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