Impacts on and population trends of Scopoli's shearwater Calonectris Diomedea in the Maltese islands

Abstract

The Scopoli’s Shearwater Calonectris diomedea, in Maltese Ċiefa is the subject of this study. A pelagic seabird that breeds in the Maltese islands. Procellariformes, have a long breeding season spanning from late February to late October, laying only one egg each year. Therefore, the long period on land makes this species very vulnerable to predation and disturbance by terrestrial mammals, including humans. This study seek to evaluate this relationship in four study areas. It also looks at the effects of existing legal protection measures on the breeding population of C. diomedea. The breeding colonies that are being discussed are found along the southern sheer cliffs of Malta, the north-western cliffs of Gozo, and on offshore islands like Filfla. There never were any specific studies on the species until 1982 when an extensive study on the breeding biology and ecology of this species was initiated by the present researcher. This study covers a period of 38 years from 1983 to 2020, making use of data collated by the present researcher. A total of 158 study nests were under observation, mainly on the islands of Malta and Gozo as well as on some of the smaller islands, most notably on Filfla island. This present study analyses and presents results on population trends from a sample of four study sites namely, Ħal-Far, Għar Lapsi, Għarb and Filfla. An overall decline in the breeding population, particularly in two colonies: Ħal-Far in Malta and Għarb in Gozo is evident, which is mainly due to direct (killing) and indirect (urbanisation etc.) human activities. The numerous existing policies and legal notices should, in theory, provide adequate legal protection measures to the breeding sites as well as to the species in question. The study highlights the various threats and the lack of protection measures for the protection of these seabirds. The study concludes that at the current rate, based on the results obtained, the ongoing decline is projected to lead to the extinction of Scopoli’s Shearwater from the Maltese islands in less than fifty years’ time. The methodology used and the results attained are put forward as a basis for the conservation of this and other pelagic seabird species breeding in the Maltese islands.