Habitat Choice, Home Range and Territory L6 Flashcards
What is Habitat choice and what is its restrictions?
This implies self-selection
Most of the time the individual organism is stuck with having to use sub-optimal locations, this therefore means they have access to only sub-optimal resources
What is a habitat?
A habitat is a specific place in the environment where an organism lives
It can be the natural home or environment of an animal, plant or other organism
There is no connotations to do with behavioural or conservation characteristics, it is just what it says.
The location of which contains the relevant resources for the survival and perpetuation of a particular species.
Often very specific habitat and species association
Can be highly specific and widespread, like stony and sand deserts for Sand cats
High specific and localised
What is Habitat preference?
Habitat preference = individuals struggling for the best sites
These sites are sought after and will be competed for
The distribution of competitors reflects this competition
What two things cause Species/Habitat association?
- Random dispersion and differential mortality: Meaning individuals that happen to end up in favorable habitats establish and reproduce. If they do not, they will die.
- Preference for places that are like to enhance reproductive success: this is for independently mobile animals.
How was genetic role discovered to be a part in determining preference?
An experiment on mice and bees showed habitat preferences that originally is expected to evolve over generations of natural selection.
Wecker did a similar experiment with relation to Prairie Deermice, giving them a choice of woodland or grassland habitats on release.
- Both captive-bred and wild-caught mice preferentially chose grassland habitats
- This is then indicates a likely genetic role in determining preference
What is the perfect situation for an organism?
A perfect situation for an organism would be equal resources available and individuals have an equal chance of finding them in result, this is an in Ideal free distribution.
What is the most common modification of the environment?
The most common modification of the environment is interference competition, The habitat quality is reduced by interference between competing individuals.
Also differences in competitive abilities of individuals intraspecific competition and predator-prey interactions
This is very important from an evolutionary perspective as individuals and species that can successfully reproduce in these circumstances persists.
What does Habitat choice require?
For habitat choice it requires individuals to move around, this includes migration and dispersal.
Important to separate out longer-distance movements from short-range and territorial movement. For example foraging
What is Calculated migration?
Distributions are informed by site conditions and quality
What is Non-calculated migration?
This is when the quality of the destination is unknown
What are Evolutionary ecologists views of dispersal?
This is when individuals switch populations and influence genetics structures and hence evolution.
What are Population dynamicists views of dispersal?
Movements in a matrix (metapopulation dynamics) without considering individual motivations
What are Strict behaviourists views of dispersal?
They are interested in the decision-making which occurs and the interaction with the mosaic of habitat
What are Animal behaviour and wildlife conservation views of dispersal?
They cover all 3
- Evolution
- Movements in a matrix
- Decision-making
How do organisms avoid in-competition and inbreeding?
it is best to change social groups
However it doesn’t have to be changed over great distances
To avoid competition between the conspecifics, it may need to be longer distances, this is mainly if the population is made of many groups
The distances to change habitat type is greater than the distances required to change units of kinship or social units.
What is Migratory dispersal?
These are annual or seasonal movements due to spatial changes in the distributions of resources or predictable environmental pressures (Cold or moisture related).
What does Migration imply and result in?
Migration also implies that there is larger-scale movement, which involves some considerable distance
This results in groupings of individuals into groups that are larger than usual (See as a By-product group)
There are parts of continents which have larger land corridors and small gaps which act as routeways for individuals and large groups to move.
What is Lifetime Track?
This is all movement which is either local, regional or global that is undertaken by the animal between birth and death.
What is Fine-scale?
Which tree to go into, which regular path to take
What is Larger scale?
when to leave for migration, which specific direction to take
What are the factors that together constitute the lifetime track of organisms?
- Stasis:
- Station keeping
Taxes and Kinesis
Foraging:
Commuting:
Territorial behaviour:
Ranging:
home range:
Movement not under control of organism
Accidental displacement
What mainly and severely influences Disruption to dispersal?
Dispersal is mainly and severely influenced by edges and barriers. Roads and routeways are one of the significant effects.
They affect gross movements and also instigate particular behavioural characteristics such as hesitation and uncertainty which could in the long run be fatal.
A lot of the current research being undertaken in order to establish the restrictions on dispersal in fragmented areas and to determine what effects this has on population viability.
Explain the Home range
This means the spatial extent or the outside boundary of a habitat which is used by an animal during its everyday activities
Explain: A territory
Meaning an area which is defended by an individual which normally includes a reproductively-active male. They defend against another individual, that generally includes another male. This is generally for purposes of mating and raising offspring.
What is similar between The Home range and A territory?
Both Home range and territory may have identical boundaries, however their functions are different.
What is the acquisition and defense of a territory an a example of?
intrasexual competition
What does Territoriality mean?
Meaning the establishment and maintaining of a territory
It is implied when there is a greater distance between individuals than expected by chance
It often reflects the vigour of the main territory holder or grouping
What does the greater amount of black on the breast of a male great tit mean?
The greater amount of testosterone
More aggressive/dominant the male is likely to be
Greater the likelihood it will acquire a territory
The greater the likelihood it will acquire a high-quality territory
What does Dynamic territories mean?
Territories are dynamic, meaning often changing in size and shape with season, population, age or other factors
What is Elastic-type behavior or contraction and expansion limited by?
aggressive actions
How is Optimal Territory size determined?
Cost-benefit analysis can be used to determine optimal territory size
What mating systems do territories normally have?
polygamous or monogamous mating system.
Explain Territory as Resources
The resource is the territorial space and also includes food, shelter and breeding sites which are found within that space.
The Territorial behaviour is often vigorous as defending this resource is central to reproduction success
What are the costs and benefits of the defense of a resource?
Defence of a resource has:
- Costs meaning the energy expenditure, risk of injury and more
- benefits meaning the priority of access to the resource
Territorial behaviour which is favoured when benefits are greater than costs
What is a territory essential for?
A territory is essential for a dependable breeding site
Given an explanation of Super territories
A territory will exclude competitors to poorer quality sites, this is one explanation for super territories, which an animal defends an area much greater than its predicted needs.
Explain Resource predictability and territoriality
With a more predictable and spaced out the resources in the habitat the more likely animals will acquire territories.
If instead it is unpredictable and/or clumped resources will lead to alternative behaviours. An example of this is flocking which is a by-product of resource availability.
Explain the relation between Territoriality and population size
If territory density reflects population density, this will cause an increased number of males which will lead to a greater number of smaller territories.
A territory will have a minimum viable area meaning a minimum level of resource.
Meaning therefore territory density is usually independent of population density but related more to resource availability.
How does good food years and poor food years affect the males control of a territory?
When a good food year occurs, this leads to a smaller territory however territory density will be higher and more males will be able to breed.
But if a Poor food year occurs the territories will be larger meaning territory density will be lower.
Competition for a smaller number of territories increases and any surplus males are excluded.
The makes which are less able to compete for a territory are known as low status individuals
A territory which is best well provisioned are more attractive to potential mates.
What does the possession of a territory reflect?
The possession of a territory will reflect:
- The owners status
- His reproductive success
- His fitness
All this ties in with the idea of the polygyny threshold
-A female might prefer to mate with an already mated male in a high quality territory rather than a non-mated male in a low-quality territory.
Define lifetime track of organism
All movements (local, regional, global) undertaken by the animal between birth and death.
What is Stasis?
-Stasis: meaning the organism is stationary, which can include coral or a hibernating organism
What is station keeping?
-Station keeping: meaning when the organism is kept in home range
in relation to factors that together constitute the lifetime track of organisms: What does it mean by Taxes and Kinesis?
Taxes and Kinesis: meaning the changes in direction or rate of movement
in relation to factors that together constitute the lifetime track of organisms: What is Foraging?
Foraging: meaning the process of searching for resources
in relation to factors that together constitute the lifetime track of organisms: What is commuting?
Commuting: meaning the regular short-term movement for resources
in relation to factors that together constitute the lifetime track of organisms: What is Territorial behaviour?
Territorial behaviour: meaning movement which is directed towards neighbours or intruders.
in relation to factors that together constitute the lifetime track of organisms: What is ranging?
-Ranging: meaning the exploratory movement
Movement which is no directly responsive to resources
in relation to factors that together constitute the lifetime track of organisms: What is home range?
home range: Migration meaning undistracted movement
in relation to factors that together constitute the lifetime track of organisms: How is movement involved?
Movement not under control of organism
in relation to factors that together constitute the lifetime track of organisms: What is Accidental displacement?
-Accidental displacement: ,meaning an organism doesn’t initiate movement.
What is a conspecific?
An organism belonging to the same species as another
