Abstract
BackgroundIn many cooperatively breeding vertebrates, subordinates assist a dominant pair to raise the dominants' offspring. Previously, it has been suggested that subordinates may help in payment for continued residency on the territory (the ‘pay-to-stay hypothesis’), but payment might also be reciprocated or might allow subordinates access to reproductive opportunities.Methodology/Principal FindingsWe measured dominant and subordinate female alloparental brood care and reproductive success in four separate experiments and show that unrelated female dominant and subordinate cichlid fish care for each other's broods (alloparental brood care), but that there is no evidence for reciprocal ‘altruism’ (no correlation between alloparental care received and given). Instead, subordinate females appear to pay with alloparental care for own direct reproduction.Conclusions/SignificanceOur results suggest subordinate females pay with alloparental care to ensure access to the breeding substrate and thereby increase their opportunities to lay their own clutches. Subordinates' eggs are laid, on average, five days after the dominant female has produced her first brood. We suggest that immediate reproductive benefits need to be considered in tests of the pay-to-stay hypothesis.
Highlights
Subordinate individuals in group-living vertebrates may assist a dominant breeder pair by helping to raise the dominants’ offspring [1,2,3]
Potentially reciprocal alloparental care could be initiated by the dominant or the subordinate, in the majority of cases subordinates could engage in alloparental care first, and dominants could react to this investment by adjusting their level of alloparental care
Subordinates were consistent in their level of alloparental care provided: there was a significant positive correlation between the proportion of alloparental care given in sequence t vs sequence t+1
Summary
Subordinate individuals in group-living vertebrates may assist a dominant breeder pair by helping to raise the dominants’ offspring [1,2,3]. In these cases, helping behaviour cannot be attributed to kin-selected benefits and, subordinates are expected to gain other benefits Such benefits might include establishment of a work force that will be present already when the subordinate inherits the dominant breeding position [11,12,13], being allowed to stay in the group (‘pay-to-stay’) and receive survival benefits [8,14,15,16,17,18,19], or access to breeding resources for the subordinate’s own reproduction [20,21]. Group membership confers access to group-held resources and increases a subordinate’s likelihood of surviving long enough to obtain a breeding position in the future In this view, a subordinate is helping in return for an increase in its expected future reproductive success. It has been suggested that subordinates may help in payment for continued residency on the territory (the ‘pay-to-stay hypothesis’), but payment might be reciprocated or might allow subordinates access to reproductive opportunities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
