Do green roofs provide habitat for bats in urban areas?

Published source details Pearce H. & Walters C.L. (2012) Do green roofs provide habitat for bats in urban areas?. Acta Chiropterologica, 14, 469-478.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Create or restore bat foraging habitat in urban areas Action Link

Create or restore bat foraging habitat in urban areas

A replicated, controlled, site comparison study in 2010 of 39 green roofs in Greater London, UK (Pearce & Walters 2012) found that ‘biodiverse’ green roofs had higher bat activity than conventional roofs, but ‘sedum’ green roofs had similar or lower bat activity than conventional roofs. When a small amount (<33%) of natural foraging habitat was located within 100 m of roofs, bat activity was higher over ‘biodiverse’ green roofs (average 7 bat passes/night) than conventional roofs (average 1.3 bat passes/night), and similar over ‘sedum’ green roofs (average 1 bat pass/night) and conventional roofs. However, when higher amounts of natural habitat cover were located within 100 m of roofs (33–66%), bat activity was similar between ‘biodiverse’ green roofs (average 10 bat passes/night) and conventional roofs (average 12 bat passes/night), and lower over ‘sedum’ green roofs (average 4 bat passes/night). Four bat species or species groups were recorded in total (see original paper for data for individual species). All green roofs had shallow substrate (20–200 mm). ‘Biodiverse’ roofs were planted with a variety of wild flowers, herbs, sedums, mosses, and grasses. ‘Sedum’ roofs were planted with low-growing succulent plants. Conventional roofs were flat or shallow pitched with bitumen felt or paving slabs. Bat activity was recorded over each of 13 biodiverse, nine sedum and 17 conventional roofs for seven full nights in May–September 2010.

(Summarised by: Anna Berthinussen)