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.
Just a thought on the Gall/Knopper Gall/Wasp thingy, for the first time ever I saw a couple of wild roses today that 'may' have been affected too, can anyone confirm or is this something different
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It is not an "anti-squirrel rant", more a recognition that grey squirrels are an alien species in the uk which do what alien species do anywhere, such as rabbits in Australia or foreign bees in South America - increase exponentially and cause havoc among other species, and sometimes with people (see bees). As far as I know the only legal ways to deal with squirrels are to trap them in squirrel cages and take them to a vet to be humanely destroyed, or to shoot them. I understand that it is not legal to drown them, or to release them into the wild once caught.
On a sunnier note, squirrel-wise, I recently visited Brownsea Island (in Poole Harbour) - one of the last remaining refuges for red squirrels in southern Britain - and was delighted to spot LOTS of reds! They're doing really well there. Didn't think to look at acorns, so I don't know if the wasp problem has reached there, but the squirrels certainly seemed to be finding enough to eat.
Have there been any reasonable proposals - preferably humane! - to reduce or control the numbers of grey squirrels in Britain? I'm new to the UK and have been saddened to see how the transatlantic tree rats have taken over and almost eradicated the native squirrels. I know it's not the greys' fault personally, so to speak, but especially as I come from Australia - where introduced species (mainly from Britain!!) are a HUGE and devastating environmental problem - I just wish something could be done about this.
I had a quick look at several oaks along lanes in SW Norfolk yesterday. Some trees seem unaffected, but about half had strange shaped acorns - but also healthy acorns on the same tree. This seems to be turning into an anti-grey squirrel rant - I don't have much of a problem with them - but they are certainly increasing in number. OK they raid the bird feeders, but the real demons at garden-wrecking are slugs - but I can't kill them as the hedgehogs will go hungry! However to return to the acorn problem, there are fewer acorns than usual on all the oaks I saw yesterday - and fewer conkers on the horse chestnuts. I guess this is the result of the weird weather this year which has affected apple and pear crops locally. Oh and the jays are also on the increase round here!