1.3 Populations

1.3 Populations

http://www.whale-images.com/endangered-mammals-80-pictures.htm

Carrying Capacity

• It’s the maximum population that an environment can sustain.

• Seychelles Paradise Flycatcher needs one acre of mixed forest per breeding pair. They live on the little island of Madagascar

http://www.rareconservation.org/blog/index.php?paged=2

4 factors that determine carrying capacity

• 1) MATERIALS & ENERGY

• Limited by the quantity of light. energy

• Amount of water, carbon & other materials

http://www.condorjourneys-adventures.com/costarica_nature.asp

http://weathersavvy.com/Q-Climate_DesertsHot.html

4 factors that determine carrying capacity…

• 2) Food Chains• Limited by the

quantity of available food

• Limited by predators

http://www.intarttiles.com/robertekennedy.htm

Predation

• Prey have developed defence mechanisms to prevent them from getting eaten:– Poison– Mimicry– Camouflage– Armour– Secretions

Poison

MimicryNorth American Monarch or the Viceroy – can you tell the difference?

Poison! Warning!(Except one isn’t!)

• Coral Snake • King Snake

Camouflage

• Evolution of moths before and after the industrial revolution

Protective Armour

Protective Secretions

4 factors that determine carrying capacity

• 3) Competition

• For food, water, mates & space.

• Intraspecific Competition: Between individuals of the same species.

• Interspecific Competition: Between different species.

http://www.maxi-fond-ecran.com/fond-ecran-photo-paon/paon/telecharger-fond-ecran-photo-paon-p18507.html

http://www.tnstate.edu/ganter/B412%20Lab2%20PlantComp.html

http://www.allposters.com/-st/Elephant-Posters_c646_p3_.htm

4 factors that determine carrying capacity

• 4) Population Density : Number of individuals that are living in the same place at the same time.

http://reliableanswers.com/images/wallpaper/penguin_party.jpg

http://www.naturetrek.co.uk/wildlife-holidays/wildlife-holidays.asp?ID=3

Density dependent Factors• When the density has gone

beyond an appropriate level • Over-population can:

– Increase stress & lead to the easier spread of diseases and parasites

– Increases aggressions & causes parents to neglect offspring

• So, then the population will decrease

http://www.envirowarrior.com/animal-abusers-the-worst-polluters/

Density Independent Factors

Limits the population- no matter what the density is.

-Forest fires

-Earthquakes

-Volcanic Eruptions

-Tornadoes

http://tiee.ecoed.net/vol/v3/issues/frontier_sets/yellowstone/sci_teaching.html

Show your Understanding

• Complete: pg. 24 # 1 – 6

• Homework: Complete worksheet on Population Density