Abstract:
Observations made on the eastern gray squirrel (Sciurus carolinensis. Glemin) have
shown an increase of melanism in populations close or in urbanized areas (Hall and Balogh,
2019). Although the genetic cause of melanism for this species is known to be caused by a
mutation at the MC1R gene McRobie et.al (2009) we still do not understand the driving force as
to why this phenotype is reappearing. Many theories have been proposed as to why prevalence
of melanism has been increasing such as thermoregulation Ciurej et.al (2015) but no previously
proposed theory has given a satisfactory answer as to why this trait is increasing. This has led
some researchers to look at the possibility that melanism can influence aggression leading to
increased dominance in a population. If this is true dominant melanistic male would have more
opportunities to mate (Koprowski, 1993). This proposal is for a study to determine if melanistic
individuals are more aggressive through observation using video recordings of squirrel
interactions at constructed feeders. Individuals that actively chase away others will be
classified as dominant, have their phenotype recorded, and labeled with a +1 (dominant).
Those who actively retreat or avoid the feeding station when another squirrel is present will be
classified as submissive labeled with a -1(submissive). In the case that neither squirrel can be
classified as dominant nor submissive they will both be labeled with a 0 (equal). This data will
then be analyzed using Chi-square. My project will also determine the density of melanistic S.
carolinensis within the city of Muncie IN by conducting observational surveys.
