Tree silhouettes in winter

Every autumn, as the last leaf falls, I've had good intentions of recording a set of images of the characteristic silhouettes of different tree species in winter. They are all distinctive and beautiful in their various ways.

This winter I finally made a start but I hadn't bargained on how difficult it would be to find good isolated examples of trees silhouetted again a clear sky background, so progress has been slow. Anyway, here are a few, that I hope to add to before bud burst begins in a few weeks' time.  

Sycamore Acer pseudoplatanus. Only the tree on the left has had enough space to develop symmetrical growth; the two on the right have got in each other's way.

Horse chestnut Aesculus hippocastanum. Those almost horizontal heavy lower limbs are characteristic; in the rare absence of grazing animals they'll sweep almost down to the ground and are usually the first to be shed from old trees in gales.

Ash Fraxinus excelsior. The upward sweep of the rather thick twigs is characteristic.

Durmast oak Quercus petraea