Originally fieldwork at the Capri Bird Observatory concentrated on the spring migrations, and the Italian PPI-related fieldwork here still is done during the tropical birds’ main passage between April 15 and May 15.

South of Villa San Michele rises Monte Barbarossa, on whose summit, about 100 metres above the Villa and 400 metres above the waters of the Bay of Naples, stands the ruined fortress “Castello Barbarossa”. This mountain and its surroundings are an important resting place for migratory birds on their journeys every spring and autumn between their breeding grounds in Europe and their winter quarters in Africa. Previously the inhabitants of Anacapri hunted these migratory birds in great numbers here as food, and it was mainly to protect the birds from this that Axel Munthe bought the mountain in 1904. The fortress, which today houses the bird observatory, originated in the Byzantine Age but is named after the 16th century Moorish admiral and pirate Khair-ed-Din or “Barbarossa” (“Red Beard”).

Ottenby Bird Observatory

Since the early 1980s Italian ornithologists also work up here. Ornithologists at work: weighing, measuring, ringing and registering the trapped migratory birds – before they are soon set free again. Currently the Swedish ornithological activities on Capri are run by the Ottenby Bird Observatory on the Swedish Baltic island of Öland. Ottenby also studies the migratory birds in their winter quarters down in tropical Africa, currently in Nigeria.

Capri is thus a station halfway between the breeding grounds around the Baltic Sea and the winter quarters south of the Sahara – but it is also centrally located in the Mediterranean winter quarters for the bird species that do not fly any farther south.

The Italian activities on Capri were started by the bird conservation organisation LIPU but are now run by the bird ringing centre at the Italian National Institute for Environmental Protection and Research (ISPRA) in Bologna as part of their Small Islands Project (Progetto Piccole Isole or PPI).

Originally fieldwork at the Capri Bird Observatory concentrated on the spring migrations, and the Italian PPI-related fieldwork here still is done during the tropical birds’ main passage between April 15 and May 15.

From 1994 to 2004, however, the Swedish activities concentrated on the autumn migratory period and for a few years (2002–2004) the birds that overwintered were also studied. Today, however, the Swedish activities down here are mainly special projects. These can be about how birds orientate themselves (navigate) during their long migratory journeys, taking samples to map the occurrence of bird-borne diseases, or, in recent years, also butterfly migrations.

The migratory birds are trapped in nets; their species, sex and age are determined, and they are weighed and measured (for example wing length). Their “fat load”, which together with their weight reveals how much “fuel” they have for the rest of their journey, is determined according to a visual measurement scale. A male oriole born last year. The oriole is one of the most spectacularly colourful migratory birds on Capri.

Swedish Ornithological Society

Since the Napoleonic Wars the fortress has not played any military role. Organised ornithological studies on Capri started in 1956, when the Swedish Ornithological Society began fieldwork at the Capri Bird Observatory at Castello Barbarossa. On the summit of the mountain, the fortress is strategically well located for studies of resting and passing birds.