Species Mapping

Priority species should be mapped in their approximate location clearly using two-letter BTO codes. Note that several species codes are single letter (i.e. Eurasian jay is J.), for clarity these should always be followed by a period (J., not J).

In addition the following information should be recorded:

• The number of individuals within an area or flock should be marked to the immediate right of the symbol in superscript (i.e. BO²)
• Juveniles should be included in counts but, where they are still in nestling plumage and have recently fledged (i.e. spotted robins or tailless, grounded blackbirds) they should be marked with ‘Juv’ (i.e. BO^2juv3)
• Any additional information should be marked with a numbered target note using a clear and suitable symbol (i.e. BO^2juv3 *1), in this case, the note attached to the barn owl target note might read, ‘barn owl pair around box with three branching juveniles’.
• Where a count cannot be made accurately it is acceptable to use a plus (+) after the species symbol and provide an estimate (i.e. HS ¹⁰⁺). Where an estimate cannot be made accurately (because the flock is hidden but vocal) use two plus symbols (i.e. HS⁺⁺).
• Sex can be marked where appropriate; either a clear Mars symbol () for male, or, a Venus symbol () for female (i.e. SH).
• Clear pairs (based on behaviour such as active mating or begging) should be marked as the Mars and Venus symbols together (i.e. BF).

Where birds are strongly associated with a particular habitat or feature, a crosshatched/ highlighted area can be drawn and marked with a numbered target note.

On the example below the target note might read, ‘Hedgerow along verge with large number of vocal house sparrow where it faces houses.’