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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 Five Major Ways • 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
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
Mutualism: Oxpeckers Clean Rhinoceros; Anemones Protect and Feed Clownfish Fig. 5-9, p. 111
(a) Oxpeckers 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