Speakman J R, Racey P A
Department of Zoology, University of Aberdeen, UK.
Nature. 1991 Apr 4;350(6317):421-3. doi: 10.1038/350421a0.
Echolocation has evolved in relatively few animal species. One constraint may be the high cost of producing pulses, the echoes of which can be detected over useful distances. The energy cost of echolocation in a small (6 g) insectivorous bat, when hanging at rest, was recently measured at 0.067 Joules per pulse, implying a mean cost for echolocation in flight of 9.5 x basal metabolic rate (range 7 to 12x). Because flight is very costly, whether the costs of echolocation and flying are additive is an important question. We measured the energy costs of flight in two species of small echolocating Microchiroptera using a novel combination of respirometry and doubly-labelled water. Flight energy expenditure (adjusted for body mass) was not significantly different between echolocating bats and non-echolocating bats and birds. The low cost of echolocation for flying vertebrates may have been a significant factor favouring its evolution in these groups.
回声定位仅在相对较少的动物物种中进化而来。一个限制因素可能是产生脉冲的成本高昂，而这些脉冲的回声能够在有效距离内被探测到。最近对一只小型（6克）食虫蝙蝠静止悬挂时回声定位的能量消耗进行了测量，结果为每个脉冲0.067焦耳，这意味着飞行时回声定位的平均成本为基础代谢率的9.5倍（范围为7至12倍）。由于飞行成本非常高，回声定位和飞行的成本是否具有累加性是一个重要问题。我们使用呼吸测定法和双标记水的新颖组合，测量了两种小型回声定位小蝙蝠飞行时的能量消耗。回声定位蝙蝠与非回声定位蝙蝠及鸟类之间，飞行能量消耗（根据体重调整后）并无显著差异。飞行脊椎动物回声定位的低成本可能是有利于其在这些群体中进化的一个重要因素。
