DOI: 10.5061/dryad.2d1d7
title: Data from: Functional responses of insectivorous bats to increasing housing density support 'land-sparing' rather than ‘land-sharing’ urban growth strategies

description: Debates about ‘land-sparing’ and ‘land-sharing’ strategies for conserving
 biodiversity in cities provide an overly simplistic characterization of
 alternate planning options. Increased urbanization manifests in a number
 of ways and sophisticated analyses of how species respond to urban
 environments are required before generalizations about the relative merits
 of either planning strategy should be made. We investigated how
 insectivorous bats respond to housing density (a measure of urbanization
 intensity) and a range of habitat variables by modelling the occupancy and
 activity of 12 species in Melbourne, Australia. In addition to
 species-level analyses, species were grouped into guilds (‘matrix’,
 ‘patch’ or ‘edge’ species) depending on their ecomorphology and level of
 patch-dependency. Housing density (dwellings per hectare: dph) was the
 dominant explanatory variable of occupancy and activity of most species
 studied. Site occupancy probabilities of patch and edge species were
 reduced by half at housing densities of just 1·1–4·5 dph depending on
 species, while their activity was halved at housing densities of 2·6–10·3
 dph. The activity of two matrix species also declined, but at higher
 housing densities (reducing by half at 4·5–7·9 dph). Patch and edge
 species responded nonlinearly to tree cover at low housing densities, with
 peaks in occupancy and activity at 20–60%. This response broke down at
 medium housing densities, however, as most species were no longer present.
 Synthesis and applications. Occupancy probability and activity of almost
 all bat species studied were substantially reduced even at very low
 housing densities. Increasing tree cover had no positive effect on the
 occupancy and activity of patch and edge species once medium housing
 densities were reached. In order for land-sharing strategies to provide
 good habitat for patch and edge bat species housing densities would need
 to be so low as to be impractical in most urban planning contexts. By
 contrast, land-sparing with forested habitat remaining in 20% or more of
 the landscape could provide positive conservation outcomes for the species
 modelled here. We discuss the relevance of our findings in planning for
 conservation of bats and their habitats in other recently established and
 expanding cities.
description: bat_data_covariatesThis dataset contains acoustic data from multiple bat species and various environmental covariates collected around detector sites. Full details are provided in Caryl F.M., Lumsden L., van der Ree R., Wintle B. 2015 Functional responses of insectivorous bats to increasing housing density support 'land-sparing' rather than ‘land-sharing’ urban growth strategies. Journal of Applied Ecology. Insectivorous bats were surveyed with acoustic detectors at 176 sites separated by &gt;250 m grouped into clusters of four within 9 km2 landscapes in February to April 2010. Four detectors suffered mechanical failure and data from the successful 172 detectors are published here. Landscape-context and site-specific environmental covariates were generated for each site (see metadata tab for details) and used to examine drivers of bat species distributions in urban landscape and identify critical environmental thresholds.