1. Scavenging removes carrion or littered food waste from the environment, providing ecosystem services including nutrient cycling, reduced pathogen spread, and reduced waste management costs. These services are particularly important in urban environments, where high human population densities result in increased littered food waste. It is unclear how the magnitude of scavenging across urban-rural gradients is influenced by agent (vertebrates and invertebrates), land-cover type and patch size.

2. We investigated scavenging provision by vertebrates and invertebrates across a gradient of urbanisation in 37 woodlands and 35 domestic gardens across Liverpool, UK.  Sites were selected using random stratification across a gradient of urbanisation based on impervious surface cover. At each site, four different bait types were deployed either within vertebrate exclusion cages or exposed to vertebrates and invertebrates. The percentage dry weight loss of bait after 48 hours was used to quantify scavenging provision.

3. Data were analysed using general linear mixed effects models (Gaussian error distribution) and a full model approach to assess 1) the relative contributions of vertebrates and invertebrates across an urban-rural gradient; 2) variation in scavenging between woodlands and gardens; 3) the effects of semi-natural vegetation cover on scavenging provision. We also consider patch size as a preliminary assessment of how fragmentation influences scavenging.

4. Vertebrates contributed substantially more to scavenging provision than invertebrates across the urbanisation gradient. Vertebrate scavenging was substantially greater in woodlands than gardens, invertebrate scavenging was similar in both land-cover types. Scavenging increased with patch size in gardens, but not woodlands. Vertebrate scavenging increased with patch size, while invertebrate scavenging decreased. Within gardens, vertebrate scavenging increased with semi-natural vegetation cover.

5. Scavenging-mediated ecosystem services are important in urban areas where food littering is frequent, and efforts should be made to facilitate these services. Urban woodlands and gardens both make important contributions to scavenging-mediated ecosystem services in urban areas, but woodlands’ contributions are much greater. There is a need to increase the cover of semi-natural vegetation in gardens to increase their contributions, and protect and expand woodlands, especially in areas with a high demand for ecosystem services reliant on scavenging.