lot like big 120-pound house cats, you can’t control them. If they seem defensive, be aware of the situation, it might have kittens. If so, back away. If they seem offensive appear dominant, be just as aggressive, fight back, but don’t push it. Mountain lions don’t want to get injured.

How many attacks on humans have there been in the past century? How many of those attacks ended in fatalities? How can we prevent this from happening?
In the U. S. there hasn’t been more than a dozen, but not everybody reports attacks and some are blown out of proportion. You’re more likely to be struck and killed by lightning than by a mountain lion.

From what I understand, most animals, mountain lions being one of them, tend to be attracted more toward women who are menstruating, is this true and if so, why might that be? Do they use the sense of smell to hunt?
Maybe with bears, but not with mountain lions. They don’t have the same sense of smell.

In 1994 sightings around the state increased significantly. In 2 separate incidents, 2 women were killed by mountain lions in California and officials in Yosemite Valley reported over 55 sightings. Now a lot of people are scared of mountain lions and tend to blow their existence out of proportion; is there any reason they should be afraid?
Don’t be afraid, but be aware. If you know a lion is around you might think twice about going for a run.

In 1996, Governor Wilson signed a bill asking voters to repeal Proposition 117, which bans the hunting of mountain lions, do you think we should repeal the proposition? What’s your position on this?
I don’t like proposition 117. I am not necessarily opposed to hunting, just many of the other things that went along with it. The mountain lion population right now is healthy enough to allow for some hunting. It’s been estimated by track surveys that there are 5,000 to 6,000 mountain lions in the Sierra Nevada’s.

I am opposed to the proposition because its decisions were based on emotion, not science. It takes the responsibility of mountain lion research out of the hands of specialists and into the hands of the public. It makes it more difficult for scientists to do research.

Proposition 117 also took money away from important projects in the California Fish and Game Service. 30 million dollars was designated to preserve mountain lion habitat, a lot of which was used up in purchasing small 1-acre parcels that benefited private landowners and didn’t help mountain lion habitat significantly. Also, there was no money set aside in this fund to maintain these lands once purchased.

Does the park have a problem with poachers?
Yes, it is a big issue in California

If so, what is being done to stop this from happening?
We have rangers monitoring the park; it is an ongoing struggle.

Thanks for your time Les, it was great learning about mountian lions!
Your welcome!

QUESTIONS?
If you have a question about mountain lions not covered here, please email Jocelyn and she'll ask Les about it.

Photos: All photos were taken by William Campbell.

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