Animal Behavior Questions
Bring on the tough stuff
1. Most animal defense techniques do not involve hand-to-hand (or paw-to-paw) combat. Why is this?
2. Why do males fight over access to females and not the other way around?
3. Why don’t species with internal fertilization have male parental care?
4. Alarm calls put the caller at increased risk of predation by drawing attention to its location. Why might this behavior be favored by evolution?
Animals that use alarm calls put themselves at risk but increase the chances of their relatives’ survival. Animals that live in colonies with alarm calls usually live in large family groups, so their genes benefit by allowing others in the group to survive. Alarm calls may be favored by kin selection.
5. What are some benefits to living in a group? What are some negative consequences of group living?
6. Viceroy butterflies avoid predators by mimicking monarch butterflies’ coloration, but viceroys are not poisonous and monarchs are. When might this mimicry stop deterring predators?
7. Say you were in charge of a bird’s nest that the parents abandoned. What might you do to help the birds recognize their own species?
8. How does schooling behavior help fish avoid predation? What is a downside to schooling?
9. What type of learning behavior do you use when training your pet dog?
10. Animals that migrate travel a very long distance away from home, which comes with a lot of risk—the possibility of getting lost, lack of food, exhaustion, injury. Why do animals bother migrating?
Possible Answers
1. Most animal defense techniques do not involve hand-to-hand (or paw-to-paw) combat. Why is this?
Most animals avoid fighting if at all possible. They might have stand-offs, or growl, and try to intimidate other animals into running away. But usually the risk of drawing blood is too high. Animals other than humans can’t just run to the doctor to get stitched up if they get injured. An injury means it will be harder to move around and find food and also easier to be injured again or eaten by a predator.
2. Why do males fight over access to females and not the other way around?
Females are the choosy sex because of the differences in male and female reproductive anatomy. Eggs are energetically expensive to produce, and females can only produce a limited quantity of eggs. Sperm on the other hand are energetically cheap and males can make unlimited quantities of sperm. So males try to maximize their reproductive success by mating as much as possible, while females try to pick the best genes for their offspring to maximize the chances of the offspring’s survival. The males fight over access to females because the females are the limiting factor—the males want to get their genes into the pool, and to do that they need females.
3. Why don’t species with internal fertilization have male parental care?
Internal fertilization is where the egg is fertilized inside the female’s body. The male has no way of knowing if the egg has been fertilized before he got there—for all he knows, the female is already pregnant with someone else’s offspring. It would be a waste of time and energy for a male to take care of someone else’s offspring that do not have his genes. This is why we see male parental care more often in species with external fertilization.
4. Alarm calls put the caller at increased risk of predation by drawing attention to its location. Why might this behavior be favored by evolution?
Animals that use alarm calls put themselves at risk but increase the chances of their relatives’ survival. Animals that live in colonies with alarm calls usually live in large family groups, so their genes benefit by allowing others in the group to survive. Alarm calls may be favored by kin selection.
5. What are some benefits to living in a group? What are some negative consequences of group living?
Living in a group provides quite a few benefits. Group members can cooperate in finding food. Group hunters can catch larger prey than individual animals can, and animals foraging might find spots where food is plentiful and all members of the group benefit rather than wasting time fighting over it. Groups can defend territories more efficiently than individuals can, and living in a group also provides better access to mates.
There are also drawbacks to living in a group. Groups may attract predators or attacks by other animals because of scents or noises. Animals living in groups also spread disease more easily than animals living on their own.
6. Viceroy butterflies avoid predators by mimicking monarch butterflies’ coloration, but viceroys are not poisonous and monarchs are. When might this mimicry stop deterring predators?
This type of mimicry depends on predators learning to avoid the butterflies. To do that, they have to taste a few to learn that they taste bad. If there are a lot more viceroys than monarchs, the predators will usually have a satisfying meal without getting sick, and will not associate getting sick (when they eat an occasional monarch) with eating the butterflies. The whole mimicry depends on predators making the association between color and poison.
7. Say you were in charge of a bird’s nest that the parents abandoned. What might you do to help the birds recognize their own species?
The birds will probably imprint on you, but you could help them out by playing bird calls from their species. You could also show them pictures or dress up to look like that species of bird. (No joke, that’s what whooping crane biologists do!)
8. How does schooling behavior help fish avoid predation? What is a downside to schooling?
Schooling is when tons of fish swim together in a tight group. Predators might avoid a school if they think it is one big fish rather than a bunch of little fish. Fish in a school also might confuse the predator because they can move in a bunch of different directions when the predator approaches.
Schooling in fish makes it easy for humans with nets to catch them. Unfortunately, many fish species have been exploited so badly that there are not enough of them to catch anymore. The same schooling behavior that protects fish from most predators allows humans to take advantage of them.
9. What type of learning behavior do you use when training your pet dog?
Dog training takes advantage of associative learning, which is when an animal associates two experiences. Dog training uses food as a reward for behavior. Just like Pavlov’s dog salivated when a bell rang, your dog sits because it associates sitting on command to getting a treat. You might have to reinforce this behavior with treats occasionally—if the dog stops getting treats when it sits, it might forget why it bothers.
10. Animals that migrate travel a very long distance away from home, which comes with a lot of risk—the possibility of getting lost, lack of food, exhaustion, injury. Why do animals bother migrating?
Animals that migrate spend the winter away from their breeding grounds to go to a place with more food. In most northern climates, there are no leaves, flowers or fruits in the winter, which means there is not much food available. Migratory animals fly (or swim) to the tropics, where food is available year-round. With warmer winters and less snow in recent decades, many animals are delaying migration by anywhere from a few days to weeks. Under future climate change scenarios, migration might be altered even more.