Interesting Science: Mountain Lion Behavior

April 17, 2012

A recent study from the Teton Cougar Project has found multiple mountain lions sharing prey in the Gros Ventre River drainage.  According to conventional wisdom, mountain lions are solitary animals, expect when breeding and raising young.  These researchers have found multiple females and young sharing elk kills and have also noted a male lion in the same location as a female and her kitten.  My own experience with bobcats supports what these researchers have seen.  I’ve seen multiple male bobcats interacting with females and kittens outside of the breeding season, which the literature says shouldn’t happen.

Jackson Hole News via Adventure Journal


Urban Bobcats – Part IV

March 3, 2011

This is the final post in a series about a bobcat research project in Southern California.  Please read Part 1, Part 2, and Part 3 if you haven’t already.

In the previous two posts, I wrote about spending a day in the field with bobcat researcher Laurel Klein.  An important point about scientific research is that you never really know where your work will take you on any given day.  This is especially true when doing field work and working with an animal that you rarely see in the wild.  One of the most challenging aspects of this project, has to be not knowing what each day will bring.  As I mentioned previously, simply maintaining the traps can take most of the day.  If Laurel actually traps a bobcat, her day just got a lot longer.

I mention this, because I really have to thank her for calling a week later and letting me know that they had a bobcat.  Waiting for me to drive down, so that I could see a bobcat up close and get some photos, meant that her day was going to be that much longer.  Thanks Laurel!

Above, is a photo of the beautiful male bobcat that I saw when I arrived.  He was actually quite calm, and Laurel does a very professional job making sure the bobcat does not experience too much stress.  There are protocols that she must carefully follow, for the well being of the bobcat, but it was quite evident that she goes above and beyond, and really cares deeply about these cats.

Once I arrived, Laurel finished preparations to anesthetize the bobcat.  Here she is preparing a blow dart with the help of NPS intern Isaac Kelsey.  Once the bobcat was darted, it was very important to be as quiet as possible and not to disturb the bobcat.  Once the bobcat was asleep, it was important to work quickly because there is a limited amount of time to get a lot done before the bobcat wakes up.

Once the bobcat was asleep, Laurel carefully moved him from the cage and carried him to the work area.  Before any other work was performed, Laurel and Tiffany Armenta weighed the bobcat.

I mostly tried to stay out of the way, but was able to help by taking photos of the bobcat from all angles, so that it might be identified from remote camera photos, or for general comparison if it was captured again.

As you can imagine, a lot of work was being done by everyone as efficiently as possible.  The primary reason for capturing the bobcats is to get blood samples to test for the presence of anti-coagulant poison and for genetic testing.  Most of the bobcats captured, will never be caught again, so it is important to get all the samples that might ever be needed.

After taking some additional measurements and tagging the bobcat, we waited for him to wake up.  While we waited, I had the opportunity to pet him (with gloves on) and was surprised that he has such coarse fur.  Laurel told me that the female bobcats can have much softer fur, more like a house-cat.  All-in-all it was an incredible day and I’m very thankful to have had this opportunity.  Research projects like this take a lot of time and effort from a few very dedicated people.  These projects are almost always inadequately funded, so I encourage anyone who has had their life enriched by these amazing animals, to volunteer or donate what you can.  I know there are many other photographers reading this, and I feel that we have a great opportunity to get involved with nature conservation and education.  I know that I’ve been humbled by reading about the generosity of many great photographers and find them an inspiration.


Urban Bobcats – Part III

March 1, 2011

This is Part 3 of an ongoing series about bobcat research in Southern California.  If you haven’t already, please read Part 1 and Part 2.

Determining where to place the traps is one of the most interesting parts of this project.  It helps to know a bit about bobcat behavior, and what draws their attention.  In many ways, they aren’t too different than we are.  They prefer to follow existing trails and are very visual creatures.  The latter part may be surprising since they do so much of their hunting after dark.  They react strongly to movement and also have excellent hearing.  The best locations are near trail intersections or between a source of water and hunting grounds.

It also helps to be good at finding telltale signs of bobcat activity, aka spoor.  There is little point in setting a trap where there are no signs of bobcat activity.   Until you start looking for tracks and scat, they are really easy to miss, but with practice they become much more obvious.  I have spent the past two years familiarizing myself with bobcat tracks and scat, and have gotten reasonably good at spotting signs of their activity.  However, Laurel’s ability to detect their presence is far more impressive.  I remember stopping at a hillside and having her exclaim that it reeked of bobcat urine.  I couldn’t smell a thing until I knelt down and really sniffed around.  Surprisingly… it doesn’t smell nearly as bad as house-cat urine.

We spend the middle of the day exploring a new location and found some signs of activity.  There was a really nice animal trail intersection near an oak tree, and it was decided that this would be the best place to put the trap.  Here’s what the location looked like before we got to work camouflaging the cage.  (If I remember correctly, she ended up catching a coyote here a few days later.)

Looking at the above photo, it would be hard to imagine that a bobcat would dumb enough to venture inside something so obviously unnatural.  However, it’s amazing what some careful arrangement of natural vegetation can accomplish.  Here’s what the trap looked like once we were done.

Once the trap was disguised, Laurel attached the radio transmitter, made sure it sent the right signal when the door was triggered, marked down the GPS coordinates and then setup a bunch of visual lures.  Interestingly, hanging old CD’s from branches and spreading feathers from a down-pillow are effective ways to get a bobcat’s attention.

Once this trap was set, we packed up and went back to the site of the bobcat sighting for a quick lunch.  There was no sign of it, although I did take the opportunity to find the place that she marked and work on training my nose.  Laurel decided that she couldn’t pass up the opportunity that this bobcat presented, so we set a trap at this location.  After that, we made the rounds again and checked on all of the traps.  No bobcats were trapped, but it was still a fantastic day.

I’m very excited about the next post.  About a week later, Laurel called bright-and-early to let me know that they had a bobcat.  I immediately grabbed my camera gear and jumped in the car.  More to come tomorrow…

Urban Bobcats – Part II

March 1, 2011

Saying that you want to do research on bobcats is easier said than done.  For one thing, cats aren’t know for being too cooperative.  In all seriousness, a research project like this requires a huge amount of planning, getting permits, finding qualified volunteers, getting access to field sites, and most importantly – finding funding.  If you haven’t read the previous post in this series, it can be found here.

While the science is important, the health and well-being of the animals trumps everything else.  Practically speaking, this means a lot of very long days because the traps (large cages) must be checked on twice a day and new locations need to be scouted in between.  While bobcats occupy their smallest sized territories in Southern California, the traps still need to be spaced quite a distance apart.  So, there’s a lot of driving and walking involved.  It is also important that the traps not be obvious to other people, so this means staying away from busy hiking trails and other areas with easy access.  If you’ve ever tried to bushwhack through chaparral, you know what an ordeal this can be.

Laurel starts a typical day well before dawn.  Many of the cages have a radio transmitter that will let her know if the cage door has closed.  However, due to the mountainous landscape, she is only able to get radio reception for a few of the study sites.  Also, the radio-transmitters aren’t foolproof, so she needs to check them in person anyway.  If one of the traps has been triggered, the first course of action is to see what’s in it.  As you can imagine, there’s lots of other wildlife around that might find their way into the trap.  I, for one, am really glad we didn’t find a skunk in one of the cages!  (This has happened, and getting them out of the cage without getting sprayed is quite a challenge.)

On the day we tagged along, none of the traps had triggered overnight, so we started the morning by checking on all of the nearby cages.  It is important to double check that they haven’t been triggered, and that the trigger mechanism and radio transmitter are working properly.  We probably spent almost three hours checking the traps near our starting point, and all of this needed to be repeated later in the afternoon.

While driving from one study site to another, we asked a lot of questions about Laurels research and shared stories of our sightings in Santa Barbara.  Ironically, I had to interrupt the conversation to point out that a bobcat was sitting completely out in the open, watching us drive by.  As you can imagine, this was the highlight of the day, and the above image is of that beautiful female, which had been previously captured by Laurel last Fall.  This particular bobcat had a bad case of mange when originally captured, and was taken in for treatment and released about a month later.  As you can see, she looks amazingly healthy and it was an incredible joy to see her out in the wild.

Once again, I’ve ended up writing far more than I expected, so the next part will talk about scouting new locations and setting up a new trap.  Stay tuned!

Urban Bobcats – Part I

February 28, 2011

Last month, I had an amazing opportunity to spend a day in the field with a bobcat researcher in the Santa Monica mountains.  Laurel Klein is a graduate student at UCLA and is incredibly dedicated to her research.  Her research is focused on studying bobcat populations living in urban environments.  Urban environments tend to have fragmented natural habitats, which may  result in individual bobcats needing access to several fragments in order to survive or find a mate.  The National Park Service has been monitoring bobcat populations between Ventura and Los Angeles for more than 15 years; and they have recently seen a decline in bobcat survival rates.  Further research has shown that the mortality is often associated with mange infection, which has been linked to the consumption of rats poisoned with anticoagulants.  In short, when the bobcats eat poisoned rats, they become more susceptible to the mange parasite.  For those that photograph and watch wild bobcats, it is important to know that mange is very treatable, so if you see a sick bobcat, please report it to your nearest wildlife care group or appropriate government agency.

In addition to researching the extent of the mange epizootic (wildlife epidemic), Laurel is also looking at the genetic diversity of the population in her study area.  Urban development has broken up formerly contiguous areas of natural habitat, and reduced the number of territories available.  An important question is how successfully these urban bobcats are breeding and whether or not their young are able to disperse and establish their own home range.  The fragmented habitat may make it less likely that a young bobcat is able to find its own territory and establish one large enough to provide adequate prey and mating opportunities.  Two additional hazards of the urban environment include roads (vehicle-strikes are the primary cause of urban bobcat mortality) and competition with coyotes (the most common cause of kitten mortality).  While bobcats almost exclusively prey on wildlife, Coyotes are opportunistic omnivores and can make use of additional food sources found in urban areas.  This additional food can help increase the numbers of coyotes, which may be detrimental to bobcats.

Understanding urban bobcat population dynamics is important.  If the mortality rate of urban bobcats is higher than their rate of reproduction, the population could be stabilized by recruitment from a nearby nonurban population.  However, this will only work long-term if the wild population is healthy and produces enough offspring to offset the mortality rate in urban environments.  Genetic studies will enable  Laurel to determine the health of the overall population and whether or not the urban populations are adequately connected to the intact wild populations.

As a photographer, who has spent a lot of time observing bobcats living in the midst of a suburban neighborhood, I have felt very fortunate to have the opportunity to document their life.  However, as a biologist, I wonder about the local bobcat population and why they are inhabiting an area so close to people.  I’m very happy that I had the opportunity to spend a day in the field with Laurel and learn more about her research.  The following post will talk more about a typical day in the field and how much work is involved.

For more information in urban bobcats, I highly recommend the book – Urban Carnivores