New research shows how geology drove the diversification and spread of songbirds, the world’s most abundant bird group
Wednesday 19 October 2016 11.53 BST Last modified on Wednesday 19 October 2016 18.27 BST
Today, songbirds are the most successful group of birds on the planet. With more than 5000 species worldwide, they form half of the world’s known bird species, and have colonised almost all corners of the world (with the exception of Antarctica).
Songbirds, or Passeriformes, are often referred to as “perching birds”, which refers to the arrangement of their toes - with three toes pointing forward and one pointing backwards - which allows them to comfortably cling to trees and branches. But to the outside world, they are best known for their well-developed vocalisations. Who hasn’t delighted in waking up in the middle of a summer night by birds enthusiastically welcoming the new day?
Zoologists divide modern songbirds in three groups. Oscines (Passeri) constitute over 4000 species and can be found all over the world. Suboscines (Tyranni) are mostly found in the Neotropics, whereas the small New Zealand wrens (Acanthisitti) are limited to, you guessed it, New Zealand.
As abundant and widespread as songbirds are today, their fossil record is meager, especially the further we go back in time. The earliest known songbird as we know them comes from the early Eocene (approximately 54 million years ago) Tingamarra fauna from Murgon in southeastern Queensland, Australia (Boles, 1997). The specimen consists of only two bones, a carpometacarpus and a tibiotarsus, but exhibits anatomical features that are also found within modern day songbirds. But how did this group rise from the isolated Australian continent to worldwide domination?