Feeding and predation L7 part 1

Question 1

List and explain the 3 animal adaptations to feeding

Answer 1

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

Question 2

Explain short-term feeding strategy

Answer 2

Short-term objectives are to survive, to optimise energy intake and to acquire appropriate nutrition

Question 3

Explain long-term feeding strategy

Answer 3

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).

Question 4

define competition

Answer 4

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

Question 5

Explain Exploitation competition

Answer 5

The presence of a competitor reduces availability of a limited resource. Competing individuals may never meet

Question 6

Explain interference competition

Answer 6

Behavior of competitors interfere with ability of individual to access the resource

Question 7

Explain Scramble competition

Answer 7

The share of resources taken by an individual depends on amount available and population density (Grazing animals in a grassland)

Question 8

Explain contest competition

Answer 8

Unequally divided, which involves winners and losers

High ranking individuals take more

Question 9

What is the difference between intra and inter-specific competition

Answer 9

Intraspecific competition: meaning competition between members of the same species

Interspecific competition: meaning competition between members of the different species

Question 10

Explain intercohort: life form food partitioning

Answer 10

Reduce competition by juvenile and adult forms differing in form, habitat and environmental requirements, including food.

Question 11

explain mutualism

Answer 11

Some of the participants show a net gain in fitness

None have a net loss

Remove ectoparasites, mucus, scales

May clean wounds

Question 12

What can predatory behavior involve?

Answer 12

Predators eat other animals, whether herbivores, omnivores or other predators

Predators need not eat flesh, food might include bloody, sweat and tears.

Question 13

explain the difference between predation and parasitism

Answer 13

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

Question 14

Name and explain morphological features that predators have ehanced?

Answer 14

Size: often predators are larger than pray but this isn’t always the case

Colour: Camouflaged for ambush

Speed: Fast movers

Question 15

Where can antipredator behavior be found?

Answer 15

Can be found in individual animals or groups of animals

Question 16

What is primary defence?

Answer 16

Reduces possibility of detection

Question 17

What is secondary defense?

Answer 17

Reduces chance of being eaten even after detection

Question 18

List examples of primary defence

Answer 18

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.

Question 19

What are the costs of cryptic behaviour?

Answer 19

Time and energy to find right background

Time spent immobile during the day

Question 20

What are warning colours used for?

Answer 20

tell the predator that the animal is poisonous or tastes horrible

Question 21

Explain Mullerian mimicry

Answer 21

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

Question 22

Explain Batesian Mimicry

Answer 22

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

Question 23

What is Aggressive mimicry?

Answer 23

A predator or parasite that resembles another non-threatening (Or even inviting) species to gain access to prey.

Question 24

What is acoustic mimicry?

Answer 24

Sound advertises distasteful moth to bats

Other moths copy sound

Question 25

Explain motion mimicry

Answer 25

Ghost pipe fish S.paraxus mimics waving of sea weed

Question 26

Explain Dynamic mimicry

Answer 26

Octopus mimics several toxic/dangerous species

Question 27

Explain slotting

Answer 27

Quick and energetic movements used to show to the predator that they wouldn't catch them

Question 28

Explain the evolutionary arms race

Answer 28

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

Question 29

What does Red Queen evolution mean?

Answer 29

Coevolution- relative success doesn’t necessarily change over time Adapting all the time just to keep up Running without moving forward

Question 30

Explain reaction distance

Answer 30

Animals decide to take flight when predators reach a perceived critical distance, which takes into account: Predator speed, Prey speed, distance to safety

Question 31

Explain Diversionary behaviour

Answer 31

Limb or tail loss False eye spots on tail Aim to avoid critical damage

Question 32

What is Thanatosis?

Answer 32

Thanatosis: pretending to be dead, also known as playing possum.

Question 33

What is Exaggeration of body size?

Answer 33

Exaggeration of body size: trying to look bigger than the predator

Question 34

The feeding strategy where animals try to average out their food intake and may store food for times of scarcity is:

Answer 34

Risk-averse behaviour

Question 35

The feeding strategy where animals gorge themselves when food is abundant and go hungry when food is scarce is:

Answer 35

Risk-prone behaviour

Question 36

___ competition is where the presence of a competitor reduces availability of a limited resource

Answer 36

Exploitation

Question 37

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

Answer 37

All the above