Social Hierarchy in Eastern Gray Squirrels

Objective

To further examine the social dominance in eastern gray squirrels in regard to the feeding behavior of dominant and subordinate squirrels. In this research, the dominant squirrel will be defined as the squirrel that successfully takes the nut and eats it. The subordinate squirrel will be defined as the squirrel that was unable to acquire and eat the nut. The reactions of the dominant and subordinate squirrels when given a nut in the presence of each other will be recorded on a digital camera/GoPro (whichever is accessible) and analyzed. The main objective is to observe whether the subordinate squirrel submissively gives up the nut to the dominant squirrel.

Meeting

Monday - Thursday, 10 AM-12 PM & 1 PM-3 PM)

Students

Mentor(s)

Blog

Week 4

June, 19 2019


This week I started to start sunflower seed trust exercises in Leonia on Tuesday mornings and Wednesdays. On Mondays, Tuesday afternoons, and on Thursdays, I am on the Bergen campus feeding the squirrels at approximately 11:30 AM and 1:40 PM and continuing to prepare my research article after I finish placing the sunflower seeds at the designated place each time. I noticed that the squirrels in Leonia are starting to eat the sunflowers because all the seeds I have placed have been eaten. This is good because if all goes well, Leonia will be an exceptional experimenting site since there is a large population of S. carolinensis.

I am hoping that the squirrels make a habit of visiting the location at a certain time every day to make it possible for me to begin conducting experiments. It is a priority for to hopefully start recording next week and begin collecting data. I have started preparing my introduction/literature review. If anyone would like to help conduct experiments please reach out to me so we can discuss the best course of action!

Week 3

June, 19 2019


This week I decided that it would be best to move the sunflower seeds to one location rather than two locations in the same vicinity to more efficiently utilize the sunflower seeds. I have yet to be successful in making the squirrels comfortable around with me to congregate around me but I am seeing success in regard to them frequently eating the food that I place for them. The branch in which the bird feeder was attached to actually broke so what this tells me is that there was probably more than one squirrel that was on the feeder and the weight caused the branch to break.

While this is terrible news for the branch, it is good news for me because it tells me that the food is being eaten by squirrels and not chipmunks because

  1. chipmunks are substantially lighter than squirrels and thus would require a significant amount of chipmunks on the same branch which is unlikely
  2. chipmunks are not social foragers and thus are more independent and isolated than squirrels so it is unlikely a large number of chipmunks caused the branch to snap. I will continue placing sunflower seeds as I cannot force the squirrels to cooperate with me and it will take a lot of patience and time (hopefully they will start trusting me soon!). The highlight of my week was spotting a very young squirrel.

Week 2

June, 19 2019


At the end of this week I was able to nearly complete my literature review. I organized my data in a spreadsheet and was able to find a major gap in the literature, which was that all the studies that I have found that were focused on the social hierarchy of S. carolinensis had similar methodologies that did not consist of direct contact (By direct contact I mean humans handing food to two or more squirrels) between humans and squirrels besides trapping, tagging, or marking them. The major difference in methodology between my research and previously finished studies makes my study capable of being published. Now some people may wonder, “How can results found from studying wildlife in controlled settings be considered valid?”. That is a strong argument, however, it can be said that all the previous studies, whether it was clear and obvious or discreet, had different levels of controlled environments (The tray of food itself is a controlled factor!). That would disqualify all past studies and the fact of the matter is my research just has a more obvious and clearly stated controlled environment compared to other studies.

With the gap having been established, I went ahead to place sunflower seeds in a chosen location (Challenger Center on the Bergen Campus-picture is attached) and also placed a bird feeder full of sunflower seeds in the same area. I did this to get the trust of squirrels to make it possible for me to do the research experiments. I have not been successful so far in getting them to trust me but I have noticed that the squirrels are using the bird feeder substantially more than the first time I placed it there. It is my hope that by next week I am able to conduct the research with the squirrels.

Week 1

June, 14 2019


My research project with Dr. Charles Sontag is to study the social hierarchy of Eastern Gray Squirrels (Sciurus carolinensis). It has been proven throughout various studies done in the past that gray squirrels have a social dominance system based on sex; Where males are dominant over females, and age; Where older squirrels are dominant over younger squirrels. We aimed to specifically analyze dominance by observing the feeding behaviors of dominant squirrels and subordinate squirrels in the same area in the presence of a human. Past studies analyzed social dominance in gray squirrels using food, but they were provided food on trays or other tools and spent hours upon hours to see how they naturally fight for food. I considered this flawed because it is unknown whether the squirrels would have displayed different behavior had the food been placed between them at the same time.

Since this was an entirely new project, I was tasked with doing a literature review to analyze previous studies that either solely focused on gray squirrel social dominance or studies that studied the behavior and phenotypes of squirrels in general. Other studies, as I mentioned before, did use food to study dominance in gray squirrels, but their methods did not satisfy my questions about gray squirrel dominance due to a lack to essentially any control over the environment. While their results are invaluable and deserve credit, my research would provide a different perspective as it shows the behavior of gray squirrels in a more controlled environment.