Northern Right-whale Dolphin 



Lissodelphis horeahs Peale, 1848 



Northern right-whale dolphins are gregarious animals, often assem- 

 bling in herds of 1,000 animals or more (},ooo have been reported j and 

 often mixing with other species. They do approach vessels and ride in 

 the bow waves, but tend to do so most frequently when accompanied 

 by other dolphins. These handsome black and white dolphins reach 

 lengths of about three meters and can swim 1 8 knots or faster for 

 protracted periods. 



The right-whale dolphin, the only finless dolphin in the north- 

 eastern Pacific, is sympatric with the Pacific white-sided dolphin, 

 probably occurring continuously across the temperate North Pacific 

 but avoiding colder northern and warmer southern waters. It is known 

 from about latitude 50 N to latitude ]o N and apparently moves 

 farther south than )o N only during periods ot intrusion of unseasona- 

 bly cold waters. Right-whale dolphins are present at all seasons seaward 

 of the continental shell oft Central and Northern California, but they 

 are found with greatest frequency within 25 nm of the coast of 

 Northern and Central California in winter and in the SCB in wmter 



FiGL'KL iS. .\ UiL-^jiMuinimg i;ruup ol norihern nghi-uhalt dolphins oit 

 Point Conception. These sleek, hnless dolphins can sustain speeds of at least 

 18 knots for protracted periods. ( Photo by R. L. Pitman.) 



and spring. In those months northern right-whale dolphins are the 

 second or third most abundant delphinid in the SCB, behind common 

 and perhaps white-sided dolphin, and they may be met within a wide 

 variety of locations. Right-whale dolphins are not usually found in 

 waters warmer than 19 C and their movements overall appear related to 

 water temperature and movements of prey. Their appearance inshore 

 most often coincides with peak abundance of squid, a major prey item. 

 Sightings of right-whale dolphins are not uncommon in and near 

 the SCB, particularly in winter. With respect to the CINMS, our 

 observations and those reported to us have been largely along the 

 southern and western shores of the four northern islands, but there are 

 records from near Santa Barbara Island and in the Santa Barbara 

 Channel in winter and spring. Some of these latter records are as close 

 as 5 nm to the mainland. In a 1979 review of the status of knowledge 

 about this species it was noted that strandmgs were not common, there 

 having been only 55 since the species was described in 1848. In 1981 

 alone, however, there were 25 specimens collected from south central 

 and southern California beaches, alone. Causes for the inshore move- 

 ments which presumably resulted in these strandings are not known. 



FlGURL 59. A northern nght-whale dolphin, the onlv linless small cetacean in 

 the CINMS, shown on the beach at Tyler's Bight, San Miguel Island, 27 

 April 1981. fPhoto by B. S. Stewart.) 



Common dolphin 

 Ddphinus delphis Linnaeus, 1758 



Common dolphins frequently assemble into enormous herds, a 

 thousand or more individuals, which create a highly visible ruckus as 

 they travel. This was likely the species that Melville had in mind when 

 he wrote of dolphins (the huzza porpoise) "which upon the sea keep 

 tossing themselves to heaven like caps in a Fourth of July crowd." They 

 are often very active, with many animals leaping clear of the water at a 



given time. They are eager and proficient bow riders and may approach 

 a vessel from a considerable distance to hitch a ride. Once on the bow 

 they may ride for long periods of time. We are inclined to agree with 

 Melville's further observation that "if you yourself can withhold three 

 cheers at beholding these vivacious fish then heaven help ye, the spirit 

 of godly gamesomeness is not in ye." 



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