Daniel Field

Today, birds are the most diverse and globally widespread group of terrestrial vertebrate animals -- there are nearly 11,000 living species, only a handful of ancestral bird lineages succeeded in surviving the mass extinction event 66 million years ago, and all of today's amazing living bird diversity can be traced to these ancient survivors.

It may have taken on the order of 100 years for the' fern spike' to begin, and about 1,000 years for forest communities to rebound, once forests were back, the ancestors of today's modern tree-dwelling birds could -- and did -- move into the trees. By a couple of millions of years after the asteroid impact, we have direct evidence of arboreal fossil birds.

Human activity is causing deforestation on a massive scale, we know that the diversity of bird communities is impacted by the availability of forests -- when forests are cut down in favor of, for example, palm oil monoculture, bird diversity is slashed. It's probable that, if this kind of deforestation continues unabated, it will leave an indelible signature on the evolution of birdlife.