'Last night, I saw a puzzling sight which I am wondering if you can offer any explanation for, please. It was a very cold night, just before 6pm and I was cycling slowly towards Wakefield on the rough narrow part of the towpath between where the canal passes under the M62 motorway and Kings Road Lock. There is a small bridge at the end of Foxholes Lane coming from Altofts crossing the canal.
'Glowing like embers'
'It was under that bridge that I saw two small red lights glowing like embers from a fire in the canal. I stopped and tried shining my bike light on them to try to identify what they were. They naturally appeared dimmer at this, so I turned the light off and they were still there. They were gently moving upstream (if I am correct, towards Wakefield), which further puzzled me at first, until I noticed other flotsam such as leaves and slime moving the same way. I explain this by the quite strong easterly wind which was presumably moving the surface water against the normal, albeit slow canal current.
'As I have never seen anything similar apart from glow worms and fire flies in France, I was puzzled. I even wondered if there were two very hardy sub aqua divers with little red lights on their backs! Certainly the lights were moving independently of each other, but only about 4 - 5 feet apart and in the same direction as if they were drifting. Next I wondered if they were reflections on the water from traffic on the motorway, but as this was directly under the bridge I am sure they were not. Finally I checked they were not aeroplane navigation lights, because although I could see one or two aircraft, I could only see white lights at the time, not the red port side navigation lights.
'I am sure there is a very ordinary explanation for this sighting and an answer from Nature seems most likely, which is why I should be most grateful if you have any ideas.'
I couldn't offer Peter any advice on this one as I don't often get out in the countryside after dark. When I saw the title of his message 'Mysterious lights on the Aire & Calder Navigation', I thought 'Aha! Will-o'-the-wisp!' as I know that plenty of methane rises from parts of the canal - whether from aquatic debris in the canal itself or from seams in the coal measures below the surface I'm not sure.
Otters are beginning to move back into the area and beneath a bridge - even a motorway bridges presumably - would be the classic place to find spraint, the sweet-smelling droppings of the otter. I don't know if their eyes glow like 'two small red lights'. And there will certainly be mink (left) in the area.
'I think animal eyes are unlikely,' replied Peter, 'as the two red glows were not constantly the same distance apart - unless of course there were two of them!'