A melanistic adder (Vipera berus) neonate born from a cryptic female: Are black vipers born heavier?

The ecological advantages and disadvantages of melanism in reptiles, especially in the adder (Vipera berus (L. 1758)), have been intensively studied over the years. General consideration would agree that, in most cases, adders which go on to become melanistic, are born cryptic, with a typical zigzag pattern, and darken with age, becoming black in the second or third year of life. In the present note we report the second known case in which a cryptic female adder gave birth to a melanistic neonate. Based on the fact that the observed body mass (7 g) of the melanistic neonate lies beyond the upper 95% confidence zone of the expected body mass (5.74g ± 0.977) calculated using the linear regression model from the cryptic neonates for a snout-vent length of 175 mm, and on the supporting literature, we propose a new hypothesis (which should be tested in future studies) according to which, melanistic adders may benefit of a significant higher fitness since birth.