footer_shadow

Study finds cheating boosts male sparrow fitness

by Imperial College London

Cheating pays. Or at least it does for male sparrows, according to new research.

A team, led by Dr. Julia Schroeder and Dr. Jamie Dunning from the Department of Life Sciences, found that male sparrows that cheat on their social partner have a higher life-time fitness—the ability to survive and reproduce.

This has been traditionally difficult to study, because in wild populations, offspring fathered outside a bonded pair can be hard to track, and some birds will simply leave the area, making it unclear what age they die.

The team studied the sparrows of Lundy Island, which hosts a 'closed' population, meaning that no individuals leave or arrive. This allows the team to collect lots of accurate data on the inhabitants, including their ages and breeding success, which have been recorded for 25 years.

They found that males that had offspring both with their bonded female and outside that relationship had the highest fitness, while "floating males," which only had non-bonded offspring, had the lowest lifetime fitness.

 

31 october 2024

 

Share this story

 

 

 

 

freetrial-badge

 

Latest articles

article_thumb

Weekly birding round up 24 Dec 2025 - 8 Jan 2026

Jon Dunn brings you his first roundup of 2026 and its a bumper edition looking back at the festive fortnight as we saw out 2025 and welcomed in a new year. More here >

article_thumb

Review of the Year 2025: Part 1

We look back at the standout rarity records and notable species recorded in Britain and Ireland in early 2025. More here >