Atlantic Seabirds Vol 2, No. 2 (2000)
2000. Longline fishing at Tristan da Cunha: impacts on seabirds. Atlantic Seabirds 2(2): 49-56.
Tristan da Cunha and Gough Islands in the central South Atlantic Ocean support globally important seabird populations. Two longline fisheries occur within Tristan’s Exclusive Economic Zone: a pelagic fishery for tunas and a demersal fishery for bluefish and alfoncino. Fishery observers have accompanied all three licensed demersal cruises. Despite attracting considerable numbers of birds and setting lines during the day, only one bird (a Great Sheawater Puffinus gravis) was killed (mortality rate 0.001 birds per 1000 hooks). By comparison, the pelagic fishery for tuna, which exceeds demersal fishing effort, probably has a much greater impact. Observations aboard one vessel in mid-winter suggest a bycatch rate of >1 bird killed per 1000 hooks; this could be even higher in summer when more birds are breeding at the islands. Stricter regulations are required for pelagic vessels, including routine placing of observers on board. The gravest threat posed by longline fishing to Tristan’s seabirds comes from vessels fishing illegally in Tristan waters, as well as vessels in international waters that do not use basic mitigation measures. There is a pressing need for better policing of Tristan’s waters.
Larus minutus. Atlantic Seabirds 2(2): 57-67.2000. Age asymmetries in the aerial display of Little Gulls
Aspects of age differences in the aerial display of Little Gulls Larus minutus are described based on fieldwork carried out in May 1983 in the Lauwersmeer area, The Netherlands. Aerial displays occur when an initiator or 'sender' approaches a 'receiving' individual. The sender initially makes (individually identifiable) kay notes, followed by several ke-kèh repeats. Once the sender has approached the receiver to within a few meters, it increases flight speed, jerks up the head to almost a vertical position whilst starting to call a repeated ke-kôo. The head-up part of the display is rounded off with a short glide over the receiver, but often the display is aborted somewhere along the sequence. This is especially the case when immatures are the initiators. Immatures seem particularly keen to exercise the display, and when doing so preferentially act towards adults. During display flights between adults, receivers tended to respond with their own display flights. However, in aerial interactions initiated by immatures the receivers tended to either flee or to retaliate by attack. I suggest that the aerial display presents a compound quality signal (possibly derived from aerial mosquito-catching movements), that requires much physical and social practising, even during the immature stages of life.
Puffinus yelkouan and its taxonomic status. Atlantic Seabirds 2(2): 68-72.2000. The feather lice of the Levantine Shearwater
Four species of feather lice (Insecta: Phthiraptera) were found on one fresh dead and five museum skins of Levantine Shearwaters Puffinus yelkouan from various localities in the Mediterranean. Two of them, Halipeurus diversus (Kellogg, 1896) and Saemundssonia (Puffinoecus) kosswigi Timmermann, 1962 (unique to P. yelkouan), had been recorded previously from this host; the other two, Austromenopon paululum (Kellogg & Chapman, 1899) and A. echinatum Edwards, 1960, represent new host-louse records. One bird collected fresh in Cyprus yielded the most lice, including 20 specimens of A. echinatum. The taxonomic position of the Levantine Shearwater is discussed briefly and the opinion that it be regarded as a distinct species is supported.
Pterodroma Feae in the Cape Verde Islands. Atlantic Seabirds 2(2): 73-86.2000. The status and distribution of Fea’s Petrel
A census of Fea’s Petrel was conducted in the Cape Verde Islands during January and February 1998. Counts were made on three of the four islands where the taxon has historically been known to breed: Fogo, São Nicolau and Santo Antão. The persistence of those colonies previously reported on these islands was confirmed and several undocumented colonies were located. The population on Fogo was c. 80 pairs, on São Nicolau c. 30 pairs and that on Santo Antão c. 200 pairs. The surveys of Fogo and Santo Antão were incomplete, so the population size could be higher there than indicated by the present data. No survey of Santiago was attempted and further surveys are needed to establish the status of Fea’s Petrel in the Cape Verde Islands as a whole. The colonies on Santo Antão and São Nicolau were generally situated on inaccessible cliff faces above dry river valleys, while those on Fogo were among boulders in dry river beds, among rubble and tubes in old lava flows and on cliffs. Fea’s Petrel continues to be threatened by human exploitation and predation by cats and rats, particularly on Fogo and some areas of Santo Antão where the colonies are most accessible.
Uria lomvia and Little Auks Alle alle alle were the commonest species encountered, but also Puffin Fratercula arctica naumanni and Northern Fulmars Fulmarus glacialis were found. Pieces of coarse trawl nets and fine gill nets were found. It is unclear if the birds drowned when the nets were still in use, or if the birds drowned in ghost-nets. Only few and brief visits were made on Jan Mayen's beaches between 1983 and 2000, but the frequency of finds suggests strongly that substantial numbers of seabirds drown in fishing gear around this remote island in the North Atlantic.2000. Seabirds drowned in fishing nets off Jan Mayen (Greenland Sea). Atlantic Seabirds 2(2): 87-91. Bits and pieces of fishing nets found at Jan Mayen island (central Greenland Sea) often contain entangled remains of seabirds. Brünnich's Guillemots
Uria aalge successfully feed two chicks. Atlantic Seabirds 2(2): 92-94. A pair of Common Guillemots Uria aalge with a small chick adopted a second and successfully reared both to normal fledging age. A single day's feeding watch suggested that the pair doubled the normal feeding rate and the adults spent little time together at the nest-site, though the chick was never left unattended.2000. Common Guillemots
News and notices
Tickell W.L.N. 2000. Albatrosses. Pica Press, East Sussex (reviewed by J.P. Croxall)
Steve Geelhoed joins editorial board
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