Abstract Context. The broad-toothed rat (Mastacomys fuscus; BTR) is distributed throughout south-eastern Australia, but its populations are restricted and dispersed. BTRs prefer cooler, wetter habitats and, as such, future climate change is projected to lead to further range reductions. However, recent changes in its distribution have not been well documented, and there is limited knowledge about the current occupancy and population size of the species in Victoria. Aims. To evaluate recent historical changes in the distribution of BTRs in Victoria, and to test whether changes in distribution are correlated with climate and elevation. Methods. We obtained all documented records of BTRs in the state before 1990 and used field notes and verbal descriptions to geo-reference their historical localities. We then used a repeated sampling design to resurvey all historically occupied sites with a geographic coordinate uncertainty of 4 km or less. We tested for the effects of climate and elevation on the persistence of BTRs. Key results. We detected BTRs at 32 of 68 historical sites surveyed. Consistent with climate model predictions, site persistence was more likely to occur at sites of higher elevation and precipitation and less likely to occur at sites with a higher temperature. Minimum temperature of the coldest month was the single best predictor of persistence. Conclusions. These results demonstrated a substantial decline in the persistence of BTRs at historical sites across Victoria and provided a benchmark for future monitoring and management efforts. Implications. The decline of BTRs from historically occupied sites across Victoria is consistent with their listing as endangered in the state, and climate correlations suggest further declines, with projected climate change compounding other threats to the species such as introduced predators, feral herbivores, fire and land use. However, the status of BTRs in Victoria and understanding of the threats to their persistence are based on sparse data, highlighting the critical need for more effective monitoring of the species.

中文翻译：

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维多利亚州宽齿鼠（Mastacomys fuscus）的持久性与气候和海拔有关

摘要上下文。宽齿鼠（Mastacomys fuscus；BTR）分布于澳大利亚东南部，但其种群数量有限且分散。BTR 更喜欢凉爽、潮湿的栖息地，因此，预计未来的气候变化将导致范围进一步缩小。然而，其分布的近期变化尚未得到很好的记录，并且对该物种在维多利亚州的当前占有率和种群规模的了解有限。目标。评估维多利亚州 BTR 分布的近期历史变化，并测试分布变化是否与气候和海拔相关。方法。我们获得了 1990 年之前该州所有 BTR 的书面记录，并使用现场笔记和口头描述来对其历史地点进行地理参考。然后，我们使用重复抽样设计对地理坐标不确定度为 4 公里或更短的所有历史上占用的地点进行重新调查。我们测试了气候和海拔对 BTR 持久性的影响。关键结果。我们在调查的 68 个历史遗址中的 32 个中检测到 BTR。与气候模型预测一致，地点持久性更可能发生在海拔和降水量较高的地点，而不太可能发生在温度较高的地点。最冷月份的最低温度是持续性的唯一最佳预测指标。结论。这些结果表明维多利亚州历史遗迹中 BTR 的持久性大幅下降，并为未来的监测和管理工作提供了基准。影响。维多利亚州历史上被占用的地点的 BTR 下降与其在该州列为濒危物种的情况一致，气候相关性表明进一步下降，预计气候变化加剧了对该物种的其他威胁，例如引入的捕食者、野生食草动物、火灾和土地利用. 然而，维多利亚州 BTR 的状况以及对其持久性威胁的理解是基于稀疏数据，突出了对物种进行更有效监测的迫切需要。