Most species of lizard are either diurnal or nocturnal, and it is extremely rare to find species that operate both diurnally and nocturnally, or that may shift from diurnality to partial nocturnality when conditions allow. However, niche expansion from diurnal to nocturnal habits (often referred to as the night-light niche) has rarely been reported in lizards (mainly in Anoles), and mostly through anecdotal reports. In West Africa, the rainbow lizard Agama agama is a conspicuous species across the region but also lives in suburban areas of towns and villages. It is a diurnal sun-basker operating at relatively high body temperatures of 36 °C and higher. In this paper, we describe a night-light niche expansion, i.e. nocturnal foraging and thermoregulation, in a small number of A. agama populations living in suburban areas. These lizards utilised radiant heat from incandescent light bulbs situated on the walls of buildings to mostly achieve target body temperatures and forage for and fed on five different groups of invertebrates. Foraging lizards had significantly higher body temperatures than inactive lizards. However, variance in body temperature was significantly greater in foraging lizards than in inactive lizards probably due to the necessity to shuttle between the incandescent night lights and cooler foraging areas during activity, a known cost of thermoregulation. Regression analysis of body temperatures against time of night in foraging lizards supported the notion that the lizards were maintaining body temperatures by actively thermoregulating whilst in inactive non-basking resting lizards during the same time period body temperatures declined. Although our results indicate a potential thermoregulatory benefit from using the night-light shift, we cannot be certain that this benefit is the direct cause of the shift, rather than an additional advantage when foraging.

大多数蜥蜴种类要么是昼行性的，要么是夜行性的，而且在昼夜和夜行性活动，或者在条件允许的情况下可能会从昼行性转变为部分夜间活动性的物种极为罕见。然而，在蜥蜴（主要在 Anoles）中很少报道从白天到夜间习性的生态位扩张（通常称为夜光生态位），主要是通过轶事报告。在西非，彩虹蜥蜴Agama agama是该地区引人注目的物种，但也生活在城镇和村庄的郊区。它是一个昼夜晒太阳的人，在 36°C 或更高的相对较高的体温下工作。在本文中，我们描述了少数A. agama 的夜间觅食和体温调节居住在郊区的人口。这些蜥蜴利用建筑物墙壁上的白炽灯泡的辐射热来达到目标​​体温，并为五种不同的无脊椎动物群体觅食和觅食。觅食蜥蜴的体温明显高于不活动的蜥蜴。然而，觅食蜥蜴的体温变化明显大于不活动的蜥蜴，这可能是因为活动期间必须在白炽灯和较冷的觅食区之间穿梭，这是已知的体温调节成本。觅食蜥蜴的体温与夜间时间的回归分析支持这样一种观点，即蜥蜴通过积极调节体温来维持体温，而在同一时期体温下降的不活动非晒太阳休息蜥蜴。尽管我们的结果表明使用夜间灯光转换具有潜在的体温调节益处，但我们不能确定这种好处是转换的直接原因，而不是觅食时的额外优势。