Vane macrostructure of primary feathers and its adaptations to flight in birds

Mechanical and structural adaptations to migration in the flight feathers of a Palaearctic passerine

“…We did not predict the existence of a significant association between barb length and migration distance. The few studies that compared feather structural characteristics across multiple avian taxa with variable flight types and life histories did not consider this trait (Pap et al, 2015(Pap et al, , 2019, so it is difficult to elucidate at this point how shorter barbs could contribute to a more efficient migratory flight.…”

“…We did not predict the existence of a significant association between barb length and migration distance. The few studies that compared feather structural characteristics across multiple avian taxa with variable flight types and life histories did not consider this trait (Pap et al., 2015, 2019), so it is difficult to elucidate at this point how shorter barbs could contribute to a more efficient migratory flight. Tentatively, barb length reduction might be explained as a counterbalance for obtaining thicker rachises and longer feathers that would impact on other feather functions not relevant for migration (Weber et al., 2005).…”

“…rachis width) can determine their mechanical behaviour (i.e. bending stiffness) and potentially be under natural selection (De la Hera, Hedenström, Pérez-Tris, & Tellería, 2010;Szép, Dobránszky, Møller, Dyke, & Lendvai, 2019), the existence of intra-feather structural adaptations to migration has been mostly overlooked, with only a few recent interspecific studies in the literature (Pap et al, 2015(Pap et al, , 2019.…”

“…Finally, we explored the relationship between several feather structural characteristics and δD f , predicting that those characteristics that might facilitate feather mechanical performance and, ultimately, long‐sustained flight (e.g. longer feathers, wider rachis and more acute barb insertion angles) were favoured in birds migrating longer distances (Ennos, Hickson, & Roberts, 1995; Pap et al., 2019).…”

Flight, symmetry and barb angle evolution in the feathers of birds and other dinosaurs

“…Consequently, feathers with different barb angles may gain different feather geometries, which may influence how the feathers respond to aerodynamic forces [4]. However, the relationship between flight feather geometry and the potential flight functions has rarely been investigated in a quantitative frame [4,14].…”