• limiting factors outside of a population that can affect it
• abiotic (physical) and biotic factors
• abiotic include:

1. sunlight
2. water
3. nutrients
4. food
5. resources

• biotic include:

1. competition
2. predation
3. symbiosis

• limiting factors that can act from inside the population:

1. changes in reproductive physiology
2. changes in behavior

• extrinsic
• include:

1. sunlight
2. water
3. nutrients
4. food
5. resources

• extrinsic limiting factors
• include:
  
  1. competition
  2. predation
  3. symbiosis

• limiting factors that can act in proportion to how dense the population has become

Density Independent Limiting Factors

• limiting factors can have the same effect regardless of how dense the population has become
• examples:

1. forest fires
2. tidal waves

• stresses the importance of disturbance (forces that disrupt a natural ecosystem)
• Charles Elton

• forces that disrupt a natural ecosystem
• two categories:

1. abiotic (forest fires, floods)
2. biotic (diseases, parasites)

• Occurs when 2 or more organisms use the same resource in a way that affects the birth rate or death rate of the competitors
• is an extrinsic density-dependent limiting factor.

• competition bet. members of the same species

• competition bet. members of different species

• the ecological role that a species plays in a biological community which is the sum total of its needs and the parameters within which it can survive
• niche=job, habitat=address

• the intensity of the competition bet. them depends on the extent to which their ______'s overlap

• address

• the full potential of a species' niche

• competition forces organisms into a much narrower niche (actual versus potential)

• occurs when one species is a better competitor than the other and forces it into local extinction

• several ways in which species can coexist:

1. can live in different geographic areas (don't meet, don't compete)
2. can live in the same geographic area but different habitat
3. can live in same geographic area and same habitat but use it at different times of the day
4. can live in same geographic area, same habitat, same time of day, but use the resource in a different way

• specialize in different feeding zones, but work together to get food
• some specialize in tops/bottoms of leaves, others get insects in wood
• have higher rate of food capture

• living in the same geographic area, same habitat, use it at same time but in a different way

• when you modify your physical shape through natural selection
• examples: Geospiza fortis, beak-size=8-12mL, same as G. Fulginosa

Scramble Competition

(a type of exploitation)

• when animals exploit resources by using them up

Contest Competition

(interference)

• to engage in a face to face contest over limited resources

• any area that an animal defends against other animals.

• the inclination of a species to be territorial

• bachelor males

• any organism that eats another organism (plant, animal, etc.)

• the organism that is either injured or killed by the predator

• the predator kills the organism and eats it

• insects lay their eggs in host (often paralized), the young hatch and then eat the host alive

• prey upon innocent plants

• meat-eater

• chase it and kill it
• two kinds:

1. solo
2. pack

Solo Pursuit

(active pursuit)

• the active pursuit by a lone predator
• examples: snakes, sharks

Pack Pursuit

(active pursuit)

• the active pursuit by a group of predators
• examples: wolves, lions

• hide and wait for prey to come to them
• examples: ant lions, sarlacc

• bold colors/patterns that warn predators against eating them

• predators co-evolve with their prey
• example: thicker the armor, sharper the claws of the prey

• populations of predators and prey settled down into a regular series of cycles

• sometimes predators are so important that the proper functioning of the ecosystem depends upon them, remove the predator and the system crumbles, like removing the keystone from an arch
• example: otters

• examines the ways in which behavior is adaptive, how behavior varies, and how it evolves

• from the order chiroptera-bats
• 155 species
• larger bats that feed on fruits, nectar

• smaller bats that feed on insects
• 725 species

• 700 species of bats have evolved the ability to hunt by sound

• 2 kinds:

1. male-male competition
2. female choice

The Good Genes Model

(Borgia came up with this)

• the males appearance, his ability to thrive, suggests that he has good genes
• as an adendum is great for making babies

• derived by Zahabi
• states that if a male can carry around huge tails or antlers and still avoid predators, feed himself, etc...he must be really great!

Aesthetic Preference

(Darwin)

• maybe females are simply making an aesthetic choice

Runaway Selection

(R.A. Fisher)

• states that a trait becomes reinforced generation after generation until it is greatly exaggerated (can be a dangerous burden)
• example: the Irish elk

• a linear sequence of dominant and sub-dominant males

• same thing as Dominance Hierarchy

• elaborate, ritualized behaviors that include songs and dances

• in many species of birds, a male's repertoire (the number of songs he can sing) is directly correlated with his reproductive success

• a courtship behavior shared by many animals (including humans)
• offer a potential mate a juicy morsel and this shows her you are interested (know how to find "groceries" in the wild)

• a courtship arena
• example: a lot of birds gather together to compete in one spot for mates

• birds that build bowers (little structures used to attract a mate)

• little structures built by bowerbirds used to attract a mate
• several kinds:

1. cleared area with decorations
2. a mat of lichens with decorations
3. avenue bowers
4. maypole bowers

• one male mates with several females

• bowers that juvenile males built (takes several years before they can build one good enough to attract a mate)

• states that certain physical traits (bright plumage, etc) attract a mate and then these traits become replaced by external objects such as bower decorations