shearwaters foraging from this colony was not larger than that of birds from much smaller colonies, indicating highly beneficial feeding grounds in the Gulf of Tunis and off Cap Bon. Considering depleted Mediterranean small pelagic fish stocks, supposed to be Scopoli's shearwater prey base, we therefore speculate that birds may now also largely feed on zooplankton, something which is supported by our stable isotopic analyses. Crucially, shearwater at-sea feeding and resting areas showed very little overlap with a conservation hotspot recently defined on the western side of the Gulf of Tunis using meta-analyses of species distributions relative to anthropogenic threats. We therefore propose a major extension to this conservation hotspot. Our study stresses the importance of detailed biotelemetry studies of marine megafauna movement ecology for refining large-scale conservation schemes such as marine protected area networks.Abstract Recent meta-analyses identified conservation hotpots at the scale of the Mediterranean, yet those may be crude by lack of detailed information about the spatial ecology of the species involved. Here, we identify an irreplaceable marine area for >95 % of the world population of the Scopoli's shearwater (Calonectris diomedea), which is endemic to the Mediterranean and breeds on the island of Zembra off Tunis. To this end, we studied the threedimensional at-sea movements of 50 breeding adults (over a total of 94 foraging trips) in 2012 and 2013, using GPS and temperature-depth recorders. Feathers were also collected on all birds to investigate their trophic status. Despite Zembra being the largest seabird colony in the Mediterranean (141,000 pairs), the per capita home-range of Scopoli's Communicated by S. Garthe.

Migratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of national jurisdictions and high seas areas for 39 species of albatrosses and large petrels. Populations from every country made extensive use of the high seas, indicating the stake each country has in the management of biodiversity in international waters. We quantified the links among national populations of these threatened seabirds and the regional fisheries management organizations (RFMOs) which regulate fishing in the high seas. This work makes explicit the relative responsibilities that each country and RFMO has for the management of shared biodiversity, providing invaluable information for the conservation and management of migratory species in the marine realm.

The ship rat (Rattus rattus) was introduced 1,500 years ago to the Zembra Archipelago (Tunisia) and was eradicated in October-November 2009 on two of its islands, Zembretta and Zembrettina. This eradication was performed 2 years after the discovery of a small colony of Yelkouan shearwaters (Puffinus yelkouan), a species recently up-listed to the vulnerable IUCN extinction risk category. For 2 years before and 3 years after rat eradication, the Zembretta Yelkouan shearwater breeding colony was checked yearly at the end of the breeding season. The number of recorded breeding pairs reaching 176 and 145, respectively, increases of 10.4 and 8.5-fold two and 3 years after rat eradication. This experiment shows that eradication of an ancient introduced ship rat population has dramatically improved the Zembretta Yelkouan shearwater breeding population very quickly. This result suggests that managing even long-introduced populations might well be fruitful

Scopoli's Shearwater (Calonectris diomedea) is a Procellariiform endemic to the Mediterranean Basin which is considered to be vulnerable in Europe due to recent local declines and its susceptibility to both marine and terrestrial threats. In the 1970s-1980s, its population size was estimated at 57,000-76,000 breeding pairs throughout the Mediterranean Basin, with the largest colony, estimated at 15,000-25,000 pairs, found on Zembra Island, Tunisia.The objectives of our study were to re-estimate the size of the breeding population on Zembra Island, to reassess the global population size of the species, and to analyse the implications of these findings on status and conservation of this species in the Mediterranean. Using distance sampling, we estimated the Zembra breeding population to be 141,780 pairs (95 % confidence interval 113,720-176,750 pairs).

In order to define appropriate conservation measures in northern Tunisia we surveyed the bat fauna of Mastouta-Bishshouk region in both roosting sites and foraging areas. A total of 11 species was recorded. We found only three occupied roosts including a maternity colony of Rhinolophus ferrumequinum, Miniopterus schreibersii and Myotis cappacinii in a train abandoned tunnel. A tunnel of water channel hosted Rhinolophus mehelyi, M. schreibersii and M. punicus. Echolocation calls were recorded at a bridge over Beja Wadi, at an artificial basin, and in crop fields. Bat activity was the highest at the bridge in late March, and null in the harvested crop fields in late August. Pipistrellus kuhlii was the most active bat species in the three sites, Pipistrellus pipistrellus was the second most active species, followed by Eptesicus isabellinus. Plecotus gaisleri and Myotis punicus were detected only once at the bridge and the basin respectively. This bat assemblage is representative of the bat fauna of northern Tunisia. Roost and foraging area surveys strongly benefit acoustic recording, even in winter when some bats remain active. The rare local underground roosts should be protected from human disturbance and the water quality of Majerda Wadi should be improved.