Bird Watching or Twitching in Andalucia Southern Spain

Stork And Raptor Migration Across The Strait Of Gibraltar

Top left: Swallows Top right: Honey Buzzard Middle: Storks

The phenomena of bird migration is a subject that has aroused human interest for hundreds of years and it is here, along the Strait of Gibraltar, where the African and European continents almost meet and where two seas, the Mediterranean and the Atlantic Ocean, merge together, that this bi-annual spectacle of bird activity can best be observed.

Birds migrate for two reasons: to reach their breeding grounds in Europe and to return to their wintering sites in the warmer climates of Africa and beyond. The Strait of Gibraltar offers the shortest sea crossing between these two continents (about 15 kms at the narrowest point) and the legendary twin Pillars of Hercules, Mount Abyla in Morocco and the Rock of Gibraltar, are obvious landmarks for migrating birds.

The spring migration (northward) of storks, vultures, eagles, kites and other birds of prey, along with many smaller bird species takes place between January and May, with the optimum time for viewing being from late February until the end of April and can be the most spectacular for birdwatchers. Surprisingly, due to wing area to body weight ratio, many of the larger birds are not strong flyers, yet they undertake journeys of several thousand kilometres. They achieve this by employing a means of flight known as soaring and gliding. This method involves finding updrafts of hot air over the land (thermals) and using these to soar upward in spirals until they reach great heights. They will then level off and attempt to glide for as far as possible before finding another thermal. As there are no thermals over the sea, the birds gradually lose altitude during the crossing from Africa and very often, especially in unfavourable wind conditions, reach the Spanish coast at very low levels, sometimes having to flap their wings frantically to avoid landing in the water and also to rise over the coastal cliffs. This event can often produce wonderful close-up views for the assembled birdwatchers. Once back over land, the birds will again search for thermals and circle upwards, sometimes in flocks several hundred strong, until they again level off and glide away on their journeys. Some of these birds will remain in Spain to breed, but many others will travel on to Portugal, France and as far north as Scandinavia.

If these larger birds arrive late in the evening they will not normally continue their journeys until the following day, when the temperature rises and thermals form. Instead, they will find roosting sites and rest overnight before continuing. When this occurs you may be lucky enough to see hundreds of birds settling down in woods and forests, just inland. Obviously, birds that rely on soaring and gliding flight are somewhat affected by the strength and direction of the prevailing wind and any planned visit to watch the spring migration should take these factors into consideration. On calm days most of the larger birds will cross the Spanish coast near to the town of Tarifa (the shortest sea crossing) and any site in the Montes de Tarifa or along Los Lances beach can prove advantageous. If there are westerly winds (toward Malaga) the birds will drift to the east and you should plan to visit suitable sites such as the Rio Palmones estuary, the hills above Los Barrios, Punta Carnero, Punta Secreta or Gibraltar. In easterly winds (toward Cadiz) your viewing chances will be enhanced by travelling further west of Tarifa to the Valle de Santuario, Bolonia or even further.

Notable exceptions to this rule are the Honey Buzzards. Although they too employ soaring and gliding flight they are also very strong flyers and may cross the coast at any point regardless of wind direction. Up to 125,000 Honey Buzzards cross the strait in spring, usually in a short period between late April and mid-May.

The smaller migratory birds: finches, warblers, swallows, swifts, martins, etc. are much stronger flyers and do not rely on soaring and gliding flight. These tend to cross the coast at far greater heights and are often much harder to see. Also, many of the smaller species make their sea crossings at night so it is hard to calculate correctly how many birds actually cross the strait, although it is estimated by experts that the number is in the millions. Article by John Butler

John is one of the foremost authorities on bird watching in Andalucia. He lives in the Doñana and organises bird watching expeditions in that area. In July John will be telling us about the Autumn Migration. To contact John either ring him on 955 755 460 or go to his web site www.donanabirdtours.com. His latest book is due out in April 2007.