van Marken Lichtenbelt, Wouter David

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Energy budgets in the herbivorous green iguana (Iguana Iguana) were studied from April 1985-October 1988 in a strongly seasonal environment on the semi-arid island Curacao (Netherlands Antilles) under the auspices of the CARMABI Foundation in cooperation with the State University of Groningen (The Netherlands). ... Zie: Summar

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   University of GroningenEnergetics of the green iguana (Iguana iguana) in a semi-arid environmentvan Marken Lichtenbelt, Wouter DavidIMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:1991Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Marken Lichtenbelt, W. D. (1991). Energetics of the green iguana (Iguana iguana) in a semi-aridenvironment. s.n.CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 07-06-2022ISUMMARYEnergy budgets in the herbivorous green iguana (lguana iguana) were studiedfrom April 1985-October 1988 in a strongly seasonal environment on thesemi-arid island Curaqao (Netherlands Antilles) under the auspices of theCARMABI Foundation in cooperation with the State University of Groningen(The Netherlands).Adaptations to this climatic regime and the associated annual pulse offresh leafy material were identified by comparison with the extensive publishedstudies on this species in the humid tropics (Barro Colorado Island, Panama).Constraints relevant to dietary choice conceming errraction of energy,water and protein, were srudied in captive igu;uras during balance trials withnatural foods. Study of the temperature dependence of digestive efficiencyrevealed that body temperature affected ffansit time of food through thedigestive tract rather than dry matter digestibility.Thermoregulation was studied in free living iguanas by temperaturetelemetry with a sensor inserted in the abdomal cavity, and through the useof taxidermic mounts. A model was developed to estimate field bodytemperatures in the course of the day by combining measurements on thetaxidermic mount and detailed positional behavioral protocols.Reconstruction of digestive function combining field data on bodytemperature throughout the 24 hour period with the balance trials ur.rderknown temperatures in the laboratory revealed different optimum bodytemperatures depending on the nutritional state.Daily energy expenditure (DEE) was measured in free living iguanasusing the doubly labeled water technique. Validation studies in the laboratoryunder high humidity levels and temperatures as met on Curagao reveal anaverage deviation of 2.1Vo compared to repirometry and balance methods.Mean DEE in the field (68.9 kJ.kg 08.dt) conform to the allometric relationshipbetween DEE and body mass in iguanidae published by Nagy and co-workers.Measurements on DEE in the field were complemented by continuous detailedbehavioral observations, allowing a subsequent estimation of the magnitudeof the various components in the energy budget. A compilation of energyallocation, including standard and resting metabolic rate, costs of locomotionand postural adjustments permits the conclusion that on an annual basis thetotal energy expenditure of the two sexes is roughly equal. Egg productioncomprises 13o/o of the female energy budget, whereas the rnale faces increasedcosts of locomotion and postural adjustments.Food selection was studied in all phases of the annual cycle combiningdirect observations on food intake, plant biomass availabil ity and nutrientanalyses of the various food items. A l inearprogramming model was used toidentify the optimality criteria, indicating that ttre water maximization criterionwas met during the dry period and that after the early rains diets conform tothe protein maximization criterion. The reproductive cycle in the green iguanais attuned to the annual precipitation cycle such that hatching coincides witht61the period when lush foliage is available. Oviposition takes place three monthsearlier, during the dry season, when intzrke is below maintenance levels. Theresults indicate a relatively short period of positive protein balance in femalesresulting in a 8-10 months gap between the acquisition of the main portion ofthe proteins required for egg synthesis and the act of laying. Despite largedifferences in climate, green iguanas show a similar reproductive pattern inPanama, where lush foliage is also resficted to a relatively short period. Thisaongmence suggests that the cycle as reported for Curagao is more generallytenable, and reinforces the growing realization that the humid tropicsthemselves show marked annual rhythms.r68

Energetics of the green iguana (<i>Iguana iguana</i>) in a semi-arid environment

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Energetics of the green iguana (<i>Iguana iguana</i>) in a semi-arid environment

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