This national survey is ongoing.
In the autumn of 2018, there was a national Tawny Owl Point Survey TOPS organised by the BTO. Various 10km squares were selected and tetrads (squares of 2km x 2km) identified within them so that results could be compared with unpublished data from Tawny Owl surveys in 1989 and 2005. Nationally it is estimated that about 54% of the tetrads were occupied compared with 63% previously. Within Hertfordshire 47 tetrads were allocated. Projects like this require external funding. For TOPS the funding was only sufficient for the autumn survey so there will be no follow up in the spring or repeat in the autumn of 2019.
The second element of the surveying is the Tawny Owl Calling Survey TOCS. This involves listening regularly from a fixed point (e.g. outside the front door!). This has recruited a large number of people new to bird surveying. In Hertfordshire, 174 individual people signed up covering 183 sites. Online data has been submitted for 123 sites of which Tawny Owls have been heard at least once in 94 of them.
Both surveys are now complete.