Holly Days

Female Blackbird picking a Holly berry

In the last few days I have watched a pair of woodpigeons and a Blackbird feeding on holly berries. This time of the year, Holly berries are an important source of winter food for of all British thrushes, including the Blackbird; robins, blackcap and woodpigeons also regularly feed on them. It is Holly tree defence by Mistle thrushes to feed on the berries that has the highest ecological significance. Holly berries keep very well even after strong frosts, and this makes them ideal trees for Mistle thrushes to defend. Mistle thrushes defence of the tree can be overwhelmed by flocks of hungry birds on periods of frost when the tree can provide emergency food than otherwise wouldn't exist. Berries on successfully defended trees can last until July, whereas undefended ones are already devoid of berries in January.

Holly berries

A bush or small tree, Holly can reach up 10 m of hight, it flowers in May and June and it is dioecious, which means that there are male and female trees and only female ones produce berries.

A large female Holly growing on a street in Hull

Holly male flowers and buds in early May

Hollies are pollinated by bees and bumblebees. Holly Blue butterflies also visit the flowers and in April the females of the Holly Blue can be seen laying their eggs on young shoots and buds at the tip of the branches.

Female Holly Blue laying eggs

Given that they are evergreen and well defended by their hard, spiky leafs, Holly is also used for shelter and as a good nesting tree by many birds.
Sources: Snow, B. and D. Snow (1988) Birds and Berries. T&AD Poyser, Calton.

A new wood for Hull: Wilberforce Wood

An oak sapling just planted

Today it was Tree O'clock, an attempt to beat the world record of most trees planted in one hour. We took a few oaks with us, some saplings we had grown from acorns we collected in Sherwood Forest three years ago, and some others we collected in a garden centre as part of the scheme. The day was promising, sunny sky, no wind and relatively mild. We chose to join forces with The Woodland Trust to help create a new forest in Hull, Wilberforce Wood. A few years ago the site was agricultural land with strongly boggy tendencies, according to the satellite photos by Google Earth, as it is right on the floodplain of the river Hull, in North Carr. We planted mostly Alder, a native species well suited to wet areas and that grows quickly. In all we managed to plant 1600 saplings in one hour, together with around 20 other volunteers. Many holes - filled with water to the rim - had been dug in advance so it wasn't back-breaking work, just very muddy. Many wolf spiders were active, Meadow Pipits and Goldfinches chirped and there were even some flowering buttercups to enliven the day.

A view of the site

Creeping Buttercup, Ranunculus repens

How to get there

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