Abstract

(…) In the original description of the vaquita, Phocoena sinus, Norris and McFarland (1958) gave the range as “certainly occurring in the upper Gulf of California and probably extending south along the Mexican coast.” Honacki et al. (1982) gave the distribution of P. sinus as the “Northern part of the Gulf of California, south to Tres Marias Isls. and N. Jalisco.” A similar distribution for this species was reported by Hershkovitz (1966). However, Brownell (1983) suggested that the species might be restricted to the upper part of the Gulf of California, as all 26 confirmed records were from this area. Here I evaluate the evidence for this hypothesis by reviewing all confirmed specimens and records of P. sinus, including 19 specimens collected since 1983, and by re-examining all reported sightings not confirmed by physical evidence. (…)