Temperatures took a real dip today and yesterday - for the first time we put the heating on in the house and ambient temperature this morning was about 7 degrees at 9am. This signals the start of tough times ahead for our bumblebee colony and is close to a minimum operating temperature for them, although of course they can generate their own internal heat to keep going: but could take a lot of energy.
So, I wasn't expecting much activity today, but we still saw 21 trips to-and-from the nest, which represents a reasonable number compared to recent days. Four of these were contributed by the Queen that has become resident. In fact, to my knowledge, 2 Queens are resident, but I'm not seeing much of one of them.
The active Queen hasn't brought pollen back for the last two days either, even though workers have. I don't have a great explanation for this. If she's ready to keep her brood warm, we would expect to see her staying the nest full time. Maybe she is doing that now and maybe it's the second queen we are seeing on her trips from the nest - perhaps mating behaviour, or hibernation-spot searching. We just can't be sure.
What I can be sure, is that for the last few days two queens have been in the box overnight - they must have been, because I've double checked the CCTV going back about 5 days and can match all the exit trips with entrance trips. So, if the trips cancel out, then by definition there must be the same number of Queens in the nest at the end of the day as at the start. And I can work that logic (and CCTV footage) back until the point where they were both confirmed in there together.
That makes today's discovery even more suprising - another Queen showed up. I have no footage for when she might have first left the nest, so it means one of two things: she is a third queen that has arrived from somewhere, or there has been a tech malfunction.
To be honest, I find both hard to believe, but the tech malfunction moreso (I know, imagine that!) BUt there are three cameras with motion detect all running on the area where any bumblebee would have to leave the nest. The sensitivity and settings have all been fine tuned and working beautifully for months. There are no errors reported on the DVR and no breaks in footage and no video-loss alarms. All seems well in CCTV land.
So, that leaves the explanation that she is a third queen. I'll admit it seems odd, she seemed able to make her way straight into the box as if she knew it. Later a Queen left and returned - I can't be sure if it was her, but that Queen did not need to do any memorisation - so if it was her, then it means she has been here before.
In which case, maybe it's one of or August queens returned to shelter?