Determinants of natal dispersal distances in North American birds

Abstract

Natal dispersal—the movement from birth site to first breeding site—determines demographic and population genetic dynamics and has important consequences for ecological and evolutionary processes. Recent work suggested that one of the main factors determining natal dispersal distances is the cost of locomotion. We evaluated this hypothesis using band recovery data to estimate natal dispersal distances for 50 North American bird species. We then analyzed the relationships between dispersal distances and a suite of morphological and ecological predictors, including proxies for the cost of locomotion (flight efficiency), using phylogenetic regression models. We found that flight efficiency, population size, and habitat influence natal dispersal distances. We discuss how the effects of population size and habitat can also be related to mobility and locomotion. Our findings are consistent with a predominant effect of adaptations for mobility on dispersal distances.

New methods for estimating the total wing area of birds

“…Given the historical limitation of obtaining total wing area estimates, the hand‐wing index has been extensively used as a proxy for aspect ratio and flight efficiency in studies of macroecology and evolution (Sheard et al, 2020; Tobias et al, 2020; Weeks et al, 2022). However, the actual aspect ratio and the lift‐to‐drag ratio are better proxies of long‐distance flight efficiency (Chu & Claramunt, 2023; Claramunt, 2021). The new folded‐wing method will make possible the use of these better proxies of flight efficiency in large‐scale comparative analyses of bird flight and dispersal in birds.…”

“…To evaluate the performance of the new folded‐wing method in a proxy for flight performance, we evaluated the correlation between aspect ratio and natal dispersal distances in North American birds. We used natal dispersal distance estimates from Chu and Claramunt (2023) and added estimates from Martin and Fahrig (2018) for an additional six species to increase the sample of small species: Cardinalis cardinalis , Archilochus colubris , Dumetella carolinensis , Passerina cyanea , Thryothorus ludovicianus , and Zenaida asiatica . We measured WL and S1 in 93 ROM specimens that reported the wingspan in their labels, including several used for the previous analyses, and estimated their total wing areas using the Ellipse model, and the corresponding wing aspect ratio (Appendix 2).…”

“…We measured WL and S1 in 93 ROM specimens that reported the wingspan in their labels, including several used for the previous analyses, and estimated their total wing areas using the Ellipse model, and the corresponding wing aspect ratio (Appendix 2). We then evaluated the correlation between aspect ratio and natal dispersal distances and compared the results with those obtained by Chu and Claramunt (2023), which used the traditional spread-wing method. We used PGLS regressions as before and compared models using the Akaike Information Criterion (AIC, Burnham & Anderson, 2002).…”

“…Since most birds disperse by flying, and flight performance depends on the morphology of the wings, it is possible to quantify the dispersal ability of species from their wing morphology (Claramunt & Wright, 2017; Desrochers, 2010). In particular, there is mounting evidence indicating that birds with more aerodynamically efficient wings (elongated, high aspect ratio) disperse further than those with less efficient wings (Chu & Claramunt, 2023; Claramunt, 2021; Weeks et al, 2022). The morphological characteristic of the wings that affects long‐distance flight efficiency the most is the aspect ratio (Norberg, 1990; Pennycuick, 2008; Taylor & Thomas, 2014).…”

Restricted dispersal and inbreeding in a high‐elevation bird across the ‘sky islands’ of the European Alps

“…However, high flight efficiency and the capability to cover large distances during migration do not necessarily imply high dispersal distances or rates: dispersal can indeed be limited in even highly mobile birds, such as long‐distance migrants, in case of high philopatry (e.g., Ceresa et al., 2016; García et al., 2021; Hansson et al., 2002; Rönkä et al., 2021). The relationship between migration habits and dispersal ability in birds is still not fully understood, and it is possible that they are decoupled (Chu & Claramunt, 2023). Limited dispersal due to philopatry likely occurs also in our study system, given the detection of closely related individuals within the same breeding areas (Figure 4).…”