Tag Archives: Nestbox

Natural History

Owl Box for Gunnersbury Triangle

Tawny Owl Nestbox
Tawny Owl Nestbox

It was a very rainy workday, and with only two of us around we wondered what to do. It was time for an indoor project that we’d been putting off … make an owl box. Tawny Owls might seem surprising citydwellers, but they are around in the leafier suburbs and larger parks.

We looked at the RSPB website for instructions, calculated the measurements of all six faces of the box on a sheet of paper, and studied the bits of plywood we had available. Just whiz along with the circular saw, screw it all together and we’ll be done.

It took a little longer. To cut the wood, we needed to be outside. Where it was raining. The wood got wet and it was hopeless trying to draw lines in pencil or biro. Felt pen worked, sort of, but gave us thicker smudgier lines. We drew, went outside, held and sawed, dusted down, came inside, made another cup of tea, drew again, went outside.

Finally we had a forlorn pile of long, dirty, improbably shaped bits. They seemed nothing like a nestbox. Let’s finish it next time, said Netty, sounding a lot less keen than she had at the start. Let’s get it done, I said. It’ll not take long now. We were a bit cold. We screwed the front to the sides, which were the thickest parts. Suddenly it had a shape. We took the extraordinarily long back and screwed it to the sides. A box. A very long box. We pushed the base into the hole. It wobbled. We pushed it down the very long hole with an umbrella and got some screws in. It was all done save the lid, which needed waterproofing with some roofing felt, and attaching with a rubbery damp-course hinge.

The next time was dry, and we took the box outside. It seemed enormous, and Netty had fixed on a long bit of dead branch as an owl-perch, but it went in a wheelbarrow and we set off with drill, ropes, and a ladder to the chosen Oak, a tall straight tree off the beaten track.

We managed to get a rope over a branch and haul the box up. Only, how to fix it and get the rope down again? We let it down, threw a thin plastic rope over the branch as well, hauled the box up, tied the thin rope onto the top of the box, and stood back. The box was up, but definitely dangling. We could easily fix some screws into the stub at the base of the box, but how to do the same for the stub at the top? We moved the ladder around the tree to find a way to reach. With the ladder in the easiest place, the box was directly above our heads. We tried it every which way, we couldn’t reach. We put the ladder back where it was. With two of us holding the ladder and one on the top rung, it was just possible. Trying to tie knots or fix a screw with one hand … is quite tricky. We were very pleased when it was done. We’ll be delighted if a family of owls takes up residence. Or even some jackdaws.

Netty fixing enormous Owl Box
Netty fixing enormous Owl Box
Conservation, Natural History, Nature Reserves

Quick, Fix Those Nestboxes! The Natural History of Nestbox Damage

Fixing anti-squirrel plates to nestboxes
Fixing anti-squirrel plates to nestboxes

Quick! Spring is in the air, the Dunnocks are passionately singing their tuneless songs, the Great Tits are yelling Zi-Za-Zi-Za-Zi-Za endlessly, the Greenfinches are wheezing out their odd song (‘Zheee’), it’s time to fix those nestboxes. Most of those in the Gunnersbury Triangle had been “hammered” by Tits or Woodpeckers, or gnawed by squirrels. And a few had been rather roughly drilled by humans. So the warden decided that all of them should be given anti-squirrel plates; all, that is, except the Robin boxes, which have a wide rectangular opening in the front.

Nestbox hole gnawed by squirrel
Nestbox hole gnawed by squirrel

A few of the boxes seemed to have been attacked by squirrels. This one has what could be toothmarks and signs of extensive tearing of the wood outwards at a shallow angle, which looks like gnawing rather than hammering. It isn’t obvious why the basically herbivorous Grey Squirrel should do this.

Extensively hammered nextbox
Extensively hammered nextbox

This box, on the other hand, seems to have been hammered at a sharp angle to the surface, whether by the Tits themselves (they certainly do this sometimes) or by Greater Spotted Woodpeckers preying on nests – although they mainly eat insects and seeds, they do take eggs and chicks when the opportunity arrives.

Old nest with tit egg inside nestbox
Old nest with tit egg inside nestbox

At least 4 of the nestboxes had substantial and reasonably fresh remnants of nests inside; this older one contained two long-addled tit eggs (just one shown here; it was 16 mm long) with a mixture of moss and down as insulation.

Tegenaria, the Giant House Spider, at home in a very messy nestbox
Tegenaria, the Giant House Spider, at home in a very messy nestbox

Finally, one very old nestbox, carefully engineered with beading around the hinged lid complete with little brass hooks, contained a Giant House Spider, Tegenaria, a lot of beetle pupae, and what could be Gypsy Moth pupae as well. The box was a messy tangle of thick sticky cobweb, and the spider was distinctly reluctant to leave, seeming to want to stand and fight off any intruder.

All in all, what might have seemed a mundane bit of metalwork turned out to be a day full of interesting natural history. (But the metalwork was fun, too.)

A nestbox goes up on a willow tree
A nestbox goes up on a willow tree