L3

Question 1

Search images

Answer 1

• Subconsciously picking out features
• Animals take longer to build up a search image if rewarded by a particular food item

Question 2

Testing the search image hypothesis

Answer 2

• Pietrewicz and Kamil used operant conditioning to investigate search images in captive blue jays
  
  • Blue jays were shown slides of cryptic moths of either the same or 2 different species
  • Recorded whether bird could identify moth
  • Single moth presented - birds picked up a search image
  • Two differently patterned moths - birds didn’t build up a search image so no template could be produced

Question 3

Finding food by smell in Skunks

Answer 3

• Striped skunk is a nocturnal forager and finds food by odour. young skunks were allowed to forage in an outdoor enclosure. Food was found at greater and greater distances as they gained experience.
  
  • Distance to food increase over days after gaining experience
  • Skunks build up an olfactory search image

Question 4

Lizard foraging: evolutionary history

Answer 4

• Ambush / olfaction
  
  • Sphenodon (ancestral lizard) still requires on vision/ambush
  • As the cladogram moves along three evolutionary events where olfactory foraging arises
  • One evolutionary event switches back to vision/ambush

Question 5

Social insects

Answer 5

• Groups composed of related individuals
  
  • Cooperation favoured by kin selection
  • deliberate communication with nestmates eg waggle dance
  • Worker helps to produce related individuals by providing
  • Help each other in capturing prey
  • Most common way is by communicating the location of food to nestmates

Question 6

Other group living animals

Answer 6

• Groups normally composed of mostly unrelated individuals
  
  • Cooperation not favoured by kin selection
    Incidental communication with conspecifics eg observing location of successful forages

Question 7

Foraging advantages for groups

Answer 7

• Take prey much larger than themselves
• Eg wolves take moose
• Nothing to stop social insects from this, ants eg take over other colonies

Question 8

round waggle dance food distance

Answer 8

food < 50m

Question 9

figure of eight waggle dance food distance

Answer 9

food > 50m

Question 10

direction of food source

Answer 10

• Angle from vertical which matches angle between sun and the food source
  
  • Dances are performed in nest on vertical combs in darkness

Question 11

distance

Answer 11

• How long the dance takes to be performed
  
  • Follower bees could use duration of waggle run and entire circuit

Question 12

communicating direction

Answer 12

• In a ‘fan test’ frisch trained scout bees to a feeder at F
  
  • He then put out feeders of equal attractiveness at all 7 stations and counted the recruits
  • More arrived at the advertised location, F than other locations
  • Most end up on target

Direction of alternative feeders

* Set them up at different distances
* Most bees went close to the advertised distance
* Show bees actively follow waggle dance

Question 13

Would bees still find food without the waggle dance?

Answer 13

• Removal directional information on a dance
  • Only horizontal combs

Question 14

Removing directional information

Answer 14

• A larger proportion of recruits come to the advertised site when combs are vertical
  
  • Directionally informed bees deviated less than uninformed horizontal bees
  • Directional information is important

Question 15

honeybee distance measuring

Answer 15

• Testing the image motion hypothesis
  
  • Lots of images = more distance

Question 16

Tunnel down which bees fly

Answer 16

• Top covered with insect netting when in use
  
  • Tunnel shown is 1x1cm random pattern
  • The tunnel can also have 1cm parallel stripes running

Experiment 1 and experiment 3 have nearly 90% of round dances
* Only 10% of bees did round dances
* Close hive still only 13% did round dances
* Majority think they have gone much further
* Information is a proxy for distance

Question 17

Benefits of the waggle dance

Answer 17

• Forager finds food more quickly
• forages at food source for the rest of the day
• scout bee after foraging drops off food and resumes search for food
• highlights recruits don’t find food earlier in the day than a scout
• recruits tend to be directed to higher quality food
• whole colony only benefits in winter when food is scarce, not in summer

Question 18

social foraging in birds: Opsreys

Answer 18

• In some coastal areas, ospreys form loose gregarious nesting colonies
  
  • Shoaling fish are a particularly good prey item

Question 19

Do ospreys watch colony mates to find fish?

Answer 19

• Two different colonies
  
  • No bird returns with prey so osprey heads out in random direction
  • In another colony when a bird catches a fish the majority of birds depart in the same direction the other bird came in
  • Information not deliberately communicated
  • Little benefit for passively informing other birds of fish direction

Question 20

Getting help from companions: Ospreys

Answer 20

• Informed birds find fish faster than naive birds. If they didn’t, there would be no benefit in receiving information

Question 21

Swallows

Answer 21

• Barn swallows nest in colonial aggregations
  
  • Why dont barn swallows act on information from conspecifics
  • In ospreys fish are in large discrete shoals
  • Fish wont have moved far
  • In swallows prey is distributed randomly over a large area
  • conspecific use is only valuable in certain areas

Question 22

Group hunting in female lions

Answer 22

• Female african lions live in groups and hunt together, group hunting carnivores take larger prey than solitary hunters
  
  • Common across other groups eg hyenas
  • Related species have diverged into large group hunting vs single small prey hunting

Question 23

is it really beneficial to hunt large prey?

Answer 23

• Single females eat as much or more food than group hunters
  
  • When prey is thin individual females do best in large groups
  • Small groups 2-4 females are not beneficial

Question 24

why do individuals continue to hunt in groups?

Answer 24

• Meat gained is only part of the hunting equation
  
  • Energy expenditure costs etc to solo hunting
  • Net energy gained increased in larger packs
  • Even tough meat is shared they don’t expend as much energy