Petrel Parents Shunt All Experimentally Increased Reproductive Costs to Their Offspring
Investment in current reproduction should be balanced against future reproduction. Thus, the allocation of resources during a breeding season is a trade-off between the needs of the parent and the needs of the offspring. Life-history theory predicts the trade-off point to favour the parent in long-lived species and the offspring in short-lived species. To investigate parent-offspring conflict in a long-lived species, the cost of flight was manipulated (by reducing wing span) in Leach's storm-petrel,Oceanodroma leucorhoa. The effect of the manipulation on adult nutritional condition was measured using ptilochronology and the effect on offspring nutritional condition was measured by tracking chick growth. No difference was found in nutritional condition between treatment and control parents. Treatment chicks gained mass more slowly and spent a greater proportion of nights without being fed by either parent. As predicted for a long-lived species, when faced with an increased cost of parental care, the storm-petrel parents apparently shunted that cost to their offspring. These results are compared with previous studies of long- and short-lived species in which parental costs were artificially increased.
Mauck, Robert and Grubb, T C. Jr, "Petrel Parents Shunt All Experimentally Increased Reproductive Costs to Their Offspring" (1995). Animal Behaviour 49(4): 999-1008. Faculty Publications. Paper 195.