Optimal Width of Movement Corridors for Root Voles: Not Too Narrow and Not Too Wide

Connectivity measures: a review

“…Some authors equate connectivity to the presence and absence of corridors between small fragments (e.g., Hess 1996;Swart and Lawes 1996;Anderson and Danielson 1997;Ims and Andreassen 1999;Danielson and Hubbard 2000;Hunter 2002), with corridor width (Andreassen et al 1996a), length (Haddad 2000) or corridor continuity (Andreassen et al 1996b). Thus no assumption is made about a particular animal, only the percentage of corridors between patches out of the possible number of corridors is considered as a measure of connectivity.…”

“…Percolation theory (Orbach 1986;Stauffer and Aharony 1991) has recently been used to predict where these critical thresholds occur and thus how landscape structure might affect ecological processes O'Neill et al 1988). Measures based on the probability of moving between patches Connectivity based on organism movements has been measured as mean probability of moving between pairs of patches, also referred to as emigration or dispersal success (Andreassen et al 1996a;Gustafson and Gardner 1996;Schumaker 1996;Ruckelshaus et al 1997;Tischendorf and Fahrig 2000a;Tischendorf 2001). It can be calculated as patch transition probability,…”

The matrix alters the role of path redundancy on patch colonization rates

“…First, movement can be passive (e.g., diffusion), in which case redundancy increases random flow through landscapes (McRae et al 2008). Second, redundancies can potentially result in greater area of paths, such that individuals may prefer to move toward areas with greater habitat amount (Andreassen et al 1996). Our results cannot solely be explained by the first mechanism, because circuit theory alone, which assumes random-walk movement behavior, was insufficient to explain colonization rates (i.e., a resistance-only model provided a poor fit to the data and movements among treatments were not consistent with predictions from circuit theory).…”

“…More recently, redundancies have been emphasized in matrix structure through the use of circuit theory, which, in comparison to least-cost paths that ignore redundancy, can better explain gene flow across landscapes Beier 2007, Moore et al 2011, but see Schwartz et al 2009). Because experiments suggest that the matrix can play a mediating role on the effects of habitat linkages (Baum et al 2004, Astrom andPart 2013), similar effects could arise in redundancies of habitat linkages and matrix paths (i.e., habitat (Andreassen et al 1996). Yet it is unclear if investigations on corridor width extend to redundancies that may occur from multiple corridors or other types of multiple linkages.…”

Riparian vegetation condition influences movement and microhabitat use by Mixophyes fasciolatus in South East Queensland

“…For example, corridor width was found to be significant in root vole (Microtus oeconomus) movement, where a narrow corridor of 0.4 m was the least efficient, due to a high entrance aversion rate, while an intermediate corridor width of 1 m showed no aversion and a high linear movement rate (Andreassen et al 1996). Risk-aversion behaviour may be attributed to the increased danger associated with movements in narrow corridors, due to factors such as predation (Simberloff & Cox 1987).…”