Mysterious by nature, leatherbacks spend their entire lives at sea, only returning to land to lay eggs. The males however? They might never return...making their mating patterns tricky to study. So how did Bispo & co do it? Using modern biology's best friend: genetics! 🌍🧪(2/6)

Using 6 microsatellite DNA markers from 15 nests in Espirito Santo, Brazil, the DNA of mothers and their hatchlings were compared to identify how many males contributed to each nest, a first for Brazil's leatherback population. But what did they find? (3/6)

60% of nests had multiple fathers (polyandry) and 41% of males fathered hatchlings in multiple nests (polygyny)! What does this mean? Polyandry benefits males by increasing the chances of them passing on their DNA, whilst polygyny can boost fertilisation success. But what about the females? (4/6)

Neither behaviour really benefits the females at all, with multiple partners actually exposing them to predators, risk of disease & energy loss. So why did this happen? Likely the result of male pressure, larger females had fewer partners, so it appears size really does matter here...(5/6)