1. Types of interaction In ecosystems

2. Interspecific Interactions Competition Predation Herbivory (herbivores eating plants or algae) Symbiosis

3. Competition Interspecific – between species Competitive Exclusion – local extinction of a population due to direct competition for resources with another species –Example – Barnacles

4. Competition Resource partitioning – differentiation in niches that allows similar species to coexist in a community –Examples Warbler species (p. 76 in text) – all feed in different parts of pine tree Different species of lizards have different feeding habitats in the same area

5. Predation Predator – kills and eats another Prey – the hunted (eaten by the predator) They both make adaptations to eat and avoid being eaten through natural selection

6. Adaptations of Predators Acute sense of smell Claws Teeth Fangs Stingers Poison Predators are usually fast or are camouflaged

7. Defenses against predation (adaptations of prey) Camouflage Mechanical defenses Chemical Defenses Mimicry –Batesian – a harmless species mimics an unpalatable or harmful model –Mullerian – two unpalatabel species that inhabit the same community mimic each other.

8. Camouflage Grey tree frog and moth

9. Mechanical Defenses Porcupine’s sharp quills

10. Chemical Defenses Poison Arrow frog

11. Mimicry http://waynesword.palomar.edu/lmexe10b.htm# mimicryhttp://waynesword.palomar.edu/lmexe10b.htm# mimicry Batesian – example a snake and a hawkmoth larva Mullerian mimicry – example – cuckoo bee and a yellow jacket Look up your own adaptations – Bring it in for class tomorrow!!Look up your own adaptations

12. Keystone Species/Predator A species that exerts strong control on community structure because of its ecological role or niche Thus, they reduce the number of the strongest competitors in the community, preventing competitive exclusion of weaker competitors Examples –Sea Star –Sea otter

13. Generalized vs. Specialized Species Generalized species – eats a variety of food Specialized species – eats one or two species only What is the advantage to a keystone predator of being specialized to feed mainly on those prey species that are otherwise the most successful amount potential prey species?

14. Answer The most competitive prey species probably represent the most abundant and dependable food source for the predator

15. Herbivory (herbivores eating plants or algae) Plant adaptations to avoid being eaten: –Chemical toxins Morphine, nicotine, mescaline, tannins, cinnamon, cloves, mint –Spines or thorns

16. Symbiosis Symbiotic Relationship is one between two or more species that live together in direct contact. Three Types –Parasitism –Commensalism –Mutualism

17. Parasitism A parasite lives on or inside host and obtains nourishment from the host One partner benefits while the other is harmed. Examples: tapeworms, ticks, pathogens (microscopic parasites)

18. Commensalism One partner benefits without harming the other Examples: algae on sea turtles, barnacles on whales, and birds that feed on insects flushed out by grazing cattle

19. Mutualism Benefits both partners in the relationship Examples: –Acacia Tree and ants