Ridley Jenna C H, Schlesinger Christine A
Research Institute for the Environment and Livelihoods Charles Darwin University Alice Springs Northern Territory Australia.
Present address: Fenner School of Environment and Society Australian National University Canberra Australia.
Ecol Evol. 2023 Aug 1;13(8):e10391. doi: 10.1002/ece3.10391. eCollection 2023 Aug.
Increased predation where ground cover is reduced after severe wildfire is increasingly implicated as a factor causing decline of vulnerable prey populations. In arid central Australia, one species detrimentally affected by repeated wildfire is the great desert skink or (), a distinctive lizard of the central Australian arid zone that constructs and inhabits multi-entranced communal burrows. We aimed to test whether or predator activity at burrow entrances varied with cover and how respond to predator presence. Using time-lapse photography, we monitored and predator activity at the largest entrance of 12 burrows ranging from high (>70%) to low (<50%) cover and at multiple entrances of two other burrows. Overall activity did not vary between burrows with high and low cover. Within burrow systems were more active at sparsely vegetated entrances, often sitting wholly or partly inside the burrow. However, consistent between and within burrow systems, skinks spent proportionally more time fully outside where cover was higher. Predators-mostly native-were detected at most burrows, with no apparent relationship between predator activity and cover. Skinks also did not appear to modify their activity in response to predator visits. Our results indicate that may spend more time outside burrow entrances when cover is higher but there was no direct evidence that this related to perceived or real predation risk. Differences in food availability, thermoregulatory opportunities and opportunities for ambush foraging associated with differences in vegetation cover or composition are other factors likely to be important in determining the activity of at burrows. Our research demonstrates the usefulness of camera traps for behavioural studies of ectothermic burrowing animals. The complex relationships between activity and vegetation cover thereby revealed, suggest outcomes of fire-mediated habitat change on predator-prey interactions are not easily predictable.
在严重野火之后,地面覆盖物减少的地方捕食增加,这越来越被认为是导致脆弱猎物种群数量下降的一个因素。在澳大利亚中部干旱地区,一种受到反复野火不利影响的物种是巨漠石龙子( ),它是澳大利亚中部干旱地区一种独特的蜥蜴,会建造并居住在有多个入口的公共洞穴中。我们旨在测试巨漠石龙子在洞穴入口处的活动或捕食者活动是否随覆盖物而变化,以及巨漠石龙子如何应对捕食者的存在。我们使用延时摄影,监测了12个洞穴最大入口处的巨漠石龙子和捕食者活动,这些洞穴的覆盖物从高(>70%)到低(<50%)不等,还监测了另外两个洞穴多个入口处的情况。高覆盖和低覆盖洞穴之间的总体活动没有差异。在洞穴系统中,巨漠石龙子在植被稀疏的入口处更活跃,常常整个或部分身体坐在洞穴内。然而,在不同洞穴系统之间以及同一洞穴系统内部,石龙子在覆盖物较高的地方完全在洞外度过的时间比例更大。在大多数洞穴都检测到了捕食者——大多数是本地捕食者,捕食者活动与覆盖物之间没有明显关系。巨漠石龙子似乎也不会因捕食者的到访而改变其活动。我们的结果表明,当覆盖物较高时,巨漠石龙子可能会在洞穴入口外花费更多时间,但没有直接证据表明这与感知到的或实际的捕食风险有关。与植被覆盖或组成差异相关的食物可获得性、体温调节机会和伏击觅食机会的差异,是可能对决定巨漠石龙子在洞穴处的活动很重要的其他因素。我们的研究证明了相机陷阱在外温性穴居动物行为研究中的有用性。由此揭示的巨漠石龙子活动与植被覆盖之间的复杂关系表明,火灾介导的栖息地变化对捕食者 - 猎物相互作用的影响并非轻易可预测的。