Nicola's picture

Mysterious holes in trees

Observed: 17th March 2012 By: NicolaNicola’s reputation in PlantsNicola’s reputation in PlantsNicola’s reputation in Plants
Holes in trees (subsequently felled)
Holes in tree from last year (subsequently felled)
Holes in tree (still standing)

Predominantly found in Oak sp. in a small patch of woodland adjacent to larger broad-leaved woodland and an area of grassland within a nature reserve. There is also a bridleway running along the edge of the small patch of woodland.

Species interactions

No interactions present.


jeremyr's picture

I found the exact same thing

I found the exact same thing in Lordship Rec. with young Alder and Beech. The holes were about 5 - 6 metres up and the trees were gushing clear liquid for 3 days. It was as if a woodpecker had shuffled around the tree whilst drumming..

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Syrphus's picture

The picture top left of the

The picture top left of the felled tree is caused by forestry machinery, I feel sure. The shape and distribution are not those produced by an animal. More puzzling are the marks on the standing trees, but I suspect the answer is still in the same area.

The exudation of sap is normal at this time of year if the damage hits the phloem vessels. This is how Birch and Maple syrup is collected.



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Nicola's picture


Thanks for your comments!

I'm unsure about the machinery theory because I was out volunteering with the Warden and he was the one that brought the holes to my attention. I will run it past him again this weekend though.

jeremyr's picture

in fact yes, yours do look

in fact yes, yours do look different, a bit like a chain saw tooth. No chance of that in this observation however

the arborist, horticulturalist and wildlife officer to whom I took to see it were all utterly mystified, any machinery being ruled out as they are too high, the branches to thin, and it's scattered too randomly throughout the wood. I pointed out at the time that ispot would not be able to cope with this, anyone told about the phenomena would immediately think of something, anyone witnessing it first hand was completely stumped. Someone somewhere must have seen it taking place, I'll certainly check again at the same time next year. Also in my version the hacks are regular but not machine regular

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Nicola's picture

Further info

I perhaps should add, the tree which is still standing the holes appear around the trunk. Not in one long spiral but in a few rows round at different levels. I will check just how high they are/go.

jeremyr's picture

apparently there are Borers

apparently there are Borers which the Woodpecker will go after, doing damage to the tree, particularly Birch, but also Beech and Alder. I do agree with Syrphus though that yours look much more aggressive like a chain saw tooth. The foresters tap chips clear from the chain I think. I can ask a forester friend to look at them, perhaps, he'd recognize any machinery

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Rob Coleman's picture

Sapsucking behaviour in Great

Sapsucking behaviour in Great Spotted Woodpecker (producing horizontal rows of marks, sometimes all the way up the tree) is known to occur, and is a plausible explanation for some of these pictures. Apparently, this may be relatively new behaviour - first recorded in the 1970s in this species. I'd agree the top left picture looks like machinery, though.

Rob Coleman