Khatiwada Sunil, Burmeister Sabrina S
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, 27599, USA.
Anim Cogn. 2022 Feb;25(1):27-32. doi: 10.1007/s10071-021-01528-x. Epub 2021 Jul 28.
The use of quantitative information underlies a range of animal behaviors. There are thought to be two parallel systems for judging quantity: a precise representation of small numbers of objects, typically less than 4, that can be tracked visually (object tracking system) and an imprecise system for larger quantities (approximate number system) governed by Weber's law. Using a spontaneous discrimination task with live prey, we examined the ability of the poison frog Dendrobates auratus to discriminate quantities of low (1-4) or high (4-16) numerosity over a range of ratio contrasts (0.33, 0.5, 0.67, 0.75). Similar to a previous study in treefrogs, we found that the poison frogs chose the larger quantity of flies when choosing between 1 and 3 and between 1 and 2. However, their performance was near chance when choosing between 2 and 3 and below chance when choosing between 3 and 4. When the numerosity of flies was higher, they did not discriminate between the larger and smaller quantity. Our findings are consistent with the ability of poison frogs to discriminate small quantities of objects using an object tracking system, but could also reflect a singular vs. plural discrimination. We did not find evidence of an approximate number system governed by Weber's law, nor evidence of a speed-accuracy tradeoff. However, total set size was associated with lower accuracy and longer latencies to choose. Future studies should explore quantity discrimination in additional contexts to better understand the limits of these abilities in poison frogs.
定量信息的运用是一系列动物行为的基础。人们认为存在两种判断数量的并行系统：一种是对少量物体（通常少于4个）的精确表征，这些物体可以通过视觉追踪（物体追踪系统）；另一种是对大量物体的不精确系统（近似数字系统），受韦伯定律支配。我们利用对活猎物的自发辨别任务，研究了箭毒蛙金色丛蛙在一系列比例对比（0.33、0.5、0.67、0.75）下区分低数量（1 - 4）或高数量（4 - 16）的能力。与之前对树蛙的一项研究类似，我们发现箭毒蛙在1和3之间以及1和2之间进行选择时会选择数量较多的苍蝇。然而，它们在2和3之间进行选择时表现接近随机水平，在3和4之间进行选择时表现低于随机水平。当苍蝇数量较多时，它们无法区分数量多与数量少的情况。我们的研究结果与箭毒蛙利用物体追踪系统区分少量物体的能力一致，但也可能反映了单数与复数的辨别。我们没有发现受韦伯定律支配的近似数字系统的证据，也没有发现速度 - 准确性权衡的证据。然而，总集合大小与较低的准确性和更长的选择潜伏期相关。未来的研究应该在更多背景下探索数量辨别，以更好地理解箭毒蛙这些能力的局限性。
