What state of tide?
This mainly applies to Atlas surveys in winter. There are no absolute restrictions, but at coastal sites counting at mid to high tide will increase the chances of birds on the sea being closer to shore, thus easier to identify and count. Obviously, the species and numbers present in a given tetrad may reflect the state of tide – e.g. feeding waders may be absent at high tide. But, on average, across sites and observers, counts will have been made in a range of tidal conditions, thus tidal influences will tend to average out – or, when interpreting maps of the final results, the influence of tide can be borne in mind.
