Blue Tit   (Cyanistes caeruleus)

The Blue Tit is one of those birds that often go under the radar but on closer inspection, is a quite remarkable mix of blue, yellow, white and green plumage. Being half the size of a Robin, it is also quite the acrobat, being able to reach the outermost of tree branches and readily adapts to garden feeders.

A common bird on Barnes and generally sedentary, food consists of insects, seeds and nuts, but especially caterpillars. The timing of emergence and abundance of these can be critical for breeding success. Birds in general will not tackle the caterpillars of the Oak Processionary Moth (OPM) presumably due to the toxic nature of the hairs but it seems Blue and Great Tits will predate the young caterpillars before the hairs begin to grow.

Hopefully, having a number of nest boxes on the Common that are often used by Blue Tits may help to an extent with the OPM issue but generally any cavity or crack in a tree may be used for nesting. Nest building begins in late March, usually with a layer of moss, followed by hair, leaves, feathers and spider webs. Interestingly, there has been increasing evidence of birds using aromatic plants such as lavender, mint and fennel leaves to line their nests, presumably sterilising the area and making it safer to raise chicks in.

Usually raising just a single brood, around 7–14 eggs are laid from late April with incubation only beginning once all the eggs have been laid.  Once hatched, the chicks spend approximately three weeks in the nest before fledging.

While the UK population appears to be relatively stable, there have been worrying reports from Germany about a new disease –  Suttonella ornithocola that seems to be affecting birds particularly Blue Tits – so we will need to be vigilant and care taken about regularly cleaning garden feeders but it looks as though the youngsters in Ranelagh Woods are doing well this year.

A Podmore

Images: A Wilson