Parent‐Offspring Conflict over Independence in the Herring Gull (Larus argentatus)

Abstract

Observations on 24 focal nests revealed that, at the time when parental investment in feeding fledging chicks declined, chicks showed a marked increase in begging, particularly in larger broods, whilst parents became less responsive to begging. That chicks suffer a cost from early termination of investment is indicated by the fact that third‐hatched chicks, who had attempted (unsuccessfully) to initiate more feeds, were absent from the territory first, rather than the more mature first‐ and second‐hatched chicks. Taken together, these results and related inter‐ and intra‐brood contrasts in behaviour are interpreted as offering support for Trivers' theory of parent‐offspring conflict over the termination of investment.

A transactional analysis of changes in parent and chick behaviour prior to separation of Herring Gulls (Larus Argentatus): A three-term contingency model

“…Initially, the food requests on the part of the chicks started to become more intense, and begin to generalize towards adults other than the parents. These previously observed phenomena (see Graves et al, 1991;Pugesek, 1990) may cause disturbance in the contingencies described above, and result in an alteration in parental behaviour. In particular, the parents' standing and bill presentation behaviour is discontinued.…”

“…A marked increase in begging has been noted in offspring prior to chick dispersal (see Graves et al, 1991), but there are few, if any, documented examples of a greater range of adults being begged from in the literature. The demonstration that chicks' behaviour to particular stimuli connected with feeding (e.g.…”

“…Such a change in parental behaviour has been noted previously. Observations made at the time when parental investment in chicks is declining have demonstrated that the parents become less responsive to begging (Graves et al, 1991). Similarly, the amount of time parents withhold food from their offspring following a begging response has been shown to increase as the offspring become older (Pugesek, 1990).…”

“…As noted above, there have been a number of studies concerned with changes in both parent and offspring behaviour during this period (e.g. Alonzo et al, 1987;Baaloudj et al, 2012;Edwards, 1985;Graves et al, 1991;Hailman, 1969;Pugesek, 1990). These studies have noted increases in chick begging (Graves et al, 1991), decreases in parental feeding (Edwards, 1985;Morales and Velando, 2013;Pugesek, 1990), and increases in parental aggression (Alonzo et al, 1987;Dickinson and McGowan, 2005).…”

Omega-3 fatty acids accelerate fledging in an avian marine predator: a potential role of cognition

“…In the Nazca booby ( Sula granti ), a long-lived seabird that fledges at around 157 days old, every 1 day increase in fledging age reduces the probability of surviving the juvenile phase by 3% ( Maness and Anderson, 2013 ). In seabirds, a rapid decrease in parental provisioning as chicks approach their typical fledging age causes a drop in nestling body condition and thus encourages early fledging ( Graves et al, 1991 ; Ritz et al, 2005 ). Finally, fledging early can also benefit a chick's parents.…”