The Physical Exam

It's 3 weeks since we saw the last activity in our Beepol nest and 2 weeks since I took advantage of help from my brother to dismantle the nest and lodge and photograph it.

It was really quite an interesting experience and much more pleasant than dismantling the Koppert box we had earlier in the season. That box was infested with wax moth and was in a fairly unpleasant state. In contrast the Beepol box was uninfested and fully intact, complete with all evidence of several colonies having existed (as we observed).

As we lifted the lid of the lodge there was a pleasant (though faded) smell of honey, mingled with the typically waxy odour. We could immediately see just how high the bedding had been raised since it was first added: underneath was a complete substructure of wax pots and pillars and the ceiling layer of bedding had been lined with a thin layer of wax too.

Peeling back the ceiling revealed a tall, compact cluster of we pots built by our last (third) queen. As expected, these pots were nearly all quite small and less well developed due the the September, October and November temperatures.

waxpots, still with honey; some still sealed; pollen in the background

Most of them had hatched, which of course accounted for all those tiny bumblebees we saw and rescued and surprisingly, only one or two were unhatched. You can see a small, prominent, fully intact wax pot in the pictures. Many of the dead bees In the box were very small too, again, part of the overall pattern.

The distinction between 'levels' in the box was very prominent too. The original colony had suffered heat damage at the base of the nest and the wax was a darker brown colour and more roughly textured. It was very buried below the added bedding and a whole new upper layer of fresher, more yellow wax from the subsequent colony. There was no doubt at (at least) two distinct colonies developed in the nest.

undeveloped bumblebee eggs in a wax pot

We also tried to find the 3 queens we expected to be in the box - and we did indeed find 3 larger bumblebees although they looked surprisingly shrunken and reduced in size in their still and curled up unfuzzy state, to the extent I would have struggled to perhaps recognise them as queens if I hadn't already known they should be in there. [The backstory: The original 'mother' queen had come out of the nest to die, but one of her brood had stayed on permanently and started brooding. She seemed to get to weak or too large to leave the nest and died inside. But another 3 queens also turned up in succession and two of those seemed to brood. We did of course rescue last one of these and she died in our care, but the other two also died in the nest.]

Something that was completely new to me in this nest was a number of wax pots broken open with a white sticky substance in them. In some pots it looked like a solid mass, but in others was quite clearly composed of smaller lumps and 'clumps'. It seemed these would be eggs or early larvae of some kind, but what I wasn't sure was whether this was from a moth (we'd seen one or two in the nest) or flies (also seen inside). I turned to my expert at Dragonfli, suppliers of the Beepol nest, and he confirmed this appeared to be bumblebee eggs. Until now I had assumed that only one egg was laid per wax pot, but he confirmed that actually they do lay half a dozen to a dozen eggs in a pot then seal them in with some pollen..

There were quite a number of pots in this condition, symptomatic of a very busy queen who was struggling against the odds to get a brood to develop to critical mass. Sadly she never made it because her offspring could just not develop successfully in the cold temperatures of October and November. She kept trying day after day, and indeed, pretty much died trying - but it could never be.

So, this represents the end of the 2011 season, although the work is not complete as we clear up and decommission our setup (nest. CCTV etc), write it all up and then begin to prepare for the 2012 season.

Finally, a picture of a developing larvae as it starts to reach the callow stage. I removed her from a sealed wax pot. You can see the wings are not quite developed yet and the usual white down actually has a warm golden colour. Whilst sad, for me there is something starkly beautiful about this picture... 

Big Mamma & her gang

Well, another week has flown by and our bees have been busy flying too. There's no doubt now that we have at least 6, if not 8 bumbles in the colony.

The number is never static or definitive because obviously there is birth and death occuring, as well as the fact that some bees will stay out overnight (see picture), and any males will be leaving the nest to mate. So, at times it can be tricky to be 100% sure how many are colonising the nest at any one time, but what I can do is come up with some numbers based on those I can distinctly identify by sight and also tracking how many are in and out at any one time. 

A cheeky bee that stopped out all night, sloping in at 6.30am!

It's this latter metric that gives my current estimated count; at one point this morning there had been 6 exits from the nest without a corresponding return, which means there are a minimum of 6 bees on active duty. However, at the same time I had two on undetermined status - I had seen two leave the night before, with no corresponding return in the meantime.

Bear in mind, it doesn't matter about matching each bee with its own exit and return, it's just a case of counting 1-in-1-out and seeing how the numbers tally. If three leave and two return, it doesn't matter which ones they are, or what order, it means that there is still one out. That's the basis of my counting. 

So, I had two unaccounted for away from the nest and then another six on top of that. It's at this stage you start to go slightly bonkers and wonder whether you have miscounted or whether the tech has missed recording some of the activity, because it all seems a bit incredulous when you have no idea whether a queen has been laying and how much (or whether) hatching is going on!!

Anyway - that's 6 - 8 bees actually on active outdoor duty, but we can still add to that...

Who's the boss here?

This week I've had 3 additional glimpses of "big mamma" as I affectionately call her.

A rare glimpse of big mamma - she easily spans the two horizontals

She hasn't been out of the nest, so she is not counted in the above numbers. She is the biggest bee in the nest and her description fits one of the five or so big bees we saw before our holiday while we were still lifting the nest lid at night. Our gut feeling is she is a queen and is responsible for the brood that has been developing. This is fitting with the following facts: 

1. we did see these big bees collecting pollen a few weeks ago, which is what they would do before their brood is underway
2. she's now in hiding - she doesn't leave the nest and barely comes into view - just occasionally having walked across the camera zone
3. not forgetting we've had some hatching, so we must have had a queen and she must have laid something, even if she has stopped doing so

It's possible that the three sightings of "big mamma" relate to more than one big bee, as it's not possible to prove they are identical from the CCTV footage. However, this seems unlikely from a behavioural point of view, as although bumblebees are eu-social, they do also fight over owning the brood, so it's hard to imagine several queens co-existing harmoniously. Although, of course, we did directly observe them co-habiting for a short while a month ago before we went on holiday. 

A rather large and long bumble at the entrance - could this be a queen?

Crunch time

The other thing we observed yesterday was the strange crunching/crackling sound that has troubled me in the past. It lasted about 15 minutes and through the CCTV system it sounds rather like a kind of crunching or munching sound. It's the volume that surprises me, and every time I hear it I dread that it's the sound of wax moth larvae destroying the nest, chewing their way through the wax. Our last check inside the nest was two weeks ago and at that time there was no evidence of such an infestation, so I am hopeful this is still the case (despite having seen a tiny moth in the nest yesterday, but not - I think - a wax moth). 

It was shortly after this burst of sound, which was accompanied by a reasonable degree of buzzing, that we caught a glimpse of big mamma. 

My revised hunch is that this is the sound of hatching - of a baby bumblebee, known as a callow - breaking free from its wax pot, helped by its co-workers. I would love to see this in action to confirm this, and just to see it anyway, so I'll be giving some consideration for how to achieve this next year. 

This ties up with another part of my hunch, which is that there may be another new callow in the nest. What I've seen is a small bee darting about the place for a while, exploring as if learning the layout of the nest. It moves quickly with apparent curiousity and goes to the entrance, explores, but doesn't leave. Having seen this a few times, I think it's the behaviour of a new-born as it orientates itself and prepares for its launch into the big wide world. In the meantime it is able to stay in the nest, supplied with food by its sisters and helping with any remaining brood and various nest duties. Indeed, the smaller bees are thought to generally adopt this as their role.

So, I'll be on the lookout for this small one, particularly if it leaves, in which case we'll hope to spot it memorising the nest on its first flight. 

Census

Here's a rundown of the current occupants we know about:

• Big Mamma - the largest in the nest, rarely seen
• "Stripy bee" - there have been two of these, fairly large, with unusual tail markings; one was a nest fixer, the other collected pollen - we haven't seen much of the nest fixer lately, so may not be around any more
• Mid-size - there are at least two midsize bees on duty
• Small - there is at least one small bee on duty; it's quite hesistant about coming back into the nest when it returns - it always seems to fly up then leave for 15 - 120 seconds before actually coming in. Don't understand why!
• tiny - there was a tiny bee we saw last week, the first confirmation we had of new births. We've seen her occasionally, but not sure really what she's up to if still around

These numbers don't add up to my earlier total, so there must be some lookalikes in there I haven't accounted for.

Oddly there is no real apparent "nest fixing" or patrolling going on now, although on of the "stripy bees" continues to stick its bum out of the door to check the temperature in the morning!

sticking the tail out as a thermometer

Times are tough

It's also proving hard work for the team to collect pollen, though they are very busy trying. During the warm sun the activity levels have been quite high, almost to the level when we first got the nest with the original (though small) colony. But the pollen is in short supply, with them often returning with a small amount, and never the bulging pollen baskets that we saw during the summer. In some cases they return only for a sip of the honey water in the entrance, and go straight back out again. Trip times can now be anything from 10 minutes to an hour or two.

Thankfully they are still finding something (orange and light yellow) and we have actally tried putting out some artificial flowers with a bit of pollen on to see if they will try visiting them. We don't really expect it to work and so far it hasn't!

Each day brings a new surprise and it is fascinating to see our colony fighting for survival, a colony that has emerged against all the odds and proved just how remarkable our little Bombus friends are.

There's no doubt about it, a hat tip is due to Big Mamma.