My first visit to the Desembocadura (= rivermouth) de Rio San Pedro this September did not disappoint as I managed to see my first lifer in Spain for a decade or more - Elegant Tern. The second wasn't too bad either as I had Lesser Crested Tern. With such a track record it's no surprise to discover that this site (along with Montijo beach, nr Chipiona) has a growing reputation as THE site to see rare terns in Cadiz in autumn. Playa de los Lances (Tarifa) once almost had a monopoly of 'orange-billed' terns in the area but I suspect that in large measure this reflected where the birders were as much as where the terns were. This site seems to be best for roosting terns and gulls about an hour or so before high tide when birds are pushed up along the river as the vast expanse of the mud & sand on the seaward side of the Los Toruños peninsula disappears. A 'scope is invaluable here since the birds are generally c100-150m away on the far side of the Rio San Pedro (although I got lucky with the Elegant Tern as it lingered for a while on the nearside of the river). If you get your timing right expect to see hundreds of gulls (inc. Mediterranean, Slender-billed & Audouin's) and a good mix of terns (Caspian, Sandwich, Common & Black). Orange-billed terns are generally to be found amongst Sandwich Terns and, unless they're sleeping or hidden by other birds, shouldn't be too hard to pick out with a 'scope. However, distinguishing Lesser Crested and Elegant (see Orange-billed terns photo ID guide - BirdGuides) is another matter so I was happy to be with birders who'd seen the species before! The site also has a good range of waders although these too tend to be distant and other sites in the area are better. Small passerines shouldn't be ignored as the pines along the esplanade can hold a good numbers of flycatchers, redstarts, etc in the autumn. eBird account lists 106 species for this site (see https://ebird.org/hotspot/L11907457 ).
I also had Elegant Tern at Montijo beach but, unlike Rio San Pedro, this site is better when the tide is lower and should be avoided on summer weekends when the beach can be busy.
About me ...
Hi I'm John Cantelo. I've been birding seriously since the 1960s when I met up with some like minded folks (all of us are still birding!) at Taunton's School in Southampton. I have lived in Kent , where I taught History and Sociology, since the late 1970s. In that time I've served on the committees of both my local RSPB group and the county ornithological society (KOS). I have also worked as a part-time field teacher for the RSPB at Dungeness. Having retired I now spend as much time as possible in Alcala de los Gazules in SW Spain. When I'm not birding I edit books for the Crossbill Guides series.