Introduction:

Climatic unfamiliarities are an important dictator of humans' everyday life. Whether it be the clothes we wear or the food we choose, we are always faced with the challenge of coping with climate change. Does climatic changes have as great of an impact on wildlife as it does on humans? In this study, I dug deeper into the behavior of grey squirrels. This magnificent species is known for their nutty behaviors and quirky interaction. It has been observed that as the climate changes, so does their daily life, but to what extent? For this experiment, I studied the eating and foraging behavior of grey squirrels native to a humid continental climate, western Pennsylvania, versus those squirrels native to a humid subtropical climate, southeastern Texas.

Climatic Differences:

According to Weather-US.com, areas with a climate classified as humid continental, experience hot and humid summers along with cold winters opposed to areas with subtropical climates, which experience hot and humid summers, but mild and highly tolerable winters ( "Weather Atlas", n.d.). Figure.1 and Figure 2. seen below were found in the Weather Sparks articles, "Average Weather in Houston, Texas," and "Average Weather in Monaca, Pennsylvania," and illustrate the climatic differences between the cities. According to the two graphs depicted, Monaca, PA has a warm season that lasts between May 28th to September 18 (3.8 months), versus in Houston, TX, where the hot season lasts from June 2nd to September 22nd (3.6 months). Pertaining to the periods of lower temperature drops, the cold season in Monaca, PA lasts from December 2nd to March 4th (3.1 months), and the cool seasons in Houston, TX lasts from November 27th to February 25th (3 months). It is important to note the difference in the terms used to describe the times that these cities have lower temperature drops. Houston's season is referred to as cool while Monaca's is referred to as cold, thus putting emphasis on the degree of climatic change. This fact is proven by the data given that Monaca, PA has a high of below 45 degrees fahrenheit, and a low of 21 degrees fahrenheit during its cold period, while Houston, Texas has a high of 70 degrees fahrenheit, and a low of 47 degrees fahrenheit. Despite the fact that in a subtropical climate, the temperatures drop sooner, their winters are considerably mild to those in a humid continental climate ( "Weather Spark", n.d).

Hypothesis:

Because northern environments are subject to colder and longer periods of temperature drops opposed to southern states, I hypothesized that grey will allocate more of their time to foraging and/or eating instead of running, resting, and/or interacting with other squirrels, in preparation for cold winters here PA than those squirrels in TX.

Methods:

In order to test my hypothesis, I observed the activity of grey squirrels over a span of 20 days. No additional materials were needed besides a writing utensil, paper, and a camera or phone to record squirrel activity.

Pennsylvania:

Over a period of 10 days, I observed squirrels every other day strictly around the Penn State Beaver campus. Each observation was done in the morning, 9:30 A.M. for a duration of 30 minutes. Though all behaviors were observed, eating and foraging time were the main focus of these observations. During the observations, focal sampling was used.

Texas:

Over Thanksgiving break, I followed the same procedure as performed in PA. I went outside every other day, however, the location where the squirrels were observed was at a local park. Each observation was done was still done in the morning, 9:30 A.M. for a duration of 30 minutes, and the main focus was eating and foraging time. Once again, focal sampling was used.

Data collection:

For both environments, the ethogram seen below was used for minute by minute observational notes. At the end of the 30 minutes, the average eating time was calculated.

results:

Pennsylvania:

As predicted, majority of squirrels observed allocated majority of their energy to eating and foraging during the 30 minute time frame. Only on one observation day did I see the squirrel prefer to rest and run around rather than eat. Results can be seen below.

2 days out of the observational days, day 2 and 5, it is seen that the eating/foraging time is almost triple the time spent performing other activities. Additionally, on day 1, the eating/foraging time is almost double that of the time performing other activities.

Video shows the squirrel's eating activity in the tree outside of the Bistro on the Penn State Beaver campus.

Video shows squirrel's constant foraging and eating activity on the Penn State Beaver campus.

Texas:

As predicted, it was rarely seen for squirrels to be eating and or foraging, as they were typically resting, running, or climbing. Because of how quick the squirrels were traveling, and the fact that they were in tall trees, very few pictures and videos were able to be taken.

Discussion:

After conducting various observations and analyzing data, it is shown that my hypothesis, grey will allocate more of their time to foraging and/or eating instead of running, resting, and/or interacting with other squirrels, in preparation for cold winters here PA than those squirrels in TX., is supported. As seen in Figure 2., Pennsylvania has drastic temperature drops during the cold season in contrast with the cool season of Texas seen in Figure 1. Opposed to other species, grey squirrels native to western Pennsylvania do not hibernate during the winter season. Because of this, in preparation fo drastic temperature drops, the grey squirrel will maximize its food consumption in an attempt to almost double their body mass (Peterson, 2015). This idea can be seen in Graph 1., as for four out of the five observational days, the allocation of energy was directed towards foraging and/or eating opposed to Graph 2. showing results that squirrels in Texas preferred to rest. This increased body mass serves one main function for this species- to keep their body heat regulated. The allocation of time towards eating and foraging are calculated risk, but beneficial if successful. In order for a grey squirrel to successfully survive winter, the use of fat reserves must yield a great profit or the fatty insulation layer will be consistently lost leading to death ("Eastern Grey Squirrel", n.d.). If the fatty insulation layer is lost, body temperature will not be maintained, causing the squirrel freezing. However, because this species is an endotherm, they have to ability to maximize their heat through their metabolism, which comes from these fat reserves. Because of the constant reporting by sensors in the blood vessels to the brain, body temperature is easily regulated ( Peterson, 2015).

Despite the fact that my hypothesis was supported, it is still important to recognize the limitations of my experiment. In my procedure, I only used focal sampling. Because I only focused on one subject at a time, while the squirrel that I was observing could have been eating, another one in the area could have very well been playing or running around.

conclusion:

In conclusion, climatic differences do play a role in how many species native to particular areas decide to allocate their energy.

references:

Barker JM, Boonstra R. Preparing for winter: Divergence in the summer-autumn hematological profiles from representative species of the squirrel family. Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology. 2005

Bonnington C, Gaston KJ, Evans KL. Relative roles of grey squirrels, supplementary feeding, and habitat in shaping urban bird assemblages. PLoS One. 2014

Eastern Gray Squirrel. (n.d.).

Hanmer HJ, Thomas RL, Fellowes MDE. Introduced grey squirrels subvert supplementary feeding of suburban wild birds. Landscape Urban Plann. 2018

Peterson, S. R., Peterson, S. R., Evans, A. P., Gosselin, C. E., & Teti, C. M. (2015, October 20). SiOWfa15: Science in Our World: Certainty and Controversy.

WeatherSpark.com. (n.d.).

Yu Media Group. (n.d.). Houston, TX - Detailed weather forecast, long range monthly outlook and climate information.