River Lagan, Belfast: Going through puberty is an exhausting business, but that is effectively what our birds are doing this time of year

In the high wind, black-headed gulls are shrieking like teenagers on a rollercoaster. Quick and graceful as terns, they swerve and jockey over the river, goading each other with jealous cries. As I continue walking along the bank, I watch for the flash of white at the leading edge of their wings – a more reliable cue to species identity than the mutable head colour.

The dark head of an adult black-headed gull, Chroicocephalus ridibundus, is actually chocolate-brown. Along with sharply defined black wing-tips and carmine-red bill and legs, a complete hood is an “honest signal” of sexual maturity. Good genes and good nutrition can’t be faked.