24.11.30: population ecology
cengage chapter 5: population ecology
Five main types of species interactions:
- interspecific competition
- predation
- parasitism
- mutualism
- commensalism
Interspecific competition: two species, niches overlap, compete for resources (e.g. humans and many animals)
Resource partitioning: one resource is shared by species, but in different ways:
Predation: predator-prey (one always dies, the other survives)
See also predator prey growth cycles
Predator strategies:
speed (e.g. cheetah)
teamwork (e.g. lions)
camouflage (e.g. praying mantis)
chemical warfare (e.g. spiders)
teamwork (e.g. lions)
camouflage (e.g. praying mantis)
chemical warfare (e.g. spiders)
Prey survival strategies:
speed (gazelle)
senses (sight, sound, smell)
physical (shells, spines, thorns)
camouflage (arctic hare)
chemical warfare (octopus)
mimicry (looking like something else)
senses (sight, sound, smell)
physical (shells, spines, thorns)
camouflage (arctic hare)
chemical warfare (octopus)
mimicry (looking like something else)
Coevolution: predator gets better, prey gets better, predator gets better...
- bats use sound to find moths (echolocation)
- moths evolve to hear the sounds, evade
- bats change the frequency
- moths evolve to create their own sounds, blocking the bats
- bats evolve to listen for the moth sounds
Parasitism: One lives off of energy and nutrients from the host "it is bad manners for the parasite to kill the host"
Mutualism: both benefit (birds eating bugs on cattle)
Commensalism: one benefits, the other does not care (orchids in trees)
Ecological succession:
Primary succession: from bare rock, no organic materials
Secondary succession: building blocks for live are there, have been removed (e.g. forest fire)
Commensalism: one benefits, the other does not care (orchids in trees)
Ecological succession:
Primary succession: from bare rock, no organic materials
Secondary succession: building blocks for live are there, have been removed (e.g. forest fire)
