title: Urban gardens promote bee foraging over natural habitats and plantations.
abstract: Increasing human land use for agriculture and housing leads to the loss of natural habitat and to widespread declines in wild bees. Bee foraging dynamics and fitness depend on the availability of resources in the surrounding landscape, but how precisely landscape related resource differences affect bee foraging patterns remains unclear. To investigate how landscape and its interaction with season and weather drive foraging and resource intake in social bees, we experimentally compared foraging activity, the allocation of foragers to different resources (pollen, nectar, and resin) and overall resource intake in the Australian stingless bee Tetragonula carbonaria (Apidae, Meliponini). Bee colonies were monitored in different seasons over two years. We compared foraging patterns and resource intake between the bees' natural habitat (forests) and two landscapes differently altered by humans (suburban gardens and agricultural macadamia plantations). We found foraging activity as well as pollen and nectar forager numbers to be highest in suburban gardens, intermediate in forests and low in plantations. Foraging patterns further differed between seasons, but seasonal variations strongly differed between landscapes. Sugar and pollen intake was low in plantations, but contrary with our predictions, it was even higher in gardens than in forests. In contrast, resin intake was similar across landscapes. Consequently, differences in resource availability between natural and altered landscapes strongly affect foraging patterns and thus resource intake in social bees. While agricultural monocultures largely reduce foraging success, suburban gardens can increase resource intake well above rates found in natural habitats of bees, indicating that human activities can both decrease and increase the availability of resources in a landscape and thus reduce or enhance bee fitness.
authors: Institute of Ecology Leuphana University 21335 Lüneburg Germany; Faculty of Science, Health, Education and Engineering University of the Sunshine Coast Maroochydore 4558 Australia; Department of Animal Ecology and Tropical Biology University of Würzburg 97074 Würzburg Germany.
authors: Benjamin F
authors: BF
authors: Kaluza
authors: Faculty of Science, Health, Education and Engineering University of the Sunshine Coast Maroochydore 4558 Australia.
authors: Helen
authors: H
authors: Wallace
authors: CSIRO Ecosystem Sciences Brisbane 4001 Qld Australia.
authors: Tim A
authors: TA
authors: Heard
authors: Chair of Nature Nature Conservation and Landscape Ecology University of Freiburg 79085 Freiburg Germany.
authors: Alexandra-Maria
authors: AM
authors: Klein
authors: Department of Animal Ecology and Tropical Biology University of Würzburg 97074 Würzburg Germany.
authors: Sara D
authors: SD
authors: Leonhardt
keywords: Anthropogenic activities; climate factors; meliponines; resource availability; urbanization