Parent\u2013offspring conflict and transition to cr\xe8che phase in Chinstrap Penguins (Pygoscelis antarctica)

Virginia Morandini,Josabel Belliure,Javier Viñuela,Miguel Ferrer

doi:10.1007/s00300-021-02930-4

Abstract

Parent–offspring conflict theory predicts that offspring seek to prolong the parental care period, while parents strive to shorten it as much as possible. Transition to the crèche phase in penguins involves changes in the dynamic of parental investment in chicks, and thus may be modulated by interests that benefit parent or offspring. We explored parent–offspring interactions in the Chinstrap Penguin (Pygoscelis antarctica) to understand the influence such interactions would have on transition to crèche phase. We studied the effect of hatching date, nestling age, brood size, and nest location on parent–offspring interactions and the length of the guard phase. All behavioral variables related to nestling demands for parental investment increased as well as parental aggression towards their chicks, with increased nestling age. Brood size showed significant effects on both nestling and parental behavior. Hatching date was negatively correlated with the age at crèche. Consequently, the decision to leave the chicks unguarded seemed to be more based on the condition of adults rather than of the chicks. Given the short time available for breeding in Antarctica and that penguins are long-lived birds with several opportunities to breed, there may be conflicting selective factors between investment in feeding chicks versus extending the period of resource acquisition and storage prior to moult.

Highlights

According to parent–offspring conflict theory (Trivers 1974; 1985), offspring are selected to prolong the parental care period, while parents are selected to cease investing in offspring once the cost of parental care exceeds the benefits obtained in terms of lifetime reproductive success
The study was conducted at the Vapour Col Chinstrap Penguin nesting colony on Deception Island, South Shetlands, Antarctica (63° 00′ S, 60° 40′ W), during the austral summer of 1993–1994
Number of approaching movements by chicks to parents increased in frequency with nestling age (with an observed range from 0.00 to 14.12 h−1, and were not affected by brood size (Table 1)

Summary

Introduction

According to parent–offspring conflict theory (Trivers 1974; 1985), offspring are selected to prolong the parental care period, while parents are selected to cease investing in offspring once the cost of parental care exceeds the benefits obtained in terms of lifetime reproductive success. One of the adults protects the nestlings at the nest while the other is foraging at sea; males and. A number of adaptive advantages have been proposed to explain the tendency for chicks to form crèches; these include protection against predation and huddling to stay warm in cold weather or even protection against aggressions by other adults (Seddon and Heezik 1993; Penteriani et al 2003; Wilson 2009). Chinstrap Penguin (Pygoscelis antarctica) chicks, as in many other penguin species, form crèches, a habit believed to offer protection from predators such Skuas (Catharacta maccormicki) or defense against non-related adult aggressions (Penteriani et al 2003)

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