Evolution of Parental Care

by

James Gilbert

• LAST REVIEWED: 30 September 2013
• LAST MODIFIED: 30 September 2013
• DOI: 10.1093/obo/9780199830060-0131

Introduction

Parental care is such a fundamental behavior to us that we often forget that it requires an evolutionary explanation. Around us in nature, though, we see a vast diversity of parental care strategies. Bird parents, like us, cooperate tirelessly to raise chicks, while most mammal mothers have to suckle alone; insect parents usually abandon their eggs to the elements, but occasionally, very rarely, they tend single offspring intensively. Fishes may broadcast-spawn millions of eggs into the ocean, but some fathers prepare nests and carefully fan their eggs with oxygenated water until they hatch. Parental care, however defined, is a fundamental investment by an animal into the fitness of its offspring, ranging from the briefest of periods of guarding eggs to intensive tending and feeding of offspring through to adulthood (and sometimes beyond). It is inextricably linked with an animal’s life history and its pattern of reproductive allocation, so the reader is strongly advised also to consult the companion Oxford Bibliographies Online article Reproductive Allocation in Animals for a wider overview of life-history strategies. Parental care occurs all over the animal kingdom and takes many forms, is performed by either or both parents, and is an arena for some amazing stories of cooperation, but it can be the source of extensive conflict. After an initial rush of theory, empirical descriptions, and physiological measurements, parental care research has now settled into a pattern-finding period in which comparative researchers are identifying tantalizing trends in testing the early theories, behavioral ecologists are providing ever more credible measurements of costs and benefits of different components of care, and recently, perhaps most excitingly, geneticists are beginning to exert their strong quantitative influence on the field. With these developments, model systems are becoming increasingly important, such as great tits, sticklebacks, earwigs, and burying beetles, all of which play a large part in the literature cited here. As ever, vast swathes of diversity remain unstudied, and when detailed experimental and genetic manipulations are not possible, the natural historian still has a job making careful observations. Room remains also for relatively major theoretical advances, as the following sections will show.

General Overviews

No reader serious about studying parental care should be without Clutton-Brock 1991, the authoritative volume on the subject. Throughout this article this work will be cited sparingly only when especially relevant, but the reader should consult this book generally as a first step for all sections of this article. For more general context within behavioral ecology, Davies, et al. 2012 and Krebs and Davies 1997 cannot be beaten and should be on the bookshelf of any self-respecting behavioral biologist. For an update to Clutton-Brock 1991 and for more bleeding-edge research on the topic and summaries of very recent work, including (for example) the latest genetics, Royle, et al. 2012 is an excellent reference and chapters of this volume are cited throughout the article. Allport 1997 is a popular and comprehensive treatment of the topic suitable for dipping into for pleasure. Where relevant, general overviews of topics covered by specific sections are cited in the section in question.

• Allport, S. 1997. A Natural history of parenting. New York: Harmony.

  Engagingly written popular treatment of the topic, suitable for all levels from undergraduate upward, covering many topics addressed here and well worth dipping into for pleasure as well as research.

• Clutton-Brock, T. H. 1991. The evolution of parental care. Princeton, NJ: Princeton Univ. Press.

  Textbook. Classic, comprehensive, extremely well-written and interesting text. The first port of call for anyone seriously interested in this subject from undergraduates to advanced researchers. On technical details it is showing its age slightly and readers requiring the absolute cutting edge should consult Royle, et al. 2012.

• Davies, N. B., J. R. Krebs, and S. A. West. 2012. An introduction to behavioural ecology. 2d ed. Chichester, UK: Wiley-Blackwell.

  Textbook. Excellent and thoroughly readable introduction to all key concepts in behavioral ecology. including all concepts discussed in this article. This very recent edition provides a useful update to the well-known 1993 volume by Krebs and Davies. Contains an entire chapter on parental care and its evolution. Intended for undergraduates but suitable for all levels.

• Krebs, J. R., and N. B. Davies, eds. 1997. Behavioural ecology: An evolutionary approach. 4th ed. Oxford: Blackwell.

  Edited volume. Slightly more in-depth than Davies, et al. 2012, volume of contributions to a spectrum of topics in behavioral ecology. Suitable for undergraduates in their final year and more advanced researchers.

• Royle, N. J., P. T. Smiseth, and M. Kölliker. 2012. The evolution of parental care. Oxford: Oxford Univ. Press.

  Edited volume. Very recent publication that is not widely available yet but appears very comprehensive and well-conceived. Targeted toward advanced researchers and contains cutting-edge summaries of most topics addressed in this section. Foreword by Tim Clutton-Brock.