improved visibility --lifting of haze. 

 The low values at 7 a. m. and noon 

 may (?) represent human errors of 

 some kind. 



Increased visibility in late afternoon 

 was demonstrated again in 1956-57, 

 when the count of whales at La JoUa- 

 Scripps from 3 p. m. to 5 p. m. 

 equalled 29 percent of the count at Point 

 Loma from 7 a. m. to 5 p. m. (2 hours 

 against 10). Had whales been observed 

 at the same rate for the 2 hours as 

 for 10 hours, the proportion would 

 have been one -fifth or 20 percent. 



Social Behavior 



Gray whales, like most large whales, 

 travel singly or in small groups. The 

 frequency distribution of groups in the 

 1952-53, 1954-55, and 1956-57 seasons 

 is given in table 1 . Single animals 

 predominate in November and Decem- 

 ber. These are mostly large individ- 

 uals, presumably pregnant females, 

 traveling alone to the lagoons and 

 bays to calve, and presumably not 

 physiologically ready to mate. Most 

 single animals, traveling later, are 

 thought to be adult males, nonbreeding 

 females, or yearlings. Little is known 

 about differences in migratory behav- 

 ior according to age and sex. 



Groups of two and three are com- 

 monest in January. At that time, the 

 animals are mating or courting en 

 route. Groups of three would perhaps 

 most logically be composed of two 

 males and one female. (See section, 

 below, on behavior on the winter 

 range.) Groups of four perhaps include 

 three males and one female, or two 

 pairs joined by coincidence. Pregnant 

 females are probably solitary, as are 

 the yearlings not yet integrated into 

 social groupings. 



BEHAVIOR ON THE WINTER RANGE 



Some observations of behavior were 

 made during the aerial census, when 

 animals were seen on the breeding 

 and calving grounds and wandering 



nearby. Most behavior studies, how- 

 ever, were made at close range from 

 small boats propelled among the 

 whales during special visits to the 

 breeding lagoons. 



Behavior studies on the winter 

 range were made at Estero Las Ani- 

 naas on February 22, 1953, and at 

 Laguna Scammon on February 17-25, 

 1954, February 4-14, 1955, January 

 25 to February 8, 1956, and February 

 9-18, 1957. 



In and near the breeding lagoons, 

 gray whales appear to be segregated 

 by age, sex, and reproductive condi- 

 tion. 



Outer and Intermediate Area 



Most whales seen outside the en- 

 trances of lagoons are evidently idle 

 adults, courting adults, or imnnatures. 

 No calves and no recently parturient 

 females are found here. 



The intermediate area consists of 

 channels within the entrance. Many 

 nuptial groups, some cows and their 

 newborn calves, and some wandering 

 singles are found in these locations. 

 Mating and courting is done between 

 adults without calves present. Pairs 

 of courting adults are the commonest 

 reproductive group, but groups of three 

 are also common. On one occasion, 

 three adults were identified by copu- 

 latory activity as a female, a dominant 

 male, and probably a complemental 

 male. The sex of the latter was not 

 definitely ascertained, but its nervous, 

 "sideline" participation suggested that 

 it was a male. (If only half the females 

 breed each year, as the author sus- 

 pects, and if the sex ratio is 50 : 50, 

 there will be twice as many eligible 

 males as females on the breeding 

 grounds.) Breeding pairs and trios 

 are most contimon near the outer en- 

 trance of the lagoon but also penetrate 

 the lagoon to its very head, and are 

 observed outside the lagoon. Segrega- 

 tion of courting groups and cows with 

 calves is more distinct in the Mag- 

 dalena area than in the Scammon area. 



16 



