To understand the foraging behavior and ecology of the Chinese crocodile lizard (
Shinisaurus crocodilurus
), we studied prey discrimination mechanisms through two series of experiments. The first experiment used swabs dampened with deionised water, cologne, macerated earthworm (
Pheretima
sp.) and macerated tenebrio (
Tenebriomolitor
L.) as chemical cues and the response of 11 Chinese crocodile lizard was observed. Each individual was tested 24 times to each stimulus. The results showed that all individuals of Chinese crocodile lizard responded to the swabs by tongue flicking. The number of tongue-flicks in response to the tenebrio and earthworm stimuli was significantly higher than that to the cologne and deionized water (Wilcoxon test, all
P<0.001). This indicates that the Chinese crocodile lizard can discriminate food and non-food stimuli. In the second experiment, we observed the responses of Chinese crocodile lizard to the following cues: (A) blank utensil, (B) utensil treated with macerated earthworm, (C) a live earthworm sealed in the utensil, (D) a live earthworm placed in the open utensil. Each individual was tested 5 times for each cue. Results showed that the Chinese crocodile lizard response for each cue was significantly different in dealing time, investigation frequency and attack frequency (all
P<0.001). The dealing time, investigation frequency and attack frequency in cue C (visual cue) and in cue D (visual and chemical cue) were significantly higher than in cue B (chemical cue) (ll
P<0.001). Exclusion of the visual cue, showed the dealing time and investigation frequency were significantly higher than in cue A (blank) (all
P<0.001). Under the same visual cues, only dealing times in cue D was higher than that in cue D (
Z=3.95,
P<0.001). But investigation frequency and attack frequency were not significantly different between cue C and D (for former
Z=1.53,
P=0.13；for latter
Z=1.10,
P=0.27). These indicate that Chinese crocodile lizard rely more on visual cues to discriminate prey than on chemical cues. The prey discrimination mechanisms of Chinese crocodile lizard may be related with foraging mode, phylogeny and prey.
