Free Ecology Behavioral Ecology Concepts Questions and Answers 1 — Questions and Answers
Question 1: A shorebird forages for clams of different sizes buried at various depths. It consistently ignores very small, easily accessible clams and also avoids extremely large clams that require a great deal of time and energy to unearth and open. Which behavioral ecology concept best explains this selective foraging strategy?
- Competitive Exclusion Principle
- Optimal Foraging Theory (Correct answer)
- Character Displacement
- Apparent Competition
Correct answer: Optimal Foraging Theory
Optimal Foraging Theory predicts that an animal's feeding behavior will maximize the net energy gained per unit of time spent foraging. In this scenario, the shorebird ignores small clams because the energy gained is minimal (low benefit) and avoids very large clams because the energy required to dig them up and open them is too high (high cost). It selects medium-sized clams that provide the best energy return on investment.
Question 2: In a population of jacanas, a type of tropical wading bird, a single female defends a large territory that contains the smaller territories of several males. The female mates with all the males, who are then solely responsible for incubating the clutches of eggs she lays. This mating system is best described as:
- Monogamy
- Polygyny
- Polyandry (Correct answer)
- Promiscuity
Correct answer: Polyandry
Polyandry is a mating system where one female mates with multiple males. The jacana is a classic example of this system, which often involves a reversal of traditional sex roles, with the males providing the majority of parental care. Polygyny is the opposite, with one male mating with multiple females.
Question 3: Which of the following scenarios provides the clearest example of an altruistic behavior that is best explained by kin selection?
- A Florida scrub jay forgoes its own reproduction for a season to help its parents defend their nest and feed its younger siblings. (Correct answer)
- A vampire bat that was successful in finding a blood meal regurgitates blood to feed an unrelated roost-mate that was unsuccessful.
- A male langur monkey taking over a troop kills the unweaned infants of the previous dominant male.
- A cleaner wrasse swims into the mouth of a large predatory fish to remove parasites, and the larger fish does not eat it.
Correct answer: A Florida scrub jay forgoes its own reproduction for a season to help its parents defend their nest and feed its younger siblings.
Kin selection explains altruistic acts directed toward relatives. According to Hamilton's rule (rB > C), such a behavior is favored if the benefit to the recipient (B), weighted by the coefficient of relatedness (r), exceeds the cost to the altruist (C). The scrub jay helps its close relatives (siblings, r=0.5), thereby increasing the survival of individuals who share its genes, which is a classic example of kin selection.
Question 4: The male peacock's elaborate and brightly colored tail is metabolically expensive to grow and maintain, and it can make the bird more conspicuous to predators. However, peahens show a strong preference for mating with males that have the most impressive tails. This evolutionary outcome is a direct result of:
- Founder Effect
- Intrasexual Selection
- Stabilizing Selection
- Intersexual Selection (Correct answer)
Correct answer: Intersexual Selection
Intersexual selection, also known as mate choice, occurs when members of one sex (usually females) choose mates based on particular characteristics. The peacock's tail is a classic example where female preference for an exaggerated, costly trait drives its evolution. Intrasexual selection, in contrast, involves competition between members of the same sex (e.g., males fighting for access to females).
Question 5: An ecologist observes that a male American robin consistently confronts and chases away other male robins that enter a specific portion of a park lawn, where it forages and has its nest. The area that the robin actively defends against these intruders is best defined as its:
- Niche
- Home Range
- Territory (Correct answer)
- Habitat
Correct answer: Territory
A territory is a specific area that an animal actively defends against other individuals, typically of the same species. The key component is the act of defense. A home range, by contrast, is the entire area an animal utilizes in its daily activities but does not necessarily defend, and home ranges can overlap.
Question 6: In a stable population, two behavioral strategies exist for conflict over a resource: 'Hawk,' which always escalates to a fight, and 'Dove,' which always retreats if challenged. The fitness of an individual using either strategy depends on the frequency of the other strategy in the population. This dynamic, where a mixture of strategies persists because neither can be fully displaced by the other, is a classic example of:
- An Evolutionarily Stable Strategy (ESS) (Correct answer)
- Müllerian Mimicry
- A Trophic Cascade
- Resource Partitioning
Correct answer: An Evolutionarily Stable Strategy (ESS)
An Evolutionarily Stable Strategy (ESS) is a strategy which, if adopted by a population, cannot be invaded by any alternative mutant strategy. The Hawk-Dove game is a foundational model in game theory showing how frequency-dependent selection can lead to a stable mix of behavioral phenotypes in a population, where the success of being a 'Hawk' or 'Dove' depends on how many of each are present.
Free Ecology Behavioral Ecology Concepts Questions and Answers 1
A shorebird forages for clams of different sizes buried at various depths.
It consistently ignores very small, easily accessible clams and also avoids extremely large clams that require a great deal of time and energy to unearth and open.
Which behavioral ecology concept best explains this selective foraging strategy?