EN
We have applied counting of annual cementum lines in canine root to estimate the age of 165 Iberian wildcats Felis silvestris Schreber, 1775. Results indicate that (1) closure of apical foramen of canine root occurs from 6 to 18 months of age, (2) cementum lines are formed in autumn-winter, (3) the first autumn-winter, either a non-continuous line, a continuous "kitten line" or no line can be formed, depending on individual variation in timing of closure of apical foramen, (4) since 7% of wildcats form a kitten line, it needs to be identified in order to avoid an incorrect counting, (5) the first continuous line useful for counting is formed during the second autumn-winter, when animals are 21 months old. For Iberian wildcats, age in years can be estimated by adding 1 to the number of continuous lines. For a more accurate estimation, we propose a formula including months from birth to first line formation, number of annual tines, and months from last line formation to death (A = 9m + Ly + Mm).