GLOSSARY 



The following terms used in fur seal research and management on the Pribilof 

 Islands have special meanings or are not readily found in standard dictionaries. 



age class Age group. Seals of the same age 

 (usually used when referring to seals 

 older than pups). See year class. 



at time of sampling A phrase used to qualify 

 estimates of the pup population based on 

 sampling for a marked to unmarked ratio 

 in the summer of birth. A pup population 

 estimate "at time of sampling" does not 

 include pups of the year class that died 

 earlier in the summer or before the pups 

 were marked. See "at time of tagging." 



at time of tagging A phrase used to qualify 

 estimates of the pup population based on 



(1) sampling for a tagged to untagged 

 ratio in the summer of birth, or on 



(2) tag returns at various ages. Pups 

 that died before tagging are not included 

 in the estimates. See "at time of sam- 

 pling." 



checkmark A notch, slit, hole, or other mark 

 made on a seal flipper when a tag is ap- 

 plied, to insure later recognition of an 

 animal which has lost its tag. 



clinch or clinching The device or action by 

 which metal tags applied to seal flippers 

 are fastened. A metal point is bent over 

 a narrow band in order to form a closed 

 ring. 



drive The act of surrounding and moving 

 groups of seals on land from one location 

 to another. 



escapement Seals that were not killed be- 

 cause they were not the proper size or 

 were not available. 



extra mortality Above normal mortality. For 

 example, tag wounds and other injuries 

 associated with tagging may cause tagged 

 pups to die at a greater rate than untagged 

 pups. 



hauling grounds An area, usually near a rook- 

 ery, on which nonbreeding animals con- 

 gregate. 



haul out The act of seals moving from the 

 sea to a rookery or hauling grounds on 

 shore. 



homing tendency The inclination of seals to 

 return to the rookery where they were 

 born, that is, home rookery or rookery 

 of birth. Homing tendency is expressed 

 as a percentage by comparing the number 

 of tagged seals in a specific group that 

 were found on their natal rookery with the 

 number that were found on some other 

 rookery or island. 



known-age Applied to seals for which age is 

 definitely known because they bear an 

 inscribed tag or have a certain com- 

 bination of tag scar and checkmark. 



marked Seals that have been tagged, sheared, 

 or otherwise artificially marked so they 

 can be identified. 



marked to unmarked ratio See tagged to un- 

 tagged ratio. 



mortality rate Percent of a year class dying 

 over a specific period. 



pregnancy rate Percent females that were 

 carrying or had borne pups in the year 

 examined. For example, the pregnancy 

 rate of 5-year-old females was 60 per- 

 cent. 



return The return or survival of seals from 

 a year class. For example, 10,000 3- 

 year-old seals from the I960 year class 

 returned in 1963. 



round The sequence in which hauling grounds 

 on the Pribilof Islands are visited in order 

 to collect seals for harvest. Current 

 practice is to make a complete circuit 

 or round of the hauling grounds in 5 days. 



roundup The act of surrounding and collect- 

 ing seals to be drivenfor harvest, tagging, 

 or other purposes. 



tagged Describes a seal having an inscribed 

 metal tag or tags attached to one or more 

 of its flippers. 



tag-lost A term applied to a seal that is known 

 to have been tagged because of a check- 

 mark and, in some cases, a tag scar but 

 no longer has a tag. 



tag scar A hole or torn area near the usual 

 tag site on a seal's flipper. Tags fall out 

 because of poor clinching or wear and are 

 torn out by catching in rock crevices or 

 driftwood. Possibly some are torn out 

 by the tagged seal. 



tagged to untagged ratio The number of tagged 

 seals compared to the number of untagged 

 seals, usually expressed as a decimal 

 fraction. Example, 5:20, ratio = .25. See 

 "marked to unmarked ratio." 



tag lost to tag ratio The number of seals that 

 have lost tags as compared with the num- 

 ber retaining tags. Usually expressed as 

 a decimal fraction. 



unmarked Not marked. 



untagged Not tagged. 



year class Group of seals born in the same 

 year. See age class. 



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