Silber: Phocoena sinus in the northern Gulf of California 



341 



BAJA CALIFORNIA 



Figure 2 



Phocoena sinus sightings and vessel transects 

 conducted in 1986, 1987, and 1988 (top) and 

 aircraft surveys on 3-5 May 1988 (bottom). 



(x 18.3 ±6.10 SD; range 2.4-32.2) (Fig. 6, Table 1). 

 Water clarity at sighting locations ranged from 0.9 to 

 12 m. During four vaquita sightings the boat's depth 

 sounder indicated concentrated layers at 15 {n = 2), 23, 

 and 25 m, possibly representing schooling bait fish or 

 squid upon which the porpoises may have been feed- 



ing. On numerous occasions, vaquita surfaced in or 

 alongside surface slicks or long bands of flat water sur- 

 rounded by rippled water. 



Calves represented 9.37% of all individuals. One very 

 young calf was observed on 9 April 1987. It was esti- 

 mated at <2 days old because of its size, a dorsal fin 



