Taxonomy |
Closely related to the White-chinned
Petrel, this species is appropriately known as the Ringeye by
Tristan Islanders by virtue of its striking white facial markings. As a
breeder, it is restricted to Inaccessible Island within the Tristan
da Cunha group, positioned in the South Atlantic almost midway between
South America and Southern Africa. The main reason for full species status
are the differences in vocalizations Spectacled Petrels produce a deeper
(and apparantly more harmonious) groans and rattles than White-chinned
Petrel (Ryan, 1998). Play-back experiments suggest this might be an important
isolating mechanism. In addition, Spectacled Petrels are slight smaller
and breed a few months earlier than White-chinned Petrel.
Identification |
Not well understood. Has distinctive spectacles at all ages, even in downy chick. Care must be taken because White-chinned Petrels sometimes have small areas of white on the head, especially on the nape.
Close-up of a Spectacled Petrel
(Procellaria conspicillata). Photographed off southeastern Brazil, on the
shelf between Santos and Rio de Janeiro, where they are common attending
longliners. Photograph copyright of Fabio Olmos©, 2000.
Where and When |
Breeds only on Inaccessible Island in Tristan
da Cunha group. Disperses in a broad band across the South Atlantic between
25 deg. and 40 deg. South, the majority of the population going to waters
off southern Brazil where they are common around fishing boats in summer.
Significant mortality in long-line fishing, comprising up to 8% total deaths
in tuna and swordfish fishery off southern Brazil and Uruguay (Ryan, 1999).
Interestingly, once occured off
Amsterdam
Island in the Indian Ocean but not seen anymore. May have been a breeding
species but extripated by introduction of pigs (Ryan, 1999).
Photographs on the web |
Detailed
view of heads of an adult and chick and three adults on water. Photos
by Peter Ryan and Fabio Olmos.
Acknowledgements |
Many thanks to Fabio Olmos for allowing
me to use his photograph.
Literature |
Camphuysen C.J. & J. van der Meer (2000)
Notes on the distribution of the Spectacled Petrel Procellaria conspicillata
in the South Atlantic. Atlantic Seabirds 2: 13-18.
Peter Ryan (1999) Spectacled Petrel, Procellaria
conspicillata. World Birdwatch 21(1): p24-25.
Peter Ryan (1998) The taxonomic and conservation
status of the Spectacled Petrel Spectacled Petrel, Procellaria conspicillata.
Bird Conservation International 8: 223-235.
Enticott, J. W. and O'Connell, M. O. (1985)
The distribution of the spectacled form of the White-chinned Petrel (Procellaria
aequinoctiallis conspicillata) in the South Atlantic Ocean. British Antarctic
Survey Bulletin 66: p83-86.
Olmos, F. (1997) Seabirds attending bottom
longline fishing off southwestern Brazil. Ibis 139: 685-691.
Fraser, M. W., Ryan, P. G., and Watkins,
B. P. (1988) The seabirds of Inaccessible Island, South Atlantic Ocean.
Cormorant 16: 7-33.