Interview‐based sighting histories can inform regional conservation prioritization for highly threatened cryptic species

SummaryThe use of robust ecological data to make evidence‐based management decisions is frequently prevented by limited data quantity or quality, and local ecological knowledge (LEK) is increasingly seen as an important source of information for conservation. However, there has been little assessment ofLEK's usefulness for informing prioritization and management of landscapes for threatened species, or assessing comparative species status across landscapes.A large‐scale interview survey in theAnnamiteMountains (Vietnam andLao PDR) compiled the first systematicLEKdata set for saolaPseudoryx nghetinhensis, one of the world's rarest mammals, and eight other ungulates. Saola conservation is hindered by uncertainty over continued presence across much of its proposed distribution. We analysed comparativeLEK‐based last‐sighting data across three landscapes to determine whether regional sighting histories support previous suggestions of landscape importance for saola conservation (Hue‐QuangNam: top‐priorityVietnamese landscape;PuMat: lower priorityVietnamese landscape;Viengthong: high‐priorityLao landscape) and whether they constitute an effective spatial prioritization tool for cryptic species management.Wild pig and red muntjac may be the onlyAnnamite ungulates with stable populations; the regional status of all other species appears to be worse. Saola have declined more severely and/or are significantly rarer than most other ungulates and have been seen by relatively few respondents. Saola were also frequently considered locally rarest or declining, and never as species that had not declined.In contrast to other species, there are no regional differences in saola sighting histories, with continued persistence in all landscapes challenging suggestions that regional status differs greatly. Remnant populations persist inVietnam despite heavy hunting, but even remote landscapes in Lao may be under intense pressure.Synthesis and applications. Our local ecological knowledge data suggest that intact saola populations probably no longer exist, but individuals persist in all three landscapes, making management activities to reduce hunting pressure on ungulates in each landscape a conservation priority. Analysis of last‐sighting histories can constitute an important conservation tool when robust data are otherwise unavailable, and collection of last‐sighting records should be incorporated more widely into field studies and management of other highly threatened, cryptic species.