Little rain had fallen since our last visit to the lagoons at Fuente de Piedra in March and by early May evaporation of some of the huge amount of water that had fallen during the previous November’s storms had led to a fall in water levels. This left some of the lagoons shallow with damp muddy margins. These are perfect conditions for shorebirds to drop in to refuel on their long migrations from Africa to their northern, often arctic, breeding grounds. The passage of these birds through essential stop-over sites like Fuente de Piedra lasts several weeks in spring but each group of birds remains for only a few days before moving on to higher latitudes. As a result, there is a frequent turnover of birds that use the site, producing excitement for birders who are able to visit frequently and witness the constantly changing array of species.
During my visits in the first week of May 2019, Dunlins, Curlew Sandpipers and Little Stints were well-represented and during this week the number of Ringed Plovers built up. The evening departure of Ringed Plovers is particularly striking. As dusk approaches they become more and more active and vocal, taking off as a group and flying round the lagoon until eventually the entire flock ascends and heads northward with what appear to be excited calls.
The spring migration is accompanied by changes in some of the waders’ appearances as they moult their body feathers to acquire the breeding plumage that they will display when they arrive at their nesting areas. Little Stints develop chequered backs and rusty heads, Dunlins develop chequered backs and also black bellies, the heads and bodies of Curlew Sandpipers and Black-tailed Godwits become rich rusty-red, the bodies of Spotted Redshanks become largely black, and male Ruffs develop extravagantly gaudy long neck and head feathers, each bird with its unique colour and pattern.
The numbers of each species varies between years and over the course of the spring migration and there is always a chance that a lucky birdwatcher might see something unusual, such as a Temminck’s Stint or Marsh Sandpiper, both of which have occurred as rarities at Fuente de Piedra (but not when I have been there!).
While the shallow lagoons dried noticeably during the week, El Laguneto, the deeper lagoon behind the visitor centre, still has a high level of water. Importantly, this has encouraged vegetation growth on the small islands in the middle of the lagoon. These islands were constructed to provide nesting sites for ground-nesting birds that require locations that are free of mammalian predators, notably Avocets, Black-winged Stilts and Black-headed Gulls (see blog post of 17 May 2018). In spring 2019, however, the high water levels had led to lush vegetation growth on the small islands and around the lagoon margins, leaving no suitable space for these ground nesting birds to breed.
This demonstrates how a severe weather event in November can have long-lasting effects that can influence water birds in different ways the following spring. In conservation you can’t please all the players all of the time! But conservation actions, such as those practised at Fuente de Piedra, have long-term benefits that maximise the potential of the habitats within the Natural Park to support a large diversity of wildlife, especially birds. Furthermore, this wetland oasis, in the midst of vast areas of intensively farmed land (mainly olives and cereals), influences wildlife from the southern tip of Africa to the high arctic – a wetland truly of international importance.