Social Combat part 1 Flashcards
define predation
the act of an organism killing and then partially or entirely consuming another individual
define social predation
consumption of one society by another
which is more common: interspecific social predation or intraspecific social predation
- Interspecific social predation is common
- often, the only organism that can effectively prey on a society is another society.
define competition
Use or defense of a resource that results in reduced availability of that resource for another organism
what kind of interaction is competition
- a consumer-consumer interaction
- not fatal, and so allows for more complexity in interactions and outcomes
define Indirect/exploitation competition
Competition without direct contact between consumers.
define Direct/interference competition
Competition with direct contact between consumers in access to the resource
define Intraspecific competition
Competition among individuals of the same species
outcome of interspecific competition
- depresses the population growth of both species
- drive an evolutionary arms race among species to better exploit shared resources.
competition and similarity - what makes interspecific competition more intense
Similarity in resource needs
competition and similarity - Similarity in structure and function of organisms means what
they need similar resources and compete more intensely
competition and similarity - Closely related species typically have what?
- they typically have more similar structure, function, and resource needs due to common ancestry
- and compete more intensively than distantly related species.
competition and similarity - what does evolutionary history influence
the level of competition among present-day species
define nonrenewable resources
- Finite and only available when relinquished by the individuals using it, or when it is directly taken
- e.g. space.
define renewable resources
- Constantly replenished by other processes
- there are 2 ways it can be renewed
renewable resources - 2 ways it can be renewed
- Renewed within the focal ecological system
- Renewed from outside the ecological system
renewable resources: renewed within the focal ecological system - example
births in a prey population constantly replenish predator resources.
renewable resources: renewed from outside the ecological system - example
Migrations of prey species
Axes of complexity in competition
- Indirect vs. direct competition.
- Intraspecific vs. interspecific competition.
- Similarity vs. dissimilarity in traits and resource needs (often increased via relatedness).
- Renewable vs. non-renewable resources
complexity in competition - Given a set of conditions, how intense will competition be?
The stronger the competition in social species, the stronger the selection for social combat traits.
Individual combat traits
- Morphological combat traits.
- Chemical combat traits.
- Behavioral combat strategies.
what are morphological combat traits
- Evolution of key morphological combat traits
- evolution of individual fighting prowess.
morphological combat traits - categories of traits
- Size/strength.
- Weapons.
- Armor.
- Speed.
morphological combat traits - size/strength
- Individual strength dictates size of prey that can be effectively captured.
- Individual size also dictates outcome of competitive interactions over shared resources.
morphological combat traits: weapons - the Jacana bird example
- Females are larger than males and have wings spurs (looks like thorns on their wings)
- They establish large breeding groups with many males (female led harem).
- They defend a territory of water lilies (limited resource) against other groups looking to expand.
morphological combat traits - armor examples
- exoskeletal armor in turtle ants
- thickened defensive skin in elephant seals
morphological combat traits: speed - 2 adaptations
- Adaptations for speed in predator-prey interactions
- Adaptations for speed in competitive interactions — especially in exploitation competition
chemical combat traits
- ancestral chemical combat traits
- derived chemical traits
chemical combat traits - ancestral
stinger with venom
chemical combat traits - derived
acid squirting nozzle
Behavioral combat strategies
Behavior can provide unique defense strategies, and modify and improve the effectiveness of morphological and chemical defenses.
Common behavioral strategies for avoiding combat
- Bursts of speed.
- Foraging route complexity
- Stealth.
- Direction changes.
- Playing dead
behavioral strategies - confusion and avoidance
example: Springbok jumping
define interspecific competition
Competition among individuals of different species.
