Citizen science and the ecology of urban mammals and birds

Compared with groups like birds, many wild mammal species in Britain are relatively cryptic and tend to avoid humans, making them difficult to survey effectively. As well as making it difficult to assess the conservation status of mammal populations, lack of reliable data on spatial and temporal variation in mammal abundance presents an obstacle to understanding and managing impacts of mammal populations on other species of conservation or economic concern. Camera traps can be an effective means of collecting data on mammal presence and activity. The MammalWeb scheme enlists members of the public to deploy camera traps in their gardens or other areas local to them. Images are made available to volunteers via an online platform (www.mammalweb.org) and collaboratively classified to provide information on species occurrence and activity. This initiative has the potential to greatly enhance our understanding of its mammal populations.
Gardens represent one of the most convenient and straightforward habitats in which members of the public can operate camera traps. Additionally, mammal populations in urban habitats are interesting, both in their own right and because of their interactions with other species and with people. While urban habitats are typically associated with reduced biodiversity, urban gardens and other green spaces can serve as significant resources - or even refugia - for wildlife. A number of garden-based citizen science initiatives already enlist members of the public to monitor the occurrence, abundance or activity of certain taxa. One of the largest of these is the British Trust for Ornithology's (BTO) Garden Bird Watch (GBW), a survey with approximately 12,000 volunteers, who regularly submit records of birds and, increasingly, mammals observed in their gardens. The data from birds have shown, for example, significant impacts of garden feeding on bird populations and communities, but there is still much more to understand, particularly in relation to the mammals and how these interact with the bird communities, as well as how the management of gardens impacts upon wildlife. Many mammals benefit from supplemental feeding in gardens, or can access supplemental food from refuse, leading to increases in numbers of species such as foxes and some public concerns over safety. Other charismatic species such as hedgehogs have seen dramatic declines in rural areas, but urban populations may be bucking the trend.
This project will link data from MammalWeb and the BTO GBW scheme, as well as those available from other BTO surveys, to improve our understanding of garden-based mammal populations and their interactions with other species. In doing so the project will build capacity within MammalWeb for monitoring over large spatial scales. The findings of the project will have relevance for the fields of citizen science, mammal monitoring, urban ecology and landscape-level conservation management.