The changing status of imperiled species in British Columbia over the last 15 years in the absence of a dedicated species at risk law

Gaps in biodiversity protection occur in Canada due to limited jurisdiction of federal species-at-risk laws and the absence of dedicated legislation in many provinces, including British Columbia (B.C.). While lacking legal protection, B.C. maintains Red, Blue, and Yellow Lists of threatened, special-concern, and secure species, respectively, using a NatureServe ranking system. We compiled historical data on species status in B.C. between 2008 and 2024 from the B.C. Conservation Data Centre. B.C. is home to 5,485 Yellow, 1,116 Blue, 491 Red-listed species. Changes in status over this time period were reported for 967 animal species, with an even split in uplistings (more imperiled) and downlistings (less imperiled). More status changes were reported for plants (2,902), mainly due to updated methodology leading to a lower risk status. Analysing the accompanying explanation for each status change revealed that most changes were non-genuine (e.g., new information, taxonomy, or methodology) rather than genuine (e.g., true changes in population size, range, or threats). Genuine improvements in the status of species in B.C. have been exceedingly rare. This analysis indicates that current laws and regulations have been insufficient to recover species at risk within B.C. Plain-language summaryBritish Columbia is the most biodiverse province in Canada, yet 1,607 species are imperiled in the province. We analysed trends, finding a 16% rise in the number of species at risk since 2008. By analysing the provided explanations, we found that status improvements were mostly "non-genuine", caused by changing methodology and/or new data. Strengthening legal protections is essential to prevent biodiversity loss in the province.