Trites et al : Diets of Eumetopias jubalus in Southeast Alaska 



243 



50 



25 



Rookery 



Haulouts 



Jun-Aug 



Sep-Nov 



Dec-Feb 



Mar-May 



12345678 12345678 1234567 

 Number ot prey types per scat 



12 3 4 5 6 7 



Figure 6 



Frequency of number of prey types per Steller sea lion t Eumetopias jubatus) scat 

 from the Forrester Island rookery complex in summer (Jun-Aug) 1993-99 and 

 from haulouts in fall (Sep-Nov) 1993 and 1995-96, winter (Dec-Feb) 1996-97, 

 and spring (Mar-May) 1996. Data were pooled for each panel across months, 

 years, and sites. Number of scats collected (n) and mean number of prey per scat 

 ( X ) are shown by season. 



0.0 



-T 



0,3 



06 0,9 12 



Scat volume (L) 



15 



1 8 



Figure 7 



Number of prey types versus volume of Steller sea lion {Eumetopias jubatus) scats 

 for three Southeast Alaskan rookeries (Forrester, Hazy, and White Sisters: ;i = 699) 

 in summer (Jun-Aug) and from haulouts (n = 508) the rest of the year (Sep-May) 

 during 1994-99 (volume of scat was not measured in 1993). Plotted number of 

 prey types per scat were jittered by adding random variation (0.2) to each value 

 to improve the visual representation of the counts. The fitted line is a locally 

 weighted smoothing of the data (LOWESS, ^=2/3 1. Box plots in the margins show 

 the distribution of scat volume and number of prey types per scat collected at 

 haulouts (H) and rookeries (R). 



