social behaviour Flashcards
(26 cards)
types of sociality
- gregarious (fond of company)
- sophisticated social groups
- solitary
- massive societies
- hierarchies
- machiavellian groups (cunning)
physical benefits of sociality
- large number of fruit fly larvae breaks up food and encourages yeast growth
- water flea aggregations can survive alkaline water
- warmth
protection benefits of sociality
- defense mechanisms of musk oxon
- flocks and shoals/schools
- mutual protection
predation benefits of sociality
- pack hunting
- info sharing
costs of sociality
- competition for food
- reproductive interference
- disease and parasites
- conspicuousness
- subordination
mutualism effects
effect on donor - pos
effect on recipient - pos
effects of selfish behaviour
effect on donor - pos
effect on recipient - neg
effect of reciprocity
effect on donor - neg then pos
effect on recipient - pos
effect of altruism
effect on donor - neg
effect on recipient - pos
effect of spiteful behaviour
effect on donor - neutral or neg
effect on recipient - neg
examples of spiteful behaviour
- Three-spined
stickleback prefer to
eat eggs that are more
valuable to the ‘victim’
than themselves. - Herring gulls kill, and
don’t eat, conspecific
young.
examples of reciprocal altruism
- reciprocity requires memory or honesty
1. Pied flycatchers
observing two groups
mobbing an owl, will
help the group that
helped them previously
2. Vampire bats share
blood meals when
needed
example of altruism
- Belding’s ground squirrel. Produces
warning whistle when badgers or
coyote approach. - The ‘whistler’ is more likely to be
killed
kin selection
- An individual could still have a reproductive
fitness, even if they have no direct offspring - “Inclusive fitness” takes into account all those who
share genes with that individual - J.B.S. Haldane famously said, “I would lay down
my life for two brothers or eight cousins”
hamilton’s rule
C < b*r
C- fitness cost to the altruist
b - fitness benefit to receiver
r - relatedness
eusociality
1.There is cooperative brood-care
(including protection)
2.There is reproductive division of
labor.
– Reproductives: queens or males.
– Workers: sterile females.
3.Overlapping generations.
– Offspring assist their parents
haplodiploidy
- Hymenoptera show a unique genetic structure:
– Females are diploid (chromosomes from mother
and father)
– Males are haploid (chromosomes from mother
only) - This alters the relatedness values between
relatives
problem with explanation of eusociality
- Not all eusocial animals are haplodiploid
– and not even all hymenoptera are eusocial - Some colonies will have more than one queen and
that queen will have mated with multiple males.
– so workers will not be as related to each other as in the
simple example
specialisation in honeybees
- reproduction
- defence
- foraging
- brood care
pheromone trails
- Returning from a food source
an ant lays a pheromone
trail. - Others follow the trail. If
they find food, they will
reinforce it. - The trail becomes more
attractive and the number of
ants on the trail rises
exponentially. - Positive feedback maximises
the rate at which ants can
utilise a resource.
studying pheromone trails in lab
Positive feedback leads to
“choice behaviour”
Slight differences in trail
strength are magnified
summarise pheromone trails
- ant trails are an example of a self organising system
- global pattern: trail network
- subunits: ants
- ants respond to local conditions
pack hunting in wolves
- tiring out prey
- Optimised for stamina
- Social groups, therefore
some organisation - Enable them to tackle
very large prey - Chasing to exhaust the
prey
pack hunting: forced ambush
- Lions and Chimpanzees have less dynamic groups
than wolves.
– More stability = more chance to develop strategy - Both show evidence of teamwork to force prey
into an ambush.
– Different animals do different tasks
