FRONT FLIPPER 

 TAGS CLINCHED AT THE HAIRLINE AND BETWEEN THE FOURTH 

 AND THE FIFTH DIGIT. 

 MARKS MADE BY CUTTING A V-NOTCH AND REMOVING THE TIP 



HIND FLIPPER 

 MARK MADE BY REMOVING THE TIP OF THE FIRST DIGIT 



Figure 8. — Examples of mark locations that have been 

 used on fur seals, Pribilof Islands, Alaska. 



Male seals ages 2 to 4 . --During the yearling 

 tagging, 1,220 small males, larger and pre- 

 sumably older than yearlings, were double 

 tagged with 2T-series tags (tables A-23 and 

 A-24). Of the 1,220 males tagged, 140 had been 

 tagged or marked as pups; 46 had R-series 

 tags, 17 had lost their R-series tag, 48had the 

 first digit on the right hind flipper cut off, 26 

 had a V-notch mark on the right front flipper, 

 and 3 had been tagged by the U.S.S.R. on the 

 Commander Islands (tag numbers T- 19559, 

 T-22757, and T-19571). We did not record 

 length for these animals. 



We first tagged males in ages 2 to 4 in 1966. 

 Recovery of the animals in the kill will provide 

 information on mortality from one age to the 

 next. 



but many of the hair follicles as well, par- 

 ticularly those producing underfur. 



In 1967, we tried exposures of 5, 10, and 15 

 seconds at -68° C. on 12 artificially reared 

 pups that were observed for up to 3 months. 

 The 10- second application gave good depig- 

 mentation without skin damage. Five seconds of 

 exposure produced insufficient white hairs, and 

 15 seconds caused skin damage. On 7 August 

 we branded about 1 1 5 pups on both forearms for 

 10 seconds at -68° C. with a copper instrument 

 in the shape of the letter "T," 1-inch (2. 5-cm.) 

 high and 3/8-inch (9.5-mm.) wide. Figure 9 is 

 a photograph taken on 11 October when the new 

 fur and guard hair were white on the treated 

 area. Further testing is required to determine 

 the proper mass-to- surface-area ratio for the 

 head of a branding instrument to be used on fur 

 seals. 



We freeze-branded 16 adult females from 

 Kitovi Rookery with 2- (5-cm.) and 3-inch 

 (7.6-cm.) copper letter "U" "S" instruments, 

 four each on the forearm, shoulder, chest, and 

 rump. Exposures of 5, 10, 15, and 20 seconds 

 will be identifiable by the position and direction 

 of the brands. Odd-exposure (5- and 15-second) 

 brands were put on the left side; even-exposure 

 (10- and 20- second) brands were put on the 

 right. Low-exposure (5- and 10- second) brands 

 were placed parallel to the spinal column, and 

 high- exposure (15- and 20- second) brands were 

 placed perpendicular to the spinal column. We 

 used 2-inch (5-cm.) brands on theforearm and 

 rump, and 3-inch (7.6-cm.) brands on the 

 shoulders and chest. 



None of the freeze-branded females have 

 been recognized since they were treated on 

 12 August. 



RECOVERIES OF MARKED SEALS 



Tagged and marked seals taken on the Pri- 

 bilof Islands in 1967 were within the length 

 limits prescribed for killing untagged seals. 

 This section deals with the recovery of these 

 tags and marks. 



Cryogenic marking . --We described the pro- 

 cess of cryogenic or "freeze" branding and 

 trials on fur seals in 1966 in the 1966 (U.S. 

 Fish and Wildlife Service, Bureau of Com- 

 mercial Fisheries, 1969) report. We made 

 additional tests in 1967. 



In 1966, the shortest exposure to the super- 

 cooled branding instrument was 15 seconds. 

 This treatment produced a legible mark com- 

 posed of white hairs, but these were guard 

 hairs only, which were growing primarily from 

 the edges of the treated area. The underfur 

 failed to grow back in. An application of 15 

 seconds was an overexposure that destroyed 

 not only the pigment cells of the hair follicles 



Recovery of Tags, Checkmarks, and Marks 

 in 1967 



A total of 5,466 marked seals recovered in- 

 cluded 2,408 males and 356 females that had 

 been tagged as pups (table 10), 1,228 males 

 and 140 females that had lost their pup tags 

 and were identified from checkmarks (table 1 0), 

 172 males and 3 females that had been marked 

 as pups but not tagged (table 10), 361 males 

 and 3 females selected and tagged as yearlings 

 (table 11), 764 males tagged at age 2 and older 

 (table 11), and 28 males and 3 females tagged 

 as pups by the U.S.S.R. (table A-25). We re- 

 covered an additional 261 males that had lost 

 two tags. 



12 



