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


Wonderful Wintry Weather

February 27, 2011

A very cold storm was forecast for this weekend, with snow levels possibly down to 500 ft.  We did get quite a bit of rain on Friday, but the precipitation was over by the time the temperature dropped.  However, all was clear at dawn the following day.   This made it really difficult to decide where to head out for the day, and I ended up staying close to home in the hopes the weather would get more interesting.  Luckily, some large cumulonimbus clouds started developing over the mountains in the afternoon.  It looked like the weather was clear along the mountaintop ridge, so I gassed up the car and we headed on up.

While at the gas station, we could see precipitation moving in from the east.  Normally, our weather comes from the south or west, so this was a bit unusual.  Even from such a distance (several miles) I could tell that the precipitation was not the usual rain.  On the way up, we started getting fat drops of rain, which then turned to icy pellets, and actually started accumulating on the road.  When we left Goleta, it was almost 55F, but had dropped to near freezing by the time we reached the ridge-top.

The precipitation had intensified greatly and a large amount of graupel was falling and accumulating.  I don’t think I’ve ever seen this form of precipitation, so it was very cool to experience something new.  Photographing in these conditions is always a challenge.  The lighting conditions and weather were changing rapidly and with the road conditions deteriorating, I couldn’t spend a lot of time up there.  However, I managed to come away with several images that I like.

“Cumulonimbus Clouds”  –  Lake los Carneros, Goleta  (2-stop, soft, GND Filter)

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Images of the Week – Feb 14-20

February 23, 2011

Birds in flight and weather seemed to be the theme of the past week.  After weeks of beautiful, but boring weather, we finally had a few storms come through.  I’ve always looked forward to stormy weather, because that usually makes for great landscape opportunities.  Now I have another good reason to cheer for the rain…  animal tracks.  Since I’m not seeing much of the bobcats anymore, I’ve come to rely on finding their tracks to know that they’re still around.  But I’m getting far off topic.

Since there are two pairs of White-tailed Kites starting to nest near me, they have been an obvious photographic target.  I already have a huge catalog of Kite photos, so I’m making an effort to photograph them more creatively, or at least photograph behaviors that I’ve missed before.  I’m also working on shooting some video, since some of their actions are difficult to photograph.

“Passing Zone”  –  Male and Female White-tailed Kites

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Images of the Week – Feb 7-13

February 14, 2011

The beautiful sunset skies disappeared last week and left us with warm days and cold nights.  Morning frost is generally uncommon here, but was in abundance last week.  Thankfully the weather is changing and it looks like it will be a wet week.  Clear skies may not make for nice sunsets, but are good for photographing White-tailed Kites hunting in the last light.  I should have spent more time photographing them and will have to work on that the next time the weather cooperates.

The theme of the past week was quite appropriate give that today is Valentine’s day.  Many birds have either paired up or are in the process of doing so.  Both pairs of Kites are actively nest building, the Mute Swans will probably start laying eggs sooner rather than later, the two Kestrels are back together, and we have seen two Cooper’s Hawks flying together in the evenings.  Not to sound too sappy, but love is definitely in the air.

“Togetherness”  –  Mute Swan pair

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Images of the Week – Jan 31- Feb 6

February 7, 2011

The theme of the past week has been the intense sunsets.  It’s interesting that I’m primarily out looking for wildlife, but when I put together a collection of my favorite images from the week, only one contained an animal.  This is one of the things that makes photography so exciting…  you never know exactly what will catch your attention on any given day.

There has been another pair of White-tailed Kites seen at LLC over the past few weekends.  I’ve only seen them on weekends, which is a bit strange.  Yesterday it was confirmed that they are intending to nest somewhere nearby.  The resident pair seems to be tolerating them so far.  It will be interesting to see how this plays out.

“Alien Landing”  –  Goleta, CA

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