News and social media in mapping the endangered Mediterranean monk seal: exceptional data gains but persistent bias

News and social media are increasingly recognised as valuable sources of species observation data, particularly for rare and endangered species. However, these data sources are prone to biases arising from uneven observation efforts, which poses challenges for their effective use. Despite this issue, the drivers and extent of such biases remain understudied. Here, we investigate the contribution of social media and news media towards improving the availability of observation data for a rare and endangered species, the Mediterranean monk seal Monachus monachus , in Madeira and Porto Santo. We also assess the relationship between the observational data and socio-human factors likely to determine spatial and temporal variation in observation effort. Media sources provided a considerably higher number (27-fold) of observation records (n = 302) compared to reference biodiversity observation data repositories such as GBIF, iNaturalist, and Observation.org combined (n = 11). The number of observations exhibited seasonal variation, with annual peaks in the summer months. A generalised linear model assessing the spatial distribution of observational data also revealed a strong positive association with areas of high human concentration. Significant predictors of species observation included human population density, hotel density, and proximity to coastal recreational hotspots such as diving sites and bathing areas or non-open beaches. Our results underscore the potential of news and social media for documenting species distributions, but they also emphasise the importance of accounting for observational biases. This ensures reliable and effective use of news and social media data for species conservation and management.