After pondering the infra-red question for a week, I decided to try and get some answers in the field. I decided to pay another visit to the sett, to observe the badgers as best as I could without using the infra-red and then, once I was sure that the badgers were comfortable and that there was nothing I was doing that was disturbing them, I would turn on the IR and observe any reactions.
It was a great plan. The problem is, to paraphrase Helmuth von Moltke, no plan survives contact with badgers. I made my way through the wood as stealthily as possible and arrived at the sett by 8.00pm. Unlike last week, when the weather was very clear, the night was quite cloudy. This meant that there was more of a glow in the sky – the horrid orange reflections of the streetlights in distant towns. This glow was enough to make it possible to use the night vision scope in passive mode, without the infra-red illuminator. There was just enough light for it to work properly – I could see trees, undergrowth and the spoil heaps of the sett.
Unfortunately I couldn’t see any badgers. I waited for 40 minutes but saw and heard nothing. If the badgers had come out I would have seen them. Maybe they were frightened by my approach, but I don’t think so. Maybe they had left already and were out foraging. Maybe they didn’t emerge until after I had left.
It was a pleasant enough evening, listening to the lambs in the field and the tawny owls in the wood behind me, but I didn’t get to test my theory. I’ll try again next week and see what happens.