What is a bobcat?
Bobcats (Lynx rufus) are a species of small wild cats that are approximately twice the size of a domestic cat. They are adaptable to many environments and are found throughout the U.S. in deserts, swamps, forests, and even urban environments. They get their common name because of their short bobbed tail, while their scientific species name rufus refers to their brown coat coloration. Bobcats are often confused with mountain lion adults or cubs in the Santa Monica Mountains area. Biologists receive many reports of someone having seen a mountain lion adult or cub that is actually a bobcat, even though they look very different and are considerably different in size.
Although bobcats are known for their bobbed tail, many people are surprised to learn that the tail can be around 6 inches long! Many people are also surprised to learn how small bobcats are, and perhaps this is why they are often thought to actually be mountain lion cubs when they are seen by some people. Many people expect them to weigh between 40 to 80 pounds and to be the size of a medium-sized dog, but in reality, they are much smaller. The females in southern California, on average, weigh around 7 kilograms (15 pounds), while the males on average weigh around 8-9 kilograms (18 pounds). Of 300+ bobcats sampled in the Santa Monica Mountains since 1996 by National Park Service and UCLA biologists, the largest was a beautiful male in Moorpark, CA that weighed 11 kilograms. That puts him at 24.2 pounds! This may be the the upper weight limit of the weight of bobcats in the Santa Monica Mountains.
Bobcats are the most widely distributed wild cat in North America. They are also found in Southern Canada and in parts of Mexico. Given their wide distribution, they are not considered endangered species. It is even legal to trap bobcats for their fur in many parts of the United States, including California. In southern California, they can be found in many protected park areas, even those parks that are surrounded by intense urban development. Bobcats are considered relatively adaptable to urbanization, and so may persist in urban habitat patches. Thus, bobcats may also be found in areas highly fragmented by urbanization. For example, bobcats may be found in the Hollywood Hills and Griffith Park (where the Hollywood sign is), even though these areas are considered highly urbanized and are also just a few miles from downtown Los Angeles.
Bobcats are strict, but generalist, carnivores. Their diet is entirely made up prey species (ie., other animals they prey on), but they don't specialize on any one prey type. Bobcats primarily eat small mammals, but may also prey on birds and reptiles. Although bobcats are known to hunt deer in some parts of their geographic distribution, in southern California National Park Service biologists have not observed this behavior. However, bobcats will opportunistically feed on a freshly killed deer (for example, in the case that they stumble upon a mountain lion kill, see 'Mountain lion' page). In southern California, a National Park Service study found that bobcats most frequently eat rabbits, but also often prey on gophers, ground squirrels, and woodrats. In southern California, residents that reside near open space have often reported that bobcats were responsible for an attack on a domestic dog or cat. However, neither National Park Service nor UCLA biologists have ever documented bobcat attacks on domestic dogs or cats, and in diet analyses, National Park Service biologists have never found evidence that a domestic pet was consumed by a bobcat.
Bobcats are primarily nocturnal animals, especially near urban areas where they try to avoid human encounters. In fact, bobcats that live in areas highly fragmented by urbanization, bobcats are even more nocturnal than bobcats that live in remote areas. Like most wild cats, they are solitary and territorial, and the the territories that each individual occupies is called a home range. Both sexes establish home ranges and typically, the males home range can be approximately twice as large as a female bobcat's homer ange. In Santa Monica Mountains National Recreation Area (in Ventura and Los Angeles Counties), the average male homerange size is 5.2 square kilometers (3.2 square miles). Female homeranges are generally 2.3 square kilometers (1.5 square miles). Bobcat home range size is most likely primarily influenced by resource abundance, such as the abundance of food, mates, and secure areas for resting or reproduction. Home range size may also be influenced by population density. For example, when population density is high (ie., when there are a lot of bobcats in a given area), the home ranges will be smaller. Males tend to overlap 2–3 female home ranges and during mating season, the males will mate with the females encompassed within his home range. To mark the boundaries of individual home ranges, both sexes are known to mark their territories with scrapes, scent, and scat. In the video below (captured in the Santa Monica Mountains), a bobcat displays his territory marking behavior.
Female bobcats can breed during their first year (9–12 months old), though this rarely occurs. Males are sexually mature at 2 years of age. Bobcats have a mating and kitten season. The mating season in southern California is generally from around December to February. During this time, bobcats tend to mark their territories and trails more frequently, and so their scrapes may be more obvious during mating season (it's a good time to keep your eye out for bobcat sign!). Once a female is pregnant, the gestation period is 60 days. Females typically have litters of 2–4 kittens, but in the Santa Monica Mountains, at least one female has had a litter of 5 kittens! The female will give birth to her kittens in a den that she has found, and then she will stay with her kittens in the den for a few months, rarely straying far from the den site. The den is not a structure the mother bobcat will construct herself, but a spot she considers safe and hidden for raising her kittens. Den sites are often abandoned woodrat nests, thick piles of vegetation, or even sometimes in urban areas in the backyards of residential areas. Urban den sites may provide safety from predation by coyotes, although why female bobcats choose particular den sites is unknown.
Local bobcat research
The National Park Service has studied bobcats in the Santa Monica Mountains since 1996. Most of the research has been focused on populations around Thousand Oaks and Agoura Hills regions, although more recently, sampling efforts were expanded across the entirety of the Santa Monica Mountains and nearby regions. Since the study began in 1996, more than 300 animals have been humanely captured (see 'Research Methods' page for more information), tagged, and samples collected. Many of these animals have also been radiocollared in order to study their movement patterns and behavioral ecology. The general goal of this research has been to understand how urban development affects the behavior and ecology of this charasmatic species. The research has also more recently expanded to encompass studies on bobcat genetics, health, disease, and anticoagulant rat poison exposure. Much of this recent work has been in collaboration with University of California (Los Angeles) biologists. The result of some of this research has included studies on bobcat homerange size and diet that is described above.
A few quick facts about Santa Monica Mountain bobcats
- Bobcats are obligate carnivores (the only eat meat) and locally prefer to eat rabbits, ground squirrels, gophers, and woodrats.
- Bobcats are solitary and territorial.
- Male home ranges are around 2 square miles, while the female home ranges are around 1 square mile.
- Bobcats will cross secondary roads (ie., smaller than freeways), but are less likely to cross freeways regularly.
- Bobcats are susceptible to the same diseases as domestic cats, and disease can be transmitted between domestic cats and bobcats (or vice versa). This is just one reason to keep your pet cats indoors.
- One of the biggest threat to our local bobcat populations is rat poison exposure. Bobcats may be exposed to rat poisons starting before they are born and for the duration of their lifetime. They are exposed because people use the poisons in a variety of urban settings such as in and around the home, at schools, watershed areas, parks, golf courses, landfills, commercial buildings, etc.
- Bobcats locally have never been documented to eat people's pets or attack people.
- Bobcats in southern California tend to avoid human interactions.
- Bobcats usually have 2-4 kittens in a litter sometime between February and June each year. The mother raises the kittens alone.
- Benson, J.F., Chamberlain, M.J., and Leopold, B.D. 2006. Regulation of space use in a solitary felid: Population density or prey availability? Animal Behaviour, 71: 685-693.
- Fedriani, J.M., T. K. Fuller, R.M. Sauvajot, and E. C. York. 2000. Competition and intraguild predation among three sympatric carnivores. Oecologia, 125: 258-270.
Critical threats to California bobcats