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Justin YNA 2012

Justin

Grade: 8 | State: California

Selective Territoriality Among Foxes

justin-gray-fox

Gray fox, Urocyon cinereoargenteu


It was only a few years ago that my parents gave me my first game camera for Christmas. A game camera is simply a motion-activated camera, often used by hunters to track their game. The first night I put it outside, I was shocked in the morning to find that it had photographed a passing coyote. It was in that instant that I realized that the wild creatures I once thought were rare were suddenly in my view because of my second set of eyes—electronic motion-activated eyes, that is. Suddenly, my interest in filming and researching wildlife skyrocketed, and I was inspired to continue deeper into the world of North American wildlife. One of the most common animals I observed through my game camera was the gray fox (Urocyon cinereoargenteus), so I decided to continue my observations and see if I could share something new with the world.

Background Research

The gray fox (Urocyon cinereoargenteus) is a small, agile canid species that primarily inhabits the western states. Though it is smaller than its relative, the red fox (Vulpes vulpes), it is a very unique animal. Like most foxes, the gray fox is omnivorous, but it is far more herbivorous in its typical diet than its counterparts. Also known as the tree fox, the gray fox is an avid climber and can hunt out and consume bird’s eggs as well as fruits, nuts, and berries. However, despite its abundant food choices, the gray fox is very territorial in its quest to acquire and secure bountiful and productive feeding grounds. Because of this, foxes compete as soon as they become independent to gain a territory of their own. Once a fox has claimed a territory, it patrols, marks, and maintains its territory boundaries. It can do this in several ways, the most common being urination, similar to what your dog does when it urinates on a fire hydrant or a tree. In that urine are pheromones, chemical signals that carry specific information. The urine sends out scent molecules carrying the pheromones, which are then received by olfactory receptors in another fox’s nose. The information from the scent molecules is then sent to the olfactory bulb of the brain, which allows the fox to identify the smell and gain information about the individual from which it came. This then spurs a fox to remark its territory.

Supposedly, a fox, through olfaction, can determine many characteristics of the individual from which the scent came, including the individual’s health. If this is true, then a fox should be able to determine, simply by smelling the urine of a rival coyote, the physical state of the individual coyote. This made me wonder whether a fox would choose to remark its territory on the urine of a healthy coyote rather than the urine of an unhealthy coyote, because a healthy coyote would be a greater territorial threat.

Excess protein in the urine, called proteinuria, is a sign of a serious health problem involving an animal’s kidneys and can be a sign of disease, especially when present in amounts of over 2,000 mg/dL (the normal urinary protein content is 10mg/dL). Thus, I chose to test the reactions of gray foxes to the protein content in coyote urine. This would be a comparative study, testing gray foxes’ response to healthy coyote urine with 10 mg/dL protein content (which may be called the control) versus foxes’ response to unhealthy coyote urine with 5,000 mg/dL protein content (which may be called the variable).

Scientific Process

Question: Do gray foxes (Urocyon cinereoargenteus) selectively choose to defend their territory from coyotes (Canis lantrans) with healthy urinary protein content (0-10 mg/dl) over coyotes with proteinuria of 5,000 mg/dl?

Hypothesis: Gray foxes will selectively choose to defend their territory from coyotes with a urinary protein content of 0-10 mg/dl over coyotes with proteinuria of 5,000 mg/dl 60% of the time because of the foxes’ ability to determine the contents of urine through olfaction, and because proteinuria is an indication of serious ailment.

Procedures

  1. justin-game-camera

    game camera


    Gather materials (listed below)
    • 2 infrared game cameras
    • 2 SD cards (4GB or more)
    • 8 D batteries
    • 2 tripods
    • 6 pints of coyote urine
    • 15 teaspoons of egg-white protein powder
    • bottle or cup to carry and mix urine in
     
  2. Choose two locations within a known fox territory at least 50 feet away from one another to serve as Sample Set 1.
  3. Choose two different locations at least 50 feet away from the original two and at least 50 feet away from one another to serve as Sample Set 2.
  4. Place fresh batteries in each of the two game cameras.
  5. For each test:
    • Bring 1 game camera with an SD card, a tripod, and ¼ pint of coyote urine to Location 1 for Sample Set 1.
    • Deposit ¼ pint of coyote urine on plants and brush within a two-foot radius at the location.
    • Set up tripod directly facing the spot where the urine was deposited, approximately five feet away.
    • Place game camera, loaded with an SD card, on the tripod facing where the urine was deposited.
    • Turn the game camera on and set it for “Video” mode.
    • Bring one game camera with an SD card, a tripod, ¼ pint of coyote urine, and 1.25 teaspoons of protein powder to Location 2 for Sample Set 1.
    • Mix 1.25 teaspoons of protein with ¼ pint of coyote urine.
    • Deposit ¼ pint of coyote urine with protein mixed in on plants and brush within a two-foot radius at location.
    • Set up tripod directly facing the spot where the urine was deposited, approximately five feet away.
    • Place game camera loaded with an SD card on the tripod facing where the urine was deposited.
    • Turn the game camera on and set it for “Video” mode.
    • Leave the game cameras on at the locations for one night.
    • Collect cameras and tripods.
    • Analyze data on the SD card. 
  6. Repeat Step 5 two nights after the first night at Sample Set 2.
  7. Every two nights, alternate between the two sample sets, repeating Step 5 every two nights for a total of 12 testing nights.
  8. Analyze data (see the data-analyzing format below).
  9. Draw conclusions.
 

Data-Analyzing Format

Data will be analyzed with the goal of finding whether gray foxes selectively choose to defend their territory from coyotes with healthy urinary protein content over coyotes with proteinuria. Each night’s experimental results will be classified as positive or negative. Results classified as positive will support the idea that gray foxes selectively choose to defend their territory from coyotes with a urinary protein content of 0-10 mg/dl over coyotes with proteinuria of 5,000 mg/dl. In order for results to be classified as positive, gray foxes must respond territorially to Location 1 of the sample set (the location with protein content of 0-10 mg/dl) and not respond territorially to Location 2 of the sample set (the location with proteinuria of 5,000 mg/dl). Any other results will not be considered positive. Results classified as negative will negate the idea that gray foxes selectively choose to defend their territory from coyotes with healthy urinary protein content over coyotes with proteinuria. In order for results to be classified as negative, the results must be anything other than positive results. This includes, but is not limited to, a fox territorially responding to Location 2 and not Location 1, a fox territorially responding to both locations, or a fox not responding to any of the locations.

Territorial Response Criteria     

justin-3-fox-behaviors

Three responses: urination, rubbing, defecation


In order for a fox’s response to urine to be classified as a “territorial response,” it will be judged against the general territorial behavior of a fox, along with other criteria based on the circumstances.

Results

justin-sample-sets

During the process of experimentation, individual test results were recorded in the data table form. An “X” on the table signifies a territorial response by a fox. An “O” on the table signifies no territorial response by a fox.

Overall, the foxes responded 6 out of 12 nights, a successful turnout considering the foxes’ large territories and relative shyness. What I clearly distinguished through these exhibited results was that only twice did the foxes support my hypothesis through their behavior. Out of twelve nights, only on two occasions did the foxes respond territorially to the coyote urine without proteinuria, and not respond territorially to the coyote urine with proteinuria. In fact, in two cases the foxes responded territorially to the urine with proteinuria and not to the urine without proteinuria, the exact opposite of my hypothesis. Along with this, twice the foxes responded territorially to both locations, showing no distinction between the urine with and the urine without proteinuria. Thus, the overall ratio of positive results to negative results was 1:5, meaning the fox selectively chose to defend its territory from the coyote urine with healthy protein content over the coyote urine with proteinuria only 16% of the time. The graphs on the followingpage illustrate these results.

justin-pie-charts

justin-fox-photos

Though these statistics make up my primary results, some of the most interesting and curious results can be analyzed only by observing the types of behaviors shown during each test and the patterns they form. The strict data concerning individual behavior is shown on the data tables on the previous page. However, we can gain even greater insight by using the stills taken from the game camera’s videos. It is clearly visible in the images that foxes exhibited more rubbing behavior when exposed to urine from a healthy coyote and exhibited more urinating behavior when exposed to coyote urine with proteinuria. This information is represented in the graphs below.

justin-graphs

Conclusion

By analyzing my results, I can come to several conclusions about my research. First, I can conclude that the basic territorial response of the gray fox (Urocyon cinereoargenteus), not including the type of response, generally does not vary depending on the health of a coyote rival, as previously thought. In fact, I proved my hypothesis wrong, and can conclude that gray foxes selectively choose to defend their territory from coyotes with healthy urinary protein content over coyotes with proteinuria only 16% of the time. I can conclude that gray foxes are equally likely to respond to coyotes with proteinuria over healthy coyotes. I can certainly conclude that 33% of fox responses to coyote urine do not distinguish between coyotes with proteinuria and coyotes with healthy urinary protein content. My primary and perhaps most useful conclusion is this: The urinary protein content of a coyote’s territorial marking does not make a gray fox more or less likely to respond to it territorially.

However, I can also conclude from the results that the type of territorial response exhibited by a fox on coyote urine does differ depending on the protein content. My results showed that gray foxes are four times more likely to exhibit a territorial rubbing behavior on coyote urine with a protein content of 10 mg/dL than on coyote urine with proteinuria of 5,000 mg/dL. They also showed that gray foxes are 1.5 times more likely to exhibit a territorial urination behavior on coyote urine with proteinuria of 5,000 mg/dL than coyote urine with a protein content of 10 mg/dL. These conclusions are discussed below.

Discussion

One of the most interesting patterns visible in my results was the type of fox territorial response depending on the protein content of the coyote urine. As seen in my conclusion, the foxes exhibit rubbing behavior more often when exposed to coyote urine with healthy protein content. They exhibit urinating behavior more often when exposed to coyote urine with proteinuria. By urinating more often on the urine with proteinuria than the urine with healthy protein content, the fox may be indicating that it is less likely to defend its territory from a healthy coyote than from an unhealthy one. By urinating, the fox is clearly claiming the territory for itself, and thereby risks facing a territorial challenge from the coyote. A fox would stand a much greater chance in a territorial brawl against an unhealthy coyote than against a healthy coyote, and thus may have felt more comfortable claiming its territory by urine.

The fox more often exhibited rubbing behavior on the coyote urine with healthy protein content. The fox might have been more comfortable rubbing atop healthy coyote urine because by rubbing it is emitting a scent through its glands rather than its urine. Scents emitted through glands are generally weaker than scents emitted through urination. For example, the scent emitted through the fox’s toe glands only lasts about 20 minutes, while the scent emitted through a canid’s urine may last up to two days. If the fox was uncomfortable about challenging a healthy coyote, it might defer to rubbing. The rubbing likely diminishes the scent of the coyote urine and adds a short-lasting fox marking. In this way, the fox would not necessarily be challenging the coyote but would still decrease the coyote’s scent marking, thereby claiming the territory without risking a fight with a coyote.

If these presumptions are correct, my research would suggest that foxes can distinguish a healthy coyote from an unhealthy one by the scent of the coyote’s urine, and that the foxes vary their territorial response depending on the health of the rival individual coyote.

Usefulness and Practical Application of Data

We currently live in a society that is industrialized and built-out. A frequent concern is how wildlife is to adapt to these changes. I performed the research for this test in a wildlife corridor stretching through suburban areas and connecting larger parks and reserves. The information collected in my test could be vital to understanding how wildlife live and thrive in these areas. By knowing that there is a distinction between healthy canid individuals and unhealthy ones, and that variable this affects animal sociality, we have the opportunity to evaluate wildlife management programs by observing the territorial responses of foxes to individual coyotes’ urine, and determining the coyote’s health simply by the fox’s response. Though this would require comprehensive data from large samples, it could be an idea for the future.

Future Research

Following the results and conclusions of this research, I have plans to investigate another idea along the same lines. I would test whether coyotes selectively choose their mates based on the health of the individual coyote as determined by urinary protein content. This would be logical because diseases such as lupus (which are hereditary) can be signaled through proteinuria. If I have the time and resources, I may consider following up on this question.

Acknowledgements and Comments

I was blessed to have carried out this research with help from my loving and supportive parents. My mom always takes the time to remind me, back me, and encourage me. I also appreciate the assistance of my dad, who consistently works alongside me, helping with my research. From carrying tripods to mixing urine, my dad is a great hand and a reassuring voice. My parents are fundamental to everything I do, and I’d like to acknowledge them for it. I enjoyed the research process, and I’m excited to find out more and more about the wild animals I observe.

Bibliography

“Proteinuria.” Wikipedia. 2012. Retrieved from the World Wide Web on 3 March 2012.  
http://en.wikipedia.org/wiki/Proteinuria.

“Gray fox.” Wikipedia. 2012. Retrieved from the World Wide Web on 3 March 2012.
http://en.wikipedia.org/wiki/Gray_fox.

“Red fox.” Wikipedia. 2012. Retrieved from the World Wide Web on 3 March 2012.
http://en.wikipedia.org/wiki/Red_fox.

Williams, Lauren. Davidson College student in animal behavior. Personal communication. 19 October 2010.
http://www.bio.davidson.edu.

 
 

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