Bumblebee (B.pratorum) nest removal, relocation, diary & video

November 5, 2012

in A selection of my garden wildlife videos, Bumblebees and their ecology, Gardening For Wildlife

“All my articles and videos, available free, are funded by my  teaching and sales of award winning bumblebee nest boxessolitary bee boxes,  and wormeries. Please help by spreading the word and forwarding this link to your friends and colleagues. http://nurturing-nature.co.uk  Thank you” George Pilkington

Bumblebee nest removal, relocation, diary of events with video

28 May 2012, after finding a B.terrestris nest site* on a Liverpool allotment, in the soil of a raised strawberry bed, I was approached by an allotmenteer who told me that yesterday, a bumblebee nest had been accidentally exposed by her neighbour as he was digging over the soil in his raised bed. She said the bumblebees were still alive and busy around the old nest site and could I have a look to see if I could do something. It was a very hot sunny day and I went to see the damage, before the sun made matters worse. They were B. pratorum and a few workers were busy outside fanning the nest remnants whilst on top of the soil! The nest had been chopped up and fragmented into numerous pieces, looking around the area, I saw large fragment with a smaller fragment a few feet away.

Dead larvae and dead bumblebees

The nest had been dug up early yesterday morning, which meant that they had been exposed to hot sun all that day, exposed overnight and again exposed to the sun today all morning and now it was almost mid afternoon. I saw several dark brown, dried dead  larvae, presumably cooked alive in the sun. A few dead bumblebees were lying on the soil surface, as were nest fragments. Both larger nest remnants showed signs of bumblebee activity. Whilst observing them for evidence and behaviour likely to assist in determining which remnant housed the queen, or even if she was alive, the queen herself appeared momentarily outside of the larger remnant. Bingo! I decided to rescue this part of the nest and leave the smaller remnant, as it would prove difficult with only having one container to temporarily house the nest. Using a large plastic tub with lid, I put a few air holes in the lid and placed soft tissue paper on the bottom, locating the tub next to the nest segment.

Environmental precautionary principle!

Bumblebee nest relocation equipment!

Taking courage into my hands, (which were now gloved in heavy duty suede gauntlets!), I watched as numerous bumblebees came and went into the nest remnant. After a large influx of foragers had just entered, I swiftly scooped up and under the nest as best as I could, with both hands, placing it into the tissue lined tub. Lid on…. tightly!! Back into the van and transported it home and placed the tub in the garage where it was cool to settle them down. Later that evening, gauntlets on(!) I moved the tub to one of my bumblebee nest boxes, which I had prepared for its new arrivals by removing the lid, removing the red window and covered the bottom of the nest chamber with shredded and tissue paper. Luckily, this species nests above the ground generally, other species nest below the ground so I did not have to adapt the nest box for them, (called a false underground nest box).

Nest transfer and bumblebee frenzy

Quickly I prised open the tight fitting lid, which agitated the bumblebees inside. I replaced the lid but did not press it home to fit tightly. After several minutes the bumblebees settled down again. Lifting the tub directly over the nest box, I removed the lid and immediately bumblebees started to fly around the top of the tub,. As fast as I could, I emptied the tub contents into the nest box, leaving the tub over the nest and the bumblebees. They soon found their way out from under the tub though the shredded paper and flew around it and the nest box itself. After several minutes, some bumblebees appeared to start orientation flights and some even started to forage on nearby flowers in my garden and returned to the open nest box and underneath the tub. However the initial frenzy at the beginning of this procedure soon turned into a more orderly foraging and orientation flights activity! I decided to wait a while, pondering what to do next.

The window gap entrance 

Firstly I waited until the activity died down, blocked up the purpose built nest entrance hole with tissue and sealed closed the bumblebee cat flap, a feature developed to minimise wax moth (Aphomia sociella) entering into the nest. I swiftly emptied out the tub letting the contents slide out and into the nest box, cushioned by the tissues and shredded papers. Immediately I replaced the red window, making sure to leave a couple of inches gap open to the elements, to allow bumblebees to enter and exit. Several bumblebees flew out of the nest as it was sliding into the nest box. They soon returned to the nest once it was inside the nest box via the window gap. Initially I wanted bumblebees to use the window gap and later force them to use the nest entrance hole exclusively. Progressively I gently slid the red window along the top runners gradually reducing the gap little by little. Bumblebees were leaving and entering all the time via the window  gap.

Confused bumblebees

I watched as bumblebees were returning to the nest box and going to the place where, I suspect, they had actually left the nest. They could not re enter the nest box now exactly where they had exited as the exit they had used was now covered by the red window. The gap was slowly being closed. This confused them and they started walking all over the window, alighting again and again dangling their legs gently on top of the window. At first I thought that they may be trying to detect the bumblebee odour deposited from their feet to find the exact spot they exited by, which they may have been doing. Then again as they cannot see red could they see the nest below their feet and were confused that their chosen flight path was somehow blocked? No wonder they were confused! Eventually they found their way back inside after walking all over the window and finding the window gap at the front end of the nest box, which still allowed bumblebee nest odour to escape. Dusk was drawing in.

Strategy to force usage of the nest entrance hole

I did not want the window gap to be the main entrance and exit for the bumblebees. I wanted them to get used to using the nest entrance hole. I removed the tissue from the nest entrance hole and lifted open the bumblebee cat flap. This was done to attract bumblebee workers that had not left the nest previously via the window gap. I waited until one worker left through the nest entrance hole and closed the window gap, leaving a very small gap making it impossible to enter or leave. Unable to leave via the window gap, bumblebees soon started to use the nest entrance hole, thereby scenting it as they entered and exited, attracting others to do likewise. I watched as they undertook their orientation flight, a lovely sight to behold, indicating that it was their first flight out of the nest entrance hole. When a bumblebee returned to the window gap, meaning it exited that way and not via the nest entrance hole proper, I slid the window along a fraction to widen the gap and down she would fly into the nest, replacing the window again leaving the barest minimum of a gap. Sometimes I would close the window gap almost completely to see what returning foragers would do. Not one tried to use the nest entrance hole even though it was busy being used by other bumblebees. Instead they dangled their legs touching the window with their legs, like dipping them into a pond! It was rather humorous to watch. When a bumblebee returned and insisted on trying to return to the nest via the much narrower gap, probably detecting the nest odour, I opened it just enough to allow it to enter and closed it almost shut again.

Success in using the bumblebee nest entrance hole.

Bumblebees were using the entrance hole now as intended. Eventually fewer bumblebees were returning to the nest trying to enter via the window gap. I stayed out till it was dark to make sure I had allowed all previous ‘ window gap leavers’ to enter the nest! This procedure took about about 3 hours until it was dark! The bumblebee cat flap was then sealed closed. Later in the evening, I added kapok, a natural warm and soft material bumblebees love to work with, on top of the live colony. Later on I watched as they busily set about working the bedding by drawing it between their legs, under their abdomen and over the exposed wax cells, just like a blanket.

Early morning visit to the early bumblebees

29 May up at 5am and there they were, queuing inside the nest chamber at the sealed bumblebee flap! I opened the bumblebee cat flap and started the ‘training procedure’, (which takes about 2-3 days).

4 June these bumblebees are known as the early bumblebee and sure enough they did live up to their name. Just a few days after they had settled down into their new posh home, I noticed a few queens were leaving and returning to the nest some with pollen and some without, presumably with honey sacs full of nectar.

A few days later we had heavy rain, it was cold and windy. I did not notice any activity from foragers or queens leaving the nest. I could see many bumblebees huddled together on top of the wax cells and underneath the soft kapok bedding. Others were tending the cells or feeding from nectar filled wax pots. The weather forecast was bleak, continued rain and cold weather. To save them starving, I mixed fructose with water using a jam jar lid and placed it inside the nest box later that evening. The next morning the fructose had disappeared. Replacing the fructose water mix, after a very short period, I saw some avail themselves of this new and welcome resource almost immediately. On one day during this period, it stopped raining briefly early afternoon and I watched a few workers leave the nest followed by one single male, presumably off to find the love of his life after being possibly cooped up for days!

10 June we had a break in the weather and I saw a male and queen mating on my lawn a few feet from the nest box, which was filmed.

12 June returned to site on the allotment where the founding nest had been originally. To my absolute amazement, there were B. pratorum bees entering and leaving a hole in the soil. So whether a queen had developed and restarted a colony or whether a few eggs had hatched into larvae and were being fed I am unsure. Certainly it was busy with foraging bee activity, as video shows.

18 June several queens inside the nest box.

Regular comings and going into nest in between poor weather…

13 July poor weather and noticed queen with workers and saw another male leave the nest.Workers still entering and leaving the nest. Not as active now with numbers.

24 July saw (foundress?) queen with 2 small workers inside with 2 larger workers who are foraging entering nest with pollen. Filmed a pair of B. terrestris mating in the morning. Checked late at night to observe numbers inside nest box and without disturbing the nest too much only saw queen with 4 workers, the largest of which was the most aggressive, displaying such by laying on her back in a threatening posture. The smaller workers melted into the kapok.

25 July late evening check, same numbers as above. I suspect the 2 smaller workers stay inside the nest and the 2 larger ones are foragers. I never saw the smaller workers leave. Always busy tending inside.

28 July 2 bumblebees still foraging with a few wax pots full of nectar. No signs of any larvae. Same numbers inside.

31 July only 2 very small workers and queen with empty wax pots visible. I felt it was rather sad to witness bumblebees starving to death before my very eyes and decided to fill a couple of wax pots with a fructose mix, using a syringe. Watched the 3 of them start to feed.

1 August as yesterday but empty pots. Thought that if I fed them how long would they live if I kept feeding them? Days, weeks, months even? I was only delaying the inevitable, their existence would be rather sad, so decided not to feed them fructose. The queen was still prepared to defend her nest, even though she may have been dying of starvation by displaying the warning posture. I sealed opened the cat flap and left it open overnight to see what may happen.

2 August, I saw the queen dead, her life was not in vain as she had a accomplished her mission in life, a successful colony. Just one small worker still alive next to her body. Inside the nest I found a rove beetle and a grey field slug, Deroceras reticulatum, along with various mites and a few bathroom flies. I never looked again for a week or so.

Read a case for bumblebee nest boxes in gardens?

ee my new Registered Design award winning solitary bee box and bumblebee nest box both of which are radical, practical and educational, offering them a safer nesting environment in which you can observe the bees. Great for schools!

For more information about solitary bees and wasps visit BWARS

For more bumblebee information and to help save bumblebees join the Bumblebee Conservation Trust at Stirling University

* video shortly

{ 2 comments… read them below or add one }

Kit Welchman November 28, 2012 at 10:22 am

Dear George,
I just got round to reading and viewing your account and video of the nest removal and recovery. It’s a wonderful story of rescue and survival, of the revival of the bees, their capacity to adapt to catastrophic change; the human hand assisting, watching and guiding, and the bees eager response to it as they renewed the life of their nest; the mating on the lawn; the decline of the nest and the queen dying, her work accomplished. We catch some of the absorbing interest you must have felt watching and assisting over the days, and thank you for sharing it with us. There is so much to be learnt from such a glimpse of real bumble bee life, and so much yet to learn, both about bumble bee life, and the ways in which we can observe and assist. You have put a lot of time and effort into developing the nest technology (I found some of it a bit hard to follow without practical experience!). I was interested to see the pratorum bees who had survived back in the allotment entering a nest that seemed definitely underground in solid earth, so it does seem that B pratorum are quite adaptable in choice of nest site.

With best wishes

Kit

Reply

nurturingnature November 30, 2012 at 11:02 pm

Thanks Kit, for your appreciative words. I found the whole exercise wonderful,interesting,informative and very satisfying. I was astonished to find some bees still active on the allotment site. Yes our little B.pratorums are big on nest site selection and even bigger on survival! I hope my videos will stimulate and motivate others to share and add to the pool of practical knowledge and bumblebee experiences. Cheers George

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