Species interactions such as competition, predation, parasitism, and mutualism affect population sizes and resource use. Competition is the most common interaction where two species cannot coexist using the same limited resources, often resolved by migration, changing diets/behavior, population drops, or extinction. Predation influences species distributions and regulates populations, while coevolution leads to an arms race between predator techniques and prey defenses. Parasitism and mutualism also impact biodiversity through host regulation or reciprocal benefits between species.
5. Interspecific CompetitionInterspecific Competition
• Resolved by:
– Migration – move somewhere else
– Shift in feeding habits or behavior – eat something else
– Population drop – fewer individuals
– Extinction – die out
6. Intense competition leads toIntense competition leads to resource partitioning –resource partitioning –
each species becomes more specializedeach species becomes more specialized
Cape May
Warbler
Blakburnian
Warbler
Black-throated
Green Warbler
Yellow-rumped
Warbler
Bay-breasted
Warbler
Fig. 5-2, p. 81
15. CoevolutionCoevolution
• Predator and prey Relationship
• Intense natural selection pressure on each other
• Each can evolve to counter the advantageous traits
the other has developed called Coevolution.
– Bats and moths
16. ParasitismParasitism
• Parasitism – one individual, known as
parasite, feeds on another individual,
known as the host.
• Parasites promote biodiversity – help keep
populations of hosts in check
19. MutualismMutualism
• Both species benefit
– provides food, shelter, or some other resource
• Nutrition and protection
• Gut inhabitant mutualism
20. InteractionsInteractions
• Commensalism – is interaction where
one species benefits and the other is not
affected.
–Movement of buffalo and birds eat
insects and lizards