Hefty Birds Fly More Efficiently, Study Finds

It may sound contradictory, but fat birds fly more efficiently than skinny ones, according to Swedish researchers.

Wind tunnel tests described in Thursday’s edition of the journal Nature show that the birds’ wing muscles are significantly more efficient when their body weight has doubled. Many birds put on large amounts of extra body fat before migrating, presumably as a fuel source.

In a separate study in the same journal, French researchers found that pelicans flying in a “V” formation flew more efficiently than those flying solo, presumably because birds in the rear of the V could fly in the leader’s airstream. Birds flying in a V had heart rates that were 14.5% slower than those flying outside a V; their flap rate was lower as well.

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Compiled by Times medical writer Thomas H. Maugh II