Challenging a good theory

Hard to believe we've had out beepol lodge almost a week! So, it's time for an update. 

It's been a week of cold and changeable weather, so the first few days in particular were not very active. Moreover, our plastic lid was still trapped (loose) inside the nest and we think it was possibly impeding the bumbles a bit from freely leaving the nest. Plus they had to recover from their travel trauma. 

By the weekend I'd cleared the lid and we definitely had some new first flights occuring. That enabled me to calibrate the motion detect on the CCTV and make sure all the tech was working properly. The weather was still a mixture of wet and windy and very cold at night, so we weren't surprised to see much happening, though it was certainly noisy and busy inside the nest itself.

The down-facing camera gives us a great, sharp view and good audio too; so this year I'll be taking some recordings and doing some frequency analysis. 

Monday on the other hand was a different kettle of fish, with a hive of activity - if you don't mind me mixing my metaphors and literals. This was the day that our new borns really decided to go for it. One after the other, time and time after time - almost a stream of babies coming out on their first flight - at times it seemed like one a minute. And returing with pollen too - greyish yellow by the look of it. It was amazing to see them all so busy and carrying out their programming! (incuding their first memorisation flights). 

Two babies - one about to leave, one just performing her first memorisation flight, looking at the nest (top left)

A few were nervous - not sure about pushing on the flap, or not sure about launching off the nest ledge, and either coming back in from flight after 10 seconds or just going back in the nest. A few were not sure about the nest - returning with pollen and then heading back outside with it, before realising the inside was definitely where they were meant to be. 

Some of the tiniest didn't seem to figure out the nest entrace at all - even though it was wedged open - instead scratching at the connecting gap on top of the new wax-protection module. Had they forgotten where they came out? Was their eyesight not so good? Or was the smell of the nest stronger from there? As ever, each observation leads to many questions. 

Here are a few more observations:

A night time we sometimes have a solitary bumblebee standing guard on the front wall of the lodge, here's one tonight - she's been there several hours: 

standing guard over nightUsing our cunning reflective size guide, we can say she is about 12mm long. 

She is by no means the smallest or largest bee in the colony. I've seen one I estimate at about 8mm and have been seeing several large ones tonight. I'm not sure if the largest of these is the queen or not: we'd love to see her. Certainly there is a large bumblebee that moves slower than the others and is seen occasionally doing a tour of the area under the camera. It's her combined size and (slow) speed that makes her stand out. At one point this particular bee paused for a while over the wax pots we can see - was she laying?  I'd love to see that - see what the process is - how and when she lays and how the other bees (presumably) seal the pot. 

This is a very big bumblebee - slightly side on - in the centre of this picture:

could this be our elusive queen?

And look at this tail end at the top of this picture. It's massive - at least twice or thrice the size/width of any of the others:

Or is this our queen's tail?

We think we saw our active queen only once in our Koppert box, this time last year, so we are not sure what her behaviour patterns are and how much of the nest she uses. We think this is probably a good spot though - directly under the infrared heat from the camera - so I wouldn't be surprised if se was to lay something near here. 

Honeypots 

It's a bit of an unintended, but delightful, consequence that the infrared from the camera is providing "catchlights" in the wax pots that contain liquid honey, as this gives us an easy way to identify and count the honey pots over a fixed area. Our friends from Dragonfli posed the question about how the stores get used and we are keen to understand this too. 

This morning when I first looked I could identify 4 - and 90 minutes later only 3. I wondered if one had been consumed giving the inclement weather and lack of foraging activty (very windy this morning). By this evening there were 7 indetifiable catchlights. So, not only had it been apparently refilled, but others made too. 

In the final analysis, however, I think the pot from 9am this morning that seemed to have been consumed was just slightly obscured by a bee - or at least the line of the reflective light was - and so I don't think this pot got used. However, I have seen one bumblebee apparently drinking some honey tonight (not much) but more interestingly another bee spending a good deal of time during the day actually resting over the pot and covering it. 

You can see this top left in the following picture, where the pot at "11 o clock" is obscured. This bee had its belly over the pot, hanging face down over the side (as I write it's doing exactly the same again). I'd love to uncover an explanation for this - it might just be coincidence - i.e. the spot it likes to rest - but one thing that is clear from looking at these pictures is that even with a time gap in between, it (or a sister) has come back and chosen exactly the same spot. 

bumblebee hanging over honey pot at "11 o clock"

Quiet in the night

Another thing we have noticed after the first few evenings of real activity is that night times have become a lot calmer and quieter. At first there was constant activity under the "down" camera almost 24x7, but again, as I look tonight, it's quiet. A few bees are in view resting, but only occasionally does one mooch past. They are resting and keeping warm. There is occasional buzz from a single bee and something we really want to do it uncover any patterns in the sound.

We sometimes hear sustained buzzing from a single bee (occasionally a second) in longish bursts. The we sometimes hear a high pitch squeak in short repetitions of about 1 per second. We wonder if this is associated with hatching?

Certainly the bees can be silent when they choose - as they are doing so tonight - with just the occasional high pitched buzz from somewhere unknown. If we can establish a link between bee size and pitch, then we can start to gauge what size bees are making the sound. Intuitively it seems that small callows trying to emerge from a pot might make a high pitched buzz, but it's pure hypothesis at this stage and remains to be tested/observed. To that end we are recording some of the sound patterns from the nest. 

The change in sound during the day poses the question why?

Certainly when threatened a co-ordinated "fizz" seems designed to ward attackers off and possibly communicate the threat throughout the nest colony. Some noise may be due to fanning - keeping the nest cool. Some of it, of course, may be vibrating to keep the nest warm - although perhaps we'd expect more of that during the night time rather than the day - so that is not a convincing explanation.

So - the question remains, is some of the sound associated with communication? Prevailing theory is no, but we love to challenge a good theory!

Flying for the thrill of it

It's a cloudy and overcast day, about 19 degrees, with windspeeds up to 7.5 mph (not counting gusts).

Common wisdom says bumblebees don't fly in the wind, though of course you'd expect them to have some provision to do so, at least to overcome the challenge of being caught out in a breeze.

Of course, above a certain speed, like a canoeist paddling upstream, they wouldn't be able to make progress against the wind.

Unlike an aeroplane, however, Bumblebees do not rely on air-speed over their wings in order to generate lift (which is what gave rise to the popular myth "scientists say bumblebees shouldn't be able to fly; a comparison with the physics of fixed wing flight doesn't work for bumblebees).

It seems our bufftails are a hardy bunch - whilst activity is much reduced today, it hasn't stopped a few hardy ones venturing out to collect pollen and/or find a mate; time is, after all, of the essence as far as both are concerned. The one I've just seen has been out for about 30 minutes and come back with a decent stash of pollen.

And one final nail in the coffin for the concept of "dull days" - cloudy and overcast it may be, but the light inside our nest box has increased to a level where the infra-red camera is occasionally switching to full colour daylight mode. All that white cloud and reflected light is making it bright.

Maybe the brightness of the day is tempting the bees to venture out. Or maybe they just enjoy the thrill of a windy flight.

Mind your head!

We've now got to the point where our CCTV DVR system has been tweaked with all the motion detection and camera angles that we can fairly quickly run through our footage and look for interesting activity. Over the next few postings I'll post a few of the videos we have found that have caught our attention.

Today's is just a funny little clip. BCW actually spotted this as it happened - a bee flew in and instead of flying into the entrance, just flew straight into the box and fell the ground! It then seemed to buzz off into the nearby lavender to recover! The clip below is in slow motion so you can see what happens more easily. 

It's not actually the only instance - we've seen this happen at least one other time. We don't really have an explanation other than a last minute brake failure!