Until recently the shearwaters were devided in two genera Calonectris and Puffinus, but based on dna-analysis Penhallurick and Wink (2004) have proposed a splitting of the shearwaters into three genera: Calonectris for the large shearwaters of the Northern Atlantic, the Mediterranean and the waters around Japan, Ardenna for a group of large Southern Hemisphere breeders and Puffinus for the smaller shearwaters such as the Manx’ group, Audubon’s and Little Shearwaters. This new taxonomy is now widely accepted, but not by all and is stil subject of discussion.
Listen to the sound of Balearic Shearwater
Copyright remark: Most sounds derived from xeno-canto
recorded by Miguel McMinn Grivej
|wingspan min.:||80||cm||wingspan max.:||88||cm|
|size min.:||32||cm||size max.:||37||cm|
|incubation min.:||50||days||incubation max.:||54||days|
|fledging min.:||70||days||fledging max.:||54||days|
census is impossible except by indirect estimates. Some colonies occupy similar habitats in islets.
Little excavation is reported, only a slight hollow in caves with clay ground. There is no
significant material carried to the nest.
Nowadays the species seems to occupy sub-optimal habitats due to human disturbance and
introduced predators. Fossil remains show that important colonies were on the mainland of the
major isles. Breeding places of P. mauretanicus at 500 m far from coast in Cabrera Island has
been described (Araujo et al. 1977). Bone remains have been found in caves far from the coast
but at the present the species is extinct from this island.
rearing period extends for ca. 65-70 days.
plunges from 1 or 2 m height (the common height of flying) with open wings, entering the water headfirst. The dives last up to 40 seconds. The maximum depth recorded is 26 m. Capture of discarded fish has also been reported in Balearic waters, though not frequently. Uses of trawler discards appear to be important in the Mediterranean off the Iberian Peninsula during
the breeding season and in the Bay of Biscay during the post-breeding period. Use of mid-water trawls have increased dramatically since the mid 1980’s, and changes in post-breeding distribution can be related. During the breeding season the main feeding areas are on the Eastern Iberian Peninsula coast. Recent displacement northward in their winter distribution has been reported and explained due to changes in the clupeiform abundance
Video Balearic Shearwater
copyright: Stuart Fisher
Puffinus mauretanicus breeds in the Balearic Islands, Spain. Its breeding population has been recently estimated at 1,750-2,125 pairs and at 1,447-1,927 pairs, both significant reductions from the 3,300 breeding pairs estimated in 1991. However, there has been no exhaustive census due to the inaccessibility of breeding sites and this precludes an accurate estimation of population trends. Up to 70% of the population breeds in cliffs on Formentera and surrounding islets. The remainder of the population are on Mallorca, Cabrera, Menorca and Ibiza, primarily on islets rather than the main islands themselves. In winter, it occurs in the Balearic Sea and on the north-east Spanish coast with most of the population concentrated between Valencia and Catalonia from November to February. Some birds migrate north to seas off the British Isles and the south of the Scandanavian Peninsula.