Chapter 55, Problem 1TY

Summary Introduction

Introduction: All the organisms interact with each other and with the environment to survive. The branch of science that deals with the study of the interaction of organism and nature is called ecology. Behavioral ecology is a type of ecology that studies the behavior of a species.

Answer to Problem 1TY

Correct answer: The proximate reason for the male deer fighting over females is the changes in day length. Hence, the correct answer is option d.

Explanation of Solution

Reason for correct answer:

Proximate causes are the genetic and physiological factors that influence the behavioral pattern of organisms. It has been observed that the male deer fight with each other to mate with female deer. This is because of the changes in the day length which brings hormonal changes in male deer. These are physiological changes as the male deer fight only in case of altered day length and not in the day with normal length. Therefore, the proximate cause of male deer fighting over female is changes in day length.

Option d. is given as “Because changes in day length stimulate this behavior”.

The changes in day length stimulate behavior that causes the male deer to fight over females. Hence, the correct answer is option d.

Reasons for incorrect answer:

Option a. is given as, “To determine their supremacy over other males”.

Proximate causes occur due to genetic and physiological factors. The determination of supremacy over other males is a social factor. It does not show any genetic or physiological pattern. Determining supremacy is not a proximate cause of male deer fighting over females. Hence, option a. is incorrect.

Option b. is given as, “To injure other males so that those males cannot mate with the females”.

The proximate causes include two factors, namely genetic and physiological. Any attack on male deer to reduce their mating chances is not a proximate cause as it does not include any genetic or physiological factor. Hence, option b. is incorrect.

Option c. is given as, “To maximize the number of genes the male deer pass on”.

Proximate causes include genetic and behavioral factors. The number of genes is a genetic factor. However, maximizing the gene number cannot be achieved by male deer fighting over females. Hence, option c. is incorrect.

Option e. is given as, “Because fighting helps rid the herd of weaker individuals”.

The fighting of males to get rid of weaker individuals cannot be a proximate cause. This is because, it does not include any genetic or physiological factors. Hence, option e. is incorrect.

Hence, the options a., b., c., and e. are incorrect.

Conclusion

Therefore, the proximate cause of the male deer fighting over the female deer is changes in day length.