Monday, 27 November 2017

Fully-fledged Frogmouths

Two well-grown frogmouth fledglings with their father on the right
On the 18th October this year I posted a feature on the first brood of Tawny Frogmouths to fledge in my study area, in Canberra. They left the nest on the 15th, and last weekend when they were six weeks old, they were fully-fledged, well almost. Compare the recent image above with that below of the same brood last month.

The youngsters now have fully-grown tail feathers, and in these pictures it can be seen how the young birds have rounded tips to these, while those of the adults are pointed. This is a common feature in birds.

Also, the young birds' under-tail coverts are still downy and white, while the adult's coverts are stiffer feathers and coloured for camouflage.

The same three birds on the 15th October - six weeks previously
Six weeks ago the young birds were only just out of the nest and still downy. Although they had well-enough developed flight feathers to flutter between trees for safety and to follow their parents around as they hunted.

The downy newly-fledged chicks 
The chicks have now lost most of their downy feathers, but a few still hung around their faces, giving the birds that still-young appearance. They could be dependent on their adults for another month yet and stay with them for longer, into the autumn or even stay with them till the next breeding season.

So at what stage can they be considered as having fledged? Well, for my study, I use the day they leave the nest as that is the only figure I can count for every breeding attempt. Many of the birds disappear into the woods after that. This is standard procedure to describe birds that have left the nest. Other birds which I study, such as Golden eagles, fledge at about twelve weeks old, but stay with their parents for another three months.

Soft downy face feathers
As is usual, it was the male who perched close to the young birds. He is larger and can give more protection against predators. The female was perched on an adjacent branch of the same tree, ready to fly in and help if any danger did approach.

The adult female