Lecture 3: The Evolution of Feeding Behaviour

Question 1

predators and prey are often locked into a___

Answer 1

co-evolutionary struggle

Question 2

Tinbergens discovery regarding search images

Answer 2

he observed that when a new type of caterpillar appeared in woodlands, songbirds rarely brought it to their nests. But once a few had been located, birds collected them at a greater rate –> birds has come to recognise the caterpillars and formed a search image

Question 3

search images in Humans:

Answer 3

look for cues that match what you’re looking for

Question 4

Pietrewicz and Kamil used operant conditioning to investigate search images in captive blue jays::

Answer 4

blue jays were shown slides of cryptic moths of either the same or 2 different species

• -the birds built up a search image only when shown one species, not when given both species
• favours rare moths?? Can’t learn multiple

Question 5

are search images always using sight?

Answer 5

NO, other senses can be used : Olfactory

Question 6

example of animal who uses olfactory senses to create search image

Answer 6

Striped skunk, nocturnal forager and finds food by odour

-as skunks aged they could find food at further distances away & max distance it could be found also increased

Question 7

Lizard foraging: 2 methods for predation (Vision/ambush and Olfaction/searching) Evolutionary history

Answer 7

3 evolutionary events?

started as Ambush, some evolved to become olfactory searchers

Question 8

whats the difference in Social Insects and Other Group living animals??

Answer 8

• social insects: groups
• -composed of related individuals, cooperation
• -favoured by kin selection
• Other group living animals:
• -groups normally composed on unrelated individuals
• -cooperation not favoured by kin selection

Question 9

social insects communication is

Answer 9

deliberate communication with nestmates, e.g. waggle dancing, direct leading, pheromone trails

Question 10

Other group living animals communication is

Answer 10

incidental communication with conspecifics , e.g. observing location of successful foragers

Question 11

other foraging advantages for groups:

Answer 11

Take much larger prey than themselves e.g. wolves take moose; army ants take large anthropoids/other insect colonies

Question 12

Social insects:

Answer 12

• Groups composed of related individuals
• workers help by capturing prey (e.g. army ants) or defending a food patch, communicating the location of food to nest mates (wage dances in honey bees)

Question 13

Key man for the Waggle Dance

Answer 13

Karl von Frisch

Question 14

two types of waggle dance

Answer 14

• Round dance = food < 50m

- Figure of Eight Dance = food >50m

Question 15

Figure of 8 waggle dance =

Answer 15

• food >50m

- Dances are performed in nest on vertical combs in darkness

Question 16

waggle dance = what provides the distance and direction information and two tests used by karl von frisch

Answer 16

• duration of entire circuit
• duration of waggle run
• direction = angle
• -Fan test & feeding stations along transect

Question 17

Experiment on honey bee foragers: removing directional information

Answer 17

• natural combs are vertical

- when put horizontal combs, bees dance orientating to a directional light source instead of gravity

Question 18

Social foraging in birds: Ospreys

Answer 18

• watch other birds returning to nest with fish, others leave in same direction to find shoaling fish
• informed fish find food quicker than naive birds

Question 19

army ant colony =

Answer 19

small ants can capture larger prey by working together

Question 20

Group hunting in Female Lions

Answer 20

they live in groups and hunt together. Group hunting carnivores take larger prey than solitary hunters
-6-12X higher

Question 21

group hunting in varying females number of groups and food intake

Answer 21

• prey abundant = high one alone and in small groups

- prey scarcity = high when alone low in small groups, big food in high groups

Question 22

why continue to hunt in group? Creel and Creel

Answer 22

benefits in meat gained but also in terms of energy expended chasing prey