Our best day so far looking at the birds and exploring the domaine de Certes et Graveyron helped by a very nice guide on site. We saw spoonbills, great egrets, kingfishers, herons, hundreds of coots, grebes, a common snipe, sanderlings, cormorants, siskins, a green woodpecker, a fly catcher, a nuthatch, and possibly an osprey. Will certainly return again with such helpful staff. Finished off with some fruit from a strawberry tree! (arbutus unedo). Anyone tried it? Very nice.
This place really is worth a visit. We were bowled over by how welcoming and helpful the staff were. If you ring them a couple of days in advance they will even arrange a guided tour (lasting up to 2 hours) at a time of your choosing free of charge! More info here: https://www.gironde.fr/environnement/decouverte-des-espaces-naturels-de-gironde/domaine-de-certes-et-graveyron
Well done. You have had a wonderful trip.