Nature Notes (18th Dec. 2014)
I look out of my window and there is our splendid oak tree, now devoid of leaves, its architecture made visible as are the squirrels, tits and finches that make such good use of it. To my right my neighbour’s holly tree still has some berries left though most have already been gobbled up by wave after wave of blackbirds on their movement south for winter and, nearer the house, the trellis arch is covered in a thick pelt of ivy. As the old song has it:
“The oak and the ash and the bonny ivy tree,
They flourish at home in my ain countree.”
Of course, ivy is not a tree. It’s a climber – though in fact it runs along the ground as happily as it scrambles up walls and trees. The other day as I was driving towards Ilkley I noticed a man pausing at the roadside, scrutinizing an ivy-covered wall. Ivy actually flowers as winter approaches and its nectar-rich flowers are a vital food plant for late flying insects. The loud buzzing that these make on a sunny winter day is very arresting! Its berries ripen through the winter providing food for birds when few other wild fruits are left. The thick covering in hedgerows, on trees and on my trellis provide perfect protection for roosting and nesting birds. An important plant then – and, contrary to popular belief, – not harmful to the trees it climbs on its way to the light.
The rather insignificant greeny-white flowers on holly provide nectar for insects emerging in early spring. A holly tree bears either male or female flowers, not both, so is very dependent on pollinating insects. As a result, only female trees bear berries. When I was a child we knew where these trees were – and such knowledge was a closely guarded secret! We also had a den in a holly thicket. Rather prickly to get into – but, once inside, like a cave and, the dead leaves swept aside, you were snug, well insulated by those thick leaves – a refuge for many wild creatures as well as children.
One of our prettiest butterflies – the holly blue – overwinters as a pupa, emerges around April and lays its eggs on holly buds on which the larva feed. The second generation thus produced lay their eggs on ivy, the food plant for their larvae. It pleases me to think that the plants featured in my favourite carol are united by such a delightful harbinger of Spring.
Photo by Stuart Wilding [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons