Study into fertilisation of Hermann's tortoises
Baby Hermann's tortoises have been paternity tested to find out whether fertilisation is affected their mother's ability to store sperm from multiple partners inside their bodies for years.
It was discovered that the mating order of partners did not affect their fertilisation success. This differentiates from previous studies into similar species, which have found a higher proportion of eggs are fertilised by the last mate.
Dr Sara Fratini, Giulia Cutuli, Dr Stefano Cannicci and Professor Marco Vannini from the University of Florence have published their findings in the Behavioural Ecology and Sociobiology journal.
The team expected a "last in first out" hypothesis, in which the first sperm to enter the female's reproductive system would be the last to come back out when emptied. However, the findings did not match this hypothesis.
In fact, the team found that the sperm became randomly mixed inside the female's oviduct - the passageway from the ovaries - and those males that contributed more sperm fertilised a greater proportion of eggs in a clutch.
The experiments involved setting up a series of planned matings and conducting paternity tests on tortoise hatchlings from 16 egg clutches.
Forty-six per cent of clutches were fertilised by two or three males and a "significant contribution" of the previous years' partners' DNA was present.
The BSAVA has opened submissions for the BSAVA Clinical Research Abstracts 2026.
