Urban scavenging: Vertebrates display greater sensitivity to land-cover and garden vegetation cover than invertebrates

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..., , , # Urban scavenging: Vertebrates display greater sensitivity to land-cover and garden vegetation cover than invertebrates

\"urban.scavenging.csv\" contains data regarding the percent dry weight loss of each bait type at each site, by vertebrates or invertebrates. Each site has a corresponding land-cover type, patch size, and the percentage impervious surface of the grid cell it occupies. Latitude and longitude have been provided for woodland sites, but not garden sites to protect the addresses of residents.

\"urban.scavenging_garden.features\" contains data regarding the percentage cover of vegetation within each garden site. A semi-natural vegetation variable was created by summing the values for tree, wildflower, hedge, and shrub cover. \"Lawn\" refers to the percentage cover of mown amenity grass, \"ornamentalflowers\" refers to the percentage cover of ornamental flowering plants, which are typically selectively-bred varieties cultivated for display.

1. 食腐行为（Scavenging）可清除环境中的腐肉（carrion）或散落的食物垃圾，提供包括养分循环（nutrient cycling）、减少病原体传播（pathogen spread）及降低垃圾管理成本在内的生态系统服务。这些服务在城市环境中尤为重要，因为高密度的人口会导致散落食物垃圾增多。目前尚不清楚城乡梯度（urban-rural gradients）上的食腐强度如何受食腐主体（脊椎动物与无脊椎动物）、土地覆盖类型（land-cover type）及斑块大小（patch size）的影响。

2. 我们在英国利物浦的37片林地和35个家庭花园中，调查了脊椎动物与无脊椎动物在城市化梯度（urbanisation gradient）上的食腐供给情况。研究地点基于不透水表面覆盖率（impervious surface cover），通过城市化梯度的随机分层法（random stratification）选取。在每个地点，四种不同类型的诱饵分别放置于脊椎动物排除笼（vertebrate exclusion cages）内或暴露于脊椎动物与无脊椎动物中。诱饵48小时后的干重损失（dry weight loss）百分比被用于量化……，# 城市食腐：脊椎动物对土地覆盖及花园植被覆盖的敏感性高于无脊椎动物

"urban.scavenging.csv" 包含各地点每种诱饵类型的干重损失百分比数据，按脊椎动物或无脊椎动物分类。每个地点对应有土地覆盖类型、斑块大小及所在网格单元的不透水表面百分比。林地地点提供了纬度和经度信息，但为保护居民地址，花园地点未提供该信息。

"urban.scavenging_garden.features" 包含各花园地点内植被覆盖百分比的数据。半自然植被变量通过求和树木、野花、树篱及灌木的覆盖值创建。"Lawn"指修剪过的公共绿地草皮覆盖百分比，"ornamentalflowers"指观赏花卉的覆盖百分比，这类花卉通常是为展示而培育的选育品种。