-103- 



Figure 23. Collective evidence for changes in pregnancy 

 rates and age at sexual maturity in female fin, blue, 

 and sei whales and advancing age at sexual maturity in 

 crabeater seals (After Laws, 1977a, incorporating data from 

 Lockyer, 1972, 1974; Gambel, 1973; Laws, 1977b), 



Crabeater seal maturity 



19.10-31 40-41 50-51 60-61 



Antarctic season 



I 





70-71 



