As I've wandered the trails around The Lodge recently, I've noticed something strange. Where there should be smooth, shiny, ripening acorns dangling from the oak twigs, there are distorted, crinkly growths which - to my eyes, anyway - look a bit like Ferrero Rocher chocolates...
It turns out that this is the work of a small wasp which goes by the snappy name of Andricus quercuscalicis. The weird growths themselves are known as 'knopper galls' - the word knopper being derived from a word for a knob, stud, tassel or hat.
The 'gall' is the growing acorn's response to the wasp grubs developing inside after eggs were laid there earlier in the year. In a similar way, you might have seen the robin's pincushion gall before - it's a common sight on wild rose bushes, with a tangled mass growing from the stem eventually turning red.
At The Lodge, at least, there are not many acorns to be found this autumn. The galls are turning brown and falling off the trees, and the newly-hatched wasps making their escape.
Jays are famous for their love of acorns, able to store away as many as 5,000 for a rainy (or cold) day. What will they do here this year?
As members of the crow family - clever, bold, adaptable and omnivorous - I doubt jays will go hungry. They just might need to look for some different foods in different places, so I wonder if that could mean an influx of jays to garden bird tables? In the same way, might we see squirrels launching a hunger-fuelled assault on our feeders?
Let us know what you see!
Have you spotted knopper galls on your local oak trees? Leave a comment and let me know.
The Oak tree in my garden in Bexhill, East Sussex is well and truly knoppered.
Tony
Magpies are my main pest in the garden-as soon as I replace the bird blocks or fat balls for the smaller birds, the magpies peck away at them before anything else gets a chance. I have tried every kind of feeder protector but to no avail- any suggestions? Also I have three oak trees in my garden and all have deformed acorns on them- and have done for the last few years. Unfortunately the trees are all under preservation orders so we can do nothing to them to alleviate the problem. I have no problems with the squirrels and find the way they solve the problems of obtaining the food which I try to stop them from getting is very amusing at times.
Grey squirrels, or American tree tree rats (!) may look like dear little things but they are really quite unpleasant at times. I have had bluetit babies taken from the nest, they destroy the new growth on young trees and if cornered can be quite vicious and give a nasty bite. A family invaded a colleague's airing cupboard where they started a nest and destroyed a large quantity of linen. I have nothing against red squirrels which are much more rare and are native. Invasive grey squirrels a threat to our natives,are also mutating and black ones are now being seen.
I work on the Open University campus in Milton Keynes and all of the oak trees there have been affected by the gall. Very sad... I'll start taking food in for the squirrels now.
I dont at all like the idea of a squirrell cull, dear little creatures - its not their fault - they have to eat - and pigeons are my favourite garden visitors of the birds - they have such personality!