Question

9. The territorial behavior in Yarrow’s spiny lizard (Sceloporus jarrovi) has been studied extensively.

a) Provide evidence to briefly explain why the push-ups and head-bobbing displays behavior of Yarrow’s spiny lizard are probably honest signals of a lizard’s strength. (4 points)

  

b) Provide TWO hypotheses to briefly explain why you might expect a resident lizard to successfully repel intruders (i.e. don’t just name them). (6 points)

  

c) Under what conditions (characteristics of the two males) would you expect a contest between two lizards to escalate through several different types of displays to each other in a contest over a territory or a female? What is this process called? (4 points)

Answer 1

9. A.Yarrow's spiny lizard also known Scleroporus jarrovii is found certain areas of Mexico and in Arizona, US. This specie has several differential characters which marks them different from the other species. One such characteristic is their terrestrial behaviour of doing push ups and head lobbing which according to researchers is an honest signal of strength. The lizards carry out such behavior of head lobbing and push ups also often accompanied by changes on colour in order to show their strength and to mark their territory.

9. B. Resident lizards are found in areas such as the South east part of Asia where the temperature is high and humid. The lizards act as a repel to other intruders because it feeds on insects which are present in the house.

9.C. The phenomenon of contesting between two males in order to select the female they want to mate with is called sexual selection. The males lizards find the fitter female lizards appropriate for mating.