A Review of Variables and Consequences of Cougar (Felis concolor) Persistence in Urban Environments

I. Introduction

Since humans were around 2 million years ago, humans developed special relationships with wildlife. We were the best hunters on land (Strong 2013). Our social roles, man-made tools, and intelligence made us much more effective hunters than the best large social carnivores like big cats and wolves (Strong 2013). In the last 10,000 years we began developing and domesticating agriculture and animals for the use of food, muscle power, and companionship. During the first 4000 years of agricultural expansion, we slaughtered animals, such as rhinos, that were not useful for domestication and took up space. We killed animals that posed deathly threats such as big cats and wolves. If it were not from killing, habitat patchiness caused by deforestation encroached on larger species' ranges making them uninhabitable and hence indirectly causing more extinctions. Within the last 50-60 years, observing the loss of species and advancements in research directed us towards conserving biodiversity, including large potentially dangerous carnivores.  Today, some of these large carnivores are adapting to habitat patchiness in and around urban areas occupied by large numbers of humans.

Even with our developing management plans for the small populations of large carnivores, urban cities that intercept these species' ranges pose many problems. For example, cities contain vegetation and natural resources along with altered climate and habitat patchiness with the abundance of roads. Therefore it is intriguing that multiple carnivore species have acclimated in cities across the world. Cities benefit carnivores when natural prey is scarce because they can prey on livestock, house pets, or utilize anthropogenic food waste. Large carnivores derive incredible benefit from dwelling adjacent to urban areas, but sometimes at a deadly cost (Bateman and Fleming 2011). Bears, coyotes, and cougars can become road kill if there are no safe corridors to cross through cities. Another deadly threat to carnivores is the juxtaposition of illegal hunting and lethal pest control.  Against these factors, some predators do well within urban landscapes such as coyotes and cougars, whereas bears and wolves perish if they encroach upon cities.

Why do some carnivores do well while others do not?  This needs to be understood for their conservation management.  For example, cougars need corridors that are not traversed by humans whereas coyotes are not as sensitive (Bateman and Fleming 2011).  In another instance, wolves may feed on domestic animals during seasons when wild prey is unavailable whereas coyotes stick to mostly wild prey in their diet year round (Bateman and Fleming 2011).  We are unearthing the ecology of these urban carnivores which builds the road to forming management plans for them.  However, research is lacking in areas that go beyond carnivore ecology to study behavior and social structures, reproduction, and compare and contrasting urban versus suburban and rural population dynamics.  Further research on urban carnivores is significant because as more cities are built and habitat availability decreases, we will encounter these creatures more often.  Human-carnivore encounters generally lead to the animal’s death. If we understand how large predators survive around cities, we can create protective management plans.  In this review, I will report ecological discoveries on urban cougars.  They are a large carnivore that repopulated North America after most of them were executed during European conquest.  I will then discuss factors that inhibit or facilitate adaptability of large cougars persisting in cities.  Finally I will discourse about implications of cougars living in urban cities and where research should progress to better understand them.

II. Urban carnivore ecology

Understanding the ecology of urban carnivores will help identify the factors that facilitate living in the city. Physical factors such as available shelter along with resources like food and water play an essential role in selecting habitat. Research has been done on cougars to determine their ecology within and around cities.

Cougar (felis concolor) ecology such as their home range, movements, and diet within cities has been studied to some extent.  The cougar’s range extends from Yukon in Canada down to the South American Andes mountains (figure 1).  In the past, cougars’ city range generally lied on the periphery, called the wild-urban interface (Beier1995).  To visualize this, six individual cougars were tracked by radio telemetry showing they all came within 100 meters of parklands that were heavily occupied by people. (Beier 1995).  Today, cougars continue to habitat the periphery of cities and but are often found further than 100 meters away (Ordenaña et al 2010).  This may be because cougars also have a negative relationship with anthropogenic structures such as roads, lights and houses and prefer native vegetation that provides shelter (Beier 1995 and Ordenaña  et al 2010).  Thus as cities grow, they shy away to remain on the periphery.  Nonetheless, living in this type of range while still proximal to the city allows the cougar to have a diverse diet. 

Cougars are a solitary and adaptable species that have a variety of prey from wild ungulates and rodents to domestic and companion animals (Iriarte 1990).  Living on the periphery allows cougars more dietary breadth from the wild but also domestic animals if wild prey is unavailable (Ordenaña  et al 2010).  In addition, habitat choice on the outskirts of cities may be influenced by adaptability, habitat requirements and interspecific interactions with other carnivores and humans (Ordenaña  et al 2010).  Beyond locating prey, cougars do travel through cities to reach other habitats to establish territory and find mates.

Corridors are areas of suitable habitat that connects wildlife ranges to one another.  Cougars face a deadly problem in urban areas because their habitat across a town is patchy.  The corridors generally available today are unnatural such as golf courses, dirt trails, and freeways (Beier 1995 and Dickson et al).  Anthropogenic corridors tend to be “population sinks” that are positively correlated with a high number of cougar deaths.  Cougar dispersers readily approach highways but stop within 50-100 meters of them to wait until night time to cross.  This still poses a threat especially when 4 of 9 tracked cougars encounter fatal traffic accidents in one study (Beier 1995) as seen in table 1.  In another 5 year study, all but one cougar died crossing freeways (Dickson et al 2005).  Poorly managed corridors or no corridors at all for cougars to travel through could quickly decrease the size of a metapopulation.  This signals a major conservation implication that requires more attention explained next. 

Table 1. Dispersal timing, fate, distance traveled, and intensity of radio tracking for 1 female and 8 male juvenile cougars in southern California, 1990-92 (Beier 1995).

Living near cities that divided the cougars’ range resulted in living on the periphery to satisfy habitat requirements such as vegetative cover, dietary needs, and reduce confrontations with interspecific carnivores and humans (Ordenaña  et al 2010).  In addition, a patchy habitat requires a cougar to travel through a city to find mates, establish territory boundaries and locate food that may be temporarily scarce in the wild.  Traversing through an urban area requires the use of corridors.  Unfortunately today, there are few natural corridors but many anthropogenic ones such as roads which are “population sinks” for cougars today.  Research shows that roads are unsuitable but lacks what types of corridors are appropriate.  Cougars require the availability of some natural areas for their persistence in today’s growing cities (Ordenaña  et al 2010).  Future studies should measure the effect of suitable corridors on the persistence of cougars so they can remain living alongside humans.

III. Factors Influencing Adaptability

            The cougar is an adaptable generalist species that is found in many habitats in the Americas (Iriarte 1990).  Although during the human colonization of the Americas, they were almost wiped out.  Cougars repopulated, spread their range more east in the US, and as cities grow, people are reporting more cougar encounters.  Understanding the biology behind cougar adaptation will help explain their role as urban carnivores which can be applied to apprehending other re-establishing urban carnivores such as wolves and bears (Bateman and Fleming 2012). 

            Cougar’s ability to adapt to various landscapes with different prey within its range makes it one of the more adaptable generalist carnivores (Iriarte 1990).  Outside of urban areas, cougars are found preying on large animals such as ungulates, whereas closer to cities their diet consists more of medium prey items. Although the cougar is well constructed to kill large animals, prey availability and vulnerability influence their prey choice to sometimes smaller animals (Iriate 1990).  Other than the ability to eat multiple prey items, what else contributes to the success of cougars after their prior decimation?

            We know cougars have the largest range of any mammalian carnivore in the US deeming them adaptable (Iriate 1990).  However, the biology, physiology and behavior that supports why they are adaptable is still obscure.  Cougars are extremely solitary and fully carnivorous which are factors that likely make urban living more unlikely (Ordenaña  et al 2010).  In addition, loss of habitat, corridors, and numerous fatal traffic collisions increase the difficulty of living near urban areas (Ordenaña  et al 2010 and Beier 1995).  With these elements supposedly hindering cougar populations, they are still deemed successfully adaptable generalists species.  Perhaps cub dispersal, near or far away from the mother, plays an essential role in the dynamics behind cougar persistence (Beier 1995).  In a study where cubs were tracked after being dispersed by their mother, half were killed by vehicles (Beier 1995).  The reason behind this was due to the number of manmade corridors such as roads versus natural and minimally disturbed landscape.   Thus it is possible that cities with safe corridors allow easier adaptation to living near urban areas.  A comparative focus on the effect of safe versus dangerous corridors has not been tested on cougar population growth.  If we knew the answer behind why cougars are adaptable to urban environments, we could apply similar tests on other carnivores like wolves and bears that are not as successful in population growth. 

IV. Urban Cougar Implications

            As human populations grow and cities enlarge, the chances of cougars encountering humans increases.  Cougars may be more likely to use urbanized resources in order to stay persistent (Bateman and Fleming 2012).  However, using more anthropogenic resources may be short lived as cities become more urban, the wildlife interface obscures, and unprocessed land decreases (Bateman and Fleming 2012).  This may prove difficult for cougars to continue living near cities.  Authors suggest that the future diversity of cougars and other large urban carnivores will decrease due to anthropogenic action (Bateman and Fleming 2012).  Even with diversity dwindling, as we encroach on cougar’s wild lands, we are likely to encounter them more often.  

Consequences of further urban development are cougar-human interactions, and predation on livestock.  The human-cougar interactions continue to be rare, but predation on livestock may be increasing.  Sources show that there are very few attacks on humans (Beier 1995 and Löe and Röskaft 2004).  Nonetheless, cougar attacks on humans that cause injury or fatality result in negative attitudes towards cougar conservation efforts (Löe and Röskaft 2004).  For example, humans respond with illegally hunting or forming hunting-campaigns to kill cougars (Löe and Röskaft 2004).  Evidence suggests that removing the cats or altering human behavior during an encounter can influence the outcome or prevent attacks (Löe and Röskaft 2004).  Understanding what we can do to deter an attack and prevent them will help conserve cougars.  Applying these methods to other carnivores will hopefully yield similar results. Wolves and cougars avoid humans when possible, but data shows that methods such as shouting and throwing objects proves effective in preventing an attack (Bateman and Fleming 2012).  This is important to know because as cities grow and habitat becomes more fragmented, it is likely there will be more encounters.

Further than direct consequences of cougars around cities, accounts of cougars preying on livestock are likely to be frequent if wild prey are less available because of urbanization (Cunningham et al 1999).  Data from cougars preying on livestock in cities of Arizona shed light on whether cougars will prey on cattle more often as their habitat continues to fragment.   Results indicate that cougars will prey more on livestock even when wild ungulates are more abundant(Cunningham et al 1999) see table 2.  This could lead to economic losses and more humans killing cougars for preying on their livestock (Cunningham et al 1999).  However, understanding how cougars will respond to encroachment on wild land will help configure management plans and safety plans for cougars and cattle.

Table 2. Selection of 3 prey species by cougars based on frequency of occurrence in mountain
lion scats and proportion available as determined from aerial surveys, Study Area (Aravaipa-Klondyke), Arizona, 1991-93. (Rabbits, rodents, and desert bighorn sheep were not recorded during surveys) (Cunningham et all 1999).

V. Conclusion

            Effectively understanding the ecology of cougars will reveal what they need to survive the process of human urbanization.  This information can then further be applied to other large carnivores such as wolves and bears, whose urban populations are not as successful as cougars’.  For example, information about the type of corridors that can aid a cougar successfully travel through a city to other habitat can assist in creating corridor management plans that may help wolves and bears in their habitat.  Other than safe corridors and variability in diet, understanding factors leading to cougar success over wolves and bears is still obscure.  Research on cougar biology, physiology, and behavior may help uncover this perplexity.   Albeit, beyond conserving these predators, human and livestock safety is necessary.  This is why researching why cougars attack and how to avoid them requires more research.  What we find can be applied to other large carnivores who are more endangered such as wolves and bears.

Brown Bear Conservation and human interactions and influences

Brown bears have been a “threat” to humans since the 1500s when they were extirpated from North Africa, and eventually over the Middle East, North America, Europe and Asia (McLellan 2008).  However it seems we are the “threat” to brown bear persistence.  They have been under protection from us since the 1973 Endangered Species Act.  Populations have increased in some areas and declined in others.  Charles Schwarts, Mark Haroldson and Gary White in 2013 studied the populations of grizzly bears in The Greater Yellowstone Ecosystem to provide for the first time, a comprehensive assessment of variables possibly affecting survival under current management among the ecosystem..

The grizzly bear (Ursus arctos) of The Greater Yellowstone Ecosystem (GYE) was listed as threatened in 1975, delisted by the United States Fish and Wildlife Service (USFWS) in 2007, and then relisted in 2009 (Schwartz 2010).  Currently, GYE grizzly bears live close to human populations and are considered by Scott et al as “conservation-reliant species” (as cited in Schwartz et al 2010).  These conservation-reliant species are constantly threatened resulting in necessary continuous management to maintain population dynamics.  They are constantly under risk of threat because of humans are their primary factor in the grizzly bear’s mortality.

          The goal of Schwart et al’s study was to focus management activities for grizzlies by inventing a hazard model.  Previous studies used time-series models from 1975 to 1990s to address causes of grizzly bear mortalities.  However they did not provide an ecosystem-wide comprehensive evaluation of factors affecting bears under modern management (Schwartz et al 2010).  To create the comprehensive ecosystem-wide assessment of grizzly bears in the GYE, monthly survival was monitored to determine features of the landscape best describing special variability in grizzly bear survival.  The two other objectives were, illustrating differences in hazards across the GYE and demonstrating the landscape model with female survival to identify source and sink habitats within the GYE.  Schwartz et al hypothesized that human activities would underlie grizzly bear spatial distribution and survival.

          The study area included grizzly bears occupying about 37,000 km² in the GYE concurring with occupied grizzly bear range (Fig. 1) (Schwartz et al 2010).  The results of the study followed the hypothesis that human disturbance best describes grizzly bears hazards and spatial heterogeneity of their mortality (Schwartz et al 2010). Humans were responsible for both determining grizzly bear survival and sources of hazards in the GYW.  This was discovered first through analyzing the effect of food availability on grizzly bear survival.

Features of the landscape that were assumed to relate to bear survival, such as food, proved incorrect.  Schwartz et al monitored grizzly bears movements, plastically shifting among habitats to eat seasonally available food (as cited in Schwartz et al 2010) such as fish-spawning streams, cut worm moths, and whitebark pine seeds. A result showed that bears migrate to lower elevations during poor pine seed years, and this change in elevation does not itself predispose bears to increased mortality (Schwartz et al 2010).  However, humans still were the main variable determining bear persistence in the GYE.   This was because bears that shifted to lower elevations in human modified areas were at much greater risk of mortality, than bears that shifted to non-human modified environments.  In the lower elevations, bears were killed by humans either by vehicle collision, humans hunting for ungulates, humans hunting bears, poaching or malicious killings (Schwartz et al 2010).  These high risk of death areas are called population “sinks”; a map of the sink and source areas for GYE grizzly bears can be seen in Fig. 2.

To conclude, scwartz et al studied grizzly bears of the Greater Yellowstone Ecosystem to create a comprehensive assessment of variables possibly affecting survival under current management among the ecosystem.  Upon natural ecological habitat selection for food, humans’ developments and activities pose threats to bears and play a major role in their spatial distribution.  If we link the grizzly bears population direction with a habitat selection model, then managers may evaluate the state of grizzly bear habitat at various spatial scales (Schwartz et al 2010).  Managers may also measure consequences of prescribed management activities and the effects of changing food resources on the fecundity or habitat selection in conserving grizzly bears (Schwartz et al 2010).  Finally, understanding the movements of grizzlies over the seasons adds a variable to consider when creating successful management plans.

Connecting the Dots can save our Jaguars

 (Panthera, 2013)

You are touring the Amazon River and enjoying the sight of remarkable vegetation on the river’s edge, the sounds of chirping insects, and the calls of the many birds.  Then you spot a huge jaguar on the river’s edge, crouched down and stalking through some high grasses.  As you peer further, you see a large guinea pig-like creature, a capybara.  In a flash the jaguar darts toward the capybara, lunges on it, and in a split second the animal is dangling in the feline’s jaws.  A sight like this is priceless but may never be seen again, as jaguars are near threatened according to the ICUN red List of Threatened Species.  Jaguar populations are threatened by humans from deforestation, hunting, and competing for the same wild prey.

Why are jaguars important? 

The jaguar is an apex predator, existing at the top of its food chain and is not preyed on by any other animal ("Jaguar" 2013). This large cat is also a keystone species, like the single important stone at the apex of an arch, without it, the arch would collapse. As a keystone species, jaguars control the population levels of prey, such as leaf and grain eating animals, which manifest to controlling the structural integrity of forest ecosystems. 

What can be done to protect the jaguar? 

The Problem

The jaguar is the largest cat in the New World and it is enormously symbolized in South America ("Jaguar" 2013). Humans across the domain have co-adapted with this mesmerizing animal, inspiring many folk tales leading to their stance as a national symbol in some Latin American countries. Even though the jaguar fascinates the native people, many constantly live in fear and are biased towards the animal. Because of deforestation and hunting, jaguars are forced to live in close proximity to humans resulting in conflicts. According to Panthera, the international leaders in wild cat conservation, the jaguar is most threatened throughout its range because of habitat loss, hunting, and lack of prey.

Habitat Loss

Adapted from (Panthera, 2013)

Like shaking an etch-a-sketch to erase a masterpiece, 40 percent of the jaguar’s forest habitat has been eradicated for agriculture, cattle pastures, and urban development (Panthera 2013). This results in patchy terrain, isolating jaguar populations making them increasingly vulnerable to human conflict. These big cats are most vulnerable when traveling from one forest patch to the next. For example, jaguars are shot on sight when traveling through an agricultural field and especially if they prey on cattle (Panthera 2013).

Loss of Prey

There is an arms race between people and jaguars for wild prey. Humans and jaguars both hunt deer and peccaries (related to pigs). Because of this completion for food, approximately 27 percent of jaguar’s area of distribution, or range, has been severely deficient of most prey (Salom-Pérez 2013). Conjoining less food and more pastures results in jaguars being forced to prey on cattle. Because of this, they are often shot on sight, even with legislative protection

(Panthera, 2013)

Hunting

            Jaguars have been historically hunted for their luxurious pelts and for human protection. In South America, jaguars were historically seen as deity-like creatures and signaled power in man.  However in the 1500s, missionaries settled and convinced the natives that Jaguars were dangerous, so they quickly began killing them for protection (Rabinowitz 2010).  Later in the 1960s, jaguar pelts became extremely popular. Historic sale numbers reveal that an astonishing 10,000 pelts were imported to the US in 1969 alone (Rabinowitz 2010).  Commercial hunting radically declined in the 1970s due to anti-fur campaigns, but today there is still illegal demand for paws, teeth, and other products per the IUCN.

You may notice a cycle here.  Agriculturists and ranchers cut down forests leading to close proximity between cattle-hoarding natives and hungry jaguars who hunt the same wild prey.  Less prey for jaguars plus the adjacency to pastures (because of deforestation) results in cattle becoming part of the jaguar’s diet.  In consequence, the ranchers kill jaguars while continuing to clear forests for more development and eating the same wild prey as the jaguars.

The Solution

Many complex problems aren’t simply fixed with one single solution.  Therefore, conserving the jaguar requires multiple facets to fix the problems of deforestation, hunting, and diminishing prey.  Alan Rabinowitz, Panthera’s CEO, along with a cohort of scientists, has been studying diminishing jaguar populations for over 30 year to find a solution to those problems.  The solution in mind is to formulate a premier management plan that partners with local communities, governments, and other conservation organizations. 

Like a drafting artist selecting the tools to create a masterpiece, Panthera’s tool is an expert research team used to draft a jaguar management plan. After more than 30 years of studying and planning, Panthera commenced “The Jaguar Corridor Initiative.” The basis of this plan was to connect the dots, connecting the forest patches (the dots) with corridors (safe forest passageways) for jaguars to traverse.  

Why the Corridors?

           

Adapted from (Panthera, 2013)

Jaguars have a trans-continental range in which their territories include 1 to 7 adult individuals per 39 square miles; and only one male can live with multiple females in a given territory (Winter 2011).   In order for maturing males to find their own territory and for all jaguars to hunt and find mates, they must travel far (Winter 2011).  Today their habitat is like a checker board, with the black squares as safe forest cover while the white ones have no forest and are occupied by humans with guns.  Because jaguars are most vulnerable when they pass through open areas to the next patch of forest, they require safe habitat connections, or corridors.  In the case of South America, an example of a jaguar corridor is a cattle ranch, a citrus plantation, someone’s backyard, essentially a place where jaguars can proceed through unharmed (Panthera 2013).

The Jaguar Corridor Initiative

Dr. Alan Rabinowitz, a biologist and jaguar expert, began research on the cats in the 1980s.  Studying them, but knowing they were in danger, he helped create the first jaguar reserve: Belize’s Cockscomb.  But of course that was not enough.  In 2000, a surprising blood analysis revealed that there were no subspecies of jaguars (Panthera 2013). Whether they live in Mexico or Argentina, they are the same exact species. Of the world’s large, wide-ranging carnivores, jaguars are the only ones with genetic continuity throughout its existing range. With this insight, to increase jaguar numbers without inbreeding within the small populations, the solution is to connect all the small populations with forest corridors (Panthera 2013.  This discovery led to the making of the Jaguar Corridor Initiative.

            This initiative plans to connect 90 populations of jaguars, linking their habitat, while also protecting prey, collaborating with local communities to relieve conflict, and partnering with local governments (Rabinowitz 2010).  Connecting jaguar populations will help reduce chances of inbred individuals that are prone to disease.  Panthera’s solution includes tagging as many jaguars as possible to track where they go and locate the most used corridors to select for protection (Rabinowitz 2010).  In addition, Panthera understands that people have an issue with the jaguars preying on their livestock.  They are helping ranchers with husbandry and to care for their animals.  This is a repayment for not killing the jaguars and in the end, their livestock are healthier and remain in higher numbers (Panthera 2013).  Panthera also works with communities to mitigate jaguar-human conflict.  In this prospect, Dr. Rabinowitz states that with urgent and strategic action, this species can not only endure, but thrive.

To conclude, I love the work that has been done for jaguars which is also being extended to other large cats.  I feel that this same amount of effort should be applied to other large carnivores in danger.  If we increase our efforts and research, this knowledge should allow us to put forth even more powerful conservation management plans.  Thank you for taking the time out to read my blog.

References

Athreya V et al. 2013. Big Cats in Our Backyards: Persistence of Large Carnivores in

a Human Dominated Landscape in India. PLoS ONE. April 8;8(3): e57873

Bateman, P. W. and P. A. Fleming. 2011. Big City Life: carnivores in urban environments.

Journal of Zoology 287:1-23

Beier, P. 1995. Dispersal of Juvenile Cougars in Fragmented. Journal of Wildlife Management

59(2):228-237

Caso, A., Lopez-Gonzalez, C., Payan, E., Eizirik, E., de Oliveira, T., Leite-Pitman, R., Kelly, M.

and C. Valderrama. 2008. Panthera onca. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. Accessed 16 May 2013. <www.iucnredlist.org>

Cunningham, S., Gustavson, C. and W. Ballard. 1999. Diet selection of mountain lions in

southeastern Arizona. Journal of Range Management 52(3):202-207

Dutta, Diptendu. "A leopard gets ready to pounce on a forest guard in this attack in

July, 2011. Six people were mauled." Image. 2011. TheStar.com. Web. 19 April 2013.   

<http://www.thestar.com/news/world/2013/04/15/leopard_attacks_in_mumbai_prompting_parents_to_keep_their_kids_inside.html>

Iriarte, A., Franklin, W., Johnson, W., and K. Redford. 1990. Biogeographic variation of food

habits and body size of the America puma. Journal of Oecologia 85: 185-190

Jaguar. (n.d.). In Wikipedia. Retrieved 16 May 16, 2013, from

http://en.wikipedia.org/wiki/Jaguar

Loë, J., and E. Röskaft. 2004. Large Carnivores and Human Safety: A Review. A Journal of the

Human Environment 33(6):283-288

Loveman, G. "Zeus, an 11-year-old Maine coon cat, had a curious encounter with a young

mountain lion about

6:30 p.m. Thursday in the Pine Brook Hills area of Boulder". Image. 2011. Denverpost.com. Web. 29 April 2013.  http://www.denverpost.com/breakingnews/ci_19138303

McLellan, B.N., Servheen, C. & Huber, D. (IUCN SSC Bear Specialist Group). 2008. Ursus arctos.

In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 29 May 2013.

Ordeñana, M. A., Crooks, K. R., Boydston, E. E., Fisher, R. N., Lyren, L. M., Siudyla, S. Haas,

C. D., Harris, S., Hathaway, S. A., Turschak, G. M., A. K. Miles and D. H. V. Vuren. 2010. Effects of urbanization on carnivore species distribution and richness. Journal of Mammalogy 91(6):1322-1331

Panthera leaders in wild cat conservation. Panthera Inc. Website. Accessed 16 May 2013. 

<http://www.panthera.org>

Rabinowitz, A. and K. Zeller. 2010. A range-wide model of landscape connectivity and

conservation for the jaguar Panthera onca. Journal of Biological Conservation, 143, 939-945

Salom-Pérez, R., Polisar, J., H. Quigley and K. Zeller. 2013.  Jaguar corridor initiative: a

biological corridor and a long-term commitment to conservation. Mesoamerica, 14(3), 25-34

Schwartz, C., M. Haroldson and G. White. 2010. Hazards Affecting Grizzly Bear Survival in the

Greater Yellowstone Ecosystem. Journal of Wildlife Management 74(4):654–667;DOI: 10.2193/2009-206

Strong, D. (2013). Before the Anthropocene [PowerPoint slides]. Retrieved from

https://smartsite.ucdavis.edu/access/content/group/3721e822-a83b-4877-9d71-              

68a75273a71e/Lectures/02.The%20Anthropocene.pdf

Winter, S. “The Jaguar Freeway”. Smithsonian.com. October 2011. Website Article. Accessed

16 May 2013. < http://www.smithsonianmag.com/science-nature/The-Jaguar-Freeway.html?c=y&page=1>