Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2013 Dec;199(12):1093-104. doi: 10.1007/s00359-013-0852-4. Epub 2013 Sep 5.
Rattlesnakes use their facial pit organs to sense external thermal fluctuations. A temperature decrease in the heat-sensing membrane of the pit organ has the potential to enhance heat flux between their endothermic prey and the thermal sensors, affect the optimal functioning of thermal sensors in the pit membrane and reduce the formation of thermal "afterimages", improving thermal detection. We examined the potential for respiratory cooling to improve strike behaviour, capture, and consumption of endothermic prey in the South American rattlesnake, as behavioural indicators of thermal detection. Snakes with a higher degree of rostral cooling were more accurate during the strike, attacking warmer regions of their prey, and relocated and consumed their prey faster. These findings reveal that by cooling their pit organs, rattlesnakes increase their ability to detect endothermic prey; disabling the pit organs caused these differences to disappear. Rattlesnakes also modify the degree of rostral cooling by altering their breathing pattern in response to biologically relevant stimuli, such as a mouse odour. Our findings reveal that low humidity increases their ability to detect endothermic prey, suggesting that habitat and ambush site selection in the wild may be influenced by external humidity levels as well as temperature.
响尾蛇利用面部颊窝器官感知外部热波动。颊窝器官的热敏感膜温度下降，有可能增强它们的吸热猎物和热传感器之间的热流，影响颊窝膜中热传感器的最佳功能，并减少热“后像”的形成，从而提高热探测能力。我们研究了呼吸冷却对提高南美响尾蛇捕食、捕获和消耗吸热猎物的行为的潜在影响，这些行为是热探测的指标。在攻击时，具有更高程度的吻部冷却的蛇更加准确，攻击猎物更温暖的区域，并更快地重新定位和消耗猎物。这些发现表明，响尾蛇通过冷却颊窝器官来提高探测吸热猎物的能力；而使颊窝器官失能则会导致这些差异消失。响尾蛇还通过改变呼吸模式来调节吻部冷却的程度，以响应生物相关的刺激，如老鼠的气味。我们的发现表明，低湿度会提高响尾蛇探测吸热猎物的能力，这表明在野外，栖息地和伏击地点的选择可能会受到外部湿度水平以及温度的影响。
