A few updates on my anticoagulant rodenticide research

Recently, a lot of interest has been swirling around the topic of anticoagulant rat poison use on public and private lands. This interest revolves around some recent legislative changes in the regulations regarding the availability and use of second-generation anticoagulants in California. Additionally, P22, the Griffith Park mountain lion, was recently captured and tested for anticoagulant exposure. Much to the surprise of many, two types of first generation anticoagulants (which are less toxic than the second-generation compounds, and to which the new California regulations do not apply) were detected in P22's blood.  So, this has raised a lot of questions for people, concerned about the potential impacts of the first-generation compounds on wildlife, and the meaning of detecting those compounds in P22's blood.  A few people recently emailed me to ask specific questions about what I thought about the P22 findings, and how much risk the first-generation compounds pose. Additionally, folks have been curious about whether the detection of the first-generation anticoagulants is common.  I figured I'd put my email response here, and also add some updates about the anticoagulant research I've been doing on bobcats over the past 8-years.

For this research, I tested 195 bobcat blood samples for exposure to anticoagulants. 39% of animals were exposed, and diphacinone (a first-generation anticoagulant) was the most frequently detected compound. In 77% of blood samples of the 39% in which we detected exposure, diphacinone was detected.  In terms of other first-generation compounds, we also detected chlorophacinone and coumachlor in the blood samples. Diphacinone was detected 3 times as frequently as as second-generation compounds. Given our findings, we concluded that diphacinone, a first-generation compound, is probably the most frequent compound that bobcats are exposed to across our study areas, which included a significant number of samples from Ventura, Los Angeles, and Orange Counties, but also some samples from Santa Barbara and San Diego Counties.

During this study, I also tested 172 bobcat liver samples, and in those samples, I most frequently detected second-generation compounds brodifacoum and bromadiolone. We probably do not detect diphacinone in the liver as frequently because it has a significantly shorter half-life than either second-generation compound (up to several months for diphacinone vs.  6+ months for second-generation compounds).    

During previous research by the National Park Service, and more recently, by myself, we have found a strong association between notoedric mange, an ectoparasitic disease, and anticoagulant exposure in bobcats.  Although we have not found a specific association between mange and first-generation anticoagulants, we have tested for an association only using results from anticoagulant testing using liver samples (we don't have enough blood samples from mangy animals to do the same testing using blood). And as mentioned above, we do not detect first-generation compounds as frequently in liver samples because they have much shorter half-lives than the second-generation compounds. One of our significant findings using this method is that we learned we have been underestimating wildlife (or at least bobcat) exposure to first-generation anticoagulants by relying solely on liver samples to do the testing.  In summary, we use liver samples to test for an association between mange and anticoagulants, and because we underestimate first-generation anticoagulant exposure when we test liver samples, a lack of association between mange and first-generation anticoagulants could potentially be driven by a bias in the shorter tissue half-life of first-generation compounds compared to second-generation compounds. 

Overall, in terms of relationships between mange and anticoagulants, we did find evidence that multiple exposure events to anticoagulant may be the critical component in the development of severe mange. In bobcats with mange, we typically find higher residue concentrations and exposure to more different compounds compared with bobcats without mange, suggesting that multiple exposure events could be a critical factor. In fact, we find a strong association between bobcat exposure to 2 or more compounds, and mange- where bobcats that are exposure to 2 or more compounds are more than 7 times more likely to die of mange than other sources of mortality.

Another interesting note- we more frequently detected anticoagulant exposure in blood samples (and those detections were most frequently first-generation compounds) during the dry season (May- October). Bobcats are 2.6 times more likely to be exposed during the dry season, and we detect 55% more anticoagulant exposure during the dry season. Interestingly, we also 67% more mange cases during the dry season (which I speculate could be related to increased exposure to anticoagulants).

Finally, during some more recent literature research I've done, I discovered that diphacinone itself could potentially pose dangers aside from its effect as an anticoagulant. Similar to warfarin (or coumadin), it has been used therapeutically to prevent thrombosis in humans.  But because a small, but significant, percentage of the human population who have used the drug develop a hypersensitive, immune-stimulated reaction, the drug is banned in the US.  It is still used in Europe, however, but some papers have been published showing that human use of the drug can also result in suppression of certain types of immune-related cells and kidney failure.  Whether these effects occur for animals that are exposed to diphacinone is unknown, but of potential concern. Overall, diphacinone, or other first-generation anticoagulants, should not be viewed as a safe alternative to second-generation anticoagulants.


How To Catch A Cat Part III: Setting the trap

This blog post is part of a series that covers how biologists go about catching the wild cats they study.  In the last post I described how to choose a trap site.  Once a trap site is chosen the next step is to actually set the trap.  Different kinds of traps are used for wild cat studies including cage traps and snares.  For use in research, each type of trap offers advantages, and for the purpose of this post, I'll cover how cage traps are set since I exclusively used this type for my bobcat research.

There are a few key tools used when setting cage traps. First, of course, you need the trap itself.  A lot of people ask me exactly what the trap looks like, and in the the pics below (that show the trap setting process) you will get a glimpse, but the traps I almost always use are heavy wire cage traps approximately 2 foot x 3 foot x 4 foot.  They have a single entry point at one end of the cage, and at the back of a cage is a wire treadle plate that when the animal steps on it, the door shuts.  In addition to the cage itself, I always maintained a "tool bag" that I used for setting traps.  In my tool bag I carried a hammer, wire, fishing line, scent lures, a hand shovel, a cloth bag, and a GPS unit.  When trying to trap an animal, it is very important to understand the biology of that animal. Cats, wild or domestic, are very visually-oriented creatures, and so it is important to cater to their visual sensitivity. That's why, among the tools in my tool bag, are always visual lures ones such as a feather pillow, a couple of antlers or bones, and old CDs, big feathers, or old soda cans that can be used as ornaments around the trap to attract the attention of animals.

In my last blog, I described picking a trap site and so once I know where I need to carry and set the trap, I gather all my tools and the cage and head off to the trap site to set the trap.  The cage itself weighs around 35 pounds, so that, along with the tool bag, can make for an interesting walk to the trap site if it is far or through a heavily vegetated area.  For some sites, a 20 min walk can easily double if you are carrying a huge and heavy cage with you.  The benefit though is that it gets you in shape fast if you are setting traps regularly!
When I set the trap that I'll describe below, it was luckily an easy spot not too far off from a human hiking trail The picture below shows a spot I picked out to set a trap. Vegetation in the Santa Monica Mountains can be very dense, so it is hard to tell but it is just on the edge of a natural animal trail, is flat, and is a position that is just between two sage bushes which will be great for disguising the trap. The red arrow in the photo below shows where the trap will be set.

Once I get to my trap site, I set all my tools down, and in the photo below you can see the cage along with my tool bag while I'm getting ready to set the trap.  Here you can see only half the cage, the feather bag inside the cage, and my toolbag on top of the cage.  


 Next, I put the cage in position.  I want it sandwiched between vegetation with the door to the cage just about flush with the animal trail.  This way, any bobcat that walks along the trail won't miss the trap.  It can be quite difficult to get a wild cat to go in a cage trap, but a great first step is making sure that the trap is in a position along a trail that increases the odds a bobcat will actually see whatever lure is inside the trap. I always try to have my traps so that the door is not only flush with the animal trail, but that the trap itself is perpendicular to the trail so that no matter which direction a bobcat may be walking along the trail, it will have equal opportunity to see whatever lure is inside the trap.  In the photo below, I have set the trap in the position I want it.


In the pics below, there's a great view inside the trap.  Here we are looking into the cage trap when the door is set open.  In the photo on the left, notice that the bottom of the trap is a hard wire mesh. Because bobcats are ambush predators that like to sneek up on their prey, they can be sensitive and deliberate about where they put their feet.  They are very careful not to make too much noise when hunting since it might alert their prey. Often, the visual lures that are put inside a cage trap to entice a cat inside will resemble potential prey for the bobcat.  In the photo on the right, I've placed a decoy foam rabbit, with the nose of the rabbit facing the back of the cage.  From this view, we see the decoy from behind and it resembles the white tail of a rabbit.  If a bobcat is tricked by this decoy, it may try to stalk and then pounce on it, so I always try to disguise the bottom of the cage with dirt so the bobcat won't feel the hard wire mesh on the bottom.  Putting dirt in the bottom also lends the cage stability, which is another great way to try to eliminate as many "unnatural" things about the trap as possible.  These photos give a great view of the treadle, or the "plate," in the back of the trap where the animal needs to step to trigger the door to shut.  Its hard to see, but the treadle is linked with a chain that controls a bar that keeps the door open.  If the treadle is pressed, the chain pulls the bar, releasing and shutting the door.


Now that the cage is in place and there's dirt on the bottom of the cage, it is time to start disguising it!  That means gathering a lot of vegetation to put both inside and outside the trap.  On the inside, the treadle needs to be disguised.  On the outside, the trap itself needs disguising so that bobcats that see that trap from the outside don't get suspicous before they even get close enough to see what's inside.  In the photo on the left below, grass goes on the treadle underneath the foam rabbit.  On the right, I've started to put vegetation all around the trap to make it look more natural.

Next, I start putting the finishing touches on!  Vegetation is put on top of the door, and I make sure that all the vegetation on the outside looks natural and is relatively stable.  The vegetation should stay in place even if it gets a little windy at the trap site.  In the photo on the left (below), the red arrow is pointing to the front of the cage trap.  At this point, its hard to even see where the trap is, which is what I'm shooting for!  It looks natural on the landscape.  In the photo on the right, I've put some white feathers just inside the trap and on the trail.  These feathers will help grab the cat's attention when it walks by the trap, hopefully getting the cat to stop and take a look inside the trap and be enticed by the fake rabbit.  The feathers come from the feather pillow that I have prepared with my other cage setting supplies.

At this point, the trap setting is done!  Before I leave the trap, I test the treadle to make sure the trigger action of the trap is just the way I want it, and that if a cat enters the cage and steps on the treadle, the door will shut properly.  When its all done, I'm ready to head out to set another trap, check what traps were already set, or head home for the day.  Now, it can be hard to even see the trap, although the feathers are a dead giveaway!  


Heading out, I take one last look at the trapsite (photo below).  Now it really blends in to the landscape (red arrow pointing to trap below).  I'll be back early the next morning to see if I've caught anything.  In total, it usually takes about one hour just to set a trap. Despite the hard work, it's always fun to set a new trap because it really brings on a feeling of total optimisim that you may catch something very exciting in it!

During the next blog post, I'll cover what actually happens when I've caught a bobcat in a trap.  I'm heading out of town next week to visit another urban carnivore study area in South Africa, so it'll take me a few weeks to get the next post up.  Sorry for the delay, but maybe I'll also have a good story to tell from South Africa!  

How To Catch A Cat Part II: Make sure you have a question and a few trapping basics to consider before setting the traps

My first blog entry in this series focused on the very first important step in catching wild cats for research: learning where there may be wild cats to study!  Once you've learned where there are cats to study, you need to also have a good study question that you are going to focus on that requires capturing animals. So this is a good chance to talk a little bit more about my research and why I ended up studying bobcats across the Santa Monica Mountains.   

My study focuses on how urbanization affects the health of bobcats in the urban, fragmented landscape around Los Angeles.  To perform this research, I spent more than two years conducting intensive bobcat trapping so that I could collect samples (blood, urine and fecal material) to measure health indicators in our local bobcats. These health indicators are very similar to what your vet would be interested in if you took your dog or cat to a vet to do a routine check up. Your vet may collect fecal samples to check for internal parasites like tapeworm or roundworms and blood samples to test for viral or bacterial infections.  With blood we can also test whether the animal has a healthy immune system and with both blood and urine samples, we can test whether the animal has normal organ function. So my aim was to evaluate these various factors in wild bobcats in the Santa Monica Mountains since for bobcats living in/near urban areas, they may be exposed to pesticides (like rat poisons), can contract diseases carried by domestic cats, may have reduced genetic health in isolated populations at risk for inbreeding, and generally can have a more stressful life since they are regularly exposed to roads and human activity.

To understand how urbanization affects these health indicators in bobcats, I needed two groups of animals so I could make comparisons between the two groups.  For my first group, I captured "control" group of healthy bobcats, largely unaffected by urban development, so that I could establish baseline values for the tests I was conducting. My second group was bobcats I captured in urban areas.  Luckily, the Santa Monica Mountains offers some areas (like the State Parks- especially Point Mugu State Park) where bobcats are less affected by urban development, and also some areas of habitat fragmented by urbanization but still host to bobcats. So, for my study, I sought samples from bobcats in State Parks (Point Mugu, Malibu Creek, and Topanga State Parks) as well as in urban habitat patches east of the I-405 (Bel Air, Beverly Hills, Hollywood Hills, and Griffith Park) and north of the 101-freeway in Thousand Oaks.

Now that I had a research question and knew where cats were (see previous blog post) in the Santa Monicas, I was ready to start trapping. To start getting your trapline ready, there are a few important things to know about trapping, and about the animal you are trying to trap.  First, once you set a trap, it can take weeks (or months for larger cats like mountain lions) before you get a capture!  A lot of people think that studying these wild cats must be a daily exciting adventure involving seeing wild cats every day at work. But the truth is that biologists studying wild cats actually very rarely see their study animals since they are solitary, territorial, have large homeranges (making it so there are few individuals in a given area) and on top of it all, are very shy and elusive! 

So when you set your traps in a bobcat or mountain lion's territory, you may have to wait for weeks until a cat even walks by the trap.  Of course, setting multiple traps increases your odds, but another important note- we check our traps everyday twice a day- once in the morning and approximately 12 hours later in the late afternoon/early evening! So by time alone, you are limited in how many traps you can get to during the morning before you have to start your afternoon checks.  Another important element biologists must consider is that since wildcats are mostly nocturnal, we are more likely to find cats during the morning trap checks and so you want to make sure it only takes no more than a few hours to check all your traps in the morning so that animals aren't stuck in the traps unnecessarily long.  For bobcats, and sometimes mountain lions, we use large cage traps that, although very safe for the animal caught in them, we always aim to minimize the amount of time animals are in the traps so they aren't unnecessarily stressed. 

Because wild cats do tend to have large homeranges (about 1-3 square miles for bobcats and 60-200+ square miles for mountain lions) you also don't want to have your traps too close together.  Remember that these animals are solitary and territorial, so for bobcats in a 1-3 square mile range, you may only have 2-3 animals roaming around.  So ideally, you want to cover many square miles with your traps, but travelling from trap to trap then increases the time to check your traps, which you are trying to keep to less than 3 hours.   

On average, I had 15-20 traps set at all times during my trapping seasons.  For this number of traps set, I would definitely need two people for every morning trap check to ensure that we covered the ground quick enough.  One of the great things about doing field work like trapping cats is that there can be a LOT of hiking involved!  It is very hard work (I'll cover that in the next blog) as when traps are set, they are open 24/7. Everyday you must check the traps.  We keep traps open 24/7 during trapping season because if a cat only walks by a trap once over a 3-4 week period, you don't want your trap closed the day the cat ends up passing by the trap!  At the end of the day, it's a lot of hard work and requires a LOT of patience. For me, I enjoy being outdoors, hiking around, and doing hard work.  I can be patient to wait for captures to happen, and so when they do, they are very exciting!  

For the next blog I'll cover how the traps themselves are set, and after that, what happens when we get a cat!

How to Catch a Cat, Part I: Finding cats!

I've been studying how urbanization affects the health and disease susceptibility of bobcats in and around the Santa Monica Mountains since 2006.  This work has involved capturing bobcats to collect samples from them.  I've been fortunate to not only maintain my own trapline for this effort, but to collaborate with the National Park Service to get samples from the animals they trap for their own ongoing long-term bobcat research. From 2009-2011, I intensively trapped bobcats for nearly the entire two years (taking breaks only during kitten season when females could have young kittens to tend to).  Because of this work, I've been blessed to have handled at least 100 bobcats, and have myself trapped approximately 60 individuals. In addition to the bobcat work, I've aso been fortunate to collaborate on the National Park Service mountain lion project, also in the Santa Monica Mountains. I've not seen nearly as many mountain lions as bobcats, but working with both species, I've learned important techniques for trapping and handling cats.
When describing my work to both scientists and nonscientists alike, most people first ask how we catch the cats to get the samples. So I thought it would be a good blog topic- or topics.  Its a multistep process, so for this entry, I'll focus on the first step- figuring out where the cats are so we know where to put our traps! *(See note at end of entry about trapping ethics)
Diving into how to catch a cat...the first step is figuring out where the cats are!  There's a couple ways to do this- when working in a new study area where it is unknown whether your species of interest is present, biologists may set up remote wildlife cameras to determine what species live  in the area. For example, when National Park Service biologists started their mountain lion project in the Santa Monica Mountains in 2002, they had no idea whether there were even mountain lions in the Santa Monicas! Mountain lions are found throughout California but they are very sensitive to urbanization and habitat fragmentation.  So in areas where there is a lot of habitat fragmentation and urban development, there may be areas of "local extinctions" where populations are unable to survive longterm and their populations go "extinct" in a localized region. Given that the Santa Monicas are next to one of the largest cities in the world, its not stretch to imagine that it would be difficult for a healthy mountain lion population to persist in the region! So, to discover if mountain lions were even still present in the Santa Monicas, NPS set up heat-triggered remote wildlife cameras around the Santa Monicas where every time an animal walked by the camera, a photo would be taken. It was using this method they discovered that there were mountain lions in the park!

Another method is to get out in the field and look for animal tracks and sign. Every species of animal has a distinctive track and many have distinctive fecal material (also known as "scat"). Some animals (like bobcats or mountain lions) mark their territory with distinctive scrapes on the ground.  The scrapes for bobcats and mountain lions look very similar, but mountain lion scrapes are much larger than bobcats!  So, as a local carnivore biologist, I've learned some distinctive signs (scat, tracks or scrapes) for fox, mountain lion, coyote, skunk, and raccoon.  Using both this method of looking for animal sign, along with the remote cameras, is useful to not only identify what animals live in an area, but also learn what are common paths that animals use.  Knowing the best paths is the next step to knowing how to catch a cat!  My next entry will focus on choosing a trap site, so keep posted for that! 

*An important note- we (myself along with my National Park Service collaborators) do not take trapping and handling animals lightly.  When trapping and handling animals, it induces stress in the captured animals and there's always a risk that something can go wrong for the animal or the biologist.  For projects that involve this invasive techniques, we must have our protocols reviewed by animal ethics committees and weigh the cost of stressing an animal with the benefit of the research where the benefit must outweigh the cost.





Not So Urban Carnivores

In September, the UCLA lab I work in took a trip to Yellowstone National Park.  Our lab, the Robert Wayne lab, is a conservation genetics lab, specializing in dog and especially wolf genetics.  Most of the lab members study domestic dog or wild dog species, such as grey wolves and Channel Island foxes.  But just because people in our lab study these animals, it doesn't mean we are always around these animals!

So, in order to see some wolves in action, we decided to take a trip to Yellowstone.  Given the expense of flying to the Yellowstone area, many of us drove the long 17-19 hours to the park.  Once we got to Yellowstone, everyone in my car was excited to see some wildlife and take a nice long hike!

Watching wolves in Yellowstone mostly involves a lot of driving around.  In order to see them, you generally have to go to the open valley areas where, with binoculars or spotting scopes, you can observe them from a distance. To find them, you have to drive around to see if you can spot them- or spot the people that have already found them and are standing with binoculars and spotting scopes looking off in the distance.  In the open valley areas, you don't have vegetation blocking the view.  Wolves and other wild dogs are quite different than most wild cat species in that you can actually observe them!  With wild cats, because they are elusive and solitary, it makes it difficult to find them, let alone observe them for an extended period of time.

What's particularly amazing to me about the wolves in Yellowstone is that when they make a kill, it is sometimes possible to see them feeding on their kills.  And their kills also attract other scavenging animals like grizzly bears, coyotes, and ravens to name a few.  So if you are lucky to find a fresh kill close enough to the road, you may have the chance to see multiple species feeding and potentially interacting with each other.

Unfortunately for us, we didn't see bears feeding on any kills, but we did see wolves, including wolf pups, feeding on a fresh kill they made.  We also observed a coyote scavenging an older kill. The coyote we had the chance to see seemed almost nervous to scavenge the old wolf kill! Perhaps it was nervous to encounter any wolves potentially still on the kill.  

Beyond wolves and their kills, we did see other amazing things.  We observed a coyote hunting for what appeared to be gophers (see photos in slideshow below). One thing that's interesting about the Yellowstone coyotes is they look vastly different from coyotes in the Santa Monica mountains!  Their coats are a lighter grayish brown, rather than reddish brown. They are also larger and a little bulkier.  This isn't surprising given the colder climate the coyotes face in Yellowstone vs. in the Santa Monica Mountains. The bulkiness of Yellowstone coyotes helps them survive the winters, and their coat color helps them blend in better with the Yellowstone environment.  

We also saw bald eagles, golden eagles, a big grizzly, tons of elk, and pronghorn antelope. Pronghorn are really cool animals- they aren't true antelope, though the fill a similar ecological role as antelope in Africa. They are actually unique in that they are the only surviving members of the family (a type of classification for organisms) Antilocapridae.  One cool thing about them though is that they are the fastest land mammal in North America and can run up to 65 miles per hour.  They evolved their speed due to pressure from the now extinct North American cheetah that once roamed the plains of North America.  The cheetah went extinct thousands of years ago, but the pronghorn remains.  

One other cool thing we observed was that we heard elk bugling- something the males do to attract the females. Since it the elk were in rut (the mating season), there were large harems of female cow elk, with males watching over and claiming them as his own!

see the youtube video to hear and see it : http://www.youtube.com/watch?v=pYzWmKlZtrU)
Overall, the Yellowstone trip was quite a success!

An unusual scene

Over the weekend, I went out with a couple friends, Tanner* and Johanna, to investigate what appeared to be a lion kill that Johanna stumbled upon the day before.  Johanna and Tanner are citizen scientists, meaning that although not trained in biology, they have a keen interest in biology and desire to contribute to scientific research locally in southern California.  Because of their passion for local wildlife and learning what they can about wildlife in their natural habitat, they spend most of their free-time hiking around various open spaces honing skills such as wildlife tracking and the use of remote cameras to study carnivore behavior.  Their skills in tracking and remote camera use exceed those of many biologists I know, and every time I go out with them, I learn something new!  So when Johanna stumbled upon a dead deer but was unsure how it died, I was only too eager to go check it out.  The deer appeared have died at some point earlier in the week, but had no overt signs that something was feeding on it. One possibility, of course, was that it was killed by a mountain lion earlier in the week (though the there were not signs it was still eating the deer if that's what happened), and if so, this provided a potentially opportunity to gather mountain lion DNA (swab any bite marks or look for mountain lion scat that they sometimes leave at their kills).  It is unusual for a lion to kill something and not feed on it, but not impossible for that to occur.  I should clarify before continuing with the story- we did not expect to encounter a mountain lion, and if we believed there was a reasonable risk of encountering one, we wouldn't have revisited the dead deer.  So, although we should all acknowledge that mountain lions live in our local State Parks and we should all act accordingly, we weren't out there to chase down a mountain lion. 

So, we headed out to the Santa Monicas where Johanna found the deer, and where Tanner also happened to also have wildlife cameras as part of his volunteer work with the National Park Service.  By time we got there, the deer's head was covered with maggots, and no bite wounds were visible either on the head or neck, so it remained unclear if a mountain lion was responsible for the death (although Johanna did get the pics below when she first discovered it, and no maggots were present).



 However, Tanner happened to have a remote camera within 10 feet of the dead deer, but where the deer died was just out of the visual field of the camera.  The camera still picked up some very interesting footage that provide some clues as to what may have happened.  In the video, we see two deer startled by something out of view of the camera.  The deer seem to be attempting to run from whatever startled them.  Then, out of view of the camera, we hear loud breathing and a few grunts, presumably by the deer, or perhaps whatever startled it.  The startled running combined with the sounds do lead me, at least, to believe that the deer was killed by a mountain lion.  There was a patch of missing fur that seemed perhaps licked off by whatever killed it just under the left elbow of the deer (see photo).  I did swab that region, so perhaps if the fur was licked off by a mountain lion, I will get DNA off the swab.  If no DNA is present, perhaps this will remain a mystery forever!  But check out the video footage and see what you think!     



*Please note: Tanner is a volunteer with the National Park Service, and so the work he does with cameras in State Parks within the Santa Monica Mountains National Recreation Area falls under research permits conducted by wildlife biologists with the National Park Service.  

Coyotes always to blame for a missing house cat?

Yesterday a colleague (who studies salamanders) asked me about whether potential neighborhood coyotes were to blame for a domestic cat that was found dead in a nearby yard.  He described the scene of finding the pet, and given that it was an urban, residential area, we narrowed down quickly potential predators.  Since coyotes are so frequently blamed for missing pets, he asked if I thought this was the case.  I will spare the details, but to me, it didn't sound like a coyote was responsible for this cat's death.  One interesting thing about predatory animals is that different predatory species may rely on different methods to kill and consume their prey.  In this way, without actually seeing the predatory animal kill their prey, we may be able to gather clues about which predatory species did the killing!   The scene my colleague described did not sound like coyote kills that I've heard about, read about, or seen.  It sounded to me like perhaps a predatory bird- possibly a great horned owl- was the predator in this case.  Most people don't imagine that great horned owls will, or can, hunt domestic cats.  But they can!  The Cornell Ornithology Lab has a great online resource where you can read about basic life history traits of many different species of birds, as well as learn cool bird facts.  Here you can find information about prey that great horned owls will take. 

Coyotes are often blamed for missing pets, and while this is sometimes the case, they may not always be the culprits.  The Cougar Network has put together a very nice guide which describes the differences between canine (either domestic dog or coyote) kills and wild cat (such as mountain lions or bobcats) kills.  Here you can learn about tell-tale signs of domestic dog or coyote kills in case you ever find an animal that has clearly been preyed upon and you want to try to figure out which predatory species is responsible (though mountain lions generally avoid urban areas so keep in mind that they are not likely responsible for missing pets).  If you live in an urban area or near a natural park and are worried about your pet's safety, the best thing to do is not let your pets outside unattended.  Outdoor cats will be at risk for being attacked by the natural predators that manage to survive in and near Los Angeles.  We cherish our pets and so we should also be aware of the risks the face outdoors.  However, it's quite amazing that predatory animals like coyotes, great horned owls, raccoons, and even bobcats manage to persist in and around a metropolis such as Los Angeles!  Thus, we should regard our amazing nature with respect, and protect our pets by keeping them indoors when possible.

Santa Monica Mountain Lion Death

Today's news about the mountain lion shot in Santa Monica is tragic and unfortunate.  The individual was a young male.  He likely originated from the eastern portion of the Santa Monica Mountains and was looking for a safe area to disperse to and establish his own home range.  We have obtained tissue samples that we will use for genetic analysis in the Robert Wayne lab at UCLA to establish whether he originated from the Santa Monicas.  Jeff Sikich with the National Park Service was able to obtain the tissue sample, and while there, established that the mountain lion did appear to a wild mountain lion (rather than a captive mountain lion that wandered astray).

Mange, Mange, Mange!

Notoedric mange is a disease that seems to be an increasing issue for bobcats in California (see 'Disease' page for more information about this disease).  For me, this is a disease that is very interesting to study for several reasons.   Prior to 2002, a mange epizootic (the equivalent of an epidemic for humans) had never been documented in any species of wild cats.  In 2001, biologists with the National Park Service (NPS), working in Santa Monica Mountains National Recreation Area, observed their first notoedric mange case in a bobcat in the Thousand Oaks, CA.  Lead NPS biologist, Dr. Seth Riley, was startled at what he observed for this bobcat (see photos below of bobcats with mange).  Having studied bobcats for nearly 10 years by 2001, and never before observing a bobcat in this state, he was naturally shocked!  He decided a veterinary pathologist was needed to diagnose what had happened to the bobcat.  So, a pathologist with the Center for Animal Health and Food Safety performed a necropsy and ran a battery of tests on the bobcat.  The pathologist found that the bobcat was extremely emaciated, was covered in notoedric mange mites, and after running a panel of potential toxicants the individual could be exposed to, found that it was exposed to high levels of anticoagulant rodenticides.


In 2002, a full-blown notoedric mange epizootic hit the bobcat population in Thousand Oaks.  Over the next few years after 2002, more than 50% of radio-collared bobcats died of notoedric mange.  Scat (fecal) surveys NPS performed along multiple fire road and trail transects in the same area mirrored the trend observed for radio-collared bobcats.  Nearly 90% fewer bobcat scat was collected in the same area, confirming that during that time, the local bobcat populations were severely impacted.  In recent years, since 2006, mange has been observed to affect multiple A map of California with the counties highlighted that presently have bobcat mange epizootics occuring. The starred areas indicate regions where research on bobcats is occuring and through the research, mange has been documented.bobcat individuals and populations in Orange, Riverside, San Diego, Santa Barbara Counties and 3 other northern California Counties.  There are two potential things occuring with apparantly increasing notoedric mange:  

1) Because bobcats are elusive and difficult to study or observe, notoedric mange could be something that has affected their populations in the past but now we are more aware of the disease impacts because of biologists studying them in the State and because of increasing urbanization encroaching upon bobcat habitat.  

2)  Something is changing increasing bobcat susceptibility to the disease.  This isn't necessarily one thing that could be different.  Rather, it could involve multiple factors like higher bobcat population densities increasing opportunity for transmission of mange between individuals, potential stress from living near urban areas, increased opportunity to contract the disease from domestic cats, and exposure to toxicants like anticoagulant rodenticides.  Bobcats are exposed to many factors in the wild, and there are also lot of unknowns for this disease that complicate the picture even more.  For example, we are unsure whether bobcats always carry low mange mite numbers, or if it is a novel disease for them contracted instead from domestic cats- known carriers for the disease.  It's possible that even the bobcat's prey items (woodrats, rabbits, or ground squirrels) are carriers of the disease!  So, this makes the issue VERY difficult to study, and tease apart the many factors affecting bobcats!

Where Do We Stand On Understanding This Disease Now?
Notoedric mange has been one of the focal points and inspiration for my Ph.D. bobcat disease susceptibility research.  I've been studying this issue for the past 6 years, and although some days I feel we are no closer to understanding this issue better, I have to keep things in perspective!  First, research takes time.  My research has required that I go out and design a project to study the issue, raise money to support myself and the research (as a graduate student at UCLA, I've been responsible to pay for ~85% of my research expenses, living costs, and tuition), trap bobcats to collect samples (including ones with the disease!), perform the lab work to get data from the samples and then analyze and write up a report about the data I collected.  After 6 years on this path, and because of some of the samples I have and data I've collected, I've started collaborating with vets, epidimiologists, a gastroenterologist, and a toxicologist at UC Davis.  Additionally, we have a vet and veterinary pathologist working for Department of Fish and Game now on the team to evaluate California bobcat health.  Finally, we are increasing our communication with others studying bobcats across California to increase our opportunity for sample collection and monitor the state of other populations.  This team we've assembled is a group of folks with varied expertise to help crack this problem.  To start off, they have already recommended additional tests to run on the samples I've collected and are helping to interpret our findings thus far.  Our team met last week at UC Davis, and we discussed what is known already and some data I and the state pathologist has collected on bobcats with notoedric mange.  

Conclusively, we can still say that all bobcats that die with mange, whether in southern or northern California, are exposed to anticoagulant rat poisons.  And, bobcats that are exposed to anticoagulants at greater than 0.05 parts per million residue concentration (measured in liver tissue) are 7 times more likely to die of notoedric mange!  When they die, they are extremely emaciated.  Some have evidence of anticoagulant toxicity, but anticoagulants are not the primary cause of death.  One bobcat with severe mange that died while I was attempting to transport her to a wildlife rehab facility had a delayed clotting time (the mode of action of anticoagulants is to prevent the formation of some clotting factors essential to prevent uncontrolled bleeding).  Most bobcats that die with mange have tarry-looking fecal matter (a sign of blood in the stool) and some have had blood in their stomach or intenstine.  Both could be associated with anticoagulant toxicosis.  Also, it seems there is no other disease that bobcats are first exposed to that is increasing their susceptibility to notoedric mange.  

But why would anticoagulants increase bobcat suscpetibility to notoedric mange and how would it increase their susceptibility?  That is what our new assembled team hopes to address!

One problem we are finding in dissecting available physiological health data collected from bobcats just before they died with severe notoedric mange is that they are so sick, it's hard to know whether what we are finding in these data is because of the anticoagulants or because of the disease.  However, because we have some stored samples available from bobcats with mange, our bobcat health team is reccommending additional tests to try to tease these factors apart further.

Overall- the issue is very complicated, not the least bit straightforward, difficult to study under the best of circumstances.  Some of the challenges that make this all the more difficult is a lack of information about notoedric mange and all the species it affects.  We also have limited funds to run the tests we need to get more information both about healthy bobcats and those with notoedric mange and/or anticoagulant exposure.  It would also be very helpful have a pathologist perform all of our bobcat necropsies, but since those cost $200/animal we biologists perform them ourselves and although we do our best, we are likely missing critical information that could help us understand this issue better.

A pretty amazing week

Last week I was out of town to visit family and friends in Texas.  I was gone for the entire week and it was great to catch up with everyone.  Just before I left, I checked some of my remote cameras I have out in Topanga (placed with the objective to get pictures of B290), and I discovered another bobcat with notoedric mange in the area.  The mange on this bobcat, like B290's when I caught him, is not yet a severe case.  So, a primary objective I had upon returning from Texas was to get traps set for the mangy bobcat.

Like B290, I hope to capture him, treat him for the mange, get samples, and if I'm lucky, put a radiocollar on him (assuming a collar happens to be available- they are expensive so I rely on collaborators to provide the collars).  I finally got everything together and on my way home from work at UCLA, was going to set a few traps on Tuesday.  However, Jeff Sikich called me to tell me that a trap was set for P19 and let me know he'd be waiting near the trap that evening to see if she decided to go into the cage trap.  So, instead of setting traps for bobcats, I decided to put it off for a day and go try to see a mountain lion! 

We waited for P19 until around 8pm, and although she was near the trap (we know because she had a GPS-enabled radiocollar and could determine her location using the radiocollar signal), we were skeptical she would go into the trap.  She'd already been cage-trapped two times, and some animals will eventually wise-up to the trapping methods we use to capture them.  So, we called it a night, though left tracking equipment with a project volunteer, Julie, that happens to live near the trapsite and could hear the trap signal from her house (we had a radio-transmitter on the trap that would emit a specific radio-signal if it was triggered)!  So, periodically through the night, Julie listened to the trap and at 1:30am, success!  The trap was triggered and P19 was in the trap vicinity!  We wouldn't know if P19 was actually in the trap until we physically checked the trap.  So, upon getting the call at 1:30am, we went to the trap site and in the dark, we hiked to the trap with all the capture gear in tow in case it was P19 in the trap.  And indeed, she had gone into the trap.  We drugged her in order to get samples and change her radiocollar.  The radiocollar she was already wearing was placed on her before she had her last big growth spurt, so it was time for her to get a larger collar.  To drug her, we blowdarted her through the cage, and since she was very mellow and calm in the cage, all went smoothly with the drugging.  Upon drugging her, we would have approximately 1 hour to get samples, assess her health, and change her collar.  All went well and after 1 hour, she was off, recovering from the drug and walking back into the mountains, her natural habitat.  We walked out of the trap site and were back at our cars at 4am.

With samples in tow, I now had to begin processing them.  At captures, because my overall 'bobcat disease susceptibility' project relies heavily on blood samples, I have taken on the responsibility to process all blood samples collected at captures that I am present for- mountain lion, bobcat, or fox.  Some blood samples we collect at our captures require that we centrifuge them for approximately 20 minutes ASAP and then flash freeze the samples in liquid nitrogen.  Usually we have a centrifuge that we carry with us in one of the National Park Service vehicles, but having been woken up in the middle of the night, we didn't have the right vehicle with us this time.  Luckily, we weren't too far from the NPS warehouse that also has a centrifuge.  I headed straight there to start tending the samples.  These samples that reqire the most immediate of care will give us information about the clotting time of the individuals from which we collect samples.  They are called PIVKA samples, which stands for 'proteins invoked in Vitamin K absence.'  Using these samles, we will assess whether animals exposed to anticoagulant rat poisons are experiencing the intended action of the poisons- to disrupt the Vitamin K cycle that is fundamental to the production of several critical clotting factors in the blood.  I was able to finish processing those samples by 6am and had a liquid nitrogen container in my car that I froze the processed samples in.

Once I'd finished that task, I was determined to get some traps set for the mangy bobcat in Topanga before heading to UCLA to finish processing the rest of P19's samples.  I headed straight to Topanga and had an idea of where I would put the traps.  Figuring out where to put traps can be the most time-consuming part of setting traps. 

I managed to set traps that morning, starting at 6am.  I went to the field, found two spots to get my first couple traps out in an area near where I'd gotten pictures of the mangy bobcat with a remote camera.  It takes about 1 hour to set each trap, so for a couple hours, I worked to get the first couple traps set.  For each bobcat I try to cat, I want several traps up to 1/2 mile apart from eachother- especially if I don't know the movement patterns of the individual I am targeting.  Since locally, bobcats have home ranges spanning about 1 square mile for females and about 2 square miles for males.  Therefore, having several traps spread out over about 1-2 square miles increases your odds of having your target bobcat walk by the trap. 

Knowing I had a lot of work do to at UCLA with the lion samples I'd collected, I could only get a couple traps out that morning.  At least I had something in place in case the bobcat walked by the area.  So, after setting traps, I was off to school!

I headed to campus where I "process" the blood samples I collect.  This involves making sure the samples are in proper longterm storage tubes.  To Be Continued...


My response to a few questions regarding poisons

I was recently emailed by a medical and environmentally focused writer.  She posed a few questions to me that she will be addressing in her blog.  I haven't requested permission to include her blog or her name, so I will guard her anonymity.  However, the questions she posed are frequently sent my way via email or telephone calls, so I felt it would be good to list the questions she sent and my responses in this blog.  I prefaced my responses to her questions by highlighting that I study anticoagulant exposure in wildlife, but am not an expert on rodent control practices.

Question 1 posed by writer:      I read your answers to the July Ojai article in the summer. Do you have any more updated info or can I take the stats from that?

Response: New data from my project suggests that 95% of bobcats are exposed to anticoagulant rodenticides (ARs) across our study area.  This includes data gathered from both urban areas and also from individuals in more "remote, pristine habitat" locations such as Point Mugu State Park.  Bobcats found to inhabit agricultural, urban, and even State Park lands are exposed to ARs.  This does NOT necessarily mean that bobcats in the parks are exposed to poisons placed on State Park land- merely that bobcat homeranges even for individuals that live in state park areas may abut urban or agricultural areas that the bobcats venture into.  A fetal bobcat in our area was revealed to be exposed already to ARs and so this is an issue beginning for bobcats during prenatal development and likely persisting for the duration of an individual's lifetime.

Question 2 posed by writer:      Is there any poison available in stores will not cause problems or will cause fewer?  We ended up using a neurotoxin poison from Lowes and Home Depot, hoping it was better - is there any research on those. We ended up using that for our issue but now I wonder why wouldn't there be a food chain rxn with those?

Response: The bottom line about poisons available on the market in the US is that each and every one has risks for wildlife associated with their use, either through primary or secondary poisoning.  Cholcalciforal, bromethelin, zinc phosphide, and strychnine pose both risks- primary and secondary poisoning.   Further, I'd like to add that because anticoagulant rodenticides are the most commonly used method for rodent control worldwide, more research effort has been put in their direction.  They are globally ubiquitous (perhaps with the exception of the UK, I feel like I read they are recently banned there).  If people switched to other poisons, we may become more aware of the hazards they pose.

It sounds to me like you aim to be environmentally conscientious.  In doing so, I encourage you to consider whether poisons are absolutely necessary.  Must we replace one poison with another?  This is the most frequent response of folks that I present my work to- if I can't use anticoagulants, then what poison shall I use?  If we truly care about wildlife, we should aim to mitigate our poison use entirely.  My stance is NOT that poisons, and even anticoagulants, are necessarily altogether banned.  My stance IS that any poisons should be absolute last alternative, used only when human health or structural integrity of buildings is threatened by uncontrollable rodent populations, and in the case of ARs, for use against invasive rodent populations affecting endangered native wildlife.  However, these are exceptional circumstances, and not the circumstances with which individual residents are typically faced.

I advocate the integrated pest management (IPM) approach, and according to San Francisco county guidelines for IPM - rarely, if ever, are residents truly faced with the need for poison use according to the "human health or structural integrity of buildings" concerns.  I encourage you to look in that direction, and in fact, Camilla Fox and others in Nor.Cal. have successfully pushed towards the banning of anticoagulants in Marin County, and the adoption of IPM instead.

Question 3 posed by writer:      What can the public do?  for ex, the largest pest control co here in our area assured us their anticoag was safe, even after I shared research articles with them. What should a person do to combat this misinformation? And are there some pest control company rat control practices that are better - if so what?

Response:  I encourage the public to be free-thinking educated consumers about the product they choose for pest control around their homes.  For this reason exactly I present the information on my website in its present format.  I understand what pest control companies tell people- I've heard it from folks who, like you, have presented them with information and they refuse to acknowledge the damage it does to native wildlife.  The bottom line about pest control companies is that:  1) they have a product to sell.  We must remember that they are a business and their products are poisons, 2) they are not scientists, chemists, biologists, wildlife naturalists out picking up the coyotes, owls, hawks, mountain lions etc. who have died of internal bleeding, or are chasing after the bobcats that die of notoedric mange.  Should we expect them to truly know the true extent of the damage those products do to wildlife?  I personally don't imagine them keeping up on the latest scientific research articles on the subject...particularly if it prevents them from effectively selling their product.

There are pest control agencies that practice IPM, and I encourage you to seek those out.  Again, I'm not a pest control expert- I'm a grad student at UCLA trying to get my PhD, so this leaves me little time to explore alternatives and come up with great suggestions for people across CA.  As a scientist, my first passion is research and wildlife...I hope that folks like you with an interest in trying to do well, will pick up where the research people like me do, and help find local "sustainable" pest control companies and spread the word. I personally lived for 3 years right next to Topanga State Park (ie., it was my backyard).  I had various native rodents coming into my house when I first moved there, and I was able to successfully find the holes in the house where they entered each night and plug up the holes.  It took all of half a day to remedy, and for three years, I never had another rodent enter my home.  Poisons were not necessary.  Another step I took was to NOT feed birds.  I did when I first moved there, but then I quickly saw the ground squirrel flourish, and start chewing on the house and things outside when the food ran out.  These are steps we should all take if we have rodent problems before we break out the poisons.  And people may be surprised at how effective a strategy it is!

The Burbank Cubs

As many of you might have heard, a couple of mountain lion cubs were found in Burbank this week hiding under a parked car in a residential area.  Many have been curious if we heard about it.  Well, as it turns out, we not only have heard about it, but the day after their discovery, our mountain lion biologist, Jeff Sikich, happened to be going out to the Verdugo Hills, the closest natural habitat to where the lions were found.  Many, including ourselves, may be surprised that mountain lions could exist in the Verdugo Hills.  If you look at the area on a map, you will see it is a very small space, and in itself, not large enough to support a mountain lion population.  However, although it is separated from the larger Angeles National Forest by the 210-Freeway, there happens to be an area they can cross the freeway that is relatively safe and accessible for wildlife.  So, what lions are found in Verdugo Hills are likely also using the Angeles National Forest area, and if nothing else, the Angeles Forest provides a source population for the Verdugo Hills.  The day Jeff headed to the Verdugo Hills, he found lion tracks himself, and ran into a friend that has remote cameras in the hills who has gotten remote camera photos of mountain lions in the Verdugos. 

As for the two lion cubs found, we don't know how they ended up there separated from their mom.  They were approximately 3 months old, and very emaciated, clearly unsuccessful at hunting sufficiently on their own.  Jeff Sikich was able to visit them while they were at the California Wildlife Center to confirm their age and assess their health.  Thanks to the California Wildlife Center, we also got hair, fecal, and buccal swab samples from both of them.  This is exciting since we are conducting genetic analysis on mountain lions in SMMNRA, and have samples from more continuous habitat in Ventura and LA counties to compare our animals with.  So, we will add these Verdugo Hills cubs to our samples and see how their genetics compare with mountain lions from Los Padres, Simi Valley, Santa Susanas, and of course, the Santa Monicas. 

Holiday Plans and a Lucky Find

The holidays are upon us and so just as my lab at UCLA has evacuated to head home for the holidays, so have biologists at the National Park Service closed traps and headed out of LA to spend time with family.  Traps were closed this morning and will be reopened next week by one biologist, Justin Brown, who will come back early to open traps and get back to work.  For me, staying put in Los Angeles although my family is in Texas, this means a few days of relaxation without constant attention to my phone to see if NPS has caught a cat.  It's nice to take a break from being on call 24/7.  I find it hard to relax when I never know when the next capture will occur, treating each day as a day I may have to alter the day's plans completely.  Traps are only closed for a few days this season, so not long enough for me to start missing seeing a bobcat.  I will use the time to hopefully catch up with B290 and adjust my cameras in the field.

And to get the holidays started off well, I got a nice gift today.  A resident in Beverly hills gave me a great present- a bobcat skeleton!  She found the skeleton in her very large (by Beverly Hills standards) yard.  Because she keeps her property in a natural, thickly vegetated state, and because she has such a spacious yard, she only recently discovered the bobcat, although I'd guess it's been there for quite a while.  I can't guess much about the bobcat- the cause of death, the sex, etc., but using what remained of the bobcat, I will still be able to learn a lot.  There was a little remaining tissue and hair still attached to parts of the skeleton.  I sit in my lab at UCLA now just having taken pieces of the tissue and prepared them to begin the genetic analysis process, which first means extracting the DNA.  I've cut enough tissue for genetic analysis, and put it in the proper tube to begin the extraction process, which I will do in the next couple weeks.  Although this animal is nearly 100% decomposed, I feel confident that with the remaining tissue, I will get DNA.

Once I extract the DNA, I will be able to sex the animal genetically.  I will also add this individual, BM055 (the animal mortality number I've given it meaning Bobcat Mortality #55 that we've recovered samples from in the Santa Monicas), to the pool of other samples I've gathered from the Beverly Hills area.  So, I will genotype this bobcat, and combined with all the other samples I've collected from the area (at least 21 bobcats that I captured, plus some other mortalities and bobcat scat I've collected and am also genotyping), I will learn about the genetics of the bobcat population in the area as a whole.  I will learn how healthy, genetically, the bobcats in the area seem to be.  I will learn if, since it is in a very urban, fragmented region surrounded by freeways and urban development, there is much inbreeding occuring in the population which would decrease the genetic health of the bobcats in the area.  I will learn if this bobcat was born in the Beverly Hills area, or perhaps immigrated from Topanga Canyon State Park or even Griffith Park area.  I will also be able to estimate the bobcat population size based just on the genetic analysis of all the bobcats sampled in the area. 

Using the skull, I will also be able to age the bobcat using it's canines.  So, even with a pile of bones and a little bit of fur, we can learn a lot not just about a single individual, but also add to information about the population as a whole! 


A Busy Week

This week we had the opportunity to gather samples from several animals.  On Thursday, we captured B294 near Westlake and Hillcrest.  Although she appeared quite young and small, this bobcat turned out to be an adult female weighing nearly 13 pounds.  We were able to fit her with a GPS-capable radiocollar.  So, this radiocollar will connect with satellites at regularly scheduled intervals.  We are always excited to radiocollar females because we can learn about bobcat reproduction.  Right now is the bobcat mating season, and so in a few months, our newly collared female may settle down to den and have kittens. 

On Friday, on my way to give a talk to a group of highschool students at Yeshiva University High Schools of Los Angeles (YULA), I got a call that a bobcat died in Will Rogers State Park, and a State Park Ranger kindly called to report the incident.  He was unsure the cause of death, and so contacted us to see if we were interested to pick up the bobcat and gather samples to learn what we could of this individual.  I picked up the bobcat and only several hours later after giving my talk was I able to examine the bobcat.  This bobcat was VERY emaciated, and had mild mange on it's face and all four paws. The bobcat was an adult female, weighing only 5.5 pounds.  She weighed less than half of a healthy bobcat weight for her body size.  Obviously, her extreme emaciation contributed to her death.  We are currently writing grants to test our bobcats for anticoagulant exposure.  Once we secure additional funds, we will be testing her liver to see what anticoagulants she was exposed to.

Finally, to finish off the week, we caught a mountain lion!  P13 was recaptured near Kanan and Mulholland on National Park Service property.  She looked healthy and weighed in at 75 pounds.  This weight is typical of adult female mountain lions in our study area.  We have been working to recapture her for more than 6 months.  Her radiocollar stopped working prematurely, and because she had kittens in May, 2010 that were still with her until recently, we had to be careful in our efforts to recapture her.  However, we were finally successful, and so we are excited to have her "back on the air."  Her radiocollar not only emits a VHF signal we can locate with radio-recievers, but we her radiocollar also has GPS-capabilities AND the collar will automatically be uploaded to a website where we can follow her locations from our desks!  We are essentially getting real-time data, since the collar records the location of P13 nine times a day.

B292 and a day interrupted

Yesterday I had my day planned out- but should have known better.  I had two important tasks to accomplish:

1.  Download data from B290's radio-collar

2.  Go to National Park Service office and compile the capture location data for all 291 bobcats that have been captured in the park since 1996.

And I should have known better than to think my day would go as planned!  The National Park Service has bobcat traps open until February 15, the end of this year's bobcat trapping season.  The equipment I was using to download B290's collar information is the same equipment the National Park Service uses to program the radiocollars before putting them on a newly captured animal.  So, the equipment was on very short-term loan to me and in the case that a capture occured, I would have to drop everything I was doing to bring the equipment to the bobcat capture. 

Of course, NPS caught a cat.  And I predicted it!  With the winds and cool weather blowing in the night before, I had a feeling that a capture would occur.  Knowing that my day would likely involve a bobcat capture, I got up early before the bobcat traps were being checked so I could try to get the download completed before traps were finished being checked.  However, to download the data from B290's collar, I have to be relatively close to the animal.  I had to locate him using the radio-signal being emmitted from his collar and get close enough to him for the computer to connect with his collar.  He proved difficult to locate unfortunately.  Just as I was trying to download the data (unsuccesfully), I got a call that NPS had a bobcat capture.  So, all hope of getting data from B290 yesterday was abandoned.  Instead, I drove to the capture location in Thousand Oaks.

I can't complain, however, that I was on to a new task.  I, of course, enjoy handling bobcats and getting to see new ones.   This new bobcat would be number B292, and she turned out to be a young cat - a kitten of the year.  Most of the kittens this year were born in Feburary, so that put her at about 10 months old.  She looked very healthy and the capture process went very smoothly.  She was too young to put a GPS collar on, because they weigh too much for young bobcats.  So, she got the standard VHF-radiocollar that only emits a radio-signal.  To get locations, NPS biologists will have to manually triangulate locations.  These data are generally not as accurate as GPS data and definitely not as detailed, but they are better than nothing!  Hopefully, once she is older, NPS biologists will have luck recapturing her and putting the better radiocollar on her.  In the meantime, they will still learn a lot about her movement patterns, her homerange size, what adult territory she may establish (she is still staying close to her mom at this age), and if something happens to her, we will learn her fate. 

And in case you were wondering if I at least accomplished one of my necessary tasks for the day- the answer is Yes!  After the bobcat capture, I was still able to get to the National Park Service office in Thousand Oaks to get the location data I needed for all 292 bobcats captured since 1996.  I will now use these data to understand how the genetics of the bobcat populations, disease prevalence/exposure, and rat poison exposure vary across the landscape.  Combining these data sets is one important step I'm taking to understand the biology of the bobcats on a detailed landscape level, and also advance towards completing my Ph.D.!

The Story of B290

A couple months ago, a neighbor of mine sent me a photo of a bobcat eating a chicken it had caught in his yard.  My husband and I live in Topanga Canyon- in the old community.  In fact, we are fortunate enough to live off of Entrada, the street you would take if you wanted to go for a hike starting at Trippet Ranch, a main entrance and parking area for access to Topanga State Park.   

We've lived in Topanga for a few years and my neighbors, seeing my truck loaded with traps among other, more interesting, items, know me as the "bobcat lady."  So, this bobcat photo was sent to me, and I could see in the photo that the bobcat had very beginning signs of mange!  With permission from my neighbors, I set traps on a few properties, as well as one in the State Park (I also have permission to set traps in the State Park) to try to target this bobcat.  Traps were set on October 20, and I had a timeline to follow- I was scheduled to leave or Hawaii on November 4 to go to a conference. 

October 20-Nov 4 may seem like a long time to have traps open to catch a bobcat.  However, we (the National Park Service and I) typically leave our traps open for weeks, and up to 2 months when we are targeting bobcats.  In fact, I don't like to leave my traps open for less than 3 consecutive weeks!  This goes back to their biology- they are solitary animals with territories- and this means they have low-density populations.  They can take a while to cover the entirety of their homerange, and if you set only a single trap within a bobcat's homerange, you have to wait for the opportunity for the cat to walk by your trap!  Ideally, you want set more than one trap within an area that a single bobcat uses so that you can avoid waiting for what sometimes feels like forever for the bobcat to walk by.  However, in this case, I had only a single picture taken in a neighbor's yard sent to me several weeks after the fact.  It was a shot in the dark to guess where this bobcat might be.  

So began the story of B290 (and B287).  I had five traps total that I set, and checked them daily, twice a day, as we must do.  I caught several species of animals in this effort- 2 raccoons, 2 domestic cats (people's pets!), a horned owl, a coyote, and 2 bobcats! 

On October 22, a day I was scheduled to give 2 talks, I happened to catch B287.  Of course, the captures that you may wait weeks for always seem to happen at the most inopportune time!  I checked my traps in the morning on October 22 and had nothing in them.  I gave my first talk from 1-3pm in Topanga.  Then I went out to check my traps again before heading to Franklin Canyon for my second talk fo the evening (scheduled at 7pm).  And of course, I had a bobcat in one of my traps!  B287 was a healthy young male with no evidence of notoedric mange.  So, with my husband and a friend in tow to help, we got samples from B287 and also gave him a prophylactic treatment for mange, just in case.  Then I rushed to my talk in Franklin Canyon!

I kept my traps open, still hoping to get the mangy bobcat in the neighborhood.  November 3rd rolled around, and still no sign of a mangy bobcat.  I was scheduled to leave the next day at 5pm for Hawaii, so I decided to risk it and try one more night to get the mangy bobcat.  By the rule of inopportune moments for a capture, the day I was flying out for Hawaii certainly fit the bill!  Plus, it was supposed to rain the next day, and we sometimes feel that with weather changes, we get captures. 

Since I had a lot to do before leaving, I got up at 4am on November 3rd to check my traps just in case I did have a capture.  The capture process take hours to complete starting when you find out that you have a bobcat in a trap.  So, I needed some buffer time in case I got a bobcat capture.  I went out to check the traps and sure enough, I caught a mangy bobcat!  He would be numbered B290 (the National Park Service caught 2 bobcats between October 22 and November 4).  I protected him in the cage from the immenent rain by putting a tarp over the cage while I got all of my gear together.  I also called Joanne Moriarty at the National Park Service for backup to help me put a radio-collar on the bobcat. 

This radio-collar would have GPS capabilities.  At regularly scheduled intervals that we programmed before putting the collar on the bobcat, the collar will connect to satellites to record the exact location of B290.  Then, as frequently as I feel is necessary, I can remotely download the data using a computer and a special antenna!  By downloading the data, I can see all the location events that I programmed the collar to collect! 

These data are valuable in telling us where the animal goes, if it crosses roads- where it crosses them, activity patterns, etc.  In B290's case, he was captured with mild notoedric mange.  We treated him in the field with a dose of Revolution (donated to us by Pfizer).  Now, however, we want to monitor his health and whether the medication helped the mange.   So, using the radio-collar, I will track his movements.  And because I have his detailed movement patterns, I can also place remote cameras within his homerange that will periodically take photos of him (whenever he walks by).  I can visually assess if his mange is worsening.  By combining the collar data with the photos, if his disease progresses, we will learn how the disease affects his movements.  If he deteriorates significantly, I can try to recapture him and take him to a wildlife center for rehabilitation.

So, at daybreak, Joanne and I walked to B290, still in the cage.  We drugged him, as we must do with all wild bobcats that we handle.  We assessed his health, collected samples, put on the radio-collar, and treated him for mange.  We gave him fluids to help him recover from the drug.  Within 2 hours of drugging him, he was off- with a radio-collar that would follow his movements. 

And now I follow B290 and have put cameras out to check on him.  This weekend, I will check the cameras for the first time and hopefully put out a 6th camera that a friend will lend me (I had to borrow 2 cameras and by a couple to add to the two I had!).  Stay tuned for updates on B290.