CZAAWE Resource Article

Analysis of the behavioral sequence emitted by rattlesnakes during feeding episodes II. Duration of strike-induced chemosensory searching in rattlesnakes (Crotalus viridis, C. enyo)
Publication Type 
Journal Article
Year of publication 
Behavioral and Neural Biology
Eight rattlesnakes (four Crotalus viridis and four C. enyo) were each observed in four experimental conditions: (1) snakes saw, smelled, and detected thermal cues arising from live mice for 3 sec but were not given an opportunity to deliver a predatory strike (the mice were then removed); (2) same as Condition 1, but a strike was permitted at the end of 3 sec (the mice were then removed); (3) same as Condition 2, but the envenomated, dead mice were left in the snakes' cages so that ingestion occurred; and (4) same as Condition 3, except that a second mouse was introduced (as in Condition 2) after the first was consumed. The dependent variable was the rate of tongue flicking (RTF) which was recorded for 315 min, beginning 5 min prior to each condition. A high RTF followed each predatory strike, but not the no-strike mouse presentation of Condition 1. In Condition 2, snakes continued searching for the envenomated mice for 150 min poststrike. Ingestion terminated the high RTF in Condition 3, but a second strike reinitiated high RTF in Condition 4. In the latter condition, snakes continued chemosensory searching for 105 min after the second strike. In Conditions 2 and 4, snakes remained attentive even after they quit chemosensory searching because a 3-sec, no-strike presentation of a live mouse (presented at least 120 min after RTF had returned to baseline) resulted in a reinitiation of tongue flicking. This did not happen after Conditions 1 and 3. Implications of these data for mechanisms mediating strike-induced chemosensory searching are discussed.