Ageing birds

 We are still increasing the number of birds ringed this year, with feeding stations still continuing to attract a few birds, with some Summer visiting warblers beginning to show up. 

Last week we also paid a first visit of the year to our Grey Heron colony to ring the chicks with normal metal rings and larger more easily read in the field plastic rings. We were a body short on the team which meant we had no-one to take photographs--but we hope there will be some form what we hope will be a second visit soon.

Meanwhile, here's a reminder of some of the feathers we examine in order to age a bird as 'juvenile'-ie hatched sometime in 2022, and 'adult' ie hatched sometime before 2022.

These two Greenfinch illustrate the point very well:-

This is the tail of an adult -the feathers are rounded and the ends are black with grey edgings. Compare this to a juvenile tail:-

The feathers arenot as black, and the tips are pointed with only a narrow grey edge.

The wings of the same two birds-first the adult:-

The greater coverts (1) are all the same generation, as are the primary coverts (2) which are rounded, green outer edged and tipped with grey. The alula, (3), is bright yeallow.

Now the juvenile wing:-

The outer4 greater coverts (1) are a different shape and colour ( juvenile) from the inner ones. The primary coverts (2)don't have a green outer web or tipped grey; and the alula (3) is mainly grey rather than yellow.

If you look carefully you can pick out most of these features with careful study.