Last recorded

House martins are migratory birds. Record the date on which you last see a house martin before it migrates in late August to October.

As the departure time gets closer keep a note of the dates when you do see the birds. Do this until you no longer see them and then you have your ‘last recorded’ date.

Available historic data: we have some very good data from 1906-1913 and from 1922-1999