As habitats change, highly specialised species may die or be forced to relocate. However, some obligate coral-dwelling damselfishes appear to survive the localized extinction of their primary habitat, branching coral, caused by coral bleaching. To address this apparent paradox, we documented the spatial behaviour of obligate coral-dwellers in relation to habitat quality. Focussing on two obligate coral-dwelling damselfishes (Pomacentrus moluccensis and Chromis viridis), we used KUDs (Kernel Utilisation Distributions) to quantify fishes’ short-term space use (daily 5 min observations across 6 days) and related it to live coral cover and structural complexity derived from 3D photogrammetry. Specifically, we calculated movement extent (95% KUD), core areas (50% KUD) and the temporal consistency of occupied areas across consecutive days. Structural complexity had no effect on space use. The effect of live coral cover was significant but weak and dependent on fish body-size: core areas increased with decreasing live coral cover for large fishes; smaller fishes showed little response. In contrast to weak habitat effects, there were strong differences across sites. At one site, average core areas increased three-fold to 1.1 m² for P. moluccensis and over 60-fold for C. viridis, from 1.14 m² to an average core area of 92.34 m² and a maximum recorded extent of 1471.4 m². These findings may help explain these fishes’ apparent, unexpected resilience to habitat loss. Obligate coral-dwelling fishes may prefer branching live coral, but their ‘obligate’ dependence may be more flexible and context dependent. As ecosystems reconfigure, plasticity in fine-scale spatial behaviour may be critical for the persistence of fish populations.

随着生境的变化，高度专业化的物种可能会死亡或被迫迁移。但是，一些专性的珊瑚栖居的雀鲷似乎可以幸免于因珊瑚白化而造成的主要生境分支珊瑚的局部灭绝。为了解决这一明显的悖论，我们记录了专职珊瑚人相对于栖息地质量的空间行为。着眼于两个专居的珊瑚雀鲷（Pomacentrus moluccensis和Chromis viridis）），我们使用KUD（内核利用率分布）来量化鱼类的短期空间使用（每6天每天观察5分钟），并将其与3D摄影测量法得出的活珊瑚覆盖率和结构复杂性相关联。具体来说，我们计算了连续几天的移动程度（95％KUD），核心区域（50％KUD）和占用区域的时间一致性。结构的复杂性对空间的使用没有影响。活珊瑚覆盖的影响是显着的，但影响微弱，并取决于鱼的体型：随着大鱼的活珊瑚覆盖率的降低，核心区域增加。较小的鱼没有反应。与脆弱的栖息地影响相反，不同地点之间存在很大差异。在一个位点，平均核心区增加3倍至1.1米²为P. moluccensis并比C. viridis高出60倍，从1.14 m ²到平均核心面积92.34 m ²和最大记录范围1471.4 m ²。这些发现可能有助于解释这些鱼类对生境丧失的明显，出乎意料的恢复力。专性珊瑚栖鱼可能更喜欢分生活珊瑚，但它们的“专性”依赖性可能更加灵活且依赖于环境。随着生态系统的重新配置，精细尺度空间行为的可塑性对于鱼类种群的持久性可能至关重要。