A quantitative global review of species population monitoring

Species monitoring, defined here as the repeated, systematic collection of data to detect long-term changes in the populations of wild species, is a vital component of conservation practice and policy. We created a database of nearly 1,200 schemes to review spatial, temporal, taxonomic and methodological patterns in global species monitoring. We estimate the total global number of monitoring schemes operating at 3,300-15,000. Since 2000 there has been a sharp increase in the number of new schemes being initiated in lower- and middle-income countries and in megadiverse countries, but a fall in high-income countries. Our review found a strong positive correlation between the total number of monitoring schemes in a country and its per capita GDP. Schemes that were active in 2018 had been running for an average of 21 years in high-income countries, compared with 13 years in middle-income countries and 10 years in low-income countries. In high-income countries, over half of monitoring schemes receive government funding, but this falls to less than a quarter in low-income countries. Data collection is undertaken partly or wholly by volunteers in 37% of schemes, and such schemes cover significantly more sites and species than those undertaken by professionals alone. Birds were by far the most widely monitored taxonomic group, accounting for around half of all schemes, but this bias has declined over time. Monitoring in most taxonomic groups remains very sparse and uncoordinated, and most of the data generated are elusive and unlikely to feed into wider biodiversity conservation processes. We propose ways in which these shortcomings could be addressed, especially by creating an open global meta-database of biodiversity monitoring schemes and enhancing capacity for species monitoring in countries with high biodiversity. Article impact statement: Species population monitoring for conservation purposes remains strongly biased toward a few vertebrate taxa in wealthier countries. This article is protected by copyright. All rights reserved.