School of Biological, Earth and Environmental Sciences, University of New South Wales , Sydney, New South Wales, Australia.
School of Environment, University of Queensland , Brisbane, Queensland, Australia.
Proc Biol Sci. 2024 Oct;291(2032):20241702. doi: 10.1098/rspb.2024.1702. Epub 2024 Oct 2.
Animals that hatch within a subterranean nest, such as turtle hatchlings, expend some of their limited energy reserves digging out through sand or soil to reach the surface. In sea turtles, this emergence process can take the hatchlings 3-7 days. However, we have a poor understanding of this process as it is difficult to observe what is occurring underground. Here, we utilize a novel method to characterize digging-out behaviour: affixing an accelerometer directly to newly hatched green turtles () to record movement until nest emergence. Our data revealed that buried hatchlings maintained a head-up orientation but did not move in the expected left and right swaying motion associated with alternating limb crawling. Rather, they moved using dorsal-ventral heaving and pitching as if swimming vertically through the sand to the surface. Movement activity was irregular and brief, interspersed by many short periods of inactivity, mostly lasting less than 10 min. The first 24 h of head-up activity displayed no diel patterns, but the last 24 h prior to emergence involved more intense movement during night-time hours compared with daytime hours. Thus, our results add valuable new insight, and in some cases change previous assumptions, regarding the digging behaviours during the egg-to-emergence life stage in sea turtles.
在地下巢穴中孵化的动物，如龟鳖类幼体，在挖掘沙土或土壤以到达地面的过程中会消耗其有限的能量储备。在海龟中，这个出壳过程可能需要幼体 3-7 天。然而，由于很难观察到地下发生的情况，我们对这个过程的了解甚少。在这里，我们利用一种新颖的方法来描述挖掘行为：直接在新孵化的绿海龟（）上安装加速度计来记录运动，直到巢穴出壳。我们的数据显示，被掩埋的幼体保持抬头姿势，但没有按照预期的左右摇摆运动移动，这种运动与交替肢体爬行有关。相反，它们通过背腹起伏和俯仰运动来移动，就像在沙子中垂直游泳到水面一样。运动活动是不规则的和短暂的，穿插着许多短暂的不活动期，大多数持续不到 10 分钟。抬头活动的前 24 小时没有昼夜节律模式，但在出壳前的最后 24 小时内，夜间的活动强度比白天高。因此，我们的研究结果为海龟在卵至出壳阶段的挖掘行为提供了有价值的新见解，在某些情况下改变了之前的假设。
