EnSt/Bio 295 Exam II This test is worth 100 points; you have approximately 50 minutes. Allocate your time accordingly.

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1 Name: 1 NAME: EnSt/Bio 295 Exam II This test is worth 100 points; you have approximately 50 minutes. Allocate your time accordingly. 1) Describe the following concepts in a few sentences (2 points each) Zugenruhe Intention Movements - Orientation vs. navigation Handicap principle- Mate-assistance Hypothesis 2) True-False (2 pts each) a. In some species, females choose their mates based on characteristics that enhance the male s survival or competitive abilities (like large size). This mate choice can be explained by the Good Genes Hypothesis. b If an animal is following optimal foraging theory, it should only eat low profitability items when they are in high abundance. c. A primary reason that EPC s are undesirable to both male and female partners of philandering mates is that they can lead to the raising of offspring that are not their own. d. Syntax is utilized by a wide variety of species in their communication. e. When females are attracted to the same sites for feeding (Like female cheetahs being attracted to watering holes), it favors a female-defense polygyny mating system.

2 Name: 2 T f. Even in a polygynous mating system, there is an element of female choice about whether or not to participate in that mating system F_ g. Altruistic acts like alarm calls evolve because they are good for the group even though it may cost the alarm caller their life. Evolve b/c they increase the individual s inclusive fitness, not because they help the group. Also, ind. Helped must be related. F _ h. One would only expect an individual to maintain a territory if it increase their chance of survival to the next season. Ind may defend a territory for access to mates even if it decreases survival. F _ i. The complexity of a species system of communication can be adequately described by the number of displays that they utilize. Almost all species have similar numbers of displays. Enrichment devices are the key. F j. Although it would take a few million years, if we can stop further species loss there is no reason not to think that biodiversity would rebound from the current extinction crisis as it has from previous mass extinctions. We have destroyed habitats that might allow for new species divergence. T k. Because members of different species are not normally strong competitors for the same resources, interspecific territoriality is rare. 3) Fill in the blank. Be as specific as possible. You must fill in all the blanks for a question correctly to get credit. (2 points each) a) An altruistic act will be favored by selection if it increases the individual s inclusive fitness. Note: Altruistic acts increase inclusive fitness through indirect fitness but the act will not be favored unless inclusive fitness increases even if indirect fitness does. b) An animal may choose not to forage optimally due to concerns about both competition and predation. c) The mode of communication most often used for locating others at a distance is auditory, while visual signals are very fast and can be directed, and tactile signals are very personal and cannot be overheard. d) _Discreet_ signals have evolved for maximum clarity while a graded signal can be used to convey motivational state. e) An area that an animal uses for its day-to-day activities is called its home range. f) When a dog stretches out its forepaws before playing to say that the aggressive behavior to follow is not a challenge, it is called _metacommunication. g) The type of selection that is most likely responsible for sexual dimorphism in body size is intra-sexual selection.

3 Name: 3 4) A grizzly bear walking through the woods hits his head on a branch and turns and growls in protest at the tree. There is no other animal around to hear. Is he communicating? Explain your answer.(3 points) No, communication is an action on the part of one animal that alters the behavior of another. The bear does not alter the tree s behavior and is therefore not communicating 5) Describe the waggle dance and how it is used to convey information. (4 points) Used by bees to convey food location. Need to draw dance and describe how the angle of the dance from 90 degrees conveys direction relative to the sun, and the intensity or number of waggles gives the distance to the food source. 6) List three ways a migrating bird might find their way on a cloudy day. (3 points) Any of these 3: 1) Polarized light 2) Weather/wind 3) Magnetic fields 4) Landmarks river bed, mountain range, etc. 7) List 4 functions of redundancy in communication. (4 points) 1) Reduce risk of misinterpretation 2) Repeated communication may allow individuals the opportunity to reassess each other s situation when motivational states are important or likely to change 3) Coordinate sexual arousal and maintain at a high level 4) Increased memorability 8) What are 3 areas in which males and females may conflict over sexual reproduction? (6 points) 1) Mating decisions Both sexes not always wanting to mate can lead to forced copulations. Also, scorpion fly female is supposed to get a treat for mating but male will sometimes try to take it away after mating and use it to attract another female. 2) Parental Investment Who cares for offspring? Neither sex may want to. 3) Infanticide Good for the males who do it, obviously bad for the female who has infested in those offspring.

4 Name: 4 9) Two young birds (sisters) are trying to decide if they should nest together or separately. If they nest together, the smaller one will have to forgo her own reproduction and help her sister raise her offspring. If they remain together the nest will be able to produce 10 offspring per season. If they remain separate the larger sister will produce 6 offspring of her own and the small one only 3. Will selection favor the smaller one to aid her sister or to nest on her own? Explain your answer. (4 points) For cooperative nesting to be favored, rb-c>0. r =.5, B = 4 (only additional offspring to the sister as a result of helping count), C = 3..5(4) - 3 = -1 so selection should favor the smaller sister to nest on her own. 10) Why are territory holders at an increased risk of predation? What are some additional costs to territoriality? (4 points) Because they must be visible and active to defend their space which increases exposure to predators. Magnified by the bright colors that help one be seen and defend their space. Additional costs could be any that we mentioned or that otherwise make sense. 11) Briefly explain 3 benefits that a female may receive from engaging in EPC s. (6 points) 1) Fertility insurance maybe her male is a dud, multiple matings could help to guarantee she will have some offspring 2) Improved offspring quality Female could mate with males who are better than her own in order to increase the quality of her offspring 3) More or better materials hypothesis female engages in EPC s in order to get additional services from neighboring males. Could be access to food, protection, parental care, etc. 12) What is the most critical assumption of optimal foraging theory? Is it reasonable? Why? (4 points) That animals should act to maximize energy gain. Certainly they should recognize profitable foods, but beyond that does food profitability matter. Yes, because animals have a limited amount of time for a variety of things. They should maximize their feeding to as much time as possible for other things like mating, rest, etc. Also, feeding often increases predation risk so one would want to minimize that risk.

5 Name: 5 13) While visiting the bird house at the zoo with some friends, they become fascinated with the bright plumage and extremely long tails of the males of many species and cannot understand how these traits could possibly benefit these males. Other than the Good Genes Theory, how could you explain the evolution of these traits? (8 points) 1) Runaway sexual selection Explanation must include the following components a. Genetic-based male trait that is beneficial at its extremes and a genticbased female preference for males with extreme trait values b. Two traits become correlated in the offspring and leads to correlated selection c. Correlated selection leads to rapid evolution for male trait and male trait races past optimal d. Evolution of male trait stops only when detriment of trait to male balances the advantage it confers for mate attraction. Can t go back. 2) Sensory exploitation Males evolve exaggerated traits or displays that take advantage of pre-existing female sensory system biases. If female has a bias, males will exploit it. Evidence for bias comes from swordfish, zebrafish, etc. experiments. 14) In nature, we often see males competing for mates and females being the choosier sex. How would you explain this pattern to a friend? Give an example from nature to support your explanation of why this occurs. (8 pts) 1 Parental investment In most species, females invest more time, energy, risks, in an offspring that do males. Parental investment is the opposite of reproductive potential therefore females have a reason to be more selective with their offspring, while males can increase their fitness through increasing offspring numbers. (3 pts) 2 Operational sex ratio Ratio of sexually receptive males to receptive females is usually high, even though overall sex ratio in population is 1:1. This leads males to compete for females, and gives females the opportunity to choose their mates. (3 pts) Example from nature to support explanation (2 pts): When males must invest more thanfemales for an offspring, expect to see females compete for mates and males be choosy.two examples given in class where this is the case are mormon crickets and pipefish.