Necks-for-sex or competing browsers? A critique of ideas on the evolution of giraffe

Journal of Zoology

Volumn 282, Issue 1, 2010, Pages 6-12

  Simmons, R E ^a   Altwegg, R ^a,b  

^a UNIVERSITY OF CAPE TOWN   (South Africa)

^b SOUTH AFRICAN NATIONAL BIODIVERSITY INSTITUTE   (South Africa)

Author keywords

Allometry; Ancestral giraffids; Competing browsers; Female choice; Necks for sex; Sexual selection

Indexed keywords

ALLOMETRY; BODY MASS; EVOLUTIONARY BIOLOGY; HYPOTHESIS TESTING; MATE CHOICE; REPRODUCTIVE STRATEGY; SEXUAL SELECTION; SURVIVAL; UNGULATE;

GIRAFFA CAMELOPARDALIS; GIRAFFIDAE; OKAPIA JOHNSTONI;

EID: 77956142802     PISSN: 09528369     EISSN: 14697998     Source Type: Journal    
DOI: 10.1111/j.1469-7998.2010.00711.x     Document Type: Article

References (49)

1. Andersson M. Sexual selection 1994, New Jersey, Princeton University Press
2. Badlangana NL, Adams JW, Manger PR. The giraffe (Giraffa camelopardalis) cervical vertebral column: a heuristic example in understanding evolutionary process? Zool. J. Linnean Soc. 2009, 155:736-757.
3. Bergeron P, Festa-Bianchet M, von Hardenberg A, Bassano B. Heterogeneity in male horn growth and longevity in a highly sexually dimorphic ungulate. Oikos 2008, 117:77-82.
4. Bonduriansky R. Sexual selection and allometry: a critical reappraisal of the evidence and ideas. Evolution 2007, 61:838-849.
5. Brand R. 2007, Evolutionary ecology of giraffes (Giraffa camelopardalis) in Etosha National Park, Namibia. PhD thesis, Newcastle University, UK
6. Cameron EZ, du Toit JT. Winning by a neck: tall giraffes avoid competing with shorter browsers. Am. Nat. 2007, 169:130-135.
7. Caro TM, Graham CM, Stoner CJ, Flores MM. Correlates of horn and antler shape in bovids and cervids. Behav. Ecol. Sociobiol. 2003, 55:32-41.
8. Churcher CS. Giraffidae. Evolution of mammals in Africa 1976, 509-535. Maglio VJ. (Ed.), Princeton, Princeton University Press
9. Clutton-Brock TH. The function of antlers. Behaviour 1982, 79:108-121.
10. Clutton-Brock TH, Albon SD, Harvey P. Antlers, body size and breeding group size in the Cervidae. Nature 1980, 285:565-567.
11. Colbert EH. A skull and mandible of Giraffokeryx punjabiensis (Pilgrim). Am. Mus. Novitates 1933, 632:1-14.
12. Colbert EH. The relationships of the Okapi. J Mammal. 1938, 19:47-64.
13. Cuervo JJ, Moller AP. The allometric pattern of sexually size dimorphic feather ornaments and factors affecting allometry. J. Evol. Biol. 2009, in press, doi, 10.1111/j.1420-9101.2009.01758.x
14. Dagg AI, Foster JB. The giraffe, its biology, behaviour and ecology 1976, New York, Van Nostrand Reinhold
15. Darwin C. The descent of man and selection in relation to sex 1871, London, John Murray
16. Du Toit JT. Feeding height stratification among African browsing ruminants. Afr. J Ecol. 1990, 28:55-61.
17. Du Toit JT. Sexual segregation in kudu: sex differences in competitive ability, predation risk or nutritional needs? S. Afr. J. Wildl. Res. 1995, 25:127-132.
18. Estes RD. The behaviour guide to African mammals 1991, Chicago, University of Chicago Press
19. Fisher RA. The genetical theory of natural selection 1930, Oxford, Clarendon Press
20. Geist V. The evolution of horn-like organs. Behaviour 1966, 27:175-214.
21. Ginnett TF, Demment MW. Sex differences in giraffe foraging behaviour at two spatial scales. Oecologia 1997, 110:291-300.
22. Gould SJ, Vrba E. Exaptation - a missing term in the science of form. Paleobiology 1982, 8:4-15.
23. Innis AC. The behaviour of the giraffe Giraffa camelopardalis in the eastern Transvaal. Proc. Zool. Soc. Lond. 1958, 131:245-278.
24. Kodric-Brown A, Brown JH. Truth in advertising: the kinds of traits favoured by sexual selection. Am. Nat. 1984, 124:309-323.
25. Kodric-Brown A, Sibly RM, Brown JH. The allometry of ornaments and weapons. Proc. Natl. Acad. Sci. USA 2006, 103:8733-8738.
26. Lande R. Genetic correlations between sexes in the evolution of sexual dimorphism and mating preferences. Sexual selection: testing the alternatives 1987, Bradbury JWAnderson MB. (Eds), Chichester, Wiley
27. Malo AF, Roldan ERS, Garde J, Soler AJ, Gomendio M. Antlers honestly advertise sperm production and quality. Proc. Roy. Soc. Lond. B. 2005, 272:149-157.
28. Mitchell G, Maloney SK, Mitchell D, Keegan DJ. The origin of mean arterial and jugular venous blood pressures in giraffes. J. Expt. Biol. 2006, 209:2515-2524.
29. Mitchell G, van Sittert SJ, Skinner JD. Sexual selection is not the origin of the long neck of the giraffe. J. Zool. (Lond.) 2009, 278:259-269.
30. Mitchell G, Skinner JD. How giraffe Giraffe camelopardalis adapt to their extraordinary shape. Trans. Roy. Soc. S. Afr. 1993, 48:207-218.
31. Mitchell G, Skinner JD. On the origin, evolution and phylogeny of giraffe Giraffa camelopardalis. Trans. Roy. Soc. S. Afr. 2003, 58:51-73.
32. Petrie M. Peacocks with low mating success are more likely to suffer predation. Anim. Behav. 1992, 44:e585-e586.
33. Pienaar U, de V. Predator-prey relationships in the Kruger National Park. Koedoe 1969, 12:108-176.
34. Pratt DM, Anderson VH. Population, distribution, and behaviour of giraffe in the Arusha National Park, Tanzania. J Nat. Hist. 1982, 16:481-489.
35. Pratt DM, Anderson VH. Giraffe social behaviour. J. Nat. Hist. 1985, 19:771-781.
36. R: A language and environment for statistical computing, 2.9.0. ISBN 3-900051-07-0 2009, http://www.R-project.org, R Development Core Team., Vienna, R Foundation for Statistical Computing, Available at
37. Roulin AR, Altwegg H, Jensen I, Steinsland, Schaub M. Sex-dependent selection on an autosomal melanic female ornament promotes the evolution of sex ratio bias. Ecol. Lett. 2010, 13:616-626.
38. Savage RJG, Long MR. Mammal evolution: an illustrated guide 1986, London, British Museum (Natural History)
39. Senter P. Necks for sex: sexual selection as an explanation for long necks in sauropod dinosaur neck elongation. J. Zool. (Lond.) 2007, 271:45-53.
40. Seymour R. 2001, Patterns of Subspecies Diversity in the Giraffe, Giraffa camelopardalis (L. 1758): Comparison of Systematic Methods and their Implications for Conservation Policy. PhD thesis
41. Shorrocks B. The behaviour of reticulated giraffe in the Laikipia district of Kenya. Giraffa 2009, 3:22-24.
42. Simmons RE. Tall tales: or how the giraffe got its neck. Afr. Geogr. 2008, 16:32-39.
43. Simmons RE, Scheepers L. Winning by a neck: sexual selection in the evolution of giraffe. Am. Nat. 1996, 148:771-786.
44. Smithers RHN. The mammals of the southern African subregion 1983, 562-566. Pretoria, South Africa, University of Pretoria, pp
45. Stankowich T, Caro T. Evolution of female weaponry in female bovids. Proc. Roy. Soc. Lond. Ser. B 2009, 276:4329-4334.
46. Vanpe C, Gaillard J-M, Kjellander P, Mysterud A, Magnien P, Delorme D, Van Laere G, Klein F, Liberg O, Hewison AJM. Antler size provides an honest signal of male phenotypic quality in Roe Deer. Am. Nat. 2007, 169:481-493.
47. Warren JV. The physiology of the giraffe. Sci. Am. 1974, 231:96-105.
48. Woolnough AP, du Toit JT. Vertical zonation of browse quality in tree canopies exposed to a size-structured guild of Africa browsing ungulates. Oecologia 2001, 129:585-590.
49. Young TP, Isbell LA. Sex differences in giraffe feeding ecology: energetics and social constraints. Ethology 1991, 87:79-89.