Social Interactions ER Flashcards
Study into Ground squirrels - kin selection
Sherman, 1977
- kin selection Beldings ground squirrel (Spermophilus beldingi)
- alarm calls more frequent near relatives
- females called more in presence of predators than males
- females sedentary and breed near natal sites whereas males emigrate to new sites
Study into the mole rat - kin selection
Lacey and Sherman, 1991 Naked mole rat (Hetercephlus glaber) - eusocial vertebrate - 1 queen, 2-3 reproductive males - non-reproductives dig, clean, groom and defend colony
Study into Arabian babblers - by-product mutualism
Clutton-Brock, 2002 - Arabian babbler (Sylvia leucomelaena) - may go on sentinel duty if they have collected enough food - maximises own survival in predator rich environments if no other individual is on guard - the fact other individuals can detect approaching predators by watching them may not contribute to the behaviour
Study into lions - by-product mutualism
Scheel and Packer, 1991 Lion (Panthera leo) - coopeatively hunt if prey is too large to take down themselves - provides immediate benefit for individual - will hunt solo if prey is small enough (warthogs for example)
Study into pied wagtails - by-product mutualism
Davies and Houston, 1981 Pied Wagtail (Motacilla alba) - defend riverside winter territories, foraging on insects - defender may allow an intruder into the territory - intruders that have been allowed into the territory are known as satelites - defenders only do this on days when food is abundant, this provides them with extra protection from other intruders by cooperating with the satellite individual - on days where food is scare the defender doesn’t allow any intruders in and chases away satellites from previous days
Study into game theory - reciprocity
Flood and Dresher, 1950 Prisoners dilemma T>R>P>S T = temptation to cheat, largest payoff (e.g. 5) R = reward of cooperation (e.g. 3) P = punishment for both cheating (e.g. 1) S = suckers payoff, tried to cooperate but other cheated (e.g. 0) In short term interaction cheating is always the best option but not in the long term
Study into TFT - reciprocity
Axelrod and Hamilton, 1981 - most effective long term strategy - Essentially individual A copies the previous move made by individual B - In TFT the initial encounter is always to cooperate, if this is not reciprocated it results in the player copying the previous move made by the other and thus cheating - effective because it provides the cheater with a punishment for cheating and therefore gives them a reason to cooperate - 3 defining characteristics that make it so successful; i) niceness - someone employing TFT never first to cheat ii) swift retaliation - immediate response to cheating is to reciprocate in the next move. This provides the cheater with the incentive to cooperate iii) forgiveness - partner only remembers one move back and so forgives prior defections, allowing game to continue
Study into guppies - reciprocity
Dugatkin and Alfieri, 1991 Guppies (Poecilla reticulata) - When predator is stalking a shoal of guppies, individuals will separate from the shoal and approach the predator - This behaviour is to provide the fish with information on the predator and its intentions - Works on a TFT basis - T (one partner stays back) R (Both go same distance) P (both stay back) S (one goes further accepting more risk) - To begin, both fish make approach to inspect together (niceness) - If one stops the other retaliates by also stopping (swift retaliation) - If the first fish starts moving again the second also starts moving (forgiveness) - Guppies remember and prefer individuals who cooperate over those who cheat
Study into vampire bats - reciprocity
Carter and Wilkinson, 2013
Vampire bats (Desmodus rotundus)
- Stare to death if they do not feed within 2 days
- well fed bats will often regurgitate food to starving bats to help them - reciprocal action in that they expect the action to be returned when needed
- study by Carter and Wilkinson (2013) found a lack of relatedness between the bats sharing hence not kin selection and ruled out enforcement as the reason
Study into meerkats - enforcement
Young et al, 2006 Meerkats (Surcata suricatta) - pregnant dominant suppresses subordinates with aggression - this renders the subordinates infertile by inducing chronic physiological stress - when females are evicted form the group they suffer chronic elevation of glucocorticoid adrenal hormone levels (stress hormones) - this results in increases abortion and decreased conception rates - when dominant gives birth the subordinates help raise the offspring
Study into cleaner fish - enforcement
Bishary and Grutter, 2002 Cleaner fish (Labroides dimidiatus) - cooperate with client fish by eating ectoparasites - tendency to cheat and eat mucus or skin of clients and thus are chased away, results in them changing behaviour to cooperate - study showed that when exposed to anaesthetised clients the cleaner fish would more often cheat and eat the mucus/flesh of client
