Category Archives: Uncategorized

One Tourist’s Dream, An Elephant’s Nightmare

Thailand & Cambodia 2013 787

A retired elephant at the Elephant Nature Park in Chiang Mai, Thailand. Photo: Elizabeth Matthews

The first reaction people have when told I spent my summer in Thailand is excitement and curiosity. But the first question I am always asked burns through my core, conjuring a memory that I will never forget. “Did you ride an elephant?” I see a line of elephants parading up a steep hill. Part of the tourist industry, these animals just finished giving rides to giddy vacationers, and are now out of their line of vision. On their backs now ride the elephant handlers; in each hand the herders carry a spear that is held just inches from the elephant’s eye. When the elephant is not moving fast enough, or their attention is strayed, the handlers elicit a sharp stab to their eye. Covered in scars and wounds from previous beatings, each elephant stared straight forward, the pain reflecting out of their gaze as sharply as the knives held in their periphery. Holding up the rear of the line was a small elephant, whose pain was unbearable to watch. As he passed by, his handler’s hook rested below his eye ready to strike, the elephant shot a quick glance at us as we stood silent, in shock. As he continued to march, our eyes were drawn to the elephant’s rump. With a badly broken hip, the elephant dragged one of his hind legs, clearly unable to move it. But despite his disability, his handler continued to yell and kick the creature while his body struggled to overcome the steep incline.

Riding an elephant is a dream come true for many unknowing tourists. It’s understandable; who doesn’t want to climb on the back of the largest terrestrial mammal on earth with their selfie-stick while parading around the jungles of Asia? Exactly. But with a little education on the industry, no animal lover would ever consider riding an elephant again. The training of elephants for elephant trekking is a long time Thai tradition called “phajaan,” which in English translates to “crush” [2]. It consists of ripping baby elephants at the young age of six-months from their families, entrapping them in a small cage with little room to even lift a foot, and beating them with hooks, spikes, and nails, forcing them into human submission. Each and every elephant that tourists eagerly climb onto for a ride has undergone this horrific process. Not only does this training regimen clearly result in significant physical damage, but mental and behavioral impairment as well.

Elephants are extremely social creatures; they exhibit a highly complex social structure that is key to their survival. Elephant society consists of a high degree of mothering, adult cooperation, and care and interest for ailing members of their families. In addition, raising offspring is at the central core of society, and is therefore vital for full cognitive and behavioral development [3]. But when young elephants are torn from their families at a tender age, they suffer dramatic developmental consequences. This lack of development results in abnormal behaviors, such as extreme anxiety, which is often illustrated by rocking back and forth and swaying their body. This extreme anxiety has also been shown to cause aggression, putting both elephants and humans at risk. And not only is the tourism industry harmful for Asian elephants mentally and physically, but their numbers are declining.

Once upon a time, the Asian elephant occupied the vast majority of Asia, with thriving populations occupying regions ranging from Thailand to Iran. Asian elephants have now almost entirely disappeared from Western Asia, Iran, and most of China. The surviving population of Asian elephants is estimated to be between 30,000 and 50,000, only about one-tenth of the population of African Elephants [3]. Although the greatest cause for the species decline has been habitat loss and deforestation from anthropogenic forces, the tourism industry is only exacerbating the decline [1]. The ultimate solution to put an end to the horrific methods behind the elephant tourism industry is to spread awareness. The Thai people are not the source to blame for the treatment of elephants; phajaan is an age old tradition that is encouraged by the interest of tourists. With knowledge of phajaan, and spreading the awareness of its detrimental impacts on elephants, we can take a step forward towards the conservation and protection of the Asian elephant.

– Elizabeth Matthews

Here are some sources I used for this post:



Caution – This is a video of phajaan, it is graphic but if you are interested, I would encourage you to watch it:

I volunteered at an elephant conservation center in Thailand that focuses on caring for “retired” elephants that were once in the tourism industry. The center works on providing the elephants with the best possible care for the remainder of their lives, assisting with mental and physical rehabilitation. Here is the website for the center:

The Effects of Urbanization May Be More Hopeful Than You Think

Urbanization is defined as a continuously expanding urban area or core municipality [1]. Urbanization is becoming increasingly prevalent as the human population grows. This is the main cause for habitat loss and fragmentation, two driving forces in the current extinction rate, which is 1000 times that of the historical rates [2]. Species capable of living in the urban environment tend to exhibit specific characteristics. These characteristics include high thresholds for fear (cortisone levels), short flight distance, high reproductive rates, capability of maintaining high densities (of the same species), and species adapted to high disturbance and/or edges [3]. Animals without these characteristics (and plants without the last three) are unlikely to thrive in urban development [3]. Over time this may cause a homogeneous landscape where plant and animal species are increasingly more alike and species that cannot survive in these areas to go extinct [3,4].

In a recent study conducted in Southern Australia, Isaac and colleagues used habitat selection to examine the behavioral responses of 6 arboreal marsupial species in Australia to increasing levels of urbanization [4]. There were three similar sized areas used in the study, a highly developed area with mostly impervious surfaces, an urban fringe area with a mix of impervious and other land cover, and a completely tree covered area [4]. Throughout the experiment, each marsupial species selected different habitats based on their development level splitting into three groups across the landscape: a disturbance-intolerant group (3 species), a moderate tolerance group (1 species), and a disturbance tolerant group (2 species) [4]. Therefore the potential for habitat to be suitable for these marsupials was significantly based on the urbanization gradient [4].

This study gives hope for the future of biodiversity, as it can be applied to urban development everywhere. It will be virtually impossible to stop urbanization from occurring more frequently, however people can build a civilization that is more integrated with the native environment. By creating this urban gradient some species diversity can be sustained. However, a critical piece to this is a need for ample area in the urban fringe and forest cover environments like in the marsupial study discussed above [4]. If the urban areas continue to expand, then the urban fringe section for the moderate tolerance group and the forest cover patch for the disturbance-intolerant group can get too small to sustain populations [4].

Now is a time when human development choices can forever alter life on earth. Instead of thinking of humans as a separate entity from nature why not think of them as interconnected? Debating whether something is “natural” due to amount of human influence may be irrelevant to present and future biodiversity [5]. Humans have been altering ecosystems for centuries and some of those changes are positive. For instance, pre-Columbian indigenous people in the Amazonian rainforest would compost to create sustainable forest gardens [5]. These ancient gardens continue to show a positive ecological footprint as Amazonian Dark Earth (ADE) which is one of the only soils rich in carbon found in these forests today [5]. Given the marsupial study, it is possible that present day animals have an ability to coexist with humans based on an urban gradient. This would mean that human disturbance like urbanization is capable of maintaining biodiversity if it is conducted in a sustainable way.

– Savannah Maynard


Works Referenced

  2. Carolan, Michael S. “Greenhouse Gases: Warmer Isn’t Better.” Society and the Environment: Pragmatic Solutions to Ecological Issues. Boulder: Westview, 2013. 15-39. Print
  4. Isaac, Bronwyn et al. “Simplification Of Arboreal Marsupial Assemblages In Response To Increasing Urbanization.” Plos ONE 9.3 (2014): 1-15. Academic Search Premier. Web. 3 Mar. 2015.

Illegal Hunting: What’s the Big Deal?

Illegal hunting is an increasing issue around the world, especially in Africa. Africa has many endangered species such as lions, elephants, and rhinoceros. In fact, your favorite animal or an animal you expect to see at a zoo is likely one of these endangered species. Our favorite endangered animals are being further reduced because of illegal hunting practices. So how are conservationists trying to save our favorite animals?

To combat illegal hunting, conservationists first need to know where illegal hunting is taking place. Knowing where illegal hunting is happening can help pinpoint areas to focus on that have an increased prevalence of illegal hunting and effectively reduces the amount of illegal hunting in those areas. In a recent study, published by Animal Conservation, Kiffner and colleagues were able to use animal behavior to determine if illegal hunting was happening in certain areas1. Observing the behavior of animals in certain areas can expose the prevalence of disturbances in that area. Kiffner and Colleagues eliminated other disturbances, such as approaching predators, by specifically observing how eight large herbivore species reacted to being approached by humans 1. The researchers noticed that how the herbivores responded to human disturbances was reflected in their use of the habitat and group size1.

Kiffner and colleagues chose four areas in Africa to observe the responses of these eight herbivore species to humans. The areas that were chosen were: Tarangire National Park, Lake Manyara National Park, Manyara Ranch Conservancy, and Mto Wa Mbu game-controlled area1. These areas were selected because of the differences in location, hunting policy, enforcement and human access1. In Tarangire National Park, Lake Manyara National Park, and Manyara Ranch Conservancy hunting is not allowed. However, hunting is allowed in Mto Wa Mbu with a permit but not of endangered species, of course1. Hunting is strictly prohibited in the two national parks, so rangers closely monitor them. In contrast, Mto Wa Mbu and Manyara Ranch Conservancy areas aren’t closely monitored. The reason why was not specified in the study, but I’m assuming it’s because there is a lack of money to hand out to employed rangers1.

The results of this study showed that many of the observed herbivores changed their behavior depending on the study area they were in. In Manyara Ranch Conservancy and Mto Wa Mbu, the herbivores were more aware of human presence and fled more quickly. These two areas were also less protected and had a higher predation risk. By contrast, in the two national parks, where hunting is strictly prohibited, the herbivores viewed humans as less of a threat and decreased their flight initiation distance. The researchers believe it’s because the animals had some way of knowing that the area is protected and, therefore, there is less of a predation risk1.

Only half of the herbivores that were studied responded to humans in a negative way. Therefore, Kiffner and colleagues could only conclude that observing animal behavior is merely a stepping-stone to revealing if illegal hunting is happening in certain areas1. I agree with their final conclusion that animal behavior can only be a signal for possible illegal hunting. In my opinion, it depends on how familiar the animals were with the areas that were studied. These animals could be displaying high alertness because there is a high risk of predation from other animals, not just humans. To my knowledge, the herbivores’ other predators were not accounted for in this study. This could have given the researchers false-positives of what was making the herbivores behave in the observed manner in these areas. This misinterpretation of the animals’ behavior could potentially lead to ineffective management decisions on how to reduce illegal hunting in certain areas, and in the end waste money that could have been used in other areas that are actually experiencing illegal hunting. However, if these behaviors do pinpoint areas that are experiencing illegal hunting, then conservationists can implement strategies to effectively reduce the amount of illegal hunting that is happening. Reducing illegal hunting practices is not only helping with the recovery of endangered species, but it also gives future generations the opportunity to experience these animals as well.




  1. Kiffner, C, Kioko, J, Kissui, B, et al. (2014). Interspecific variation in large mammal responses to human observers along a conservation gradient with variable hunting pressure. Animal conservation, 17(6), 603-612.


Using Behavior to Deter Elephants from Crop Raiding

Standing next to an adult elephant is incredibly intimidating; adult male African elephants can weigh more than 15,000 pounds. Many farmers fear and hate them because cropraiding elephants can destroy entire fields and even threaten farmers’ lives. Imagine an angry farmer going up against a hungry 6-ton elephant! In southern India, during a three-year period 60,939 incidents of cropraiding occurred and 91 people were killed [1]. This also presents a problem for the conservation of elephants because retaliatory killing of elephants often occur and public support of elephants is incredibly important for their survival.

There have been many methods tested to deter elephants from raiding crops, however, elephants are often too big and smart for these deterrents to work: elephants will push over fences or simply go around them [2], culling problem animals just makes way for new crop raiders, and the electrical fences set up by the government will either be destroyed by the elephants or fall into disrepair because of a lack of upkeep [3].

Some new and upcoming methods to deter crop raiders include using elephant behavior to keep them away from cultivated land. It may be humorous to think about the largest land mammal running in fear of a simple bee, but because of the thin skin around elephants’ eyes, trunk, and under their legs, they are actually susceptible to bee stings just as we are. A swarm of bees has been known to send entire herds into flight [4]. Setting up bee hives along well known paths and near key habitat areas, such as water sources near crops, has been proven to deter elephants from those areas, however, often times the elephants will go around them to get to where they want to go: the water hole, or the tasty crops [4]. Although “beehive fences” won’t completely work to deter an elephant from a whole crop, they can be used along well-established paths either to guide them away from a crop or keep them from coming near water sources near crops.

While humans rely mostly on eyesight, the elephant’s most powerful sensor is their nose. Just like a human could be blinded by a bright light, elephants are “blinded” by extremely strong scents, which is why another promising elephant deterrent is the creation of rope fences covered in chili grease. Chili grease fences are created with a mixture of chili essence, motor grease, and sometimes tobacco [2]. One farm encircled by a chili rope went un-raided for two years despite nine attempts [2]. If there is a way around the fence, the elephant will find it. However, when faced with the decision to either go near the fence and get to the crops or leave, all elephants chose to avoid the fence and the crops were protected [2]. The downside to this method is the constant upkeep of the rope: the paste must be reapplied at least once a week, more during the rainy season.

These methods of deterrence that utilize animal behavior are extremely promising because they are specialized for specific behaviors and are non-lethal to endangered animals such as the elephant. Decreasing crop raiding through effective methods that do not harm the animal is one way of improving conservation efforts for elephants. Villages with agricultural practices are much more likely to support conservation efforts when their livelihood and lives aren’t being threatened by neighboring elephants.


-Mackenzie Platt


  1. Gerhardt, K.V., Niekerk, A.V., Kid, M., Samways, M., and Hanks, J. (2014). The Role of Elephants Loxodonta africana Pathways as a Spatial Variable in Crop-Raiding Locations. Orynx 48(3): 436-444.
  2. Sitati, N., and Walpole, M. (2006). Assessing Farm-Based Measures for Mitigating Human-Elephant Conflict in Transmara District, Kenya. Oryx 40(3):279-286.
  3. Moss, C.J., Croze, H., and Lee, P.C. (2011). The Amboseli Elephants: a Long Term Perspective on a Long-Term Mammal. University of Chicago Press, Chicago.
  4. 4.Vollrath, F., and Douglas-Hamilton, I. (2002). African Bes to Control African Elephants. Naturwissenschaften 86(11):508-511.

Look Both Ways! – How Learning About An Animal’s Behavior Can Help Them Cross Busy Roadways

Look Both Ways! – How Learning About An Animal’s Behavior Can Help Them Cross Busy Roadways

By: Michelle Bernecker

Canada's Banff National Park overpass

Canada’s Banff National Park overpass
Image courtesy of The Wikimedia Foundation

Have you ever been driving on the highway when you think you see something out of the corner of your eye, and then suddenly there is a deer staring straight at you in the middle of the road? Well, every year in the United States, an estimated 400 million animals are killed in automobile collisions.  Over 1 million each day [1]! This statistic is reflective of mammals, birds, reptiles, and amphibians.  Wildlife vehicular collisions are not only a threat to wildlife, but also humans.  The most serious of these collisions involve large ungulates, hoofed mammals like deer, elk, and moose.  Fortunately, conservationists studying road ecology have taken action and began to research migration habits of these animals to reduce the number of wildlife-involved accidents.  These studies include capturing and marking of wildlife with GPS collars, recording migration patterns, and pinpointing the most prevalent road crossings of these animals.

In Idaho, along US Highway 20 and Idaho Highway 87 ‘169 recorded collisions resulting in the fatalities of moose, white tail deer, mule deer, and millions of dollars in collision damage to vehicles occurred in a 4 year span’[2]. In efforts to decrease the amount of collisions, studies have begun along these highways to determine the routes of migratory elk and moose. Due to the ungulates migration patterns between their winter and spring ranges they are obligated to cross Highway 20, as no other route is available for them to take.

Between these two seasons, the highest number of elk and moose road crossings took place.  By monitoring these patterns, six high traffic road crossing areas were pinpointed along the highway. Based on these observations, scientists brainstormed ways for a safe resolution of crossing the roadway. Simple solutions such as fencing and signs warning cars of wildlife crossing to more complex ideas such as overpasses and underpasses which give animals their own safe pathway either over or under the busy road have been taken into consideration.

Ideas like over and underpasses have proven to be an effective solution for elk crossings in Canada’s Banff National Park (pictured above). “Canada began installing 8-foot-high fences on both sides of the expanded highway. They then constructed 22 underpasses and two 164-foot-wide overpasses for wildlife. According to the park service, these changes resulted in a 96 percent decrease in mortality for the parks ungulates” [3]. In the first year of implementing this idea the park saw as few as 2 reported crossings by only two different species on the overpass, but after an 8 year period, over 50,000 trouble free crossings have occurred! By studying the behavior of these animals it allows us to create solutions to everyday problems. Without the knowledge gained from studying this unique migratory pattern, there would be no way to determine how to implement an effective solution!

Although wildlife crossings are not yet widely utilized, they have proven to become a viable solution to a worldwide, and somewhat common, issue. Threats due to busy roadways, other than vehicular collision, can also interfere with foraging and mating behaviors, fragment habitats, and divide populations. As more information is obtained on these successful solutions projects like this can begin to take place!

Key Words: wildlife, behavior, ungulates, solutions, roadways, migration

[1] Culture Change-

[2] Project Successfully Maps Out Wildlife Pathways Across the “Longest Main Street in America”- Wildlife Conservation Society.

[3] National Geographic- 2004/05/0512_animaloverpasses_2.html


A Rare and Endangered species in your own backyard

Black-footed ferret Image by Kasey Burrus

Black-footed ferret
Image by Kasey Burrus

In our growing and ever changing world, extinction rates have soared greater than ever. Around the world, species are threatened with extinction due to many issues that include: poaching, agricultural work, deforestation and urbanization. Most people know about the threatened status of the flagship species like pandas, rhino, elephants and our big cats. However, there are few people that are aware of the endangered species in their own backyard. The black-footed ferret (Mustela nigripes) was once known to freely inhabit what is now known as City Park in the town of Fort Collins Colorado (2). What is a black footed ferret some may ask? These charismatic and ferocious creatures are thought to have descended from the Eupoean polecat (Mustela eversnanni) and are closely related to the domesticated ferret (Mustela putorius) one can buy at a local pet store (1). It is not unusual for most people to have never heard of a black-footed ferret before.

The black-footed ferret has been flirting with extinction since what was thought to be its last know population was found in 1981 (2). It was 36 years ago that this species was on the verge of extinction when the last known population of 9 ferrets were brought into captive breeding to try and save. However, the captive breeding program was unsuccessful and its failure was attributed to a lack of knowledge about the species. Just 2 years later on a large ranch in Meeteese Wyoming, another population of 120 ferrets was found. This discovery was a rare and incredible find since the black-footed ferret was thought to have gone extinct. Biologists were determined to keep this population from plummeting to extinction again. However, an unexpected turn of events happened when an outbreak of K-9 distemper struck the ferret population and killed over 85% of the remaining ferrets. The team of biologists had to make the difficult decision to either bring the last 18 surviving ferrets into another captive breeding program or leave them in the wild and see if they survived (2). This time biologists were careful to observe the behavior, reproduction, feeding habits and life histories of ferrets. These key features are important for the captive breeding and rehabilitation of a species because life in captivity can be so much more fragile than life in the wild.

Another crucial aspect to protecting any threatened species is figuring out what is putting the species on the brink in the first place. After careful research and observations of the ferret’s natural habitat, it became clear that this species relies solely on extensive prairie dog colonies. The prairie dogs that live in the colonies are the black-footed ferrets primary source of food. So, the success of the colonies contributes to the success of the ferret species. Another important contribution to a successful reintroduction relies on the imprinting of killing their natural food source, prairie dogs. The imprinting that happens while still in captivity has a small window of opportunity for it to be successful and must occur within the first 60 days of life. This learned behavior is crucial to their survival in the wild once they are released and have their own kin to raise and teach.

The captive breeding program started in Wyoming but now resides in Northern Colorado Just 20 miles from Fort Collins. The facilities house over 200 ferrets and, as of fall 2014, the 3rd ferret release in Colorado happened in Soapstone, just a few miles outside of the City of Fort Collins. After 35 years, the program is looking to be very successful but still has a lot of work to do. As a breeding facility, they can contribute to the growth of the population of ferrets, but they cannot save their habitat alone. Education on prairie dog habitats and conservation is an important aspect to saving the black-footed ferret and many others species that live in this unique habitat.

– Kasey Burrus

Work Cited

(1) The Animal Files. “European Polecat.” The Animal Files. 5 Jan. 2010. Web. 23 Feb. 2015.

(2) Gober, Pete. “Black-footed Ferret Recovery. Are We There Yet?” Endangered Species Program. U.S. Fish and Wildlife Services, 23 Feb. 2012. Web. 23 Feb. 2015.



Wildlife Corridors: A Solution to Ending Roadkill?

One million! That is the number of animals killed by vehicles in the United States every day. “On U.S. highways, a vehicle hits an animal at least every 26 seconds” [1]. These animals range from small creatures like turtles and frogs, to larger mammals like deer and bears. This number even includes threatened and endangered species that are already struggling. With thousands of new drivers on the road each day, this is a problem that needs to be addressed before it gets any worse.

One way to effectively reduce roadkill is to build wildlife corridors. Wildlife corridors are “like roads for animals” [2], which help them travel across human roads safely. These animal passages, sometimes called Greenways, come in many shapes and sizes, and are common in some places around the world. Banff National Park in Canada is home to more than 25 wildlife overpasses across the TransCanada Highway [3]. In the Netherlands, over 600 underpasses and overpasses exist, making the country one of the leading experts in wildlife corridor construction [6].

Building wildlife corridors to help animals get past roads and other urban areas has been proven to reduce road kill rates. In Utah, a crosswalk system was created for local deer. After the first installations were completed, 40% more deer were able to cross the road safely than before [4]. In the Mojave Desert in Arizona, a conservation group was able to reduce turtle road kill by 93% after installing fences on either side of the highway and creating tunnels for the turtles to travel through [4].


Left: Wildlife bridge in Banff National Park, Canada. Middle: The longest wildlife bridge in the Netherlands, Zanderij Crailoo, which spans 800 meters long and 50 meters wide. Right: A wildlife bridge through the Veluwe natural area in the Netherlands [8,9,10].

Wildlife corridors range from simple bridges planted with grass to vast constructions including trees, shrubs, and sometimes even water. The most common type of wildlife corridor in the United States is the culvert, a large underpass tunnel. In order to understand why wildlife corridors are a sustainable and worthy use of our resources, we must understand something about an animal’s behavior. Why do animals cross roads, and how we can attract them to wildlife corridors instead?

Many species of turtles, for example, have specified breeding grounds which are often far from their usual habitat. In order to reach the area where they will mate, many turtles have to undergo seasonal road crossings. These turtles are not picky about where they cross the road, only that they arrive at the other side, so wildlife corridors for turtles can be relatively simple in design. On the east coast of the U.S., short fences are installed along the sides of many major highways to prevent turtles and other small animals from entering the roadway. In order to allow the animals to reach the other side, either deep buckets or tunnels have been created. In places where buckets are placed, people have been hired to collect turtles and frogs that fall into the buckets and relocate them to the opposite side of the road so that they may continue their journey. Tunnels are preferable because they do not require further human effort, but they are not feasible for roads with many lanes [5].

In contrast, wolves, such as the native populations of Yellowstone, cross roads for a different reason entirely. Packs of wolves have large territories and travel far every day to look for food and other resources. This puts them in danger every day of colliding with vehicles. An effective wildlife corridor for wolves would consist of more than a short fence next to a busy road. For larger mammalian species, bridges are preferred, but since they tend to be more expensive, large culverts are often built instead. These tunnels must be wide enough to ensure the animal feels comfortable, and not trapped. Drainage and flood water should also be kept in mind, so that the tunnels do not become inaccessible in certain weather or seasons [5].

Due to these behavioral differences between species, each corridor must be designed with a target species in mind. An underpass that works for a deer may not be effective for a frog or a bird. Therefore, it is important to understand the behavior of different animal species when considering a wildlife corridor. The behavior of the target species, including the animal’s reasons for crossing the road, must be taken into account when designing a wildlife corridor. Predation must also be kept in mind; an elk will not use an underpass tunnel if predators such as bears are often seen using the same tunnel. A corridor will only be effective if the animal feels safe using it. Therefore, different types of corridors are needed along the same stretch of road. According to Monica Bond, who has done extensive research on wildlife passages, wildlife corridors are most effective when they are placed directly adjacent to a natural area, and are planted with natural soil and foliage. To encourage animals to use underpasses and overpasses, human presence around the entrances and exits should be minimized and the edges of the overpasses should be covered in as much vegetation as possible, to prevent the animals from getting stressed at the sight of cars [5].

Many of the wildlife corridors that exist in Canada and the United States are repurposed bridges and underpasses that were no longer being used by humans. It is difficult and expensive to build new corridors around existing roads. If there are no existing bridges or underpasses available, the easiest way to implement wildlife corridors is to design them along with a new road, and then build both at the same time. This means that existing roads and highways are less likely to be fitted with corridors, because it is an expensive and time-consuming process [7].

In the larger scheme of things, wildlife corridors have been proven effective in reducing road kill rates all over the world. By studying the behavior of a target species and learning why they cross roads and how we can redirect them to a safer passage, we can make wildlife corridors increasingly effective. Supporting the creation of more wildlife corridors in the U.S. will convince municipalities to invest in building more, as well as set an example for other countries. Wildlife corridors are not a be-all and end-all solution to animal deaths, but they set the groundwork for saving species so that we can study them further and continue to learn from them.

As Beth O’Donnell Young, writer and landscape designer, said; “If you build it, they will come.”


Left: A grizzly bear in Banff National Park uses an underpass. Middle: Mule Deer in Wyoming are seen traveling through an underpass to cross a busy highway. Right: African Elephants in Kenya are seen emerging from a large underpass, measuring 15 feet high [11,12,13].

 –Renee van Ineveld

Class of 2015















Tigers and Territory: The Issues We See with Home Range Size and Conservation in these Big Cats

Many big cats have large home ranges or territories. Cats like mountain lions or pumas, tigers and bobcats don’t live in big groups like lion prides. Instead, they live by themselves most of the time, except when a mother is raising cubs or sometimes when a male and female hang out together around mating time. Many people think tigers are beautiful and majestic, but keeping them in the wild seems to be kind of difficult—they are currently listed as endangered because tiger populations have decreased by 50% in the last 30 years or so4. Tigers are native to Asia, and Asia has a lot of people (4.4 billion in 2014). When human populations get really big, it’s had for other animals to coexist with us.

For tigers, population density depends upon the density of their prey, which may also be scarcer where human populations are expanding. Tigers commonly eat other mammals, like deer and other hoofstock which are known for being skittish and can be hard to catch. One model suggests that male Amur tigers must consume at least 25 prey per year, non-reproductive females consume 20 prey/year and mothers raising 4 cubs require 54 prey/year8. That is quite a lot when your prey is hard to find and catch, so it might make sense that tigers have a big home range. They have to search pretty far to find enough food when the food is also trying not to be found. Prey density is declining in native tiger habitat6. That makes getting enough to eat even harder. Sometimes people’s livestock are easier to get, which means that livestock depredation is one of the biggest reasons we see conflict between humans and tigers.

A tiger’s home range size can vary a lot depending on the place you’re looking at. One study in Thailand found that male tigers’ ranges were around 267–294 km and female’s ranges were around 70–84 km7. But a study in Bangladesh found that a couple females had an average home range of 14.2 km2, which is much smaller.

According to World Wildlife Fund (WWF), some of the current conservation projects for tigers in the wild are focused around preserving their habitat and reducing tiger-human conflict10. Because tigers need so much habitat for those big home ranges, one of the first steps in their conservation is preserving enough habitat to support a good sized population. In order to do that, organizations like WWF are working to try to influence agriculture, paper and timber industries, among others, to use sustainable practices that minimize loss of forest land. To reduce conflict with local communities, organizations like WWF rely on innovative solutions and education. In regions where the conflict most often occurs, some strategies might include scare tactics, negative conditioning and capturing tigers to assess their condition because tigers in good condition are not usually the ones who are desperate enough to attack humans and livestock9.

So what do these big sizes and big differences in home ranges mean for conservation? A lot! We know that in order to conserve tigers in the wild, we need to conserve big enough patches of their habitat for them to move through, ideally without running into and having conflicts with people. Because the density of their prey influences their feeding behavior and potentially the size of their range, we might have to consider how to maintain those species at good levels (and figure out what those good levels are). In order to reduce conflict with humans and hence reduce killings by humans, we need to learn more about how tiger home ranges change around people, and how tigers move through populated areas. Helping people build safe enclosures for their livestock might be one thing to try. Do you have any good ideas? Leave them in a comment below!!

Here are some of the sources I used. If you’re interested in tiger behavior or tiger conservation, you should let us know what articles and papers you like, too!

– Leorah McGinnis


  1. Athreya, Vidya. et al. “Movement and Activity Pattern of a Collared Tigress in a Human-dominated Landscape in Central India.” TROPICAL CONSERVATION SCIENCE1 (2014): 75-86. Web.
  2. Barlow, Adam. et al. “Femalle Tiger Panthera Tigris Home Range Size in the Bangladesh Sundarbans: The Value of This Mangrove Ecosystem for the Species’ Conservation.” ORYX1 (2011): 125-28. Web.
  3. Bhattarai, Babu, and Klaus Fischer. “Human-tiger Panthera Tigris Conflict and Its Perception in Bardia National Park, Nepal.” ORYX4 (2014): 522-28. Web.
  4. Chundawat, R.S., Habib, B., Karanth, U., Kawanishi, K., Ahmad Khan, J., Lynam, T., Miquelle, D., Nyhus, P., Sunarto, S., Tilson, R. & Sonam Wang 2011.Panthera tigris. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on11 February 2015.
  5. Miller, C.s., M. Hebblewhite, Y.k. Petrunenko, I.v. Seryodkin, J.m. Goodrich, and D.g. Miquelle. “Amur Tiger (Panthera Tigris Altaica) Energetic Requirements: Implications for Conserving Wild Tigers.”Biological Conservation170 (2014): 120-29. Web.
  6. Simcharoen, Achara. et al. “Ecological Factors That Influence Sambar (Rusa Unicolor) Distribution and Abundance in Western Thailand: Implications for Tiger Conservation.” RAFFLES BULLETIN OF ZOOLOGY62 (2014): 100-06. Web.
  7. Simcharoen, Achara. et al. “Female Tiger Panthera Tigris Home Range Size and Prey Abundance: Important Metrics for Management.” ORYX3 (2014): 370-77. Web.
  8. Soh, Yi Hui, Luis Roman Carrasco, Dale G. Miquelle, Jinsong Jiang, Jun Yang, Emma J. Stokes, Jirong Tang, Aili Kang, Peiqi Liu, and Madhu Rao. “Spatial Correlates of Livestock Depredation by Amur Tigers in Hunchun, China: Relevance of Prey Density and Implications for Protected Area Management.” Biological Conservation169 (2014): 117-27. Web.
  9. “Solutions.” Save Tigers Now. World Wildlife Fund. <>. Accessed 21 February 2015.
  10. “The Siberian Tiger Project: Managing Tiger-Human Conflicts.” WCS Russia. Wildlife Conservation Society, 2008. Web. 21 Feb. 2015.


The Problem of Brown Tree Snakes: Why Trojan horses only work in Troy

Several years ago, while working as an Animal Care Technician for the USDA’s National Wildlife Research Center (NWRC), I became intimately familiar with the case of the Brown Tree Snake (Boiga irregularis). For those of you who are unfamiliar with the story, it goes something like this:

At the end of World War II, war-time ships were busy with activities around Guam, an island about a thousand miles south of Japan. A few Brown Tree Snakes hitched a ride to Guam, an island their species had never been to. The snakes were probably drawn to the mice already stowing-away on the ships. However, once on Guam the species started to flourish. Their numbers, with more abundant prey resources than in their native ranges, started to show exponential growth.

This snake has wiped out several bird and lizard species, including some that were endemic to Guam. This has caused an increase in the abundance of spiders on the island. Determined to regain our beautiful Helen taken by the Trojans (and also to alleviate the infrastructure problems caused by the snakes) Uncle Sam was rallied to war, and set out across the ocean to destroy its enemy.

The first attempts at controlling the snakes focused on using trained dogs, and eliminating individual snakes by hand. These measures were put into effect in 1994, 40 years after the introduction of the snake to the island. These methods were largely unsuccessful in lowering snake populations. By 1999, no headway had been made in crashing the gates of Troy, and a new strategy was needed.

Researchers from the NWRC quickly collected specimens and started testing the most effective control methods. It was found that over-the-counter grade aced into a dead mouse was enough to kill brown tree snakes. Over the next 14 years, different delivery methods were tested and implemented.

As of 2015[1], the newest tree snake eradication efforts involve injecting acetaminophen into dead mice, attaching them to a parachute, and dispersing them, by helicopter, throughout the jungle of Guam[2]. Here’s how it is supposed to work:

The little parachutes get caught in the canopy, dangling their deceptive prize for the snakes to find. Snakes that eat the mice are exposed to the toxin inside, and quickly die. It is more or less the population control equivalent of the Trojan horse, or in this case the “Trojan mouse”. The dead snakes reduce the size of the reproducing population, and (hopefully) the total population can be brought under control. It seems simple and straight-forward. However, remembering some simple concepts from evolution and behavior, the story gets more complicated.

For instance, Charles Darwin noted great variation among individuals within a species, and used this to develop his theory of natural selection. The process of natural selection is one by which the varieties of a species that are most successful in an environment reproduce more, causing an increase in the abundance of that variety, compared to other varieties. Through the many environmental pressures, species change through time to fit the constraints of their surroundings. Modern biologists have recognized that many behaviors act as variable traits that are influenced by heredity. In other words, natural selection acts on behaviors as well.

Given this, consider the snakes on Guam. Prey selection is a variable behavior in brown tree snakes, with snakes “eating a wide variety of vertebrate prey, including reptiles, birds, and small mammals…”3. In relation to the quality and abundance of these food sources, when one food source becomes scarce or dangerous, snakes that don’t rely on this food source will have higher reproductive success than a snake that does.

By dropping our “Trojan mice”, we are simply adding a human selection pressure to snakes. We are not eradicating the brown tree snake, because we cannot possibly get every snake to take the bait.  By killing the snakes that will sometimes eat a dead mouse, we have simply given a leg up to the snakes that avoid mice as a prey item. These include the snakes that eat only birds and lizards. Effectively, we have increased the relative abundance of snakes that prefer “rare meats”, and are punishing snakes that are likely to provide beneficial services, such as rodent control.

Other activities employed against the brown tree snake include “detector dogs, traps, nighttime fence searches, oral toxicants, barriers, prey reduction, and public outreach activities.[3]” The total costs of these programs is about $3,000,000 annually (although last year the budget was increased by $500,000 “for the manufacturing of an automated bait delivery system for the Toxicant Bait Drop Project[4]”). Seems like a lot of money to control some snakes.

Given that there are roughly 2,745,400 brown tree snakes on Guam (50 snakes/hectare x 54908 hectares on Guam), I propose a simpler and more effective solution. Put a bounty of $1 on snakes.

Considering the high density of snakes of the island, to make a salary of $31,000[5], a hunter would have to collect about 124 snakes per working day (31,000 snakes/250 working days in a year). To trap this many snakes, a hunter would need to cover an area of only 6.2 acres per day, or roughly 6 football fields. Given an 8 hour day, traps, trained dogs, and the human technological advantage, it seems reasonable that the activity of snake hunting could become economically profitable. Profitable hunting has been a proven eradication method of any species; look at the history Passenger Pigeon[6] if you need proof that it works.

Therefore, it seems unreasonable that we spend $3,000,000 a year applying a selection pressure, when we could spend $2,745,400 to eliminate all the snakes and provide around 85 islanders with jobs until the snakes are eliminated. If they really are a threat to biodiversity, and could potentially cost us billions of dollars, it would make sense to pick a more proven and effective method of eradication. Let’s leave the elegant deception to the ancient Greeks and focus on methods modern capitalists can support.

–Gabe Buckley
B.S. Zoology with a minor in Business Administration
Profession Science Masters in Zoo and Aquarium Management, class of 2015

[1] See page 73.


[3] See page 75.

[4] See page 73.

[5] the average salary of Fishing and Forestry Occupations in Guam. See “Annual mean wage” in “Farming, Fishing, and Forestry Occupations”.