How can we track biodiversity loss at the speed and scale needed to protect our ecosystems? The eDNA Citizen Science project combines cutting-edge environmental DNA technology with citizen science to enable residents, community groups, and local organizations to monitor aquatic and terrestrial biodiversity in their neighborhoods.

For many people spring is associated with the awakening of nature. The trees begin to paint the backdrop green again, welcoming the beginning of a new season with the chorus of frogs and bees, and the scent of flowers in the air. For Jaqueline Henrot, researcher at Naturalis Biodiversity Center and environmental consultant, spring also heralds the start of “Oevercheck” season.

The Citizen Science Lab proudly looks back on a successful first edition of the Expeditie Stadsnatuur Leiden. On the 20th of June, we concluded the Expedition with a festive handover of the results to Ashley North, Alderman for Climate, Mobility and Finance, and with a market organised for and by lovers of Leiden’s nature.

How many species of plants, animals and fungi live in urban nature? in 2026 are Leiden, Leiderdorp, Oegstgeest and Katwijk observing and recording how many unique species there are, to put the state of urban nature on the map. Together everyone from May 1st till 30th of June will record every spider, snail, mushroom or dandelion they come across during ‘Expeditie Stadsnatuur ’. The goal of the 2026 edition is to find at least 26 hundred unique species.

How many species of plants, animals, fungi and moss live in the gardens surrounding the Oude UB at Rapenburg 70? On Tuesday May 20th, the Citizen Science Lab led an investigation in the front gardens and back courtyard of the Old UB at Rapenburg 70, together with 15 colleagues working in that building.

NestWatch uses smart birdhouses to research how the city affects the development of young birds.

What plants grow along ditches in the Leiden region? What does this say about vegetation quality? Could it be better? Naturalis and Leiden University's Center for Environmental Sciences are looking for your help to answer these questions.

At almost midway through, the “Stoeplanten” (Pavement Plants) citizen science project has been very successful. This research was initiated by Nienke Beets, who while working for the Science Communication and Society research group and Hortus Botanicus, gave her contribution to the Stoeplanten project.

One of the goals of the Citizen Science lab is to be an incubator for citizen science projects. Over the years, the lab has been involved in creating and supporting various projects. Get inspired!