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G Sabrinus Research Paper

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Alex Christensen 10/21/2014 Bio 203 Lab Glaucomys sabrinus: Habit and Geography/ Forms and Function One of the most biologically complex organisms across all ecosystems is the northern flying squirrel (G. sabrinus). In the most general sense, the northern flying squirrel can be labeled an occupant of boreal conifer and mixed forests and an organism who has developed the ability to glide from tree to tree (Smith et al. 2011, Thorington and Santana 2007, Weigl 2007). This basic overview of the G. sabrinus, however, does not even begin to show the complexity of this organism’s lifestyle and the various functions that allow it to survive. This organism also serves as a very precise indicator of an ecosystems health; recently G. sabrinus has been …show more content…

2011). In the past, G. sabrinus, especially in the case of females, could be characterized as an organism who remained relatively distant from each other (Smith et al. 2011). This meant that females would share little foraging territory and nesting sites prior to deforestation (Smith et al. 2011). As a result of the harvesting of the boreal forests of the northern United States and Canada, the northern flying squirrel has been forced to group much closer together and both the northern flying squirrel and its primary predator, the northern spotted owl, are now endangered (Smith et al. 2011, Weigl 2007). The changes that can be seen in terms of spatial organization of G. sabrinus are the following: 1) overlap of northern flying squirrel foraging zones has depleted necessary food sources because they have been forced to compete for resources and 2) female G. sabrinus have become increasingly aggressive around den sites (Smith et al. 2011). Also, some interesting evidence has shown some isolated sharing of nest sites between G. sabrinus females due to increasing home range overlap, even though there is no evidence of female-female attractions within this species (Smith et al. 2011). Forage zone sharing and the isolated nest sharing among females are more good examples of the northern flying squirrels …show more content…

Small tree squirrels like the Sciurini are very good leapers and use the ability to jump from tree to tree to avoid predators, however, small tree squirrels are unable to leap as far as larger tree squirrels so the ability to glide is more advantageous to smaller squirrels then to larger ones (Thorington and Santana 2007). Also, due to the fact that smaller squirrels reach lower velocities upon falling, smaller squirrels would be safer if such a situation occurred and they would be less likely to become injured (Thorington and Santana 2007). Due to these factors, the conclusion that northern flying squirrels evolved from small squirrels is justified. Overall, the evolution of gliding in small tree squirrels allows them to more successfully avoid predators, find food more quickly, and increases the safety of the squirrel as it moves around its’ habit (Thorington and Santana 2007). The anatomical manifestation of this evolution is the patagium which is lined with muscle called the platysma II extending from the wrist to the body and from the body to the ankle (Thorington and Santana 2007). Unlike other flying squirrels, the northern flying squirrel does not possess what is called an uropatagium which extends from the ankle to the tail, despite this, G. sabrinus is a very adept glider. Another adaptation that is believed to have occurred is the

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