I CALLED round to visit Kevin, who owns land near the edge of the bog.
He came out of the house saying: "You’re just the fellow I need. There’s been this flock of little birds on the avenue all morning and I can’t work out what they are. It’s very hard to see the colour of them when you’re looking up against a grey sky".
Kevin’s interested in birds and quite good at identifying them, so this might be a tricky assignment. I got binoculars out of the car and followed him down the avenue.
It was lined with alder trees that he’d planted. It was a good choice because the soil was peaty, waterlogged and low in nutrients and the alders, because they can fabricate their own nitrogen in their root nodules, had flourished where other species would have struggled. And the trees were alive with little birds, at least 50 or 60 of them, active, noisy, acrobatic and very, very small. I had a good idea what they were, but I lifted the binoculars to make quite sure.
It certainly was hard to be precise about colour, but there was a definite hint of pale olive green. Then one of them hung upside down from a slender twig and I got it in focus. The top of its head was bright yellow. "It’s a flock of goldcrests," I announced.
I stayed to watch them for a while because I was interested in what they were up to. The bird books say that goldcrests eat small spiders and small insects that they collect high in the canopy of both deciduous and coniferous woods.
But two things have been happening recently. Firstly the numbers of small insects and spiders in the tree tops has declined because winter is coming in. Secondly the number of goldcrests has greatly increased as our resident birds have been joined by winter migrants from more northerly countries. So, like many small birds in the winter months, they had become vegetarians.
They are the smallest Irish bird, weighing only five grams and were using the advantage of their lightness to hang from the tips of the branches and to probe into the scales of the alder cones with their tiny beaks.
I picked a few of the cones myself and rubbed them in my palms, using the movement that men used to use when they were preparing plug tobacco for the pipe. The cones gave up large quantities of little cinnamon coloured seeds. These were what the goldcrests were eating.
Alders are the only trees I know that have cones, but also have leaves, rather than needles. And the alder cone is wonderful.
The alder family has male and female flowers on the same tree. The male flowers are the catkins, which are small and tight at this time of year, but will swell and turn purple as the winter progresses, and eventually shed quantities of yellow pollen. The female flowers, which tend to grow lower down on the tree, start as tight green cones about the size of a finger nail and then go brown as they ripen.
In the wild most alders grow near rivers or lakes. The ripe cones are incredibly buoyant and, because they ride so high in the water, the wind and current can carry them long distances before they land on a patch of mud and germinate. This is the only Irish tree that uses water as the main means of seed dispersal.
Pick a few alder cones. Rub the seed out of some of them and drop the rest into water and see what happens.
dick.warner@examiner.ie
a d v e r t i s e m e n t
This appeared in the printed version of the Irish Examiner Monday, November 26, 2007
