Adaptation

Physical Description                             A female Columbian black tailed deer proudly showing the white marking on her throat.

  The Columbian black tailed deer is smaller than their mule deer and white tailed deer counterparts (IHEA 2002).  The coat colors can range from dark brown, grey to light ash-grey and reddish brown (Misuraca 1999). At the throat of the black tailed deer there is a white patch  of hair (Misuraca 1999). The average weight of a male black tailed deer is between 105 pounds and 200 pounds (IHEA 2002). The average weight of a female black tailed deer is between 90 pounds and 140 pounds (IHEA 2002).

 

Antlers

            The first thi A male Columbian black tailed deer with newly grown velvet antlers. ng that is noticed when looking at a male Columbian black tailed deer is the antlers.  Antlers are different from horns(Gross 1983). They are complete made up of solid dead bone that is dropped annually (Gross 1983).  A male fawn Columbian black tailed deer will grow buttons between 6 to 8 months after being born(WDFW 2013).  Buttons are small bumps that are on top of the head.There are buttons shown in the picture to the left. The buttons grow to form the pedicels(WDFW 2013).  Pedicels are skull extensions made of bone that the antler will grow from each year (WDFW 2013). The yearly renewal of antlers is formed by the apical growth centers that are found by the pedicels(WDFW 2013).

 

          When the antlers grow a thin layerA young male black tailed deer with velvet antlers. of skin called velvet is on the outside of the antlers (WDFW 2013).  It is called velvet because of the tiny hairs that grow from the skin, making it look like velvet (WDFW 2013). Velvet also contains blood vessels and a nerve network (WDFW 2013). The velvet will dry and peel off when the antlers have completely grown (WDFW 2013). The black tailed deer get the velvet off by rubbing (WDFW 2013). Rubbing is when the antlers are brushed repeatedly against young trees and shrubs (WDFW 2013).  The act of rubbing shows other males how ready the male is for the rut to begin (WDFW 2013).

             After the rut is complete the antlers will drop from late December to early March (WDFW 2013). Antlers drop because of a hormone that weakens the bone at the pedicels. (WDFW 2013) The hormone that weakens the bone is activated by the difference in daylight during the changing of seasons (Gross 1983).  When the seasons change once again the antlers will begin to grow once more (Gross 1983). The antler structure is dependent on the hormone testosterone for growth (Gross 1983).  The sizes of the antlers are dependent on the nutrient intake and years of survival of the Columbian black tailed deer (WDFW 2013).  If the habitat of the Columbian black tailed deer is high in nutrients the number of points on the antlers will be higher (WDFW 2013). If the black tailed deer has survived many years in the forest, the number of points on the antler will also be higher (WDFW 2013).

 Alarm Walking

         A study in the Journal of Mammalogy, found a new behavior of the Colombian Black tailed deer (2008). This behavior is called aA female Columbian black tailed deer on the lookout for predatorslarm walking (Stankowich and Coss 2008).  Alarm walking is the same pattern of a prancing horse but at a slower speed (Stankowich and Coss 2008). Actually accomplishing alarm walking requires control and flexibility (Stankowich and Coss 2008). This fluid high-stepping walk has been observed more often when predators are present (Stankowich and Coss 2008). The behavior of alarm walking gives predators two important pieces of information. Frist it shows the predator that the black tailed deer is young and healthy (Stankowich and Coss 2008). Injured and elderly black tailed deer cannot alarm walk because of the lack of control and flexibility within the leg joints.  Second alarm walking shows the predator the fact that the black tailed deer is capable of escaping the predator (Stankowich and Coss 2008).  This is a great adaptation of the black tailed deer to keep predators at bay. To learn more about the predators of the black tailed go to the Interactions page.    

 

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