Sir: In addition to bluetits, coal tits, starlings, siskins and so on which feed on nut containers in winter, this year I observed robins and chaffinches on the feeders. I assumed this was a temporary aberration by unusually adaptable individuals since neither of these species seems known to feed regularly like this. However, I now see them educating their offspring to do the same. Is this evolution in the making, or simply learned behaviour being taught to a succeeding generation? Or is there an overlap?
D J WALKER