When thousands of citizens monitor common species: the French Garden Biodiversity Observatory Benoît Fontaine and Romain Julliard Muséum national d’Histoire naturelle, Paris, France 12th EEF, Avila 27 September 2011

A research project: Impact of gardening practices, garden types and landscape on common species Long-term biodiversity monitoring The Observatoire des Papillons des Jardins General public 28 common species/species groups Private or public gardens A program run by MNHN (protocol, analyses) and Noé Conservation (animation) Launched in 2006

Monthly data (March-October): maximum number of butterflies of each species seen simultaneously in the garden. Frequency of observation is up to the observer Frequency of visits

Landscape impact Surroundings Distance to closest wood/field/pasture Commune (~county)

Garden and gardening practices impact TreesFlowersGarden features

Between 2,700 and 4,000 gardens monitored each year Ca. 100,000 monthly surveys, two million abundance data collected since 2006 Six years later…

Impact of urbanization Average monthly abundance Urbanization classes

Impact of garden characteristics Garden naturalnessNectar offer

Cross-scale interactions: landscape impact vs. garden impact Urban avoiding species are more sensitive to garden practices than urban tolerant ones

One-shot operations Pictures of butterflies feeding Butterfly and plant identification « Fleurs à papillons » project

pictures - 35 butterfly species - ~300 plant species

Some butterflies species favour exotic plant species Hypothesis : these butterflies should be abundant in cities Food availability is not the limiting factor for the presence of butterflies in cities Sensivity to urbanization Exotic flower preference index

The half-full glass: a large pool of dedicated observers More than 2000 long-term participants The half-empty glass

Most participants do not stay on the long run Number of gardens Number of surveys provided

New observers are less motivated than those from 2006 Active vs. non active gardens per registration year

New observers are less motivated than those from 2006 Monthly survey results sent (year of registration)

Less and less new observers each year New observers

Are there only 10,000 potential observers in France? Cumulative number of gardens having provided at least one monthly survey

The challenge: Attracting new observers Keeping current observers

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