14.6.1 Community Ecology: Interspecific Interaction: Predation

Question 1

Community Ecology: Interspecific Interaction: Predation

Answer 1

• Community ecology examines interactions between populations and their environments.
• Predation is one form of interspecific interaction.
• Predators include parasites and parasitoids.
• Species use a variety of adaptations as protection from predation. These adaptations include:
· camouflage
· aposematic coloration
· mimicry

Question 2

community ecology

Answer 2

• The study of ecology analyzes relationships between organisms and their environment.
• For example, in the depiction on the left, the rattlesnake has developed heat-sensing abilities that help it “see” its prey (the mouse) in the dark. The mouse comes out at night to feed, and anything that preys on it must have adaptations for hunting in the dark.
• Three different levels of focus are (1) individual, (2)
  population, and (3) community.
• One aspect of community ecology involves studying
  interspecific competition (competition between different
  species).
• Community ecology looks for evidence of coevolution, the reciprocal evolution of two or more species.
• (Remember: Evolution is a population-level phenomenon.)
• Two examples of coevolution:
• 1. Small mammals/birds (left): If a small
     mammal evolves behavior to avoid flying
     predators, it will escape predation until the
     predator, in this case a bird, also evolves
     a mechanism for identifying the prey.
• 2. Edible fruit of plants/mammals: Why is
     fruit so tasty? It is a successful strategy
     of the plant to promote seed dispersal.

Question 3

note

Answer 3

• You can analyze interspecific interactions by their effects on the populations involved.
• Predators kill and eat other organisms (prey).
• Parasites are specialized predators that live in or on a host.
• Parasitoids (generally insects) lay eggs on living hosts; the larvae feed on and kill the host.

Question 4

camouflage, aposematic, and mimicry

Answer 4

• Organisms have evolved many defenses against predation. Camouflage, or cryptic coloration, enables prey to hide from predators and avoid being eaten. The frog in the illustration on the left blends in well with its environment. Aposematic (warning) coloration provides an advertisement that the prey item is poisonous or otherwise unpalatable. For the strategy to be successful, the prey population must be large enough for the predator to learn about—and subsequently avoid—noxious individuals.
• In mimicry, species imitate other, more-dangerous species. An example is the hawkmoth larva (not shown), which has a snake-like face on its posterior end. In Batesian mimicry, a harmless species mimics a harmful one. In Mullerian mimicry, two unpalatable species resemble each other. Both species are similarly marked with aposematic colorings/markings.

Question 5

Aposematic coloration is

Answer 5

• coloration used to warn predators away from the prey

Question 6

Co-evolution is

Answer 6

• changes in two populations of different species where a change in one population drives a change in the other population.

Question 7

Which one of the following is not a defense against predation?

Answer 7

• territoriality

Question 8

True or false?

Parasitoids are specialized predators that feed on their hosts, eventually killing them.

Answer 8

• true

Question 9

__________ mimicry is when one species immitates another harmful species in coloration and __________ mimicry is when two unpalatable aposematically colored species resemble each other.

Answer 9

• Batesian, Mullerian

Question 10

The study of ecology encompases three levels of complexity: __________, __________ and __________.

Answer 10

• individual; population; community