Dalkey Tidy Towns |
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Wildlife
Newsletter for the Township of Dalkey October 2007 - Michael Ryan |
I’d heard a piece on the radio in August saying there were a lot of signs that Autumn was arriving early, not because of the wet weather in summer but due to the earlier fine spell of weather in April and May which got a lot of plants trees and wildlife off to an early start. Still I was a little bit worried about a larch tree I have growing in a pot which had started to drop its leaves in August. The vast majority of conifers keep their leaves in winter but Larches are deciduous conifers, which shed their soft spiny needles in early winter. But losing them in late summer when the weather had improved was a cause for concern. Then a week or so later I noticed that on the branches were fresh young buds. It was actually producing new growth. I was happy it seemed to have survived. You can actually get attached to plants, especially to trees and if one dies in your care you can feel quite guilty. Anyhow up Killiney Hill in early September a few days later I noticed that one of the larches hanging over the path also had fresh green new needles coming on it. Had the rise in temperature in late summer triggered the trees to produce new growth I wondered but I subsequently found out that conifers do put on a spurt of new growth from August to October producing new needles to absorb the nutrients from the sun before they become dormant for the winter. Most conifers are producing new needles all the time losing the old ones gradually whereas deciduous trees tend to lose all their leaves at once at the beginning of winter. One deciduous tree that does normally produce new leaves in August is the oak and the new leaves are known as Lammas growth. August 1st used be known as Lammas Day possibly a derivation of ‘Loafmass’ when bread was made from the first corn harvested. Oak trees are always known as the most valuable host for native insects and wildlife. Their early growth is a foodstuff for lots of caterpillars which have hatched on them and many insects live on them. Subsequently the leaves get a very rough time and become very tattered reducing their ability to absorb nutrients and to photosynthesize the sunlight. So when all the caterpillars are long hatched the tree produces new growth to take advantage of the lack of predators. Oaks retain their leaves long into winter and some even keep their leaves till new growth appears in the spring especially if they’re sheltered from the wind and the temperature doesn’t drop too low. A report came to the attention of the Biodiversity officer in Dun Laoghaire that some one had released 25 Degus on Killiney Hill. What’s a Degu I wondered? I’d never heard of them but a quick search on the computer revealed they were small rodents from Chile, close relatives of chinchilla and guinea pigs. They’re vegetarian, live in colonies in burrows and apparently make charming pets. As pets they should be kept in pairs since they’re very sociable but if one has a single one as a pet it’s recommended you should talk to it and place it where it can take part in the daily life of the family! Apparently they also like cuddling with humans. Anyhow lovely creatures as they might be one place they shouldn’t be is running wild on Killiney Hill. Evidently whoever released them had more then a single animal and apparently they have something in common with rabbits as well in the way they breed. Alien species introduced into the wild have caused terrible problems, the Grey Squirrel being one of the worst. You couldn’t help feeling sorry for the Degus as well, sociable home lovers that they are, released into the wild although it’s said they can be quite aggressive defending themselves and will face up to dogs and cats. At our public bird meetings we used tell people to keep an ear open around
the 12th October when Redwings would arrive from their Scandinavian breeding
grounds flying in huge flocks. On calm misty night around the 12th the ‘tseep’
call of the birds could be heard overhead when the bad visibility keeps the
birds low and close to artificial light. Saying that, the numbers of redwings
arriving in Ireland were well down last year, again a result of changing
climate which enabled the birds to stay closer to their breeding grounds.
There’s a vast range of food available now for the birds that come
to your garden. One that has been highly regarded is niger seed, a very small
black seed which needs a special container with tiny slits for the birds
to feed from. I had one hanging ignored from a tree for months before one
curious determined chaffinch found out how to extract them. Soon enough more
birds copied the pioneer chaffinch and the seeds began to disappear quickly.
Birds spend a lot of time observing other birds and any rewarding behaviour
is quickly copied. In my local pet shop I saw he had sunflower seed hearts,
which have been shelled evidently for the bird whose life is too busy to
shell his own seeds. And they love them. |