Mechanisms of predator detection and the influence of the presence of nonlethal predators on antipredator defense behavior and metamorphic traits were studied in the Indian tree frog, Polypedates maculatus. Exposure o...Mechanisms of predator detection and the influence of the presence of nonlethal predators on antipredator defense behavior and metamorphic traits were studied in the Indian tree frog, Polypedates maculatus. Exposure of P. maculatus tadpoles to chemical cues of caged predator（crabs, Barytelphusa spp.） fed with either conspecific or heterogeneric tadpoles, or were starved elicited defense behavior（by avoiding predator zone） in them. Such a behavior was not evident when exposed to predators housed in a glass beaker（visual cues）. Both early（Gosner stage 27–28） and later（Gosner stage 35–36） stage tadpoles when exposed to caged predators（fed with conspecific tadpoles）, prey tadpoles spent less time swimming and remained motionless for longer periods. Yet, the time spent by prey in feeding was unaffected. Further, the predator avoidance behavior exhibited by them was of the same intensity regardless of whether the caged predators were fed or starved implying the influence of predator＇s kairomones. Tadpoles reared with caged predator reached the metamorphic climax stage（MC stage; Gosner stage 42） earlier than those reared without a predator. Size at emergence（Gosner stage 46） was comparable in both the groups. The findings suggest that P. maculatus tadpoles assess predation risk chiefly by sensing kairomones of the predator in eliciting antipredator defense behaviors. Accelerated development and early metamorphosis without any compromise of the size at emergence may be due to their unaltered feeding activity.展开更多
文摘Mechanisms of predator detection and the influence of the presence of nonlethal predators on antipredator defense behavior and metamorphic traits were studied in the Indian tree frog, Polypedates maculatus. Exposure of P. maculatus tadpoles to chemical cues of caged predator（crabs, Barytelphusa spp.） fed with either conspecific or heterogeneric tadpoles, or were starved elicited defense behavior（by avoiding predator zone） in them. Such a behavior was not evident when exposed to predators housed in a glass beaker（visual cues）. Both early（Gosner stage 27–28） and later（Gosner stage 35–36） stage tadpoles when exposed to caged predators（fed with conspecific tadpoles）, prey tadpoles spent less time swimming and remained motionless for longer periods. Yet, the time spent by prey in feeding was unaffected. Further, the predator avoidance behavior exhibited by them was of the same intensity regardless of whether the caged predators were fed or starved implying the influence of predator＇s kairomones. Tadpoles reared with caged predator reached the metamorphic climax stage（MC stage; Gosner stage 42） earlier than those reared without a predator. Size at emergence（Gosner stage 46） was comparable in both the groups. The findings suggest that P. maculatus tadpoles assess predation risk chiefly by sensing kairomones of the predator in eliciting antipredator defense behaviors. Accelerated development and early metamorphosis without any compromise of the size at emergence may be due to their unaltered feeding activity.
