Responses to prey and plant chemicals by three iguanian lizards: relationship to plants in the diet

Abstract

We examined responses of three iguanian lizards, the phrynosomatid Sceloporus poinsettii and the tropidurids Tropidurus hispidus and Phymaturus punae, to prey chemicals and plant chemicals. When chemical stimuli were presented on cotton swabs or on ceramic tiles, neither S. poinsettii nor T. hispidus discriminated among prey, plant, and control stimuli. In contrast, an individual of P. punae discriminated both prey and plant chemicals from control stimuli in swab tests, typically biting swabs bearing prey or plant cues. These findings are consistent with the hypothesis that plant chemical discrimination evolves in herbivorous iguanians such as P. punae. Sceloporus poinsettii, which appears to be entirely insectivorous at some times, but eats substantial quantities of flowers at others, did not discriminate among the stimuli. Because all previously tested herbivores and omnivores responded strongly to prey and plant chemicals, the absence of such discriminations by S. poinsettii raises questions about the degree and regularity of herbivory that may be required for plant chemical discrimination to evolve. The results extend the absence of prey chemical discrimination in ambush foragers to T. hispidus.

Morphological evolution of the lizard skull: A geometric morphometrics survey

“…Phylogenetically, skull characters are used in morphological phylogenetic studies of lizard relationships, including those of Estes et al (1988), Etheridge and de Quieroz (1988), and Moody (1980). Functionally, the skull and its associated musculature have been studied in the context of feeding (Schwenk, 2000), sensory systems (Cooper et al, 2001), ecomorphology (King, 1996;Herrel et al, 1998), and sexual selection (Herrel et al, 1996). Many functions of the lizard skull are still poorly understood (e.g., cranial kinesis; see Metzger, 2002), and the study of the lizard skull is still an active field.…”

Prey Discrimination Mechanisms of Chinese Crocodile Lizard (<I>Shinisaurus crocodilurus</I>)

“…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 以及 Nelling(1996) (Burghardt, 1970b;Cooper et al, 1994)。一旦 舌头检测到猎物化学刺激就能识别和确定猎物 (Cooper, 1995(Cooper, , 1997)，蜥蜴也会用这些化学线索去 确定隐藏着的猎物 (Bogert & Martin del Campo, 1956;Auffenberg, 1984)。对一些蜥蜴和蛇类而言， 嗅觉通讯在猎物化学识别方面是必需的，这已通过 实验研究得到证实 (Halpern & Frumin, 1979;Cooper & Alberts, 1991 (Burghardt, 1970b;Cooper and Burghardt, 1990a;Cooper, 1998a) (Dial & Schwenk, 1996;Cooper, 1998a, b)。去离子水作为无味刺激 (Cooper & Burghardt, 1990a)。实验进行时，缓慢地将棉花棒移到鳄蜥吻 部 1~1.5 cm 的地方。 观察鳄蜥对不同棉花棒的反应： (Burghardt, 1970b;Cooper and Burghardt, 1990a )，南非盾甲蜥 (Gerrhosaurus nigrolineatus) (Cooper et al, 2001)，巴 里 利 亚 璧 蜥 (Podarcis lilfordi) (Cooper, et al, 2001)。 在捕食模式方面，爬行动物一般有坐等(sit-and-wait) 和漫游(active)两种类型 (MacArthur & Pianka, 1966;Huey & Pianka, 1981)。一般认为漫游型捕食者比坐 等型捕食者更多的依靠化学感觉来检测食物 (Evans, 1961;Enders, 1975;Regal, 1978)，因为漫游型捕食 者的在寻找食物过程中，通过不断地舔舌来确定食 物的位置 (Evans, 1961)。它们不仅能通过化学线索 检测出隐蔽的猎物 (Bogert & Martín Del Campo, 1956;Auffenberg, 1984)，还能识别猎物的化学刺激 和控制刺激。这一点通过在缺乏视觉线索的情况 下，发生不断地舔舌以及频繁地啃咬刺激物等行为 得以证实 (Cooper, 1994a(Cooper, , 1995(Cooper, , 1997)。相反，坐等 型捕食者在等待不动的猎物时几乎不舔舌或很少 舔舌，只有移动到新的环境才发生舔舌 (Cooper et al, 1994a)。许多坐等型蜥蜴都没有表现出对猎物的化 学识别能力，而只有视觉识别能力 (Cooper, 198...…”