Adaptive divergence in the Superb Fairy-wren (Malurus cyaneus): a mainland versus island comparison of morphology and foraging behaviour

Beth E. Schlotfeldt; Sonia Kleindorfer

doi:10.1071/MU06004

RESEARCH ARTICLE

Previous Next Contents Vol 106(4)

Adaptive divergence in the Superb Fairy-wren (Malurus cyaneus): a mainland versus island comparison of morphology and foraging behaviour

Beth E. Schlotfeldt ^A and Sonia Kleindorfer ^A ^B

+ Author Affiliations

- Author Affiliations

^A School of Biological Sciences, Flinders University, Bedford Park, SA 5042, Australia.

^B Corresponding author. Email: sonia.kleindorfer@flinders.edu.au

Emu 106(4) 309-319 https://doi.org/10.1071/MU06004
Submitted: 27 January 2006 Accepted: 14 July 2006 Published: 16 November 2006

Abstract

Understanding patterns of adaptive divergence is a cornerstone for understanding the process of speciation. The theory of ecological speciation predicts that natural selection shapes adaptive divergence. In this observational study, we examined the first phase of ecological speciation, namely adaptive divergence in foraging behaviour and morphology across populations (island and mainland sites) of the sexually dimorphic Superb Fairy-wren (Malurus cyaneus) that have been separated for approximately 9000 years. Current island theory predicts larger body-size in island species, as well as more generalist foraging and occupation of a wider ecological niche that is favoured by large body-size. We examined the vegetation structure across replicate study areas on Kangaroo Island and the mainland Mount Lofty Ranges in South Australia and found significant differences in vegetation structure important for Superb Fairy-wrens (percentage bare earth, shrub size and shrub abundance). Compared with mainland birds, island birds of both sexes: (1) occupied a wider niche breadth; (2) were significantly larger in body-size; and (3) varied less in morphology. Between the sexes: (1) there were few inter-sexual foraging differences; (2) males had a larger body-size and bill-length at both island and mainland locations; and (3) females had larger bill-width and bill-depth at both locations. These findings support the hypothesis of adaptive divergence in this species, with evidence that vegetation structure is important in their foraging behaviour and affects their morphology across locations (niche breadth was potentially favoured by a different interspecific community). The lack of consistent sexual differences in foraging ecology suggests that the patterns of sexual dimorphism may be shaped by reproductive roles rather than vegetation structure in this species. The categorisation of the Kangaroo Island population as a separate subspecies (M. c. ashbyi) is supported by these findings.

Acknowledgments

This study was funded by the Conservation Council of South Australia and the South Australian Department for Environment and Heritage, with awards to S. Kleindorfer. Sincere thanks to Peggy Rismiller and Mike McKelvey at Pelican Lagoon Research Station for use of the research facility and stimulating discussion, staff at the Flinders Chase National Park for logistical support, and Diane Colombelli-Négrel, Sarah Lambert, and Margot Oorebeek for field assistance.

References

Abbott, I. (1973). Birds of Bass Strait. Evolution and ecology of the avifaunas of some Bass Strait islands, and comparisons with those of Tasmania and Victoria. Proceedings of the Royal Society of Victoria 85, 197–223.
Abbott I. (1980). Theories dealing with the ecology of land birds on islands. In ‘Advances in Ecological Research. Vol. 11’. (Ed. A. Macfayden.) pp. 329–371. (Academic Press: London.)

Adamík, P. , Kornan, M. , and Vojtek, J. (2003). The effect of habitat structure on guild patterns and the foraging strategies of insectivorous birds in forests. Biologia 58, 275–285.
Andersson M. (1994). ‘Sexual Selection.’ (Princeton University Press: Princeton, NJ.)

Belperio A. P., and Flint R. B. (1999). Geomorphology and geology. In ‘A Biological Survey of Kangaroo Island, South Australia, in November 1989 and 1990’. (Eds A. C. Robinson and D. M. Armstrong.) pp. 19–31. (Heritage and Biodiversity Section, Department for Environment, Heritage and Aboriginal Affairs (SA): Adelaide.)

Blackmore C. (2002). Male song and the dawn chorus of the Superb Fairy-wren. M.Phil. Thesis, Australian National University, Canberra.

Blondel J. (1985). Habitat selection in island versus mainland birds. In ‘Habitat Selection in Birds’. (Ed. M. L. Cody.) pp. 477–516. (Academic Press, Inc.: Orlando, FL.)

Carrascal, L. M. , Moreno, E. , and Valido, A. (1994). Morphological evolution and changes in foraging behaviour of island and mainland populations of Blue Tit (Parus caeruleus) – a test of convergence and ecomorphological hypotheses. Evolutionary Ecology 8, 25–35.
| Crossref | GoogleScholarGoogle Scholar | Darwin C. R. (1896). ‘The Descent of Man, and Selection in Relation to Sex.’ (2nd edn). (John Murray: London.)

Downhower, J. F. (1976). Darwin’s finches and the evolution of sexual dimorphism in body size. Nature 263, 558–563.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Ford H. A. (1979). Birds. In ‘Natural History of Kangaroo Island’. (Eds M. J. Tyler, C. R. Twidale and J. K. Ling.) pp. 103–114. (Royal Society of South Australia: Adelaide.)

Ford H. A. (1989). ‘Ecology of Birds: An Australian Perspective.’ (Surrey Beatty: Sydney.)

Ford, H. A. , Noske, S. , and Bridges, I. (1986). Foraging of birds in eucalypt woodlands in north-eastern New South Wales. Emu 86, 168–179.
Grant P. R. (1976). Population variation on islands. In ‘Proceedings of the International Ornithological Congress 16.’ (Eds H. J. Frith and J. H. Calaby.) pp. 603–615. (Australian Academy of Science: Canberra.)

Grant P. R. (Ed.) (1998). ‘Evolution on Islands.’ (Oxford University Press: Oxford, UK.)

Heard L., and Channon B. (Eds) (1997). ‘Guide to a Native Vegetation Survey: Using the Biological Survey of South Australia.’ (Department of Environment and Natural Resources (SA): Adelaide.)

Hespenheide, H. A. (1973). Ecological inferences from morphological data. Annual Review of Ecology and Systematics 4, 213–229.
| Crossref | GoogleScholarGoogle Scholar | Higgins P. J., Peter J. M., and Steele W. K. (Eds) (2001). ‘Handbook of Australian, New Zealand and Antarctic Birds. Vol. 5: Tyrant-Flycatchers to Chats.’ (Oxford University Press: Melbourne.)

Holmes, R. T. (1986). Foraging patterns of forest birds: male–female differences. Wilson Bulletin 98, 196–213.
Jehl J. R., Jr, and Murray B. G.Jr (1986). The evolution of normal and reverse sexual size dimorphism in shorebirds and other birds. In ‘Current Ornithology. Vol. 3’. (Ed. R. F. Johnston.) pp. 1–86. (Chapter 1). (Plenum Press: New York.)

Keast, A. (1968). Competitive interactions and the evolution of ecological niches as illustrated by the Australian honeyeater genus Melithreptus (Meliphagidae). Evolution 22, 762–784.
| Crossref | GoogleScholarGoogle Scholar | Keast A. (1976). Ecological opportunities and adaptive evolution on islands, with special reference to evolution in the isolated forest outliers of Southern Australia. In ‘Proceedings of the International Ornithological Congress 16’. (Eds H. J. Frith and J. H. Calaby.) pp. 573–584. (Australian Academy of Science: Canberra.)

Kleindorfer, S. , Chapman, T. , Winkler, H. , and Sulloway, F. J. (2006). Adaptive divergence in contiguous populations of Darwin’s small ground finch (Geospiza fuliginosa). Evolutionary Ecology Research 8, 357–372.
Lack D. (1971). ‘Ecological Isolation in Birds.’ (Blackwell Scientific Publications: Oxford, UK.)

MacArthur R. H., and Wilson E. O. (1967). ‘The Theory of Island Biogeography.’ (Princeton University Press: Princeton, NJ.)

Mayr E. (1970). ‘Populations, Species, and Evolution. An Abridgment of Animal Species and Evolution.’ (Belknap Press of Harvard University Press: Cambridge, MA.)

Mayr E. (1972). Sexual selection and natural selection. In ‘Sexual Selection and the Descent of Man 1871–1971’. (Ed. B. Campbell.) pp. 87–104. (Heinemann Educational: London.)

Mulder, R. A. , Dunn, P. O. , Cockburn, A. , Lazenby-Cohen, K. A. , and Howell, M. J. (1994). Helpers liberate female fairy-wrens from constraints on extra-pair mate choice. Proceedings of the Royal Society of London. Series B. Biological Sciences 255, 223–229.
Nias R. C. (1987). Co-operative breeding in the Superb Fairy-wren Malurus cyaneus. Ph.D. Thesis, University of New England, Armidale, NSW.

Noske, R. A. (1986). Intersexual niche segregation among three bark-foraging birds of eucalypt forests. Australian Journal of Ecology 11, 255–267.
| Crossref | GoogleScholarGoogle Scholar | Paton D. C., Gates J. A., and Pedler L. P. (2002). Birds. In ‘Natural History of Kangaroo Island’. 2nd edn. (Eds M. Davies, C. R. Twidale and M. J. Tyler.) pp. 88–110. (Royal Society of South Australia: Adelaide.)

Price, T. (1998). Sexual selection and natural selection in bird speciation. Philosophical Transactions of the Royal Society of London. Series B. Biological Sciences 353, 251–260.
| Crossref | GoogleScholarGoogle Scholar | Ridley M. (2004). ‘Evolution.’ 3rd edn. (Blackwell Publishing: Melbourne.)

Rix, C. E. (1976). The birds of Sandy Creek Conservation Park. Australian Bird Watcher 6, 209–222.
Robinson A. C., and Armstrong D. M. (Eds) (1999). ‘A Biological Survey of Kangaroo Island, South Australia, in November 1989 and 1990.’ (Heritage and Biodiversity Section, Department for Environment, Heritage and Aboriginal Affairs (SA): Adelaide.)

Robinson-Wolrath, S. I. , and Owens, I. P. F. (2003). Large size in an island-dwelling bird: intraspecific competition and the Dominance Hypothesis. Journal of Evolutionary Biology 16, 1106–1114.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Rowley I., and Russell E. (1997). ‘Fairy-wrens and Grasswrens: Maluridae.’ (Oxford University Press: Oxford, UK.)

Schluter D. (2000). ‘The Ecology of Adaptive Radiation.’ (Oxford University Press: Oxford, UK.)

Schneider, K. J. (1984). Dominance, predation, and optimal foraging in White-throated Sparrow flocks. Ecology 65(6), 1820–1827.
| Crossref | GoogleScholarGoogle Scholar | Schodde R. (1982). ‘The Fairy-Wrens. A Monograph of the Maluridae.’ (Lansdowne Editions: Melbourne.)

Schodde R., and Mason I. J. (1999). ‘The Directory of Australian birds: Passerines.’ (CSIRO Publishing: Melbourne.)

Scott, S. N. , Clegg, S. M. , Blomberg, S. P. , Kikkawa, J. , and Owens, I. P. F. (2003). Morphological shifts in island-dwelling birds: the roles of generalist foraging and niche expansion. Evolution 57, 2147–2156.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Selander R. K. (1972). Sexual selection and dimorphism in birds. In ‘Sexual Selection and the Descent of Man 1871–1971’. (Ed. B. Campbell.) pp. 180–230. (Heinemann Educational: London.)

Shine, R. (1989). Ecological causes for the evolution of sexual dimorphism: a review of the evidence. Quarterly Review of Biology 64, 419–461.
| Crossref | GoogleScholarGoogle Scholar | PubMed |

Slatkin, M. (1984). Ecological causes of sexual dimorphism. Evolution 38, 622–630.
| Crossref | GoogleScholarGoogle Scholar |

Suhonen, J. , and Kuitunen, M. (1991). Intersexual foraging niche differentiation within the breeding pair in the Common Treecreeper Certhia familiaris. Ornis Scandinavica 22, 313–318.

Tidemann, S. C. (2004). Use of space, foraging behaviour and strategies of survival among three coexisting species of fairy-wrens (Malurus). Emu 104, 31–36.
| Crossref | GoogleScholarGoogle Scholar |

Van Valen, L. (1965). Morphological variation and width of ecological niche. American Naturalist 99, 377–390.
| Crossref | GoogleScholarGoogle Scholar |

Webster, M. S. (1992). Sexual dimorphism, mating system and body size in New World Blackbirds (Icterinae). Evolution 46, 1621–1641.
| Crossref | GoogleScholarGoogle Scholar |

Whitehead, P. J. , and Tschirner, K. (1992). Sex and age related variation in foraging strategies of Magpie Geese Anseranas semipalmata. Emu 92, 28–32.

Wiens, J. A. , and Rotenberry, J. T. (1980). Patterns of morphology and ecology in grassland and shrub-steppe bird populations. Ecological Monographs 50, 287–308.
| Crossref | GoogleScholarGoogle Scholar |