Lizards odors

It is well known that the chemical senses play a critical role in the behavior of snakes (Halpern, 1987, 1992 Mason 1992 and Schwenk 1995). Tongue-flicking, a chemosensory behavior pattern unique to snakes and lizards (Gove 1979 Schwenk 1993), serves as the primary vehicle for transfer of chemical substances to the vomeronasal organ (Burghardt and Pruitt 1975 Graves and Halpern 1989 Halpern and Kubie 1980 Kahmann 1932 Wilde 1938). Snakes have well-developed vomeronasal systems and flick their tongues in response to odorants perceived in their environment. 

FIGURE 5.8 Location of the vomeronasal organ (VNO, cross-hatched) in amphibians and reptiles. Arrows show air entering through the external nares at top and exiting through the choanae at bottom. From there, VNO receives air with odors. N nasal cavity. In lizard, VNO receives stimuli from mouth cavity below, with help from tongue. (Redrawn after Romer, 1959.)... 

Odors are important in sexual behavior of snakes, but less so in lizards, which use primarily visual signals. 

Cooper, W. E., Jr. and Garstka, W. (1987). Discrimination of male conspecific from male heterospedfic odors by male scincid lizards, Eumeces laticeps. Journal of Experimental Zoology 241,253-256. 

Cooper, W. E., and Pdrez-Mellado, V., 2001, Location of fruit using only airborne odor cues by a lizard, Physiol. Behav. 74(3) 339-342. 

Early experimental work suggests similar lingual function in lizards (Kahmann, 1932). Moreover, tongue-flick rates (in combination with attack latencies) have been used successfully by Burghardt and Greene (Burghardt, 1973, 1977) to measure relative responsiveness of lizards to cotton-tipped applicators saturated with odor extracts of food items and control substances. 

Interspecific odor discrimination by male Eumeces laticeps. Lizards emitted significantly more tongue-flicks to female cloacal odors of conspecifics than to those of S3nnpatric heterospecific congeners. 

Cooper, W. E., Jr., and Vitt, L. J., 1986, Interspecific odor discriminations among syntopic congeners in scincid lizards (genus Eumeces), Behaviour, in press a. 

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