Redpolls and Goldfinches feeding on Sycamore aphids

 I'm used to finding Lesser Redpolls in the coldest days of winter, when small groups feed quietly on birch catkins. Learning their cheerful 'chi-chip' call, sharper and less liquid than Greenfinches, has helped me detecting them as they move around the city. I was surprised to hear their flight calls amongst a flock of roving Goldfinches at my local cemetery, a misty but mild morning. I trained my binoculars high up on the Sycamores and spotted them, apparently gorging on the last fat sweet aphids still under the Sycamore leaves, together with the Goldfinches. Some Chaffinches and Blue and Great tits were also on the sycamores, but I'm more used to these species feeding on insects. The distance and the poor light didn't make for great photos, but I was pleased to record a behaviour I had never seen before for both Redpolls and Goldfinches.

Sycamore aphids.

Redpoll gleaning sycamore aphids.

Lesser Redpoll.

Lesser Redpoll.

Goldfinches and sycamore aphids.

Blue tit family and Sycamore aphids

I heard the rasping begging calls of blue tit fledglings coming from a Sycamore tree, which I find it is a very common occurrence. As I approached I noticed clouds of Sycamore Aphids cascading down from the tree as the adult Blue tits moved about, searching for the aphids themselves and green caterpillars (above). It was a very impressive spectacle as the light hit the aphids and amplified the effect. The tree leaves were thickly peppered with aphids, and fledglings were having a go at finding food by themselves. One of them found a long green caterpillar and wrestled with it for a while until it was able to swallow it.

I tried to capture the density of aphids flying off around the tree in this photo.

The evenly spaced, winged Sycamore aphids (Drepanosiphum platanoidis)

A fledgling begging for food.

The adult cuts the caterpillar in half before feeding the fledgling.

This young one had caught a caterpillar on its own.

You can watch one of the adults foraging and the aphids flying off here.

Birds and sycamore aphids

Sycamore aphids, Drepanosiphum platanoidis, are Sycamore specialists - and cover your car with honeydew if you happen to park underneath. All adults are winged and sit evenly spaced under leaves. In the spring, sycamores come alive with the calls of hungry Blue Tit fledglings demanding food. It is an easy job for the adults to pick the aphids from under the leaves to feed the chicks (above). Although many leaves have fallen now, there are still some in the sycamores, peppered with the black spots of, Rhytisma acerinum, the tar spot fungus, and some aphids are still in them. In the last few weeks I have seen Great Tits and Chaffinches feeding on them. Today, I watched a chaffinch hovering under the leaves picking the aphids, a most beautiful sight, which unfortunately couldn't catch on my camera.