Skip to main content Accessibility help

We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.

Close cookie message
×
Hostname: page-component-5b777bbd6c-kmmxp Total loading time: 0 Render date: 2025-06-24T04:23:42.958Z Has data issue: false hasContentIssue false

16 - The evolution of foraging behavior in the Galápagos marine iguana: natural and sexual selection on body size drives ecological, morphological, and behavioral specialization

Published online by Cambridge University Press:  04 August 2010

By
Maren N. Vitousek ,
Dustin R. Rubenstein  and
Martin Wikelski
Edited by
Stephen M. Reilly ,
Lance B. McBrayer  and
Donald B. Miles
Maren N. Vitousek
Affiliation:
Department of Ecology and Evolutionary Biology Princeton University
Dustin R. Rubenstein
Affiliation:
Department of Neurobiology and Behavior Cornell University
Martin Wikelski
Affiliation:
Department of Ecology and Evolutionary Biology Princeton University
Stephen M. Reilly
Affiliation:
Ohio University
Lance B. McBrayer
Affiliation:
Georgia Southern University
Donald B. Miles
Affiliation:
Ohio University
Get access

Summary

Introduction

Each year thousands of tourists visit the Galápagos Islands and become intrigued by the unique habits of the world's only sea-going lizard, the Galápagos marine iguana (Amblyrhynchus cristatus), as it swims offshore and dives under the waves to feed. One of the islands' first visitors, Charles Darwin, reported fascination with watching these creatures forage, and he

opened the stomach of several, and in each case found it largely distended with minced sea-weed … [that] grows at the bottom of the sea, at some little distance from the coast.

(Darwin, 1839)

We now know that the Galápagos marine iguana is the only terrestrial vertebrate that forages almost exclusively on macrophytic marine algae. Although marine iguanas are active foragers, their short, intense bouts of foraging activity more closely resemble the activity pattern of sit-and-wait foragers. To understand why these endemic lizards have adapted such a unique foraging strategy and how it differs from the general pattern of foraging in lizards, we must examine the social and environmental selective pressures that are unique to this species and its environment.

The Galápagos marine iguana is a model system to understand how natural and sexual selection drive morphological and behavioral adaptations. In this chapter we will show how the unique foraging strategy of the marine iguana is an adaptation resulting from the forces of both sexual selection, acting through their unique social system, and natural selection by a harsh and variable environment.

Type
Chapter
Information
Lizard Ecology , pp. 491 - 507
Publisher: Cambridge University Press
Print publication year: 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Book purchase

Temporarily unavailable

References

Bartholomew, G. A. (1966). A field study of temperature relations in the Galapagos marine iguana. Copeia 1966, 241–50.CrossRefGoogle Scholar
Bartholomew, G. A., Bennett, A. F. and Dawson, W. R. (1976). Swimming, diving and lactate production of the marine iguana, Amblyrhynchus cristatus. Copeia 4, 709–20.CrossRefGoogle Scholar
Bartholomew, G. A. and Lasiewski, R. C. (1965). Heating and cooling rates, heart rate and simulated diving in the Galapagos marine iguana. Comp. Biochem. Physiol. 16, 573–82.CrossRefGoogle ScholarPubMed
Boersma, P. D. (1983). An ecological study of the Galapagos marine iguana. In Patterns of Evolution in Galapagos Organisms, ed. Bowman, R. I., Berson, M. and Leviton, A. E., pp. 157–76. San Francisco, CA: AAAS.Google Scholar
Buttemer, W. A. and Dawson, W. R. (1993). Temporal pattern of foraging and microhabitat use by Galapagos marine iguanas, Amblyrhynchus cristatus. Oecologia 96, 56–64.CrossRefGoogle ScholarPubMed
Carpenter, C. C. (1966). The marine iguana of the Galapagos Islands, its behavior and ecology. Proc. Cal. Acad. Sci. 34, 329–76.Google Scholar
Christian, K. A. and Tracy, C. R. (1985). Physical and biotic determinants of space utilization by the Galapagos land iguana (Conolophus pallidus). Oecologia 66, 132–40.CrossRefGoogle Scholar
Cooper, W. E. and Laurie, W. A. (1987). Investigation of deaths in marine iguanas (Amblyrhynchus cristatus) on Galapagos. J. Comp. Pathol. 97, 129–36.CrossRefGoogle ScholarPubMed
Darwin, C. (1839). Journal of Researches. Cambridge: Cambridge University Press.Google Scholar
Dawson, W. R., Bartholomew, G. A. and Bennett, A. F. (1977). A reappraisal of the aquatic specializations of the Galapagos marine iguana (Amblyrhynchus cristatus). Evolution 31, 891–7.Google Scholar
Drent, J., Lichtenbelt, Marken W. D. and Wikelski, M. (1999). Effects of foraging mode and season on the energetics of the marine iguana, Amblyrhynchus cristatus. Funct. Ecol. 13, 493–9.CrossRefGoogle Scholar
Dunson, W. A. (1969). Electrolyte excretion by salt gland of Galapagos marine iguanas. Am. J. Physiol. 216, 995.Google Scholar
Gleeson, T. T. (1979). Foraging and transport costs in the Galapagos marine iguana, Amblyrhynchus cristatus. Physiol. Zool. 52, 549–57.CrossRefGoogle Scholar
Hobson, E. S. (1965). Observations on diving in the Galapagos marine iguana, Amblyrhynchus cristatus (Bell). Copeia 1965, 1180–9.CrossRefGoogle Scholar
Hobson, E. S. (1969). Remarks on aquatic habits of the Galapagos marine iguana, including submergence times, cleaning symbiosis, and the shark threat. Copeia 1969, 401–2.CrossRefGoogle Scholar
Laurie, W. A. (1983). Marine iguanas in Galapagos. Oryx 17, 18–25.CrossRefGoogle Scholar
Laurie, W. A. (1984). Interim report on the marine iguana situation in the aftermath of the 1982–3 El Niño. Noticias de Galapagos 40, 9–11.Google Scholar
Laurie, W. A. (1987). Marine iguanas – living on the ocean margin. Oceanus 30(2), 54–60.Google Scholar
Laurie, W. A. (1989). Effects of the 1982–83 El Niño-southern oscillation event on marine iguana (Amblyrhynchus cristatus Bell, 1825) populations on Galapagos. In Global Ecological Consequences of the 1982–83 El Niño-Southern Oscillation, vol. 52, ed. Glynn, P. W., pp. 361–80. New York: Elsevier.Google Scholar
Laurie, W. A. (1990). Population biology of marine iguanas (Amblyrhynchus cristatus) I. Changes in fecundity related to a population crash. J. Anim. Ecol. 59, 515–28.CrossRefGoogle Scholar
Laurie, W. A. and Brown, D. (1990a). Population biology of marine iguanas (A. cristatus) II. Changes in annual survival rates and the effects of size, sex, age and fecundity in a population crash. J. Anim. Ecol. 59, 529–44.CrossRefGoogle Scholar
Laurie, W. A. and Brown, D. (1990b). Population biology of marine iguanas (Amblyrhynchus cristatus) III. Factors affecting survival. J. Anim. Ecol. 59, 545–68.CrossRefGoogle Scholar
Mackenzie, A., Reynolds, J. D., Brown, V. J. and Sutherland, W. J. (1995). Variation in male mating success on leks. Am. Nat. 145, 633–52.CrossRefGoogle Scholar
Mackie, R. I., Rycyk, M., Ruemmler, R. L., Aminov, R. I. and Wikelski, M. (2004). Biochemical and microbiological evidence for fermentative digestion in free-living land iguanas (Conolophus pallidus) and marine iguanas (Amblyrhynchus cristatus) on the Galapagos archipelago. Physiol. Biochem. Zool. 77, 127–38.CrossRefGoogle ScholarPubMed
Nagy, K. A. and Shoemaker, V. H. (1984). Field energetics and food consumption of the Galapagos marine iguana, Amblyrhynchus cristatus. Physiol. Zool. 57, 281–90.CrossRefGoogle Scholar
Partecke, J. A., Haenseler, A. and Wikelski, M. (2002). Territory establishment patterns support the hotshot-hypothesis in lekking marine iguanas. Behav. Ecol. Sociobiol. 51, 579–87.CrossRefGoogle Scholar
Quinn, W. H., Neal, V. T. and Mayolo, Antunez S. E. (1987). El Niño occurrences over the past four and a half centuries. J. Geophysical Res. C92, 14.Google Scholar
Romero, L. M. and Wikelski, M. (2001). Corticosterone levels predict survival probabilities of Galapagos marine iguanas during El Niño events. Proc. Natn. Acad. Sci. USA 98, 7366–70.CrossRefGoogle ScholarPubMed
Rubenstein, D. R. and Wikelski, M. (2003). Seasonal changes in food quality: a proximate cue for reproductive timing in marine iguanas. Ecology 84, 3013–23.CrossRefGoogle Scholar
Shepherd, S. A. and Hawkes, M. W. (2005). Algal food preferences and seasonal foraging strategy of the marine iguana, Amblyrhynchus cristatus, on Santa Cruz, Galápagos. Bull. Mar. Sci. 77, 51–72.Google Scholar
Tracy, C. R. and Christian, K. A. (1985). Are marine iguana tails flattened?Brit. J. Herpetol. 6, 434–5.Google Scholar
Trillmich, K. (1979). Feeding behavior and social behavior of the marine iguana. Noticias de Galapagos 29, 17–20.Google Scholar
Trillmich, K. (1983). The mating system of the marine iguana, Amblyrhynchus cristatus. Z. Tierpsychol. 63, 141–72.CrossRefGoogle Scholar
Trillmich, K. G. K. and Trillmich, F. (1986). Foraging strategies of the marine iguana, Amblyrhynchus cristatus. Behav. Ecol. Sociobiol. 18, 259–66.CrossRefGoogle Scholar
Troyer, K. (1982). Transfer of fermentative microbes between generations in a herbivorous lizard. Science 216, 540–2.CrossRefGoogle Scholar
Vleck, D., Gleeson, T. T. and Bartholomew, G. A. (1981). Oxygen consumption during swimming in Galapagos marine iguanas and its ecological correlates. J. Comp. Physiol. 141, 531–6.CrossRefGoogle Scholar
White, F. N. (1973). Temperature and the Galapagos marine iguana – insights into reptilian thermoregulation. Comp. Biochem. Physiol. 45A, 503–13.CrossRefGoogle Scholar
Wikelski, M. (2005). Evolution of body size in Galapagos marine iguanas. Proc. R. Soc. Lond. B272, 1985–93.CrossRefGoogle Scholar
Wikelski, M. and Hau, M. (1995). Is there an endogenous tidal foraging rhythm in marine iguanas?J. Biol. Rhyth. 10, 335–50.CrossRefGoogle ScholarPubMed
Wikelski, M. and Romero, L. M. (2003). Body size, performance and fitness in Galapagos marine iguanas. Int. Comp. Biol. 43, 376–86.CrossRefGoogle ScholarPubMed
Wikelski, M. and Thom, C. (2000). Marine iguanas shrink to survive El Niño. Science 403, 37–8.Google ScholarPubMed
Wikelski, M. and Trillmich, F. (1994). Foraging strategies of the Galapagos marine iguana (Amblyrhynchus cristatus): adapting behavioral rules to ontogenetic size change. Behavior 128, 255–79.CrossRefGoogle Scholar
Wikelski, M. and Trillmich, F. (1997). Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: an island comparison. Evolution 51, 922–36.CrossRefGoogle ScholarPubMed
Wikelski, M. and Wrege, P. H. (2000). Niche expansion, body size and survival in Galapagos marine iguanas. Oecologia 124, 107–15.CrossRefGoogle ScholarPubMed
Wikelski, M., Carbone, C., Bednekoff, P. A., Choudhury, S. and Tebbich, S. (2001). Why is female choice not unanimous? Insights from costly mate sampling in marine iguanas. Ethology 107, 623–38.CrossRefGoogle Scholar
Wikelski, M., Carbone, C. and Trillmich, F. (1996). Lekking in marine iguanas: female grouping and male reproductive strategies. Anim. Behav. 52, 581–96.CrossRefGoogle Scholar
Wikelski, M., Carillo, V. and Trillmich, F. (1997). Energy limits to body size in a grazing reptile, the Galapagos marine iguana. Ecology 78, 2204–17.CrossRefGoogle Scholar
Wikelski, M., Gall, B. and Trillmich, F. (1993). Ontogenetic changes in food intake and digestion rate of the herbivorous marine iguana (Amblyrhynchus cristatus, Bell). Oecologia 94, 373–9.CrossRefGoogle Scholar
Wikelski, M., Steiger, S. S., Gall, B. and Nelson, K. N. (2005). Sex, drugs and mating role: testosterone-induced phenotype-switching in Galapagos marine iguanas. Behav. Ecol. 19, 260–8.CrossRefGoogle Scholar

Save book to Kindle

To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×