occurred most commonly between midnight and dawn (Period 2). Figures 29 - 34 depict the 

 frequency histograms for individual and combined periods for "Van Halen" and five of the 

 whales tagged in 1990. PTT #823 (Figure 30) and PTT #839 (Figure 33) have the largest 

 sample sizes and similar distributions of swimming speeds. A mode of 2 - 3 km/hr was most 

 typical of the dawn to noon period (Period 3). 



The average speed of the five 1990 individual whales with location information are 

 depicted with standard deviations in Figure 35. The same information is summarized in 

 Table 7 by period and in Table 8 by category. 



The average swimming speed for all whales combined was 3.73 km/hr (range 2.26 - 

 4.85, N = 289). The highest average speed for all whales combined occurred between 

 midnight and dawn (Period 2). This was also the period of highest speed for the two whales 

 with the largest sample sizes (16.82 km/hr for PTT #839 and 16.15 km/hr for PTT #823). 

 The pregnant female, PTT #840 had the highest overall average swimming speed (4.85 

 km/hr), followed by female PTT #839 and her calf (4.11 km/hr). 



To determine if swimming speed was related to weather, we compared the speed 

 patterns of four whales using the same calendar "x" axis (Figure 36). There was no obvious 

 relationship between the traveling speeds of PTT #823 and PTT #839. However, the 

 analysis was subject to the limitations of how the data were collected. Specifically, much 

 greater distances and thus higher speeds may have been achieved by animals than we 

 calculated from the straight line distances between Argos locations. Also, the animals were 

 sufficiently far apart from one another at times that they may have been experiencing very 

 different weather conditions on the same date. 



We do not know the motivation behind the movements described here, but we saw 

 differences in how the whales moved, and have provided some possible explanations in the 

 section "Oceanographic Factors. ".Some whales were reasonably sedentary (e.g. PTT #825, 

 Figure 20). We had examples of whales which moved long distances apparently in a straight 

 line (PTT #823 going south. Figure 24) or in a zigzag pattern suggesting a search (PTT 

 #839 off Long Island, Figure 19). Figures 37 and 38 depict the travel speeds of PTT #823 

 and PTT #839 along the segments of their track line. Two features of PTT #823 are worthy 

 of note: 1) the reasonably fast and uniform speeds during the few days before reaching the 

 southern extent of travel coincide with a southern current in the area, and 2) the speeds at 

 the southern extreme of travel are slower than might be expected considering that they 

 coincide with a northeasterly current (see "Oceanographic Factors"). 



49 



