An inventory of biodiversity data sources for conservation monitoring

complete understanding of biodiversity trends is likely to come only from having human observers on the ground in key sites [30, 44, 50]. Recently developed monitoring protocols that include oft-neglected taxa like plants and invertebrates (e.g. [51, 52]), for example, tend to rely on methods that require a human presence in the field. Data that are collected need to be shared as widely as possible by uploading them into national, regional and global databases [50]. Databases that are not updated regularly with new data will soon become less useful [53]. Data quality and reliability is also key [54]. To be useful for monitoring, data need to be freely available, of a suitable spatial resolution, up to date, repeated and assessed for accuracy, yet only 5% of data sets on biodiversity threats meet these criteria [24] and other data sources are not likely to be better. Share data and build capacity where it is needed most. There have been numerous calls for greater efforts to build capacity for data collection and use where it is most needed in high- biodiversity countries [9, 30, 55, 56]. Capacity for data use will be much enhanced by making existing data available to conservationists, such as protected areas managers, and other end- users such as businesses. This will entail letting them know what is available, where to find it and how to access it. To lead the way we will share our full database of data sources—a combi- nation of the tables presented in this paper along with S1–S5 Tables. From December 2020, the

database will be hosted by the IUCN SSC Species Monitoring Specialist Group on its data and databases webpage (https://www.speciesmonitoring.org/data_ sources.html), with a link to the page from the Global Wildlife Conservation website. Over time, details of each data source will be elaborated and its uses explored and explained in more detail. The database will be updated regularly and made freely available as a resource for conservationists, scientists and other data users and decision makers. We will also use our networks to disseminate the database widely in high-biodiversity countries. Database managers need to help too. A recent review of Euro- pean data sets found only around a third of data-providers provides unrestricted data access [57]. Even if data are technically free to download, there are often various hoops to jump through (e.g. individuals or committees that need to approve access) or the data are not in a format known or usable to the recipient. Some data sources charge for certain uses, such as corporate access. A study to determine which funding models work best for maintaining data- bases and making them as openly accessible as possible would be apposite. Impediments to biodiversity data sharing include lack of professional recognition of scien- tific data publishing efforts [58], compounded by a lack of infrastructure for easy data sharing [59]. Therefore, it is necessary “to motivate and reward the contribution of data to interna- tional integrated databases by bringing such data into the mainstream of respected scientific

publication” [60]. This will involve the development of “mechanisms for data citation and indices of data access comparable to those for citation systems in print journals” [61]. The IUCN Red List of Threatened Species [19] sets a good example, where each assessment is saved and allocated a DOI (digital objective identifier) to make the data for a given species a citable publication. Several other databases, such as the Living Planet Index, also encourage data contributions through their website. Other options include working towards the main- streaming of data papers by making the publishing of data mandatory in research project pro- posals and performance assessments [62], and adopting standards related to data citation, accessibility, metadata, and quality control in order to facilitate integration of data across data sets [60, 63, 64]. Data will also be made more accessible if data sets are fused or integrated (see, e.g., [65]) and more effort is made to integrate non-Western data sources into biodiversity databases [66]. We conclude by repeating the call of Stephenson et al. [30] for all actors “to collaborate in harmonising databases and platforms and in enhancing interoperability and version control PLOS ONE Biodiversity data sources PLOS ONE | https://doi.org/10.1371/journal.pone.0242923 December 2, 2020 8 / 14