Social behaviour and communication Flashcards
What is the ideal free distribution?
Chances of individuals receiving same amount of food are highest when they distribute themselves in direct proportion to the relative availability of food at each site
Who studied ideal free distribution?
Harper 1982 - when food stock is replenished (therefore requires assessment at start)
How does behaviour differ when there is equal amounts of food at two equal sized troughs and food is not replenished?
Done 1996 - similar numbers of pigs at each over time
How does behaviour differ when twice as much food is placed in one of two equal sized troughs?
Done 1996 - Trough size is cue - pigs split equally as no chance to sample UNTIL old runs out at one and then redistribute to other one
How does behaviour differ when same amount of food is placed in unequal sized troughs?
Done 1996 - More pigs go to bigger one -> finished quickly and relocate sooner
Why is sampling different sites not adaptive?
Increased number of site changes correlated with lower total feeding time
- also leads to rank effect and ^ competition
How can sexual signals be applied?
- Pig - boar odour elicits lordoisis in oestrus sows > aerosol spray at females to test lordosis and oestrus
- rats - urine of proestrus females attracts males > add to rat traps
Which other species are attracted to odours of conspecifics?
- Vole - attracted to trips by odour of conspecifics
- Muskrats - repelled from traps by odour of conspecifics during breeding season
How may chemical alarm signals be utilised?
- Black-tailed deer - produce chemical alarm signals from meta-tarsal gland when disturbed > chemical used to repel deer from crops etc.
- Rat - Individuals appear to avoid urine of stressed or frightened rats > repel rats from protected areas
How do birds decide to land?
Inglis and Isaacson 1978
Number birds in field
Posture of birds > Feeding v alarm posture
- More geese flocks land when birds feeding cf. alert
When are distress signals given?
Response to actual attack by predator
How may distress calls be utilised?
Herring gull distress call = repellant
- used NE England for nesting gulls
- reservoir near Glasgow contaminated with bacteria form gulls
> Gulls responded by NOISY defence of nests
> Spread out to decrease chances of predators locating eggs, decreasing density of nests
> lead to INCREASED gull recruitment and population grew
- Distress calls only successful when NO NESTS already established
> also used at airpots - must guard against HABITUATION
Why are herring gulls a problem?
Bird strike
Spread disease
Urban nuisance
How can predator/prey signals be utilised?
- Predator feaces and urine deter prey pest species eg. rabbits
- Models of predator birds deter other species from crops
- “Eye spots” used to deter predators
Give a study looking at use of eye spots
Inglis 1990
- eye spots deter birds feeding at cattle feed store == owl eyes
