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Chapter 5 Biodiversity, Species Interactions, and Population Control. Core Case Study: Southern Sea Otters: Are They Back from the Brink of Extinction?. Habitat Hunted: early 1900s Partial recovery Why care about sea otters? Ethics Tourism dollars Keystone species. Southern Sea Otter.
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Chapter 5 Biodiversity, Species Interactions, and Population Control
Core Case Study: Southern Sea Otters: Are They Back from the Brink of Extinction? • Habitat • Hunted: early 1900s • Partial recovery • Why care about sea otters? • Ethics • Tourism dollars • Keystone species
Southern Sea Otter Fig. 5-1a, p. 104
5-1 How Do Species Interact? • Concept 5-1 Five types of species interactions—competition, predation, parasitism, mutualism, and commensalism—affect the resource use and population sizes of the species in an ecosystem.
Species Interact in 5/6 Major Ways • Intraspecific Competition • Interspecific Competition • Predation • Parasitism • Mutualism • Commensalism
Most Species Compete with One Another for Certain Resources • For limited resources • Ecological niche for exploiting resources • Some niches overlap
Some Species Evolve Ways to Share Resources • Resource partitioning • Using only parts of resource • Using at different times • Using in different ways
Resource Partitioning Among Warblers Fig. 5-2, p. 106
Blackburnian Warbler Black-throated Green Warbler Cape May Warbler Bay-breasted Warbler Yellow-rumped Warbler Fig. 5-2, p. 106
Blackburnian Warbler Black-throated Green Warbler Cape May Warbler Bay-breasted Warbler Yellow-rumped Warbler Stepped Art Fig. 5-2, p. 106
Specialist Species of Honeycreepers Fig. 5-3, p. 107
Fruit and seed eaters Insect and nectar eaters Greater Koa-finch Kuai Akialaoa Amakihi Kona Grosbeak Crested Honeycreeper Akiapolaau Apapane Maui Parrotbill Unknown finch ancestor Fig. 5-3, p. 107
Most Consumer Species Feed on Live Organisms of Other Species (1) • Predators may capture prey by • Walking • Swimming • Flying • Pursuit and ambush • Camouflage • Chemical warfare • Going to restaurant or grocery store!
Predator-Prey Relationships Fig. 5-4, p. 107
Most Consumer Species Feed on Live Organisms of Other Species (2) • Prey may avoid capture by • Run, swim, fly • Protection: shells, bark, thorns • Camouflage • Chemical warfare • Warning coloration • Mimicry • Deceptive looks • Deceptive behavior
Some Ways Prey Species Avoid Their Predators Fig. 5-5, p. 109
(a) Span worm Fig. 5-5a, p. 109
(b) Wandering leaf insect Fig. 5-5b, p. 109
(c) Bombardier beetle Fig. 5-5c, p. 109
(d) Foul-tasting monarch butterfly Fig. 5-5d, p. 109
(e) Poison dart frog Fig. 5-5e, p. 109
(f) Viceroy butterfly mimics monarch butterfly Fig. 5-5f, p. 109
(g) Hind wings of Io moth resemble eyes of a much larger animal. Fig. 5-5g, p. 109
(h) When touched, snake caterpillar changes shape to look like head of snake. Fig. 5-5h, p. 109
(a) Span worm (b) Wandering leaf insect (c) Bombardier beetle (d) Foul-tasting monarch butterfly (f) Viceroy butterfly mimics monarch butterfly (e) Poison dart frog (g) Hind wings of Io moth resemble eyes of a much larger animal. (h) When touched, snake caterpillar changes shape to look like head of snake. Stepped Art Fig. 5-5, p. 109
Science Focus: Threats to Kelp Forests • Kelp forests: biologically diverse marine habitat • Major threats to kelp forests • Sea urchins • Pollution from water run-off • Global warming
Purple Sea Urchin Fig. 5-A, p. 108
Predator and Prey Interactions Can Drive Each Other’s Evolution • Intense natural selection pressures between predator and prey populations • Coevolution • Interact over a long period of time • Bats and moths: echolocation of bats and sensitive hearing of moths
Coevolution: A Langohrfledermaus Bat Hunting a Moth Fig. 5-6, p. 110
Some Species Feed off Other Species by Living on or in Them • Parasitism • Parasite is usually much smaller than the host • Parasite rarely kills the host • Parasite-host interaction may lead to coevolution
Parasitism: Trout with Blood-Sucking Sea Lamprey Fig. 5-7, p. 110
In Some Interactions, Both Species Benefit • Mutualism • Nutrition and protection relationship • Gut inhabitant mutualism • Not cooperation: it’s mutual exploitation
Mutualism: Hummingbird and Flower Fig. 5-8, p. 110
(a) Birds and black rhinoceros Fig. 5-9a, p. 111
(b) Clownfish and sea anemone Fig. 5-9b, p. 111
In Some Interactions, One Species Benefits and the Other Is Not Harmed • Commensalism • Epiphytes • Birds nesting in trees
Commensalism: Bromiliad Roots on Tree Trunk Without Harming Tree Fig. 5-10, p. 111
5-2 What Limits the Growth of Populations? • Concept 5-2 No population can continue to grow indefinitely because of limitations on resources and because of competition among species for those resources.
Most Populations Live Together in Clumps or Patches (1) • Population: group of interbreeding individuals of the same species • Population distribution • Clumping • Uniform dispersion • Random dispersion
Most Populations Live Together in Clumps or Patches (2) • Why clumping? • Species tend to cluster where resources are available • Groups have a better chance of finding clumped resources • Protects some animals from predators • Packs allow some to get prey
Population of Snow Geese Fig. 5-11, p. 112
Generalized Dispersion Patterns Fig. 5-12, p. 112
(a) Clumped (elephants) Fig. 5-12a, p. 112
(b) Uniform (creosote bush) Fig. 5-12b, p. 112
(c) Random (dandelions) Fig. 5-12c, p. 112
Populations Can Grow, Shrink, or Remain Stable (1) • Population size governed by • Births • Deaths • Immigration • Emigration • Population change = (births + immigration) – (deaths + emigration)
Populations Can Grow, Shrink, or Remain Stable (2) • Age structure • Pre-reproductive age • Reproductive age • Post-reproductive age
Some Factors Can Limit Population Size • Range of tolerance • Variations in physical and chemical environment • Limiting factor principle • Too much or too little of any physical or chemical factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance • Precipitation • Nutrients • Sunlight, etc
Trout Tolerance of Temperature Fig. 5-13, p. 113
Lower limit of tolerance Higher limit of tolerance No organisms Few organisms Few organisms No organisms Abundance of organisms Population size Zone of intolerance Zone of physiological stress Zone of physiological stress Zone of intolerance Optimum range Low Temperature High Fig. 5-13, p. 113