Ingo Oeland/Alamy
In our local bush in Australia, there are two types of birds: those that walk, such as magpies, and those that hop, such as kookaburras. Is one of these groups more advanced than the other?
Pauline Provini, Interdisciplinary Research Centre, Paris, France
Why certain bird species walk while others hop is a question that scientists have tried to elucidate for decades. There are three main hypotheses, yet there are always exceptions among the huge diversity of bird species on Earth.
The first is linked to their phylogeny or place on the family tree. Bird species inherit their walking or jumping…
