The application of selected invasion frameworks to urban ecosystems

Urbanization is a major driver of global change. Profound human-mediated changes to urban environments have provided increased opportunities for species to invade. The desire to understand and manage biological invasions has led to an upsurge in frameworks describing the mechanisms underpinning the invasion process and the ecological and socio-economic impacts of invading taxa. This paper assesses the applicability of three commonly used invasion frameworks to urban ecosystems. The first framework describes the mechanisms leading to invasion; the second and third frameworks assess individual species, and their associated environmental and socio-economic impacts, respectively. In urban areas, the relative effectiveness of the barriers to invasion is diminished (to varying degrees) allowing a greater proportion of species to move through each subsequent invasion stage, i.e. “the urban effect” on invasion. Impact classification schemes inadequately circumscribe the full suite of impacts (negative and positive) associated with invasions in urban areas. We suggest ways of modifying these frameworks to improve their applicability to understanding and managing urban invasions.

Go to the city: urban invasions of four pipistrelle bat species in eastern Slovakia

Until now, late summer or autumn invasions into inhabited building have been regarded as phenomenon typical for the common pipistrelle, pipistrellus pipistrellus, exclusively. During the investigation of this phenomenon in the city of Košice (eastern Slovakia), we discovered that it was not always entirely specific for this species. During the period 2016–2018, we recorded 3 events out of 35 invasions, where small groups of common pipistrelles that invaded into inhabited buildings were also accompanied by individuals of two con-generic bat species, pipistrellus pygmaeus and pipistrellus kuhlii. Cryptic species p. pipistrellus and p. pygmaeus were determined by genetic test. In addition, in 2019, we recorded the first winter occurrence of another pipistrelle species, pipistrellus nathusii, in this urban environment. We conclude that areas of frequent invasive behaviour of p. pipistrellus may be sometimes associated with concomitant occurrence of other related species that share common thermal or foraging niche and such behaviour could be evidence of their urbanisation tendencies.