The Asociación Naturalista Primilla (ANAPRI) is leading Colmenar Viejo's participation in the Spring Biomarathon 2026, an initiative that is part of the City Nature Challenge. This international citizen science challenge primarily aims to document the rich flora and fauna in urban and peri-urban environments.
The event will take place between April 24 and May 10, with a renewed focus on the quality of the data collected. The organization, with nearly a decade of experience in such projects, mobilizes volunteers and residents from municipalities in northern Madrid, including Colmenar Viejo, to expand knowledge about local species.
“"The data generated allows researchers and environmental managers to improve knowledge about local biodiversity and its evolution, facilitating decision-making in conservation matters."
The City Nature Challenge is a global initiative promoted by the California Academy of Sciences and the Natural History Museum of Los Angeles County. Cities worldwide collaborate in collecting observations of flora and fauna, contributing to a global database.
The Biomarathon 2026 calendar is divided into two phases. The observation phase, from April 24 to April 27, invites participants to photograph or record sounds of living beings in natural environments. Subsequently, from April 28 to May 10, the identification phase opens, where content is uploaded to the platform, and collaboration in classifying recorded observations takes place. Global results will be announced on May 13, 2026.
A significant new feature of this edition is the emphasis on data quality. The international organization has decided to focus the challenge on the accuracy of the information collected, downplaying competition between cities. This means that casual observations will not be counted, and participants are asked to avoid recording people, pets, or cultivated plants, following the “three M's” rule: mascots, potted plants, and mortals, to focus exclusively on wildlife.
Participation is free and accessible. Interested individuals should download the iNaturalist app, create a user account, join the specific Colmenar Viejo project, and record wild species during the observation phase. It is crucial to correctly tag images and mark any observation that does not correspond to wildlife as “captive/cultivated” to ensure the scientific validity of the data.
