Wednesday, 1 September 2010

Things that go bump in the night

I checked the moth trap just after midnight and there was well over 20 moths of about a dozen species already inside or buzzing around. Half an hour later I'm in bed, the light is off when there's a thump against the window. I looked out through the window but nothing to be seen. No sign of any life in the street, only a couple of Tawny Owls 'kwicking' and hooting loudly, they must be very close.  I climbed back in bed and reported nothing to be seen. 'What if someone is in the garden then?'  I was asked so no doubt about it I was going to have to get up again. Unlocked the door and ventured out, the Owls had stopped calling and went to check the garden. It was light because the trap was on but certainly nothing obvious so went to look for evidence by the window. I stopped in my tracks as I spotted a young Tawny Owl still with a few traces of down sitting stunned under the window. I walked over to pick it up but it flew off obviously unharmed. As soon as it was airborne the 'kvicking' started again for a minute or so  but that was the last I saw or heard of the owls.
A couple of questions I suppose -
One - very late for a fledged Tawny still with a little bit of down surely, even if the pair managed a 2nd brood?
Two - How come it came to hit the window when there was no light on?
I suppose I can have a guess at the latter in that it was after a moth which it chased or saw on the window.

Quite an exciting night.

I was up not that many hours later emptying the trap which wasn't too bad at all and it certainly had an autumnal and rustic element. 44 moths of 21 species including my first Small Autumnal Moth, Hedge Rustic, and Northern Deep-brown Dart of the year and only my second ever Autumnal Rustic for the garden.

Small Autumnal Moth

Autumnal Rustic

A Canary-shouldered Thorn and late Fan-footed Wave and Willow Beauty were also present overall making it an excellent night all round.

Canary-shouldered Thorn

There were a couple of Common Wasps in the trap too but unlike several other moth-trappers, I haven't been too bothered with them this year. Some years they can be a real pain in the  *** (though usually the back of my hand), but not this year.

One of two Common Wasps in the trap

Counted the Greenfinch flock in the stubble as I passed later, 96, so still rising. A ton tomorrow?


  1. This is interesting as it's the first evidence I've heard that tawnies have their night vision temporarily disabled by bright lights, such as torches and moth trap lights. Unfortunately they are attracted -- like moths! -- to lights. This may also have been why the youngster flew into the window -- all it could see was a reflection of the light.

    Tawnies can have their vision permanently damaged by welding torches at night because they stare at them. This happened at Sangatte when the Channel Tunnel was being constructed. Tawny Owls around the tunnel entrance were found with burnt out foveas and had to be taken into permanent care.

    Re the young owl fluff, yes, it is rather unusual. The last down on the head is covered by adult feathers at 3 months and a week (100 days). so we're looking at a hatch date of no earlier than 24 May and a corresponding lay date of 28 April, which is remarkably late.


  2. Thanks for that - I must be honest that I didn't really consider that its night vision was effected by the moth trap. Moths in the garden often rest up on the walls and windows when the trap is on, especially the large & fluttery geometrids. That made be think that as it was a very young, inexperienced bird it had either misjudged trying to catch one in flight or it saw one on the window and somehow got it wrong. I have had Tawnies in the garden before after the moths (there are 3 territories within ear-shot of the garden) and once a family part of Long-eared Owl, but never had any accidents fortunately so hopefully this is a one-off.

    As to the late day of the youngster, I thought it was very late but was half expecting to be told that its not unusual for relayed clutches. Birds of the Western Palearctic shows eggs up to mid May on occasion and though does say they can re-lay, it also says as do several other reference books incl. Konig, Weick and Becking one clutch. There are however a number of mentions of 2 broods on some websites. I wonder are these incorrect?

    Really interesting note on the Tawnies at Sangatte and I surfed to find out a bit more. Excellent website by the way.