Data include counts conducted during northward migration of two species of shorebirds (Western Sandpiper Calidris mauri and Dunlin Calidris alpina) on the mudflats of Roberts Bank, British Columbia, 1991 to 2019. Count methodology detailed in Drever et al. (2014) and Canham et al. (2021). Data also include a set of covariates related to local conditions (precipitation, temperature, wind speed and direction, solar radiation, tidal amplitude, and water discharge rates from the Fraser River).

Methods described in Drever et al. (2014). Drever, M. C., Lemon, M. J., Butler, R. W., & Millikin, R. L. (2014). Monitoring populations of western sandpipers and Pacific dunlins during northward migration on the Fraser River Delta, British Columbia, 1991–2013. Journal of Field Ornithology, 85(1), 10-22.