Table 9. --Tag recoveries from male seals— that had been selected and 

 tagged as yearlings in previous years, Pribilol' Islands. Alaska, 6 July 

 to 5 August 1966 



1/ No tagged females were killed, 



ll Tags were recovered, but the canine teeth for determining ages were 

 not collected. 



ground may be important for determining 

 whether a young male seal homes or strays. 

 Small hauling grounds, for exannple, may be- 

 come overcrowded, or access from the sea 

 may become blocked by harem males. In the 

 latter situation, harem males tend to dis- 

 courage young males from using traditional 

 access ways to inland areas. 



Rookery names have been used in the text 

 and tables because the hauling grounds are 

 adjacent to the rookeries, Zapadni Reef and 

 Tolstoi Rookeries on St. Paul Island have 

 some hauling -ground areas in connmon. A few 

 tags recovered from seals taken from these 

 hauling grounds may, therefore, be incorrectly 

 classified. 



We have summarized the data on homing by 

 pooling the tag recoveries from male seals 

 killed from 1958 to 1966 and by considering 

 individual year classes for those killed from 

 1954 to 1966. The assumptions are that the 

 probability of recovering a tag on either island 

 is constant once a seal has hauled out, and 

 that the pups were on their rookery of birth 

 when tagged. 



Homing and straying, 1958-66 . - - Zapadni, 



Northeast Point, 

 St. Paul Island 

 homing (table 10) 

 the largest and 

 grounds. Homing t 

 Kitovi Rookeries i 

 (the tendency to 

 vicinity of birth 

 seals that have st 



and Polovina Rookeries on 



have the highest rates of 



These rookeries also have 



most accessible hauling 



o Reef, Tolstoi, and Lukanin- 



s much lower, even at age 5 



return to the rookery or 



increases with age). More 



rayed fronn their rookery of 



birth haul out near Zapadni and Northeast 

 Point Rookeries than near other rookeries. 

 The proximity of the rookery of birth and the 

 rookery of recapture is apparently related, 

 even for those seals that have strayed. For 

 example, seals from Reef and Tolstoi strayed 

 to Zapadni, and those born on Polovina and 

 Lukanin-Kitovi strayed to Northeast Point 

 (see figs. 1 and 2 for location of rookeries and 

 hauling grounds). The degree of straying was 

 highest for the rookeries with the least ac- 

 cessible hauling grounds. 



On St. George Island, North and East 

 Rookeries have the highest rate of homing, 

 and the rate for Staraya Artil is particularly 

 low (table 10). Homing of seals to Zapadni 

 on St. George Island was low for ages 2 and 3, 

 but increased to 59 percent at age 4. Some of 

 the samples of 5-year-old males were too 

 small to permit conclusions. 



Homing by year class, 1 954-66 . --For each 

 year class, homing increased with age on both 

 islands. For example, the percentage of seals 

 that homed to Northeast Point Rookery in- 

 creased from 61 to 91 from age 2 to age 5 

 years. For seals of a given age, homing to St. 

 Paul Island was more pronounced than to 

 St. George Island (table 11). The data on the 

 return of seals of different year classes to 

 their island of birth were generally consistent. 

 The major exception was the year class of 

 1961 on St. George Island: the percentage of 

 seals that homed was considerably higher at 

 age 2 than at ages 3, 4, or 5. In general, 

 variability among year classes decreased with 

 increased age. 



The results of homing of each year class to 

 the rookery of birth were extremely variable 

 (table A-20). The homing of 3-year-old males 

 to Reef Rookery appears to have been stronger 

 for year classes 1960-64 than for the earlier 

 year classes. 



Effects of the Time of Tagging 



To determine if time of tagging (and thus the 

 age and size of pups) has an effect on rate of 

 recovery, half of the tags used on St. Paul 

 Island in 1963 (P-series) and 1964 (Q-series) 

 were attached to pups 12-21 August and half 

 were attached 16-25 September. The data from 

 this study will not be complete until 1968, 

 when seals from both year classes have con- 

 tributed fully to the commercial kill. Some 

 comparisons, however, can now be made. 



For the tags attached to pups in 1963, the 

 rate of recovery was significantly higher from 

 the group tagged in late September than from 

 the group tagged in August (table 12). The data 

 from recoveries of tags attached to pups in 

 1964, however, indicated no such difference in 

 rate of recovery (table 12). The inconsistency 

 may have been caused by the use of different 

 sites for application of the tags (and possibly 



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