Community Ecology Notes

Habitat vs. niche Habitat - place where an organism lives Niche - how it uses the abiotic and biotic components of its habitat

Competitive Exclusion Principle

Habitat vs. Niche

Interspecies competition (-/-) If niches overlap Vs.

Predation (+/-) Lion eats Cape Buffalo Tiger eats Blesbuck

Predation Sidewinder eats a Lizard Spider eats a frog

Video: Shark Eating a Seal Student Misconceptions and Concerns For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems. Teaching Tips 1. Students have often had prior exposure to the concepts of food webs and food chains. Present a food web (perhaps Figure 37.9) to your class and challenge them to predict the consequences of a decrease or increase in the population of one of the organisms. This activity can help students understand how difficult it is to make precise predictions about these complex systems. 2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. Video: Shark Eating a Seal Use window controls to play © 2012 Pearson Education, Inc. 9

Anglerfish Use a part of their body to lure curious fish within striking distance, improving odds for success of passive strategists (0.004 seconds!!) www.teachersdomain.org/6-8/sci/life/reg/angler http://www.youtube.com/watch?v=EqJzuc9pE00

Protection against predation… Camouflage - blending in with your environment Green tree frog Chameleon Polar Bears

Video: Seahorse Camouflage Student Misconceptions and Concerns For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems. Teaching Tips 1. Rattlesnakes are a good example of a highly specialized predator. Since they are unable to move fast enough to catch their prey, rattlesnakes typically ambush them, a process facilitated by their camouflaged bodies. Rattlesnakes often feed during the cooler parts of the day, using heat-detecting facial pits to identify prey before injecting them with fast-acting venom. The prey is immediately released (perhaps to avoid damage to the snake from struggling prey), but is disabled by the venom within seconds. The rattlesnake then uses a variety of senses to track the prey the short distance to where it has collapsed. 2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. Video: Seahorse Camouflage Use window controls to play © 2012 Pearson Education, Inc. 13

Figure 37.5A Figure 37.5A Camouflage: a gray tree frog on bark 14

More camouflage… Rock grasshopper

Arctic rabbit Flounder fish

Mimicry - resemble another species Moth Leaf Insect Monarch Viceroy

Figure 37.5B Figure 37.5B Chemical defenses: the monarch butterfly 18

Symbiosis Relationship between two species that live together, usually in physical contact

Mutualism (+/+) http://video.nationalgeographic.com/video/player/animals/bugs-animals/ants-and-termites/ant_acaciatree.html Acacia trees and ants Pollination by bat

Mutualism (+/+) Cows and the bacteria in their stomach

Commensalism (+/0) Fish in coral reef Reef Shark and Remora

Video: Clownfish and Anemone Student Misconceptions and Concerns For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems. Teaching Tips 1. Students who are business-oriented may also enjoy this analogy. Many corporate leaders describe the best business deals as mutualistic, fostering a win-win relationship. For example, perhaps a new company creates a marketable product from another company’s wastes. 2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. Video: Clownfish and Anemone Use window controls to play © 2012 Pearson Education, Inc. 23

Commensalism (+/0) Mites in your eyelashes

Parasitism (+/-) Tick on a dog Flea on a dog

Parasitism (+/-) Cowbirds Mosquito

Parasitism ex. Cymothoa exigua WARNING: gross picture ahead. Be prepared.

Parasitism (+/-) Guinea worm