For over a week now, the male blackcap that wintered in our garden has been warming up his vocal chords. Seemingly oblivious to the still cold mornings, all it takes is a bit of sun for him to let slip little bursts of liquid song. ‘Our’ blackcap will most likely leave us soon, and head to Germany to breed. Some years ago now a population of blackcaps began to find that what is known as reverse migration – heading in the wrong direction, if you like – was a successful strategy, since they wound up wintering in mild, food-rich English gardens, and they’re now becoming increasingly familiar as winter denizens of suburbia.
So as welcome as it is to have blackcap song drifting through the living room window during breakfast, we may yet find ourselves devoid of it for a couple of weeks whilst we await the arrival of breeding blackcaps. Even then, our garden might not look as favourable a place for raising young as it was for seeing out the winter. I’m enjoying these little command performances while I can.
Meanwhile, chiffchaffs are performing their own complex crossover. The divide between wintering and breeding populations for chiffchaff is less clear. It is certainly possible that some stay put year round, but on the whole the next fortnight or so will see a complete changing of the guard. Whether the two or three birds chiffchaffing away at Hosehill Lake on Saturday were departing overwinterers or newly arrived migrants is difficult to say, for chiffchaffs arrive on average a fortnight earlier than blackcaps.
A few ringing stations have already seen some definite returning migrant chiffchaffs, with pollen matted into the feathers on their face. I was fortunate enough to handle, and wonder at, a bird like this last spring. They must reach stop-off points on the Mediterranean exhausted, and be in need of a quick glucose hit. Dipping deep into spring blooms for nectar, they unwittingly end up plastered in sticky pollen and then literally carry these little grains of the advancing spring north with them as they fly on.