This week’s picture shows a handsome male blackbird.
I have received an interesting letter from “I Spy” of Dunbar, who has closely studied his garden blackbirds. You may be forgiven for thinking all blackbirds are black.
In fact only the adult males like this one are. Females and juveniles are mottled brown, the juvenile males only gradually turning black by the following year, and not gaining the trademark bright yellow bill until their first breeding season.
Both adults will feed chicks in the nest but as soon as the young fledge and hide around the garden, the female has usually laid another clutch of eggs, leaving the male to feed and protect the fledged ones.
This way blackbirds can rear two, three or even four broods in a season, though, of course, mortality is high. Weather, starvation and predation ensure blackbird numbers remain fairly level, despite laying so many eggs. When you finally see the female feeding fledged youngsters, it usually means they are her last brood of the summer and she is not going to lay again that year. By this point you may have blackbirds of varying ages around your garden.
As “I Spy” says, all will look very different, with varying amounts of mottling and degrees of yellow on their bills. This is what makes bird study so challenging, one species can have numerous appearances depending on age, sex and season.
It is all fascinating stuff as “I Spy” and I obviously agree.