Predicting dispersal distance in mammals: a trait‐based approach

Abstract

Summary1. Dispersal is one of the principal mechanisms influencing ecological and evolutionary processes but quantitative empirical data are unfortunately scarce. As dispersal is likely to influence population responses to climate change, whether by adaptation or by migration, there is an urgent need to obtain estimates of dispersal distance. 2. Cross-species correlative approaches identifying predictors of dispersal distance can provide much-needed insights into this data-scarce area. Here, we describe the compilation of a new data set of natal dispersal distances and use it to test life-history predictors of dispersal distance in mammals and examine the strength of the phylogenetic signal in dispersal distance. 3. We find that both maximum and median dispersal distances have strong phylogenetic signals. No single model performs best in describing either maximum or median dispersal distances when phylogeny is taken into account but many models show high explanatory power, suggesting that dispersal distance per generation can be estimated for mammals with comparatively little data availability. 4. Home range area, geographic range size and body mass are identified as the most important terms across models. Cross-validation of models supports the ability of these variables to predict dispersal distances, suggesting that models may be extended to species where dispersal distance is unknown.

Biogeography of time partitioning in mammals

“…We found significant phylogenetic conservation in time-partitioning strategy within mammals as a whole ( (35), and 0.84 for dispersal distance (36). The global distributions of species richness within temporal niches, however, vary strikingly ( Fig.…”

Comparative Tests of Birds Support a Link between Sex-Biased Dispersal and Body Size

“…These variance/ randomization tests were significant for all seven continuous characters, except for distance ratio. Thus, all continuous characters, except for one, have phylogenetic signal, which thereby supported the use of phylogenies in their comparative tests [13]. Figure 1).…”

“…Conversely, previous studies of species-specific dispersal have focused instead on the potential effects of other life history traits such as body size and territory area [9][10][11]. In particular, prior species-specific investigations have found that the natal dispersal distances (hereafter, referred to as distances) of a group are positively correlated with body size [12,13]. In animals, one explanation for this positive correlation is that the mass-specific energy cost of transport (COT) decreases with body size, thereby making it relatively cheaper for larger species to move farther [14,15].…”

“…The significance of each correlation was tested with Pearson's r. These correlation analyses were complemented with ordinary least squares regressions whose y intercept was set to 0 [22]. Characters of mass are routinely taken in regression analyses as the independent variables [9][10][11][12][13], because body size imposes physical constraints on the variation of many biological traits [14]. Thus, the mass and mass ratio characters were treated as the independent variables in their regressions with distance and distance ratio.…”

Identifying conservation priorities when data are scanty: A case study with small mammals in Italy

“…Short dispersal distances mean that declining populations may not be sustained by immigration, and that recolonisation following local extinction may not occur (Brown and Kodric-Brown, 1977). Considering that dispersal distances are not available for most of the species considered here, the home range diameter was used as a proxy of the vagility of each species (Bright, 1993;Whitmee and Orme, 2013;Santini et al, 2013). This was calculated from the mean home range area by assuming that the range was circular, and for riparian species the total length of the linear range was used (Bright, 1993).…”