Fat Bottomed Girls - and our 1st goodbye

We've had a few bumblebees in care now, 3 in fact, all very small and missing various bits such as wings and legs. They've been getting along great together in their box and feeding well. Here they are all sleeping/resting together - very cute ☺

3 tiny bumbles resting overnightOnce BCW was back from her travels she decided to name them after the 3 Amigos (3 Abeegos, as I call them): Lucky, Dusty and Nedine (girl's version of Ned). 

Sadly, girl/worker bumblebees generally have a very short life, perhaps 1 - 3 weeks, and the small ones especially so. Lucky, the first one I rescued, took a turn for the worse mid morning - very still and listless. We offered her some honey water but she wasn't interested and it didn't help to revive her. 

Little Lucky - not feeling so wellIt looks like this evening we've lost her; sad indeed, but we are becoming used to it - all part of the short cycle of life for bumblebees and for her only perhaps 6 - 10 days old.

I've not had chance to scan the CCTV so far this week (which is not good) - but it's been so wet and windy that there's not been a lot of activity. One of the most intriguing things we'e seen is what seems to be a queen fanning. I'm surprised she is taking on a worker role. I keep doubting if it's a queen, but here's a series of pictures and I'm sure that all the large bees are queens. Indeed, some of them are easily over 25mm in length.

a very sizeable bee - queen - fanning Another shot of the same queenOther large bees - NOT queen size - fanning

 And another shot of some queens just to get the scale

3 queens resting at the entrance - huge abdomenSo, I'm pretty confident in that first image, it's a queen. 

Sisters can't do it for themselves

Our nest continues to grow and with it the activty, interest and intrigue. At the time of writing I've only managed to count in detail 2 days' worth of CCTV footage, but it's one heck of a two days!

Over the course of the two days - half of which was rainy/windy we saw:

• 304 foraging trips
• 136 memorisation procedures (equates to first flight of new bees - indicative on the minimum number of workers in the nest)
• Orangey/red and pale yellow pollen being collected
• 5 Queen bees performing memorisation (i.e. 5 new queens)
• 2 Queens bringing back pollen (normally a sign of colony building - another colony already developing?)

Here's a recap of today's additional activity.

First of all, Queens. When there's unusal activity going on in the nest, it's easy to start doubting what you are seeing. What seems to happen is I start off with an instinct that something is happening because of a short observation. Then I spend a day or two thinking I'm going mad. Then, I typically see really good evidence that shows it was happening. The I start to think I am still seeing things!

It's like that with the queens. I thought I saw one, but I assumed she was the colony "mother". Then of course I saw two so knew something else was going on. And finally at the latest count, five. 

I can count them, by the way, by combining a number of techniques. First is sequential exits/entrances. If 3 leave without returning, then I know there are at least 3. Likewise, sometimes I will have counted some that have left, and then see more in the nest at the same time, so this also gives a number. Finally, I can count the memorisations - which is done once (usually) for each new bumblebee that goes on a flight. Using all this data serves to give a guaranteed minimum number with a high degree of confidence. 

Anyway, some pics of the queens. Compare the sizes with the regular workers.

 queen returning to nest (CH1)Queen returning with yellow pollen (CH1)Queen with pollen coming into land (CH1)And then the queen goes into the nest - and you can clearly see all her pollen (shows up white under the infra red)

Queen with pollen (CH2)Another queen emerged, but had imperfect wings and was struggling to make her first flight. It took her about 20 minutes of trying to lift off, but she could not sustain flight very well. unfortunately I lost track of her.. 

Queen - foreground - with imperfect wings is pacing the ledge trying to flySince I've been doing some audio recording of the nest this year I also took the chance to measure the audio frequency of these Queens' buzz. The result was 135Hz +/5Hz.  This ties in perfectly with the samples I took from captured queens. It stands to reason that frequency and size are related (in general at least), as is true for the human throat/chest and any musical instrument. It certainly would be nice to have a clear frequency range for queens that guarantee you know what you are dealing with. (I'm not finding a lot of research on bumblebee frequencies).

Fanning

I caught one busy bee "fanning" today. This is the process of beating the wings to draw cooler air into the nest when it is too hot. To be honest, the temperature wasn't that hot. Outdoors it was 16C, and ambient in the nest was 23C (it's been hotter - thought bear in mind this is not the core). Perhaps this particular bee has a low threshold for fanning.

Actually, this was a theory I postulated last year - that different bumblebees have different trigger thresholds. Firstly, from a natural variation point of view it almost stands to reason. But secondly, in terms of a distributed "control system" for the nest that ensures fanning is not "all or nothing" but happens in a controlled way in response to increasing temperature, it makes sense that some bees are more sensitive and start fanning at a lower temperature. As the nest temperature climbs, more bees will be triggered to join the throng. Providing the fanning process itself doesn't generate undue heat, then such a system would basically be wonderfully self regulating (without the need for central command and control), because as more bumblebees start fanning, not only will the effect be greater, but fewer will be working in the nest and generating core heat. 

 bumblebee fanning near nest entranceshe's moved position - still fanning, wings clearly visible in motionThe she moves right to the entrance and continues. She was here for a good few hours (seemingly unnecessarily). 

Still fanning in the entranceI couldn't capture the sound of her fanning, but at peak temperature it sounded as though others in the nest were also doing so, so I recorded some of that and measured the frequency also. Because the sound is coming from the wings more than the thorax, it is not the usual buzz but the whisper of the wings through the air at a slower speed than normal flight (like a room fan). It's hard to determine if there is a fundamental frequency, but for what it's worth, my meter showed 135Hz sustained for extended periods of time. Interesting in that it is the same fundamental as the queens' buzz, but it is not a buzz and does not have the same characteristics. 

Rescuees

It was pretty much certain we'd get some less well bumbles to care for indoors again this year - there are always imperfections in nature. I'd hoped it wouldn't be too soon, but it was today. Actually, this box has gone longer than last years before discovering some under-formed bees. 

I actually found two - and they insisted on coming out of the nest and trying to fly but were unable to. The first one is worst off, with only 1 wing and 5 legs and I found her about 6 feet from the nest. Lucky for her really, as if I hadn't spotted her then I might never have done and she could be starved or bird-food by now. The second one has both wings, but they are crooked, one is too small, and she can't fly. (I made sure for 30 mins in the open that they couldn't, but it's obvious anyway). 

They are both similar size, and very small, under 1cm. I've not managed an accurate measurement yet, but around 8mm I reckon. Possibly smaller than Holly. I'm actually pleased to have found two as they can offer each other company and interact with each other. Last year one of the most painful things was to see Holly behaving as if she was depressed when she was alone (she had company from other bees some of the time, but she outlived them all). You think I'm kidding?  

Here are our two little darlings, just resting nest to each other. Maybe they are bonding ☺ They are certainly getting on fine:

Our two new under-formed bumbles indoors - as yet unnamedAlthough it is not recommended to revive bumblebees by feeding on honey water, we have no option. Sugar water does not provide mineral content, it is just empty energy and not nutrition, so we have to provide honey, even though there is a risk of bacteria. Last year Holly actually survived 70 days in our care, which is as astonishing life span for a worker bee (typically 15 - 20 days). 

a sense of scale

Tonight they have drunk really well and been mooching around with plenty energy, don't seem to be stressed and are co-operating just fine. They won't grow any bigger - their exo-skeleton has developed to this size and that's how it will stay, so they are amongst the smallest in the colony. Perhaps they hatched too soon, or just didn't get the temperature needed for development (which is critical). At least they are mobile. 

I hope these two have a decent lifespan, but whatever the case, we will give them a good quality of life however long it is - free from predators and starvation. 

fan-tastic

It's been very quiet in the nest outdoors for the last two days. "Quiet" meaning no activity at all, save for a small moth that seems to have been in there a few weeks - and doesn't seem to have done any harm. 

It's cold now, down to 3 degrees or so overnight at times and only peaking at about 12 degrees during the day, so we don't expect any activity and we certainly don't hold out any hope for any larvae in their wax pots that had been developing. In fact today I took the decision to remove the small infrared lamps from underneath the lodge. Chances are they were have no useful effect anyway, not to mention they are only partly functional.

Notwithstanding, we've left the nest intact for now, just in case. We've been surprised so many times this year, that we will just wait a week or so and be sure there is no life left in the lodge. Then we'll have the (fairly) gruesome job of cleaning it out and examining just how much work our 4 queens and their workers have done. We've contemplated sealing the lodge and placing it in the garage - still monitored by CCTV - just as the final stage. 

However, indoors we have a happier tale. Our tiny rescued indoor bumble, the last survivor of the nest was rescued two days ago and has survived indoors for two full nights and is now entering her third. At times she's caused us a little concern with her stillness, but in general she's been agile and we've seen her take a very good drink today, so she's getting nourishment.  

Of course her rhythms will be all over the place as she has no siblings to work with; has 5 or 6 fewer hours of daylight than would be the case in summer; is not in a fully sealed/dark location and, indeed, is subject to the artificial lighting in our home. Although we do try and maintain a fixed routine of light to help her rhythms. Having said that, it is already established that bumblebee Circadian Rhythms are rather elastic: while forgaging has to take place during daylight, we've observed much activity that takes place over night. (Take our little bee that spent 7 hours through the night fixing up the nest bedding we added!). There's lots that happens through the night, so we shouldn't be surprised if our little guest rests during the day from time to time. 

We've been helping to heat her tub a little by placing it near or on a microwaveable wheat bag, just to improve the ambient temperature. We noticed today she was particulalry responding to this - when the bag is intially hot she moves away from it to another part of the tub. When it is at a nicely warm temperature she comes and tucks up towards it as close as she can get (through the plastic box of course). You can see an example of this in the picture below. 

little bee warming up close to the wheat bag outside her tubWe noticed at one point we probably made the wheat bag too warm and she very quickly scooted off to the other side of the box! It confirms the bumbles are sensitive to temperature and definitely have a favourite comfort zone. 

In case you are wondering, for this very reason we don't heat the whole box, just a region of it. This means she has the freedom to find the perfect spot in the temperature gradient. We've also added materials she can climb on and get right away from the floor of the tub, such as a "bridge" made from a cardboard toilet roll inner-tube. We saw her climb it today which was entertaining to see! And tonight she is tucked up sleeping underneath it - perhaps she feels secure with something over her head.

We've also noticed that she tracks the temperature gradient as the box cools down. To start with she is typically tucked up close to the edge of the wheat bag, where the rest of the tub is cool. Gradually she moves as the wheat bag cools, until, as in the picture above, she is tucked up to the now-warmest part at the front of the box. Just like Holly she seems to like the warmth. 

Finding her wings

Mid morning we noticed she was stretching flapping her wings. While it's good to see her wings are well-formed, it creates a dilemma for us, because we've only ever kept bees indoors that couldn't fly. If she could fly we would feel like she was being unfairly caged - and yet she would have no chance of survival outdoors; there are no flowers in the vicinity for nectar, and one cold night could see her off. And she is so, so small, that her energy stores are small - meaning she needs to top up regularly (a bit like the way a baby has to feed regularly).  

We discussed the concept of being able to exercise her natural instincts (i.e. freedom to fly outdoors) versus a warm and secure environment meaning less stress on her body. While she might have instincts to leave the nest and forage, this is not an experience she has ever known and the stress to her system would be huge. We concluded that it is reasonable and right to keep her safe indoors.

As we watched her behaviour, wondering if she was indeed trying to take off, I realised her activity patterns matched something I have seen before: it looked like she was "fanning". This is what bumblebees do to try and regulate their nest temperature, especially when it is getting too hot - and it's something we managed to catch on video.

We noticed that she was moving around the box to the various temperature zones she'd already picked out and then buzzing her wings for a few minutes. On occasions it looked like she was moving to one spot, fanning to move the warm air around, then moving to a cooler spot for a few seconds to check the temperature, then coming back to where she had been and starting again. It certainly looked like she was trying to even out the temperature in the tub. What we can't be sure is if she was trying to make the warm zone cooler, or the cool zone warmer - but she was fanning in the warm zone.

Other factors made it look like she wasn't really trying to take off: she was often up against the tub (so much so her wings were catching it) and facing the wrong way; and the tell-tale sound was that of her wings "fizzing" in the air, rather than her thorax buzzing, which is what gives bumeblebees their disctinctive "throaty" buzz when they fly.  There's a certain stance too and a certain way of spreading their wings which, I presume, increase surface area. 

It's very quiet, but I was able to record the sound of her fanning on my iPhone - you can play it below:

Baby Bumblebee Buzzing.egg on Aviary.

If we are right, then there are two things I find amazing about this:

• Nothing has taught her this - this is inbuilt, instinctive behaviour to use her wings to control the temperature of her environment. She's not had any time with live siblings and not seen this behaviour. It's totally in her genes. 
• It means she has accepted the tub as her nest - so, even though it is missing many features, such as a Queen, other siblings, wax pots, the right smells, the right lighting, and even an exit(!), she must have accepted this is "home". This means, that although we can't let her outdoors, she can play out her nest instincts and do some of what nature intended. That makes it a little easier to accept we have her in a closed environment indoors. 

We just take each day as it comes now - every one is a bonus, for her and for us. As the remaining survivor of her family line we hope she can hang around for a little while yet. 

We all want cool air

When we went to check the nest last night, there were two bees actually resting in the entrance tunnel. This scuppered our plans to have a good check of the nest and really figure out what was going on with our Queen - who we saw inside the nest, still, between the wall of the wooden lodge and inner cardboard box. We have a picture from the previous night though - the Queen is not visible but she's down the edge on the far bottom left. 

 late night nest check

Given that she's previously spent all her time hidden away under the bedding, brooding, this is a major shift in behaviour; although of course, we've seen her wanting to leave and not succeeding, so we know that all is perhaps not well. 

Anyway, we took a decision to partially lift the lid quickly just to look for her, rather than check everything. She was in the same place, still still. The likely prognosis, of course, is that she has sadly died in the box - possibly she's even got trapped between those sides and run out of energy. I cling onto the slim hope she might have started hibernating there, but it's extremely unlikely. 

The other bees are still working the nest though - I saw four in action yesterday and three today: large, "baby" and "tiny" (or venti, grande and tall as Starbucks would call them). 

They are starting quite late now - 9.52 yesterday and 9.51 today - how about that for timekeeping!? It was another scorching day, in fact the UK record for October temperatures was broken. So, although the bees have wonderful weather for foraging, the light and length of day is not so good. And our nest is (deliberately) in the shadiest part of the day. We already discovered that their behaviour is triggered by light and temperature change, so it's not surprising they are starting significantly after sunrise.  They are finishing about 10 minutes before sunset. 

Overall activity rates are dropping though, certainly in terms of number of trips. This is not just because they are spending longer on each trip finding pollen (although for some bees that is true: our big bee spent 4.5 hours out foraging on one trip yesterday). But also because they are spending more time in the nest. Whether this is due to temperature or some other reason, I don't know. I don't imagine there is any hatching going on, so there is no requirement for them to be in the nest from that point of view. 

There is also no bee collecting regularly honey water (the one that was died) which is use to fill the honey pots. Again, they won't be needing them now anyway if nothing is hatching. So that doesn't explain the time in the nest either. Maybe they are getting old and tired. 

The last four days the trip count has been: 23, 17, 12, 13 - quite a tail off. Maybe they've twigged they dont really need the pollen! (Bombus Terrestris are known as "pollen collectors" - they gather pollen all the time, regardless of how much is needed). 

What we've also seen the last few days is "fanning" - when the nest gets hot some of the bees will go near the entrance and "fan" air into/through the nest. To be honest, one lone bee doing this in our lodge will have minimal impact, but they are still conditioned to do if needed. The biggest bee in the nest has taken main responsibility for this and actually started at 9:53 - for about 10 minutes at a time. 

There's at least one also sleeping near the entrance tonight again - which is preventing us getting into the nest at all. Perhaps they are feeling the heat and like the occasional waft of cool air.