Feeding and predation L7 part 1 Flashcards
List and explain the 3 animal adaptations to feeding
Physiological: An example is Rumen bacteria in ruminant stomachs which enhances digestion of cellulose
Morphological: For example Elephant trunk
Behavioural: For example group behaviour in search and capture of prey
Explain short-term feeding strategy
Short-term objectives are to survive, to optimise energy intake and to acquire appropriate nutrition
Explain long-term feeding strategy
To survive in order to reproduce or help with reproduction
Animals might track food availability directly, gorging themselves when food is abundant, going hungry when food is scarce (Risk-prone behaviour)
Animals might try to average out food intake, storing food when it is abundant to retrieve it in times of scarcity. (Risk-averse behaviour).
define competition
Competition: An interaction between animals in which the fitness of one (or more) is lowered by the presence of another
The resource must be in limited supply
Can be asymmetrical meaning loss in fitness of one greater than in others
Explain Exploitation competition
The presence of a competitor reduces availability of a limited resource. Competing individuals may never meet
Explain interference competition
Behavior of competitors interfere with ability of individual to access the resource
Explain Scramble competition
The share of resources taken by an individual depends on amount available and population density (Grazing animals in a grassland)
Explain contest competition
Unequally divided, which involves winners and losers
High ranking individuals take more
What is the difference between intra and inter-specific competition
Intraspecific competition: meaning competition between members of the same species
Interspecific competition: meaning competition between members of the different species
Explain intercohort: life form food partitioning
Reduce competition by juvenile and adult forms differing in form, habitat and environmental requirements, including food.
explain mutualism
Some of the participants show a net gain in fitness
None have a net loss
Remove ectoparasites, mucus, scales
May clean wounds
What can predatory behavior involve?
Predators eat other animals, whether herbivores, omnivores or other predators
Predators need not eat flesh, food might include bloody, sweat and tears.
explain the difference between predation and parasitism
Predation is a form of interspecific interaction where one actor benefits (predator gets food) and the other actor suffers (prey gets eaten). Cannibalism intraspecific
Parasitism is another form of interspecific interaction with exactly the same benefits and costs
Name and explain morphological features that predators have ehanced?
Size: often predators are larger than pray but this isn’t always the case
Colour: Camouflaged for ambush
Speed: Fast movers
Where can antipredator behavior be found?
Can be found in individual animals or groups of animals
What is primary defence?
Reduces possibility of detection
What is secondary defense?
Reduces chance of being eaten even after detection
List examples of primary defence
Crypsis: Avoid being noticed
Nocturnal or subterranean
Avoiding encounters: use of refugees such as burrows
Camouflage: Remain indiscernible from surrounding environment through deception
Masquerade: Resemblance of inedible objects. Camouflage with crypsis may be detected but no recognised as prey.
What are the costs of cryptic behaviour?
Time and energy to find right background
Time spent immobile during the day
What are warning colours used for?
tell the predator that the animal is poisonous or tastes horrible
Explain Mullerian mimicry
Mimicry: Mullerian mimicry- Convergence of common warning coloration.
Prey species that do no taste nice or are emetic (sick-making) or toxic may develop bright coloured, strongly-patterned, very conspicuous colours
Aposematic colouration- Warning colours
Similar colours and patterns so predators only have to learn a few visual clues to avoid the mimic
Explain Batesian Mimicry
Palatable species resembling toxic, distasteful or dangerous species to avoid predation
Dishonest: The hoverfly pretends to be a bee or wasp
Protected from predators only in areas where the model is present
What is Aggressive mimicry?
A predator or parasite that resembles another non-threatening (Or even inviting) species to gain access to prey.
What is acoustic mimicry?
Sound advertises distasteful moth to bats
Other moths copy sound
Explain motion mimicry
Ghost pipe fish S.paraxus mimics waving of sea weed
Explain Dynamic mimicry
Octopus mimics several toxic/dangerous species
Explain slotting
Quick and energetic movements used to show to the predator that they wouldn’t catch them
Explain the evolutionary arms race
Predators have evolved a morphology and physiology to move quickly to catch their prey
However prey species have evolved to move quickly to avoid capture
As predators evolve to move quicker, prey species do the same
This is known as Co-evolution
What does Red Queen evolution mean?
Coevolution- relative success doesn’t necessarily change over time
Adapting all the time just to keep up
Running without moving forward
Explain reaction distance
Animals decide to take flight when predators reach a perceived critical distance, which takes into account: Predator speed, Prey speed, distance to safety
Explain Diversionary behaviour
Limb or tail loss
False eye spots on tail
Aim to avoid critical damage
What is Thanatosis?
Thanatosis: pretending to be dead, also known as playing possum.
What is Exaggeration of body size?
Exaggeration of body size: trying to look bigger than the predator
The feeding strategy where animals try to average out their food intake and may store food for times of scarcity is:
Risk-averse behaviour
The feeding strategy where animals gorge themselves when food is abundant and go hungry when food is scarce is:
Risk-prone behaviour
___ competition is where the presence of a competitor reduces availability of a limited resource
Exploitation
Which of these can influence the amount of resources taken in the case of scramble competition?
Amount of resources available
Distance to home range/territory
Population density
All the above
All the above
