Water in the city: visitation of animal wildlife to garden water sources and urban lakes

Providing garden water sources (e.g., ponds, bird baths) has become a popular and strongly promoted form of wildlife-friendly gardening, yet evidence of their use by animals is scarce and limited to a few taxa and water source types. We examined the prevalence, variety and potential value to animal wildlife of supplementary water provided within gardens of Hertfordshire, United Kingdom, using an online questionnaire and field observations of wildlife visitation to urban water sources during summer 2021. Over 70% of 105 questionnaire respondents indicated the presence of at least one water source in their garden and almost 50% had two or more. Bird baths, ground water-bowls and ponds were the most common water source types provided. During 207 h of field observation, we recorded a total of 43 taxa (birds, insects, mammals, amphibians, reptiles) visiting urban lakes and garden birth baths, ponds and ground water-bowls. Taxa richness was similar at urban lakes (30) and garden water sources (27), although approximately 50% of the taxa recorded in each location were unique to that location. Visitation rates of smaller-bodied wildlife did not differ between lakes and gardens, nor among individual water source types. Multivariate analyses indicated insect assemblages visiting lakes did not differ from those visiting garden water sources, and small bird assemblages did not differ among each water source type. These results demonstrate garden water sources, especially for smaller-bodied animals, can supplement the wildlife values contributed by urban lake systems, and should continue to be promoted as an effective conservation action.