The seabird lifecycle takes place mainly in the sea, where they feed on fish and rest, while using the islands and the coasts to breed.
Seabirds are top predators in the food chain and regulate their prey populations through a top-down process.Having colonised the sky, land, and sea, they can be considered bioindicators of the health of the different habitats to which they are linked and of the ecological relationships that exist between them: the marine ecosystem has a delicate balance that is also maintained thanks to seabirds. They represent a fundamental element of the nutrient cycle which from the seabed, through phytoplankton and zooplankton are assimilated by fish and which return to the sea precisely through the release of nitrogen and phosphorus contained in their guano.
It is therefore important to safeguard them since with the progress of anthropization they are exposed to numerous threats, like climate change, industrial and unsustainable fishing, bycatch, plastic pollution, increasing presence of artificial lights, oil spill and other contaminants and the introduction of predators in their breeding sites.
Linosa is a small Mediterranean island, located about 160km from Tunisia and 160km from Sicily, just halfway between Africa and Europe. In the ‘80s around 10,000 of Scopoli’s shearwater breeding pairs were estimated on the island, so it is considered the largest colony in Europe and the second in the Mediterranean (the first one is Zembra island, Tunisia). Linosa is also a strategic place for the migration of numerous bird species stopping there during their long flights between Africa and Europe in Spring and Autumn. A group of birdwatchers (Malati di Isolitudine allo Stadio Cronico- MISC), habitual visitors of the island, reports around 200 avian species stopping in Linosa in Spring and around 150 in Autumn. Many of these species are included in the Habitats Directive (Directive no. 92/43 / EEC related to the conservation of natural and semi-natural habitats and wild flora and fauna), as well as shearwaters. In the Autumn 2021, as many as 76 bird species have been observed in one day!
Linosa is also home to an endemic lizard (Podarcis filfolensis), the eyed skink (Chalcides ocellatus), and an arthropod included in the Habitat Directive and considered “vulnerable” by the IUCN, the big-headed cricket (Brachytrupes megacephalus). Linosa was colonized only in 1845, and man has also brought with him other mammals, such as mice, rats, cats, and dogs that threaten the survival of the shearwaters and the migratory birds and that of all endemic species present in Linosa. Indeed, birds and reptiles living on islands have evolved in absence of mammals and they lack behaviours and strategies to elude such efficient predators.
Lampione is an uninhabited island and mammals are not present, but the shearwaters are subjected to the predation by seagulls.
In Linosa, shearwaters nest mainly in lava rocks of the northern coast, an area called Mannarazza. Our association, together with students and volunteers, follows their breeding success by monitoring approximately 500 nests annually.
Lampione is an uninhabited islet which belongs to the Pelagie archipelago, it has a surface of 3,6 ha and it hosts one Scopoli’s shearwater colony made up of around 230 breeding pairs, the fourth in number among those breeding on Italian islets.
Our association has been studying the domestic cats in Linosa since 2014, when we have counted 299 cats on the island and detected that the diet of some cats roaming around the part of the shearwater colony we monitor, included adult shearwaters and in several occasions events of predation on shearwater chicks have been recorded.
