Figure 6. — Pup mortality study area. Reef Rookery, St. Paul Island, 11 July 1966, 



Table 3. --Primary causes of death among pups, Reef Rookery 

 study area, St. Paul Island, 28 June to 22 August 1966 



The distribution of primary causes of death 

 is given in table 3; a summary of other findings 

 follows: 



1. Seasonal variation in primary causes of 

 death: Trauma (mostly bite wounds from 

 females) was the leading cause of death during 

 the first 2 weeks of the survey; malnutrition 

 during the next 5 weeks, and hookwornn disease 

 during the 8th week. Infections (bacterial and 

 viral) were never a leading cause of death 

 (fig. 7 and table A-7). 



2. Distribution of primary causes of death 

 by age: Table 4 shows the ages at which the 

 primary causes of death were most prevalent. 

 Of the pups that died of malnutrition, most 

 females did so from 1 to 3 weeks of age and 

 males fronn 1 to 4 weeks of age. Most of the 

 pups that died from hookworm infection were 

 over 3 weeks old. Only one female over 3 

 weeks and one male over 4 weeks of age died 

 of trauma (physical injuries). Age was esti- 

 mated by the eruption of the pernnanent canine 

 teeth and the presence or absence of an 

 umbilical cord. The permanent canines usually 

 erupt by age 3 weeks in females and by age 4 

 weeks in males. The umbilical cord drops off 

 about 1 week after birth. 



3. Body condition and causes of death: 

 There was some correlation between condition 

 index (ratio of weight to length X 100) and cause 

 of death (table A-8). Pups that died of mal- 

 nutrition had obviously lost weight, but pups 

 that died of hookworm disease, infections, or 

 undetermined causes had lost little or no 

 weight. Pups that died of bite wounds from 

 strange females were intermediate. 



4. Secondary causes of death: Enteritis was 

 a secondary cause of death in 40 of 69 pups 

 that died of malnutrition and in 3 of 29 pups 

 that died of hookworm disease (table A-9). 

 Abscesses and phlegmons were secondary 

 causes of death in 9 of 22 pups that died of bite 

 wounds. Trauma (10 bite wounds, 1 skull frac- 

 ture, and 1 liver rupture) was a secondary 

 cause in five cases of malnutrition, three 

 cases of infection, and in four cases where 

 the primary cause of death was undetermined. 



