Cardiff University Otter Project

🚨NEW PAPER🚨
https://doi.org/10.1007/s10344-026-02127-2

How old is an otter cub? Determining cub age is important for identifying and protecting breeding sites and targeting seasonal surveys, but reliable ageing methods have been lacking.

In this new paper, led by researchers at Edinburgh Napier University in collaboration with the Cardiff University Otter Project, the authors present a novel method that estimates cub size relative to their mother using pixel measurements from camera-trap footage. The method was validated using domestic ferrets of known length, then applied to footage from an otter natal den to generate growth curves for three litters, from first emergence (ca. two months old) to at least seven months old.

The method was sufficiently accurate to estimate birth season, and the authors hope in future to collate crowd-sourced video and photographs of otter families from across the Eurasian otter range, to investigate regional variation in breeding seasonality.

Anecdotally, it has been suggested by field observers that tail: body length ratio might be used to indicate cub age. Data from CUOP were used to disprove this - analysis of length data from over three thousand individuals, from tiny foetuses recovered in utero, to adult otters, showed that the ratio remains remarkably constant as otters grow.

Another engagement event 😃!

We would like to give a huge thank you to our 2025-26 placement year students, Sorrel, Sophie, and Sandy. Since September, they have helped lead several local engagement events and assisted in performing 194 postmortems. They have played a crucial role in the project over the past academic year, and we wish them all the very best for the future!

Excellent advice about responsible sharing and interacting with otter content - equally applicable to other wildlife.

We are proud to announce that we have received our Bronze LEAF certification. This reflects the project’s commitment to laboratory sustainability and reducing our impact on the environment as part of the laboratory efficiency assessment framework (LEAF). Thank you to the LEAF team for your support!

Introducing our second volunteer, Tom, who will help us over the summer!

Introducing our new volunteer, Iestyn, who will be joining us for the summer!

🌏5TH JUNE WORLD ENVIRONMENT DAY🍃

🍀🌸🍂Contaminants disrupt the balance of the ecosystem, leading to direct harm to aquatic organisms and significant effects throughout the food web.

🦦🌊🌊Apex predators such as otters are one of the mammals that are most vulnerable to the impacts of water pollution.

Happy World Otter Day from everyone at CUOP! We want to say a huge thank you to our funders and collection network who make what we do possible. In particular the Environment Agency and Cyfoeth Naturiol Cymru / Natural Resources Wales who do equally amazing work in England and Wales for otters. From September to April we received 157 otters thanks to the brilliant people supporting our project. and Somerset Otter Group.

I highly recommend training with Lee Jenkins , these courses will be excellent - Liz Chadwick

🦦 Ever wondered what otters get up to when no one’s watching?

Join us for a half‑day journey into their hidden world with expert ecologist Lee Jenkins, founder of the South Wales Otters Trust.

Across this immersive session, you’ll explore how otters live, feed, travel and shape their freshwater habitats. You’ll learn to spot the subtle signs they leave behind, and then head outdoors to put your new skills into practice.

📅 Dates: 10 May, 13 May, 7 June, 10 June
🕙 10:00–13:30
📍 Llanfoist Village Hall, NP7 9LP

Whether you’re a complete beginner or a keen wildlife enthusiast, this course opens the door to real conservation work, with opportunities to join an otter monitoring programme afterwards.

🦦 Come meet the otters of South Wales - and the people protecting them

Sign up here: https://mammal.org.uk/events

Photo credit: Will Strange