Helping Communal Breeding in Birds: Ecology and Evolution

Helping Communal Breeding in Birds: Ecology and Evolution

JERRAM L. BROWN
Copyright Date: 1987
Pages: 374
https://www.jstor.org/stable/j.ctt7zvrhd
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    Helping Communal Breeding in Birds: Ecology and Evolution
    Book Description:

    An overview of the extensive and frequently controversial literature on communally breeding birds developed since the early 1960s, when students of evolution began to examine sociality as a product of natural selection. Jerram Brown provides original data from his own theoretical and empirical studies and summarizes the wide array of results and interpretations made by others.

    Originally published in 1987.

    ThePrinceton Legacy Libraryuses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

    eISBN: 978-1-4008-5856-9
    Subjects: General Science

Table of Contents

  1. Front Matter
    (pp. I-VI)
  2. Table of Contents
    (pp. VII-XII)
  3. Preface
    (pp. XIII-XVI)
    J.L.B.
  4. Acknowledgments
    (pp. XVII-2)
  5. 1 Why Study Helping Behavior?
    (pp. 3-7)

    Helping behavior has a special meaning in biology. It is not just any behavior that may appear to be helpful. Conventional usage of the termhelpinghas been somewhat narrower than Skutch’s definition above.Helpingis parent-like behavior toward young that are not the genetic offspring of the helper. Social organizations in which individuals additional to a single male-female pair typically aid in the care of young at a single nest, not as a result of brood parasitism or brood mixing, are referred to ascommunal breeding systems(see glossary; the termcooperative breedingis also used). Paradoxically, helping is...

  6. 2 The Discovery of Helping Behavior and a Classification of Avian Communal Breeding Systems
    (pp. 8-33)

    In 1935 Alexander Skutch wrote a brief paper titled “Helpers at the nest.” In it he described the feeding of young Brown Jays, Bushtits, and Banded Cactus Wrens by more than two unhanded birds of their own species. Some of the birds must have been feeding young that were not their own; hence some were helpers. For decades this paper was known to a few ornithologists, but it stimulated almost no further work except by Skutch himself. In the 1930s, ’40s and ’50s few ornithologists were interested in field studies of social relationships and few of them could visit the...

  7. 3 Climate, Geography, and Taxonomy
    (pp. 34-44)

    Is the frequency of avian species that have communal breeding systems correlated with climate, geography, or taxonomy? Yes, there are rough patterns of correlation with each of these factors, but their meaning is not entirely clear. We hope to gain some insight into the origins of communal breeding by studying these patterns. And, turning the problem around, we hope to be able to answer why these patterns exist through detailed studies of particular species. This chapter will review patterns of correlation with climate, geography, and taxonomy, and consider some of their possible causes. We shall return to the questions raised...

  8. 4 Elements of Inclusive Fitness Theory for Field Studies
    (pp. 45-61)

    In 1954 David Lack published his influential book,The Natural Regulation of Animal Numbers. Through this book and his many papers, Lack convinced many ecologists of the overpowering importance of selection at the level of the individual and of the weakness of the argument for reproductive restraint. The latter alternative refers to the idea that animals reproduce less than they are able, often with the implication that this restraint benefits their deme, population, or species. The test case in this issue was the control of clutch size. By supplementing conventional, natural-history approaches with strong-inference experiments, Lack convinced biologists that the...

  9. 5 Delayed Breeding Sets the Stage for Helping
    (pp. 62-90)

    In order to understand the ecological factors that predispose a bird to perform alloparenting, it is necessary first to re-emphasize that helping occurs in a variety of situations and may, therefore, be favored by different combinations of factors in different cases. For example, even in one species, the Acorn Woodpecker, helping occurs by breeding males who share a female, by breeding females who lay eggs in a joint nest, and by non-breeders. In all three cases the woodpeckers may care for young not their own, but in each case the sets of ecological factors predisposing individuals to help are different,...

  10. 6 Reduced Dispersal Sets the Stage for Helping
    (pp. 91-101)

    Many communally breeding species are characterized by reduced dispersal, as well as delayed breeding and alloparental care. Dispersal is a critical process in the life of a bird because it often occurs in the transition from immaturity to breeding status. In order to place these events in a broader perspective, we consider briefly not only the movements of dispersal, but also the ecological processes that select for different types of strategies used to obtain breeding status. This sociobiological view supplements the classical approach, which emphasizes the movements themselves and the genetic population structures that result from them.

    In the spectrum...

  11. 7 Territorial Inheritance as Parental Facilitation
    (pp. 102-115)

    Dispersal typically precedes breeding in vertebrates and is often crucial if the young animal is to obtain a favorable breeding position. In group-territorial species, however, the chances that a single young and naive individual, striking off on its own, can find good territories that are unoccupied are indeed slim. Therefore, as we saw in the preceding chapter, other dispersal strategies are often employed; and these typically involve other individuals of the group from which the disperser originates.

    The major way in which the group is involved is theparent’s toleranceof the young within the parental territory and group after...

  12. 8 Mutualism, Cost-sharing, and Group Size
    (pp. 116-131)

    The addition of a breeding or nonbreeding helper to a group of two may effect a variety of costs and benefits beyond care of young. This is especially true in group-territorial species. Much has been learned about energy budgets of birds in recent years (Mugaas and King, 1981). Field studies of flocking in the nonbreeding season have yielded important insights into the energy costs and benefits of group living (Pulliam and Caraco, 1984). Yet questions of energy costs and benefits in communally breeding birds are almost untouched. The optimality model presented in this chapter is intended to stimulate further work...

  13. 9 Mutualistic Mating Systems: Polyandry and Uncertain Paternity
    (pp. 132-153)

    The study of mating systems in communal birds has opened new vistas into avian sociobiology. It has extended the classical view through the discovery of mating systems previously unknown in birds, such as cooperative polyandry (Galapagos Hawk) and polygynandry (Pukeko, Acorn Woodpecker), nest-oriented promiscuity (Noisy Miner), and semi-promiscuous monogamy (Ostrich). This chapter and the next explore the implications of these findings for the ecology and evolution of helping.

    I suggest that thesharing of a mate or nest in group-territorial animals provides a widespread mode of origin of helping behavior that is distinctly separate from origins based on the nuclear...

  14. 10 Mutualistic Mating Systems: Joint Nesting and Uncertain Maternity
    (pp. 154-168)

    Mate sharing in polyandrous systems may seem complex, but it is relatively simple compared to the systems considered in this chapter. When a second female is added to a polyandrous unit, polygynandry occurs, as in the Acorn Woodpecker and Pukeko. This possibility raises a new set of questions concerning the female in particular. In addition to strict polygynandry, other unusual mating systems also involve two or more males copulating with two or more females, as in miners and ostriches. Even monogamous species may share a nest, leading to complex decisions, as in Groove-billed Anis. In this chapter we survey a...

  15. 11 Does Helping Really Benefit the Helped?
    (pp. 169-189)

    It is generally understood that theories of helping which invoke indirect selection (Lack, 1968; Brown, 1969a, 1974; Emlen, 1982b; Maynard Smith and Ridpath, 1972; Ricklefs, 1975; Vehrencamp, 1979, 1980) require the recipient to benefit from the alloparental care provided by the helper. Early efforts to refute these theories concentrated on denying or questioning such benefits (Zahavi, 1974; Gaston, 1973, 1978b; Ligon and Ligon, 1979). Some people may have assumed that such an argument against indirect selection is, therefore, an argument in favor of an alternative hypothesis, reciprocity or mutualism. This is actually incorrect. Any form of mutualism involving helpers, including...

  16. 12 The Genetic Structure of Social Units
    (pp. 190-214)

    The theory of inclusive fitness has in the two decades since its introduction (Hamilton, 1964) added a new dimension to population genetics, namely, the study of genetic structurewithin the deme. D. S. Wilson (1975, 1977) referred to the new view as one ofstructured demes. The building blocks of these structures are the social units that characterize a population—not just its individuals, but its families and flocks.

    The earlier view tended to ignore social units and to focus on the frequencies of genes within demes. Ademeis a local population that is small enough that mating within...

  17. 13 Indirect Selection for Helping
    (pp. 215-223)

    In this chapter and the next we evaluate various hypotheses for the evolution of helping bynonbreeders. Here we consider theories that invoke indirect selection. In the following chapter we consider theories that exclude an important role for indirect selection.

    There exist two simple ways with which to reject the hypothesis that indirect selection is important in the decision of a nonbreeder to become a helper. The hypothesis must be rejected if (1) donor and recipient are typicallyunrelatedor no more than randomly related, or (2) recipientsdo not benefitfrom the decision to help. Chapters 12 and 11...

  18. 14 Direct Fitness, Mutualism, and Reciprocity
    (pp. 224-249)

    In discussions about the evolutionary causes of helping, one view is that classical individual selection, or direct selection, is primarily responsible, and that the importance of indirect selection is negligible. In this chapter we explore some conceptual bases for this view and consider what facts are needed to test it. As we shall see, there is a paucity of information on critical points.

    All theories based exclusively upon direct selection require that helping be classed as mutualism rather than altruism. It does not follow, however, that theories invoking indirect selection require helping to be altruistic; they do not (e.g., Brown,...

  19. 15 Parent-Offspring Relationships
    (pp. 250-264)

    Perhaps surprisingly, the pioneers in the evolutionary study of parent-offspring relationships have been entomologists. Students of the social insects have long been impressed with the fact that in eusocial species the queens and male reproductives are given “royal” treatment during their development while the nonreproductive workers are confined to smaller cells and a diet that does not allow them to become reproductives. What is the significance of such observations for social birds and mammals? Although birds and most mammals do not show caste systems like those of eusocial insects, the theories developed for social insects have stimulated biologists to speculate...

  20. 16 Infanticide, Dominance, and Destructive Behavior
    (pp. 265-269)

    Communally breeding birds are not always cooperative. That they may act destructively toward the nest and eggs of others in their social unit has been known since nest robbing and egg destruction were described for the Mexican Jay (Brown, 1963a) and Australian Magpie (Carrick, 1963, 1972). More recently Vehrencamp (1977) discovered that female Groove-billed Anis in the same “cooperative” unit routinely destroy each other’s eggs. Infanticide, or the destruction of eggs or young, is now known to be common also in the Mexican Jay (Trail et al., 1981) and Acorn Woodpecker (Mumme et al., 1983a; Stacey and Edwards, 1983), and...

  21. 17 Diet and Group Territoriality
    (pp. 270-275)

    Social defense of food resources occurs in a wide variety of orders and families of communal birds (Table 2 2) and mammals According to a recent model (Brown, 1982a and Chapter 8), cooperative defense of food resources is profitable for such species when the benefits of cooperation in sharable tasks exceed the costs stemming from defense, vigilance, care of young, and the more rapid consumption of resources in a group than alone Previous papers on group territoriality and associated communal breeding have focused almost entirely on their possible benefits (Brown, 1969a, 1974, Gaston, 1978c) In order to develop a predictive...

  22. 18 Synthesis
    (pp. 276-290)

    We have looked in some detail at a variety of topics and problems. Now it is time to draw together the main points, especially those that span several chapters. With a controversial problem, such as the ecological evolution of helping behavior, it is desirable to employ the scientific method rather than the method of advocacy. In the following overview I shall try to adhere to scientific formalism.

    Helping behavior poses an evolutionary paradox. Helpers are “parental” in their behavior although they are not the genetic parents of the young for which they care. Although the definition is simple, the social...

  23. Appendix
    (pp. 291-296)
  24. Annotated Glossary
    (pp. 297-308)
  25. Literature Cited
    (pp. 309-336)
  26. Author Index
    (pp. 337-342)
  27. Taxonomic Index
    (pp. 343-351)
  28. Subject Index
    (pp. 352-354)
  29. Back Matter
    (pp. 355-355)