Meerkats - subordinates Flashcards
Supressing subordinate reproduciton provides benefits to dominants in cooperative societies of meerkats
Author / date?
Bell et al 2014
How do subordinate females benefit dominant females?
- They help care for the dominants offspring
- When subs mate they invest in their own offspring which disadvantages the dom female
What happens when subordinates are prevented from breeding? (sterile)
- Dominants are less aggressive to them and evict them less
- leading to higher ratios of helpers to dependent pups
- Doms show improved foraging efficiency, gain more weight during pregnancy and produce heavier pups which grow faster
How do dominant females stop subs mating?
- Physically stop them mating - targeted aggression
- Kill the offspring (infanticide)
- Temporary eviction of subordinates from the group
Dominants alter their suppression behaviours by being sensitive to the payoffs of interfering with sub breeding, how ?
- Attacks are targeted at subs most likely to breed
- attacks are restricted to periods when resource competition peaks and dom offspring may be at a competative disadvantage.
- Attacks are entirely avoided if subs retaliation is likely to be effective.
How did the study restrict sub reproduction?
Injections of contraceptive hormones
How did doms react to treated subs ?
- They were more tolerant of treated subs
- Attacks lowered
- Treated subs were less likely to be evicted during doms gestation period
What did the study test?
- Pup : Helper ratio
- Dom female weight gain & pup emergence weight
- Sub helping effort
- Pup growth rate
How does successful sub reproduction effect dom pups?
detracts milk available for dom pups
How did treated subs act in the group?
Helped out more
How was emergence size of pups and weight gain effected treated groups?
- Pups started heavier and gained weight
- More helpers in group so increased feeding rate
