Predator prey relationships
1 / 34

Predator-Prey Relationships - PowerPoint PPT Presentation

  • Updated On :

Predator-Prey Relationships. What are Predators?. What are predators?. Carnivory Herbivory (plants vs. seeds) Cannibalism Parasitism. Human Attitudes and Predators. Humans perspectives Human persecution. OVERCOMING HISTORY. Fairy Tales: “Little Red Riding Hood”

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Predator-Prey Relationships' - clifton

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Predator prey relationships
Predator-Prey Relationships

What are Predators?

What are predators
What are predators?

  • Carnivory

  • Herbivory (plants vs. seeds)

  • Cannibalism

  • Parasitism

Human attitudes and predators
Human Attitudes and Predators

  • Humans perspectives

  • Human persecution

Overcoming history

  • Fairy Tales: “Little Red Riding Hood”

  • “ The Three Little Pigs”

  • Wolf attacks on humans

Overcoming history1

  • Old attitudes die hard

  • Urban residents and predators

Predation in natural communities
Predation in Natural Communities

  • Almost all animals have significant predators- exceptions are:

  • Herbivores:Top predators:

  • Bison Grizzly

  • Elephant Lions

  • Rhinos Polar bear

  • Hippos Killer Whale

Predation in natural communities1
Predation in Natural Communities

  • Do predators regulate prey populations?

  • Ecosystems and predator communities

Major predators of the arctic nwr
Major predators of the Arctic NWR


Polar Bear



Arctic fox

Snowy Owl

Predator prey relationships response to prey
Predator-Prey RelationshipsResponse to Prey

1. Functional Response

Tendency of the predator to eat more of a prey species as the prey become more abundant

Predator prey relationships functional response
Predator-Prey RelationshipsFunctional Response

Predator prey relationships response to prey1
Predator-Prey RelationshipsResponse to Prey

Numerical Response

Number of predators increases with an increase in the density of prey animals

Predator prey relationships numerical response buckner and turnock 1965
Predator-Prey RelationshipsNumerical Response(Buckner and Turnock 1965)

Annual cycle of a prey population
Annual cycle of a prey population


Energy shortages

Energy shortages





Percentage of Population




Population cycles
Population Cycles

Snowshoe hare


No. in thousands


Muskrat and mink
Muskrat and Mink

Paul Errington’s Classic study of muskrat populations

Muskrat info
Muskrat info

Habitat: wetlands, especially marshes

Food: marsh vegetation

Predators: mink, coyotes, great horned owls


Muskrat and predation
Muskrat and predation

  • Observations:

    • Predation and population size

    • Predation and individual vulnerability

Muskrat behavior
Muskrat Behavior

  • Population size and social intolerance

  • Population size and social outcasts

Muskrat and mink interactions conclusions
Muskrat and Mink interactions:Conclusions

  • Social interactions may be more important than predation in limiting numbers of prey.

  • The total effect of predation cannot be assessed simply by counting the number of animals killed by predators (selectivity)

Isle royale
Isle Royale

  • Size: 45 miles long x 9 miles wide

  • Protection: National Park established in 1940

    Wilderness designation in 1976

    National Biosphere Reserve 1980

  • A location of a long term study of the relationships between the moose and gray wolf

Caribou population
Caribou Population

  • Settlers arrived in late 19th century

  • Hunted caribou

  • Responsible for fire, and forest cutting

    Fires resulted in changing old-growth coniferous forests to younger deciduous forests

    Caribou became extinct on the island

Moose history
Moose History

  • Fires resulted in changing old-growth forests to younger forests

  • Around 1910, moose came across the ice from Minnesota and became established

  • Moose outcompeted woodland caribou; island was better habitat for the moose after fires (early succession, deciduous trees)

Wolfe population
Wolfe Population

  • Winter 1949, gray wolf arrives by crossing ice from mainland

Current populations on isle royale
Current Populations on Isle Royale

Winter 2000-2001

Moose 850

Wolf 29

Present wolf population on isle royale
Present Wolf Population on Isle Royale

The wolf population is now divided into 2 territories, rather than the 3 that have been present for some time:

West Pack: gone

Middle Pack: 12

East Pack: 10

Roaming animals: 5-7

Food chain
Food Chain


Moose Small rodents Beaver

Grouse berries


Wolf response to moose
Wolf Response to Moose

  • Functional Response: lots of moose,

  • Possible because wolfs are cooperative hunters

Wolf response to moose1
Wolf Response to Moose

  • Numerical Response: lots of moose,

  • wolves reproduce well

  • Immigration is unlikely since it depends on Lake Superior freezing.

Moose response to the wolf
Moose Response to the Wolf

  • Wary; formidable prey

  • Moose in good condition can withstand an attack by a wolf pack.

  • Can’t turn and run: wolf can sever back leg tendon which renders the moose helpless.

Moose response to the wolf1
Moose Response to the Wolf

  • most vulnerable moose are the very young and the old (infirm)

  • most killed moose show signs of malnutrition and disease (i.e. they are more vulnerable)

  • Males most vulnerable: go into winter in relatively poor shape because of rut

Wolf population
Wolf Population

Three major factors that control the wolf


1. Moose numbers

2. Linear dominance hierarchy in

wolf population

3. Genetic diversity (inbreeding effects)

For more information
For more Information


Or simply type in key words: “wolf”,

“timber wolf”, or “Isle Royale”