Precision of Age Determination of Northern Offshore Spotted Dolphins

摘要

The authors investigated within- and between-reader precision in estimating age for northern offshore spotted dolphins and possible effects on precision from the sex and age-class of specimens. Age was estimated from patterns of growth layer groups in the dentine and cementum of the dolphins' teeth. Each specimen was aged at least three times by each of two persons. Two data samples were studied. The first comprised 800 of each sex from animals collected during 1973-78. The second included 45 females collected during 1981.