Differences in wing morphology between juvenile and adult European Turtle DovesStreptopelia turtur: implications for migration and predator escape

Abstract

Behaviour has direct links to wing morphology in bird species. Many studies have postulated migration to be one of the most important forces of selection acting on wing morphology, particularly in relation to wing pointedness. Studies in passerines have found that adults have longer and more pointed wings than juveniles, especially in migratory species. We analysed differences in wing morphology between age groups of the European Turtle Dove, a non‐passerine migratory species that benefits from rounded wings during their daily activity, due to its ground‐feeding behaviour and acrobatic flight style. Our results show that adults of this species have longer but more rounded wings than juveniles. This suggests that in this species wing morphology in juveniles is selected to facilitate the first migration, whereas other selection forces (e.g. flight manoeuvrability) are more important after the first moult. These data also explain why juveniles are not as adept at escaping from predators or hunters as adults.

Age-Related Variation in Wing Shape Differs between Bird Orders: Implications for Interpretation of the Pointedness Index (C2 Axis) in a Size-Constrained Principal Component Analysis (SCCA)

“…Our results emphasise that the pattern of variation in wing shape between age groups is different between passerines and the studied non-passerines, due to a variable pattern of elongation in different primary feathers during the moult. Our data indicate, as has been shown previously (Cabodevilla et al, 2018), in general, with the first complete moult new primary feathers grow longer, particularly in non-passerines. However, at the same time, each feather grows in different proportions.…”

“…These species are all migrants, but they also have pronounced terrestrial habits (del Hoyo et al, 1994;del Hoyo et al, 1996;del Hoyo et al, 1997). It is possible that their juveniles are relatively more affected by the selection force of migration, where more pointed wings improve their chances of surviving the first migration (Bowlin & wikelski, 2008;Vágási et al, 2016), an interpretation that was put forward in an earlier study on the Turtle Dove (Cabodevilla et al, 2018). However, a more pointed wing in juveniles has also been found in Red-legged Partridges (nadal et al, 2017), which are not migratory.…”

“…Among the few studies that have assessed variation between age classes in wing shape in nonpasserine birds, one carried out on western Sandpipers Calidris mauri (Charadriiformes), a migratory species, found the same pattern as in passerines, with juveniles having more rounded wings than adults (Fernández & Lank, 2007). In turn, two other studies, of Red-Legged Partridges Alectoris rufa (Galliformes, sedentary) and European Turtle Doves Streptopelia turtur (Columbiformes, migratory) found the opposite pattern (nadal et al, 2017;Cabodevilla et al, 2018). This illustrates that the pattern of wing shape differences between juvenile and adult passerines cannot be generalised to all species and bird orders.…”

“…The most important variable that makes this heterogeneity possible is wing shape (Hickman et al, 2008). wing morphology is directly linked to bird activity and behaviour (del Hoyo et al, 1997;Lockwood et al, 1998;Burns & ydenberg, 2002;Swaddle & Lockwood, 2003) and thus provides information about the relative importance of different activities and behaviours in the life of birds (Pérez-Tris & Tellería, 2001;nadal et al, 2017;Cabodevilla et al, 2018).…”

“…This illustrates that the pattern of wing shape differences between juvenile and adult passerines cannot be generalised to all species and bird orders. The only pattern that seems to hold true across bird species and orders is that adults have longer wings than juveniles (Figuerola & Gutiérrez, 2000;nowakowski, 2002;Green et al, 2009;Furness & Furness, 2016;Cabodevilla et al, 2018).…”