How to increase the value of urban areas for butterfly conservation? A lesson from Prague nature reserves and parks

Abstract

Abstract. Cities contain only a low representation of natural and semi-natural habitats, existing in fragments surrounded by built-up areas. In 2003-2004, we surveyed butterflies and Zygaenidae moths in 21 reserves and 4 parks within the city of Prague, Czech Republic, situated from the periphery to city centre. A total of 85 species (47% of the Czech fauna of the study groups) was detected, 22 of them being of conservation concern. Ordination analyses of the local assemblages revealed that the richest sites were large, situated far from the city centre, on alkaline bedrocks, south-to southwest oriented, and hosting high numbers of vegetation types and vascular plant species. We then used generalised linear models to fit responses of individual species to the main ordination gradient, corresponding to increasing urbanisation. Out of 60 species that met criteria for the modelling, none responded positively to urbanisation. Twenty displayed negative linear response; these urban avoiders contained a surplus of mesophilous species presumably preferring rural landscapes. Further 29 species (suburban adaptable) responded in domed manners, peaking at the city periphery. Prevailing among them were xerophilous specialists inhabiting large grassland reserves at the Prague outskirts. Finally, eleven urban tolerant species did not respond to urbanisation at all, containing three highly mobile species, three xerothermophilous specialists, and five species utilising shrubs or trees and finding suitable conditions even in urban parks. Suburban adaptable butterflies apparently benefit from such suburban environments as gardens, road or railway verges, collectively increasing the connectivity of remnants of seminatural habitats. The fact that arboreal species persist even in urban parks, whereas common grassland species are absent there, implies that the quality of urban habitats might be increased by a more sensitive management of urban green spaces, such as leaving aside small temporary fallows or adapting lawns mowing schemes.

Abundances and movement of the Scarce Copper butterfly (Lycaena virgaureae) on future building sites at a settlement fringe in southern Sweden

“…Konvicka and Kadlec 2011). The results of butterfly monitoring schemes by residents of urban areas provide further evidence of this .…”

Timed surveys and transect walks as comparable methods for monitoring butterflies in small plots

“…Examples include surveys of small-scale species distribution in diverse landscapes (e.g., Bock et al 2007;Spitzer et al 2009), comparing butterfly faunas among multiple sites in species-rich regions (e.g., urban reserves: Konvicka and Kadlec 2011), or comparisons of recent with historical data (Wenzel et al 2006;Kadlec et al 2008). A standardisation through the time spent in the sampled site allows comparing differently sized localities (cf., Kadlec et al 2008), as well as semiquantitative recording of species abundances (Benes et al 2003;Konvicka and Kadlec 2011). As more species is observed per visit, the method is advantageous for areas with limited numbers of lepidopterists.…”

Bird Migration Advances More Strongly in Urban Environments

“…In contrast, cities may have reduced food availability of several important arthropod prey [12]. However, most studies and reviews have shown earlier plant phenology in urban areas [11]–[15], and consequently invertebrates also develop earlier and faster [14]–[17]. All of these environmental changes should positively influence bird arrival timings, and therefore we may hypothesise that cities will be associated with an earlier arrival of migratory birds than rural habitats.…”