WinkleWatch

A Community Science Project on Snail Colour

Be part of science!

We are thrilled to invite you to our upcoming beach events, where we'll collect data, collaborate, and dive deep into the fascinating science and story behind snails. Don't miss out on this unique opportunity to learn and contribute!

What are Winkles?

Periwinkles are small sea snails found across the coasts of Europe and North America. Winkles come in a rainbow of colours and patterns, but why do these little snails have so much variation in colour? We are an international group of snail scientists working hard to answer this question, but we need your help!

Color as an adaptation

Lots of animals have evolved colours that match their environments. Other animals have colours that don’t seem to match their environment.

Are periwinkles trying to blend in with their environment? Are they trying to stand out? Or have their colours evolved for a different reason?

Join our events !

Coming events

1er July 2025 - Sweden - Tjärnö Marine Laboratory, Strömstrad - Data gathering event on the shore - Contact: Luisa Kumpitsh, luisa.kumpitsch@gu.se
15 July 2025 - Sweden - Tjärnö Marine Laboratory, Strömstrad - Data gathering event on the shore - Contact: Luisa Kumpitsh, luisa.kumpitsch@gu.se
29 July 2025 - Sweden - Tjärnö Marine Laboratory, Strömstrad - Data gathering event on the shore - Contact: Luisa Kumpitsh, luisa.kumpitsch@gu.se
05 August 2025 - Sweden - Tjärnö Marine Laboratory, Strömstrad - Data gathering event on the shore - Contact: Luisa Kumpitsh, luisa.kumpitsch@gu.se

Past events

17 March 2025, Portugal, Galeria da Biodiversidade- Museum of Natural History University of Porto, Porto, Formation of teachers- Talk in a conference
25 March 2025, Portugal, Centro Ciencia Viva- Vila do Conde, Formation of teachers- Talk in a conference
29 March 2025, Portugal, Centro Ciencia Viva- Vila do Conde, Formation of teachers- event in the shore
05 April 2025 - Sweden - Vetenskapsferstivalen (University of Gothenburg) - Science Festival

The WinkleWatch project

We are an international group of snail scientists working hard to answer the question: Why do these little sea snails have so much variation in colour?

But we need your help! Using pictures of periwinkles sent to us from all across the world, we can unravel this beach mystery together!

We want to get the most out of your periwinkle pictures, so may use them in future publications.

Follow our socials and you might see your periwinkle picture posted!

Present across the northern hemisphere, different popullation display different appearence. Than's why we need people all around the world !

The research

Here we will post the progress of the analyses based on the data you provided us.

From the data recovered in 2024 we explored the association of the color of the snails to the color of the substrate. It allowed us to have a global view of what we could expect to get for the 2025 season.

Want to dive deeper? Check out:

Johannesson, K., Butlin, R. What explains rare and conspicuous colours in a snail? A test of time-series data against models of drift, migration or selection. Heredity 118, 21–30 (2017). https://doi.org/10.1038/hdy.2016.77
Anette Ekendahl, Kerstin Johannesson, Shell colour variation in Littorina saxatilis Olivi (Prosobranchia: Littorinidae): a multi-factor approach, Biological Journal of the Linnean Society, Volume 62, Issue 3, November 1997, Pages 401–419, https://doi.org/10.1111/j.1095-8312.1997.tb01633.x

Frequencies of colour phenotypes in skerry populations from 4 months after the manipulation in 1992 to 2013 (solid lines). Fitted declines in frequencies under a model of frequency-dependent selection (broken lines). Populations are coded as follows: (Top) White-1, blue; White-2, green; White-3, purple; White-4, red. (Mid) Banded-1, blue; Banded-2, green; Banded-3, purple. (Bottom) red, blue.

Johannesson, K., Butlin, R. 2017

Want to get involved but you can't join an event?

WinkleWatch flyer:

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Safety First! Looking for periwinkles can be dangerous work. Wet rocks can be slippery, so take care where you step. The sea shore can be hazardous! Follow these simple rules: be aware of the tide, do not leave children unsupervised, move carefully on slippery surfaces, only go to parts of the shore where you can move safely, do not enter private property.

Heading to the beach? Got your phone and a spare few minutes? Want to contribute to real science?

What to look for ?

Our project is only looking at the species Littorina saxatilis, commonly known as rough periwinkles. There are lots of species of periwinkles found on our shores and, unfortunately for you, they all look quite similar... But don’t worry! We have lots of handy tricks to help you find what we’re looking for.

Tips to get the best Winkle shot!

To make sure the periwinkles are happy and healthy, leave them where you found them when taking their picture!

Keep your phone parallel to the rock the periwinkle is on, holding a penny, or the scale at the bottom of the flyer, next to the periwinkle and try to snap a clear picture, without shadows.

The sea shore can be hazardous! Follow these simple rules: be aware of the tide, do not leave children unsupervised, move carefully on slippery surfaces, only go to parts of the shore where you can move safely, and do not enter private property.

iNaturalist is here to gather this kind of data

WinkleWatch can then recover them from there

Submit your pictures

If you have questions about the project, you can contact us on our social media or by email at winklewatch@gmail.com

We thank our local partners:

Contributors

Anja Westram, Rui M Macieira De Faria, Francesca Raffini, Sean Stankowski, Roger Butlin, April Monica Houghton Blakeslee, Sarah Kingston, Pierre Barry, Molly R Mathews, Marina Rafajlovic, David Carmelet Rescan, Luisa Kumpitsch, João Carvalho, Alfonso Balmori, Deepti Manjari Pate

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