Center for Reproduction of Endangered Species, Zoological Society of San Diego, Box 551, 92112, San Diego, California.
J Chem Ecol. 1992 Oct;18(10):1775-83. doi: 10.1007/BF02751102.
Monitor lizards prey on snakes. Conversely, venomous snakes prey on juvenile monitor lizards. Immediately after hatching, monitor lizards are naive to all prey items, thus correct assessment of snake prey is paramount for survival. Experiments were conducted to determine how hatchling monitor lizards (Varanus albigularis) with no previous exposure to snakes reacted to sympatric venomous and nonvenomous snakes. Hatchling lizards attacked harmless snakes, but avoided venomous species. Lizards readily accepted meat from skinned snakes, regardless of species. When invertebrate prey covered with skin segments from venomous snakes were restrained from moving, they were usually investigated by tongue-flicking and rejected. Unrestrained skin-covered prey, however, were generally attacked and eaten without prior evaluation by tongue-flicking. Attack was inhibited in trials in which unrestrained prey were tongue-flicked, suggesting that chemical cues contained in snake skins mediate avoidance of venomous snakes. Selection for the ability to perceive snake integumental chemicals may be especially strong in species that both consume and are consumed by snakes.
巨蜥捕食蛇。相反，毒蛇则捕食幼年巨蜥。刚孵化出来的巨蜥对所有猎物都不熟悉，因此正确评估蛇类猎物对生存至关重要。本实验旨在确定无蛇类捕食经验的幼年巨蜥（Varanus albigularis）对同域毒蛇和无毒蛇的反应。刚孵化的巨蜥会攻击无毒蛇，但会避开有毒蛇。巨蜥很容易接受剥皮蛇的肉，而不管蛇的种类。当被蛇皮覆盖的无脊椎动物猎物不能移动时，它们通常会被巨蜥用舌头舔舐并被拒绝；然而，不受限制的带皮猎物通常会被攻击和吃掉，而不会先用舌头舔舐进行评估。在无限制的带皮猎物被舌头舔舐的试验中，攻击被抑制，这表明蛇皮中的化学线索可以介导对毒蛇的回避。对感知蛇类表皮化学物质能力的选择可能在那些既消耗蛇类又被蛇类消耗的物种中尤为强烈。
