Wing shape determines how far birds disperse

Different wing shapes of birds from the Royal Ontario Museum Collections. Credit: Santiago Claramunt. Royal Ontario Museum
Complex demographic and genetic factors are believed to influence bird dispersal movements. Santiago Claramunt is Associate Curator of Birds at Royal Ontario Museum (ROM), and Assistant Professor in Department of Ecology and Evolutionary Biology of University of Toronto. He suggests that bird dispersal distances may depend on the morphology and flight performance of the wings. The journal Ecology published the study "Flight efficiency accounts for differences in natal distances in birds".

How far can a bird travel to establish a new territory? This is an important question in ecology and evolution. We still don't know much about young birds' movements despite great advancements in tracking technology. Natal dispersal is the movement of birds from their birthplace to a new breeding location. This has important implications for bird demography, genetic connectivity and conservation.

According to the study, it is possible to predict bird dispersal abilities from wing morphology. This could be useful in biodiversity conservation. Climate change and habitat fragmentation have a significant impact on bird populations. The ability of species to move across landscapes can help determine which species will thrive or become endangered. These impacts will be more difficult for species with lower flight capabilities. says Claramunt. Claramunt: Previous research has shown that birds without flight are more likely to die, while birds with low flight abilities may be equally at risk. "We can identify species most at risk by using museum specimens to assess flight abilities."

Three specimens of wing from the Royal Ontario Museum Credit: Santiago Claramunt. Royal Ontario Museum

The British Trust for Ornithology bird-ringing data was used to evaluate the relationship between flight efficiency, natal dispersal distances and flight efficiency for 75 British Island bird species. The measurements of the size and shape of bird wings were taken from the collections at the Royal Ontario Museum and the Louisiana State University Museum of Natural Science and the University of Washington Burke Museum.

Hirundo rustica is a species that has long wings and is efficient in flying. House Sparrows, Passer domesticus, however, have short wings and stay close to their nesting sites.

Studies in bird aerodynamics have shown that long-distance flights are most effective when the wings are long and elongated. This prediction is confirmed by a new study in dispersal distances.

Learn more Darker-winged birds are better at flying

More information: Santiago Claramunt. Flight efficiency explains differences between natal dispersal distances for birds. Ecology (2021). Information from Ecology Santiago Claramunt: Flight efficiency explains different natal dispersal distances for birds, (2021). DOI: 10.1002/ecy.3442

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