Geoff Dobbs has compiled data on the first and last dates on which some common migrant birds have been recorded in Yorkshire from the 1970s until 2019. This is a work in progress.

• click here to download a list of the average first and last dates in that period. 
• click here to download a master file containing all the early and late dates for each year in that period.
• click here to download a list of the earliest and latest dates ever recorded in the county.