Coordinated ontogeny of food preference and responses to chemical food stimuli by a lizard Ctenosaura pectinata (Reptilia : Iguanidae).

Citation
We. Cooper et Ja. Lemos-espinal, Coordinated ontogeny of food preference and responses to chemical food stimuli by a lizard Ctenosaura pectinata (Reptilia : Iguanidae)., ETHOLOGY, 107(7), 2001, pp. 639-653
Citations number
46
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ETHOLOGY
ISSN journal
0179-1613 → ACNP
Volume
107
Issue
7
Year of publication
2001
Pages
639 - 653
Database
ISI
SICI code
0179-1613(200107)107:7<639:COOFPA>2.0.ZU;2-5
Abstract
When important ecological factors change predictably during the life of an organism, the ontogeny of related behaviors must be timed to maintain appro priate behavioral responsiveness to current ecological conditions. In the b rown iguana, Ctenosaura pectinata, hatchlings in natural populations eat pr imarily insects, consuming little plant matter, whereas adults eat primaril y plants, consuming some insects as well. We conducted laboratory experimen ts on diet preferences and responses to chemical cues that the lizards samp led by tongue-flicking and used to identify food. All hatchlings ate cricke ts, but only one of six ate romaine lettuce. They responded strongly to che mical cues from prey, as indicated by elevated tongue-flick rates, but not from romaine lettuce. All older individuals ate both crickets and romaine l ettuce. They responded much more strongly to chemical cues from both cricke ts and romaine lettuce than to control chemicals, as indicated by higher pr oportions of individuals that bit and higher tongue-flick attack scores. Thus, an ontogenetic change to increased responsiveness to plant chemical s timuli was coordinated with an ontogenetic change to an herbivorous diet. T he mechanisms underlying these ontogenetic changes are unknown, but folivor y may be unprofitable before juveniles acquire intestinal flora that degrad e cellulose by ingestion of feces of adult conspecifics. Possible mechanism s are discussed, including the detection of chemical cues from appropriate food plants during consumption of feces from older individuals. Studies of other squamate reptiles suggest that exposure to these chemicals might affe ct both future responsiveness to the chemical cues and a tendency to eat th e corresponding plants.