The nest boxes on Jubilee Hill were cleaned out at the beginning of the month. There was nesting material in three of them, but no obvious signs of an old nest, whereas three had clearly been used in 2016. As last year, one box contained the remains of a bee moth (Aphomia sociella) nest (see left). When I removed it (with some difficulty - the material clings to the wood as if stuck on with super strong glue), I noticed a pattern of grooves in the lid of the box where i t had been attached. They are made by the caterpillars, which gnaw away at the wood to cover their silken retreats that hide their cocoons, thereby adding some extra camouflage to fool predators.
The Bee Moth is a small olive grey moth (left), with a pinkish area on its forewings, sometimes confused with Wax Moths (a serious pest of beehives). Bee moths often predate nests of Tree Bumblebees, which sometimes use nest boxes. They lay their eggs in a web and feed on nest material and other detritus. When the larvae have developed fully they feed on the wax cells where the bumblebee's own larvae are developing, but do not usually destroy the entire brood. The bee's wax cells are visible in the photo above.
The hole of box No. 5 (see photo right) had been enlarged by either a squirrel or a woodpecker, probably the former as the indentations around the hole look like chisel marks made by teeth. There was nesting material inside the box, so possibly it had predated some eggs or nestlings. One other box with a lot of droppings, but no moss or grass, was clearly being used as a winter roost.
On the same day I heard a chaffinch singing, the first time this year. Thrushes and blackbirds, great tits and robins are all starting to sing in the mornings, or have been for some time, and nuthatches and the ravens are very vocal. These last two species go silent when nesting begins, so they must still be in the preparatory stages.