Influence of linear versus network corridors on the movement and dispersal of the bush-cricket Metrioptera roeseli (Orthoptera: Tettigoniidae) in an experimental landscape

Abstract

Abstract. Linear landscape elements are generally considered beneficial for promoting the movements of species between isolated habitats. However, relatively little consideration has been given to the effect of interconnections (nodes) between these elements: e.g. a simple linear element offers limited options for movement, whereas a network of such structures provides an exponential increase in potential pathways. In this pilot study we compared two experimental landscapes (single versus a lattice of four interconnected linear elements) in terms of their effect on the movement of males of Roesel's bush-cricket (Metrioptera roeseli) (Orthoptera: Tettigoniidae). Emigration of released bush-crickets from experimental landscapes was greater if there was a single rather than a lattice of linear elements (corridors). In the landscape with a lattice of corridors, 50% of the bush-crickets changed their direction of movement at nodes at least once. There was also evidence that nodes were attractive to bush-crickets; a higher proportion of individuals were found in and around nodes than in adjoining corridors, with the strength of this effect (i.e. aggregation at nodes) increasing with time. Thus nodes may not only affect the direction of movement but may also act as a local attractant. These effects may have an important role in the movement of species and their success in colonizing fragmented landscapes. These results indicate that in future landscape planning more consideration should be given to the connectivity between linear landscape elements as it is likely to be important in determining the movement and distribution of species.

Rural avenues as dispersal corridors for the vulnerable saproxylic beetle Elater ferrugineus in a fragmented agricultural landscape

“…Our conclusion is consistent with several previous studies dealing with the role of linear tree or bush habitats as ecological corridors for diverse groups of organisms, including snails (Arnaud 2003), ground beetles (Jopp and Reuter 2005;Jordán et al 2007), crickets (Berggren et al 2002;Eriksson et al 2013) and birds (Gillies and St Clair 2008). In contrast, some other studies did not provide evidence for a beneficial effect of corridors (Haddad et al 2003;Ö ckinger and Smith 2008;Å ström and Pärt 2013).…”

A clue to invasion success: genetic diversity quickly rebounds after introduction bottlenecks

“…This highly controlled, long-term and detailed study setup gave us a unique opportunity to address questions on genetic processes in this non-native species and investigate mechanisms behind these. In combination with knowledge about the species' colonization history (Kaňuch et al 2013;Preuss et al 2015), dispersal behaviour (Berggren et al 2001(Berggren et al , 2002Hochkirch and Damerau 2009;Eriksson et al 2013;Preuss et al 2014) and adaptations (Kaňuch et al 2014(Kaňuch et al , 2020, this creates opportunities that, to our knowledge, previously have not existed in any other system. The introduction sites have been censused regularly in order to gather information on the species establishment success, population dynamics and local dispersal, and this allowed us to obtain fundamental information about genetic processes and patterns associated with early establishment success.…”

Gene flow relates to evolutionary divergence among populations at the range margin

“…The nymphs go through six or seven instars before they are fully developed and in northern Europe individuals usually reach maturity in July. Environmental factors as well as interactions with other individuals influence the species dispersal behaviour between habitats ( Berggren, 2004 , 2005 ; Eriksson, Low & Berggren, 2013 ). The species has two wing forms; a common short-winged form that disperses mainly through walking and an easily identified rare long-winged form that is capable of active flight and usually occurs during rapid colonisation events.…”