Habitat selection & Territoriality Flashcards
What does animal habitat use responds to?
Conflicting pressures: the productivity of the environment in terms of food density, the level of competition, the benefits of sociality, and the animal’s individual energy demands.
What are the two habitat qualities
Fundamental habitat quality is habitat quality without competition.
Realised habitat quality is habitat quality experienced with competition.
Habitat quality is:
Can be approximated by measuring the average number of young successfully weaned per individual female in a habitat
What is conspecific cueing
When an animal uses signs that others of the same species are present as a cue (or indicator) of high habitat quality.
What is the allee effect (NOT ALLELE)
When rate of population growth increases with population density.
List some mechanisms causing rate of population growth to increase
Grouping
increases breeding success (e.g. broadcast spawning, when gametes are released into water)
Fewer individuals find mates at low population density,
Predation risk is higher at low population density.
What are the benefits of grouping
Mutual information sharing regarding food locations
Defence from predators
Competitors
Infanticidal individuals & harassment,
Opportunity to find and compare mates
Thermoregulation,
Cooperative care of young.
When does sociality evolve?
When the fitness benefits of living in a social group exceed the fitness costs of competition.
Define territory
A territory is a defended area. The territory owner has priority access to resources (typically food, mates, or shelter sites).
How does home range size varies
- Energy demand: if the individual needs to find more food it will move further so have a larger home range
- Energy supply: if the environment has scarce food the animal will move further so have a larger home range.
How can territoriality evolve?
Territoriality can evolve if the benefits of territory establishment and maintenance outweigh the costs. Benefits include food, mates, high-quality breeding sites, and shelters that are safe from predators or competitors.
What relationship between home range and competitor density would be expected in Fig. 9 if this fish species was not territorial?
The opposite - if fish home ranges overlapped, home range would need to be larger where more fish were competing for food in the same area.
What is the outcome of male lizards that have a conspicuous, colourful territorial display?
Benefit from greater access to a resource on their territory than do non-territorial males
What is a linear dominance hierarchy?
A linear dominance hierarchy is when an individual is dominant to all members below it and subordinate to all members above it in rank.
This type of hierarchy reduces conflict over resources such as food and mates- more dominant individuals (with a higher rank) have priority access.
Describe the game theory model
The game theory model approach is a way to understand fitness costs and benefits of conflict in pairs of animals
Fighting behaviour depends on:
1. The decisions of opponents
2. The value of the resource at stake.
