, Volume 95, Issue 2, pp 246–256 | Cite as

Optimal foraging of a herbivorous lizard, the green iguana in a seasonal environment

  • Wouter D. van Marken Lichtenbelt
Original Papers


Food selection was studied in free living green iguanas (Iguana iguana) throughout the year in a semiarid environment, Curaçao (Netherlands Antilles). Food intake was determined by direct observations and converted into biomass intake. Comparison between intake and biomass availability of the various food items revealed that the lizards were selective, and that changes in seasonal food availability led to periodic switching of food plants. The extent to which nutrient constraints determine iguana feeding ecology was investigated. Potential constraints were the requirements for water, digestible crude protein, and metabolizable energy. By using a linear programming model that incorporates characteristics of the food (chemical composition, energy content, item size) and requirements and constraints of the green iguanas (nutrient and energy requirements digestive tract capacity, feeding rate) it was possible to identify which factors determine food choice over the year. During the dry period, when the iguanas had no access to drinking water they consumed flowers to increase water intake, though the amount of flowers consumed was too low to cover maintenance requirements for either energy or protein. After the young leaf flush, following the early rains in May, the biomass increased, free surface water was available during showers, and the linear programming solutions indicate that food selection conformed to the protein maximization criterion. Reproduction in green iguanas shows an annual cycle, in which oviposition takes place at the end of the dry season, when intake is below maintenance levels. Females show a 8–10 month gap between acquisition of most of the protein required for egg synthesis and the act of laying. Thus, as in avian and mammalian herbivores, food availability during a period prior to the energy and protein demanding reproductive season of iguanas determines reproductive success.

Key words

Energetics Food selection Life history Linear programming Nutrient requirement 


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  1. Aufenberg W (1982) Feeding strategy of the Caicos Ground Iguana, Cyclura carinata. In: Burghardt GM, Rand AS (eds) Iguanas of the World: Their Behavior, Ecology, and Conservation. Noyes Publications, Park Ridge, New Jersey, pp 84–116Google Scholar
  2. Belovsky GE (1978) Diet optimization in a generalist herbivore: the moose. Theor Popul Biol 14:105–134Google Scholar
  3. Belovsky GE (1984) Herbivore optimal foraging: a comparative test of three models. Am Nat 124:97–115Google Scholar
  4. Charnov EL (1976) Optimal foraging: attack strategy of a mantid. Am Nat 110:141–151Google Scholar
  5. Chilcott MJ, Hume ID (1985) Coprophagy and selective retention of fluid digesta: their role in the nutrition of the common ringtail possum, Pseudocheirus peregrinus. Aust J Zool 33:1–15Google Scholar
  6. Christian A, Tracy CR, Porter WP (1984) Diet, digestion and food preferences of Galápagos land iguanas. Herpetologica 40:205–212Google Scholar
  7. Clutton-Brock TH, Guinness FE, Albon SD (1982) Red deer: Behavior and ecology of two sexes. Edinburgh University Press, EdinburghGoogle Scholar
  8. Covich ML (1973) Ecological economics of seed consumption by Peromyscus. Hutchinson Mem Conn Acad Sci 71–93Google Scholar
  9. Dearing MD, Schall JJ (1992) Testing models of optimal diet assembly by the generalist herbivorous lizard Cnemidophorus murinus. Ecology 73:845–858Google Scholar
  10. Demment HW, Van Soest PJ (1985) A nutritional explanation for body size patterns of ruminant and nonruminant herbivores. Am Nat 125:641–672Google Scholar
  11. Drent RH, Daan S (1980) The prudent parent: energetic adjustments in avian breeding. Ardea 68:225–252Google Scholar
  12. Drent RH, Prins HHT (1987) The herbivore as prisoner of its food supply. In: Andel J van et al. (eds) Disturbance in grasslands. Dr J Junk Publishers, Dordrecht, The Netherlands, pp 133–149Google Scholar
  13. Dusi JL (1949) Methods for the determination of food habits by plant microtechniques and histology and their applications to cottontail rabbit food habits. J Wildl Mngr 13:295–298Google Scholar
  14. Ebbinge BS (1989) A multifactoral explanation for variation in breeding performance of Brent Geese Branta bernicla. Ibis 131:196–204Google Scholar
  15. Edney EB, Nagy KA (1976) Water balance and excretion. In: Bligh J, Cloudsley-Thompson JL, Macdonald AG (eds) Environmental Physiology of Animals. Blackwell, Oxford, pp 106–132Google Scholar
  16. Emlen JM (1966) The role of time and energy in food preference. Am Nat 100:611–617Google Scholar
  17. Freeland WJ, Janzen DH (1974) Strategies in herbivory in mammals: the role of plant secondary compounds. Am Nat 108:269–289Google Scholar
  18. Goering HK, Van Soest PJ (1970) Forage fiber analyses (appararatuss, reagens, procedures, and some applications). U S Dep Agric, Agric Handb 379Google Scholar
  19. Janzen DH (1978) Complications in interpreting the chemical defenses of trees against tropical arboreal plant-eating vertebrates. In: Montgomery GG (ed) The Ecology of Arboreal Folivores. Smithsonian Institution Press, Washington D C, pp 73–84Google Scholar
  20. Karasov WH (1985) Nutrient constraints in the feeding ecology of an omnivore in a seasonal environment. Oecologia 66:280–290Google Scholar
  21. Lechowicz MJ (1982) The sampling characteristics of electivity indices. Oecologia 52:22–30Google Scholar
  22. Leigh EG, Smythe N (1978) Leaf production, leaf consumption, and the regulation of folivory on Barro Colorado Island. In: Montgomery GG (ed) The Ecology of Arboreal Folivores. Smithsonian Institution Press, Washington D C, pp 33–50Google Scholar
  23. MacArthur RH, Pianka ER (1966) On optimal use of a patchy environment. Am Nat 100:603–609Google Scholar
  24. Marken Lichtenbelt WD van (1992) Digestion in an ectothermic herbivore, the green iguana (Iguana iguana): effect of food composition and body temperature. Physiol Zool 65:649–673Google Scholar
  25. Marken Lichtenbelt WD van, Albers KB (1993) Reproductive adaptations of the green iguana on a semi-arid island. CopeiaGoogle Scholar
  26. Marken Lichtenbelt WD van, Wesselingh RA, Vogel J, Albers KB (1993) Energy budgets in free living green iguanas in a seasonal environment. Ecology 74:1157–1172Google Scholar
  27. Mautz WJ, Nagy KA (1987) Ontogenetic changes in diet, field metabolic rate and water flux in the herbivorous lizard Disposaurus dorsalis. Physiol Zool 60:640–658Google Scholar
  28. McBee RH, McBee VH (1982) The hindgut fermentation in the green iguana. In: Burghardt GM, Rand AS (eds) Iguanas of the World: Their Behavior, Ecology, and Conservation, Noyes Publications, Park Ridge, New Jersey, pp 77–83Google Scholar
  29. McDonald P, Edwards RA, Greenhalgh JFD (1981) Animal nutrition. Longman, London and New YorkGoogle Scholar
  30. Milton K (1979) Factors influencing leaf choice by Howler Monkeys: a test of some hypotheses of food selection by generalist herbivores. Am Nat 114:362–378Google Scholar
  31. Moberly WR (1968) The metabolic responses of the common iguana, Iguana iguana, to activity under restraint. Comp Biochem Phys 27:1–20Google Scholar
  32. Morton Boyd J, Jewell PA (1974) The Soay sheep and their environment: a synthesis. In: Jewell PA, Milner C, Morton Boyd J (eds) Island Survivors: The ecology of the Soay sheep of St Kilda. The Athlone Press, London, pp 360–373Google Scholar
  33. Nagy KA (1972) Water and electrolyte budgets of a free-living desert lizard, Sauromalus obesus. J Comp Phys 79:39–62Google Scholar
  34. Nagy KA (1982) Field studies of water relations. In: Gans C, Pough FH (eds) Biology of the Reptilia, Vol 12. Academic Press, New York, pp 483–501Google Scholar
  35. Nagy KA, Schoemaker VH (1975) Energy and nitrogen budgets of the free-living desert lizard Sauromalus obesus. Phys Zool 48:252–262Google Scholar
  36. Owen-Smith N, Novellie P (1982) What should a clever ungulate eat? Am Nat 119:151–177Google Scholar
  37. Pianka ER (1976) Natural selection of optimal reproductive tactics. Am Zool 16:775–784Google Scholar
  38. Prop J, Deerenberg C (1991) Spring staging in brent geese (Branta bernicla): feeding constraints and the impact of diet on the accumulation of body reserves. Oecologia 87:19–28Google Scholar
  39. Pulliam HR (1975) Diet optimalization with nutrient constraints. Am Nat 109:765–768Google Scholar
  40. Rand AS (1978) Reptilian arboreal folivores. In: Montgomery GG (ed) The ecology of Arboreal Folivores. Smithsonian Institution Press, Washington D C, pp 115–122Google Scholar
  41. Rand AS, Greene HW (1982) Latitude and climate in the phenology of reproduction in the green iguana, Iguana iguana. In: Burghardt GM, Rand AS (eds) Iguanas of the World: The Behavior, Ecology, and Conservation. Noyes Publications, Park Ridge, New Jersey, pp 142–149Google Scholar
  42. Robbins CT (1983) Wildlife feeding and nutrition. Academic Press, New YorkGoogle Scholar
  43. Schall JJ, Ressel S (1991) Toxic plant compounds, and the diet of the predominantly herbivorous whiptail lizard, Cnemidophorus arubensis. Copeia 1991:111–119Google Scholar
  44. Schoener TW (1969) Models of optimal size for solitary predators. Am Nat 103:277–313Google Scholar
  45. Sinclair ARE (1975) The resource limitation of trophic levels in tropical grassland ecosystems. J Anim Ecol 44:497–520Google Scholar
  46. Stephens DW, Krebs JR (1986) Foraging theory. Princeton University Press, Princeton, New JerseyGoogle Scholar
  47. Troyer K (1984a) Diet selection and digestion in Iguana iguana: the importance of age and nutrient requirements. Oecologia 61:201–207Google Scholar
  48. Troyer K (1984b) Structure and function of the digestive tract of a herbivorous lizard Iguana iguana. Physiol Zool 57:1–8Google Scholar
  49. Verlinden C, Wiley RH (1989) The constraints of digestive rate: an alternative model of diet selection. Evol Ecol 3:264–273Google Scholar
  50. Westoby M (1974) An analysis of diet selection by large generalist herbivores. Am Nat 108:290–304Google Scholar
  51. White TCR (1985) When is a hebivore not a herbivore? Oecologica 67:596–597Google Scholar

Copyright information

© Springer-Verlag 1993

Authors and Affiliations

  • Wouter D. van Marken Lichtenbelt
    • 1
    • 2
  1. 1.Carmabi FoundationCuraçao, Netherlands AntillesNetherlands
  2. 2.Zoological LaboratoryUniversity of GroningenHarenThe Netherlands

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