Parent–Offspring Conflict over the Transition to Independence in Nicrophorus vespilloides: Parental Chemical Cues and Offspring Begging

Authors


Per T. Smiseth, Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, UK.
E-mail: per.t.smiseth@ed.ac.uk

Abstract

In species where parents provide their offspring with food, the offspring must undergo a transition from nutritional dependency to independence. Parent–offspring conflict theory predicts that the optimal timing for this transition will differ between parents and offspring and that the realised timing depends on each party’s ability to control the transition. The burying beetle Nicrophorus vespilloides is an excellent species for studying conflict over the transition to independence; the larvae beg for pre-digested carrion from their parents until they cease begging around 72 h after hatching. The cessation of begging is not associated with changes in parental behaviour, suggesting that the transition is mostly under offspring control. However, recent work has demonstrated that caring parents express distinct chemical cues that stimulate larval begging, the expression of which varies between breeding and non-breeding beetles, suggesting that parents might exert control over the transition to independence by altering these cues throughout development. If so, we predict that begging larvae should behave differently towards parental chemical cues from different stages of development and that larvae of different ages should behave similarly towards parental chemical cues from the same stage of development. We found no evidence for either prediction: begging larvae did not behave differently towards parental chemical cues from different stages of development, and larvae of different ages still behaved differently towards parental chemical cues from the same stage of development. Our results provide no support for the hypothesis that parents can control the transition to nutritional independence by altering their chemical profiles.

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