After "losing" the two previous redtails during the night we decided we would persevere with our "new tube" strategy today, but avoid sealing the bees in from now on (even for a short time). It was a hot day again today so we left our hunting until later in the evening. BCW had been unsuccessful, but as I was on the way out to meet her I decided to wander along the ditch at the side of the field, just to try a slightly new tactic.
As per usual I was giving up hope having only seen one bee zooming across the field on the way home. At that moment I saw a bufftail nest hunting in the embankment and I was able to catch her!
We have learnt that we now have to be looking out for Cuckoo bees and make sure we get a proper Queen, so I was very careful to try and examine her. I also took a photo so that I could check after the fact too.
We are pretty confident this is the real deal and not a cuckloo bee. The band across the abdomen is an indicator and it looks as though the legs are correct: i.e. long hairs on the upper parts with a smoother "pollen basket". In contrast the cuckoos have more-uniform, shorter hairs on their legs, because they don't carry pollen.
Our strategy for introduction to the nest box is the same as before: using the pot directly against the entrance until the bumble climbs in. However, instead of leaving it at that, our latest technique is to add a length of tubing (about 10 cm) into the entrance (on the outside). We have proven the bees can get down this tube ok. The reasoning behind this technique is to try and trick the bee into thinking it is going further underground than it is. Some suggestions we have seen say the tube should be inside the box, but we have avoided this for the sake of our cameras, so it's a bit of a compromise. Also, of course, our bee will only get to experience the tube on the way our, rather than on the way in: so we don't know if it will have any useful effect.
We also made another adjustment tonight, which was to tape a pen-lid full of honey-water inside the box. I wanted to see if having access to some sustenance would encourage BB23 to stay longer and whether she would even bother to try drinking from it.
She took about 15 - 20 minutes to go into the box and, unlike many of the other bees, headed straight for the back upper corner of the box, near where I had put the honey-water. In fact, she seemed to pause over this momentarily, maybe she did actually take a drink. Rather frustratingly she settled somewhere higher up in the box, behind camera 2, where there is no visual coverage! Just our luck. But we could hear a bit of scratching on and off and she was very placid.
Within about 30 minutes she'd stopped making any noise, so to the best of our knowledge she is still in the box! (The advantage of box 1 with the two cameras is that the entrance is much better covered and it would be hard for her to leave without us getting visual confirmation. This is a good thing as in low light the end of the new tube is hard to see, since we have disguised it within some grass.)
The difference in behaviour is quite different to what we saw when the entrance is sealed, and it is immediate. That is to say, it's not as if the bee tries to find the exit then satisfies herself it's unblocked, but just seems to immediately know this is the case; almost instinctively. At this stage we can only surmise that the levels of light (even if low) and perhaps slightly cool air coming through the tube are sufficiently detectable and relevant to her.
BB23 has also shown a different behaviour to other bees introduced to an unblocked box, in that she has gone much further from the entrance, rather than staying very close to it. Only tomorrow will tell if this means anything significant. Meanwhile we hope she is having a lovely slumber.