What size should the holes be in a bee hotel? PART II - Results

Please watch PART I first! This video gives the results from my bee hotel experiment. Sorry the sound is out of sync for the first few seconds!

[@spencersanderson1894]

Hi Dave, fantastic experiment, remember watching part 1 and I was really excited. I have a few bee hotels in my garden with the typical bamboo in it for the bees, and I’ve seen the smallest of holes covered up, it’s fascinating what the will squeeze into if other holes are occupied.

[@joanbrady3603]

Fascinating! I'm only in my 2nd year on bee-hotel watch, lots or Red Masons, a few Blue Masons, 2 or 3 sps of leafcutters, AND, this year lots of the smallest bamboos used by Common Yellow-faced bees, the "cellophane-like" seal of their holes is distinctive.

[@animalplanettorgny]

Nice video! It will be interesting to see what you get in the thinner tunnels next year. I have many hotels in a few places with around 1000 plugged holew at this point. Smaller holes do attract many solitary bees and wasps, and sphecoid wasps. Some common species in my hotels + diameter: Spilomena spp 1,2-1,7mm Chelostoma campanularum 2-2,5 Passaloecus corniger 2-4 Hylaeus communis 2-4 Trypoxylon clavicerum 2,5-4 Hoplitis leucomelana 2,5-3,5 Heriades truncorum 2,5-4 Symmorphus bifasciatus 3-4 Chelostoma rapunculi 3-4 Chelostoma florisomne 3-4 Deuteragenia bifasciata 3,5-4 Trypoxylon figulus 4-5 Crossocerus cetratus 4 Hoplitis claviventris 4-5 Ectemnius continuus 4-5 Osmia parietina 4-5 Osmia caerulescens 4-5 Pemphredon lugubris 4-6 Osmia leaiana 5 Colletes daviesanus 5-7 Osmia bicornis 6-7 Ancistrocerus parietinus 6-7 Megachile willughbiella 7-8

[@sorkny]

Thank you for that list. At my place in the northern parts of Sweden smaller holes (2-4mm) are the most popular. Most of them are occupied by Hylaeus , species yet to be determined. And of course, they have their followers like Chrysididae and probably others. This year i also have Megachile lapponica in a 5mm hole, so far. And of course, Thanks Dave Goulson!

[@bearhustler]

For me Masons were great this year but my leaf cutters were well down. All my bee boxes are full except one. The bee box with the removable 'drawers', those cleanable boxes, the bees investigated this box but wouldn't nest. I also had Resin Bees this year. Leafcutters always prefer 10mm holes with me.

[@TheSamba37]

Having a diversity of hole sizes and the coinciding diversity of nesters can also help curb disease among those populations.

[@raymondkilminster2194]

Hi Dave what a interesting video . i've had the same thing this year with my mason bee's being low in numbers and then disappearing early. while my leaf cutter bee's have had a good year with up to a dozen nest holes being filled and sealed .

[@Kalamain]

What a shock.... To actually get a good mixed bag of attraction for your hotel you need to have a mixed bag of hole sizes! I mainly go from 6 to 10mm... I used to go smaller (Down to 4mm?) but never got anything in them that I found? I find though that my leafcutter don't like my hotels. I'm really surprised that yours got some use? Maybe it's because my Yorkshire bees are more picky! One VERY exciting thing for me this year was seeing my wool carder bee making a nest... I planted lambs lug JUST to see if they would appear... And appear they did! I'm so happy they are now resident in my garden almost permanently!

[@bradleywoods3742]

I think leafcutters tend to go for drilled holes or holes in clay bricks (the same clay bricks used for hairy footed flower bees will be used by leafcutters), but they are very tedious and will also use bamboo. I'm not sure anyone knows the exact conditions leafcutters need, but if you hang up the bee hotel maybe at the end of june when the red masons have gone over then less of the holes will be taken up by them.

[@Kalamain]

@@bradleywoods3742 I have a vid of a leafcutter making a nest in the hole on the handle of my wheelie bin! They will use any gap they can fit in that is not otherwise taken.

[@lindalaw9616]

Brilliant information Dave, as always. Thank you so very much.

[@michaelgodding8572]

Stumbled upon this and it's awesome. Have you considered maybe setting up a motion camera to capture what birds or other animals are making the rounds?

[@benhewlett1695]

Dave you should check out john little from the grassroofcompany. He has experimented with loads of hole sizes with great results! Also leaves alot of dare substrate for ground nesters too

[@patrickturnbull8811]

Thanks for sharing. Did not realise that some holes would be stuffed with clay. Leaf cutter bees are my favourite because they are so carelessly untidy. Am going to make one of these for my RSPB stall and emphasise need for diversity of sizes. (PS start of video was reminiscent of old kid's programme 'Heidi' because the sound / pic was out of synch!)

[@tomndines]

Very interesting. We have a series of bamboo tubes that for two years now have been jam-packed with large headed resin bees (heriades truncorum). They seem to prefer 3-6mm holes. We also found a few mason bees using 6mm holes, though they seemed completely uninterested in the 8mm paper tubes I bought!

[@mm-dz2pm]

Are paper tubes worthless? Do you also have a link to the tubes for me?

[@Narnendil]

Great video! I've been looking forward to seeing the results in this video! This year the solitary wasps on my balcony have only reused the holes they used from last year and the ones that were empty last year are still empty this year, even though they are the same sizes. I wonder why that is? Do they have a preference to reuse? And some people say you should clean out the holes in between uses but how am I supposed to know when they are all out of their holes?

[@klmrk9961]

I made a bee hotel last year and drilled holes from 3 to 12 mm and the 3-4 mm holes were most popular. I don't know bees very well yet so I don't know what species showed up though. Interesting anyway. I couple of times a greater woodpecker have pecked away, but it didn't do much damage.

[@tedchoi243]

Very useful, thank you. Have you published these results?

[@Goodtimes523]

Great Video! Do you clean out the holes and if so, when? Thank you!

[@TheBlinto]

Great experiment

[@elliotlane3225]

Excellent. I have plans to add more hotels for next year and will ensure l drill various holes. My shop bought beehotels seemed popular this year with leaf cutters. Can l ask how deep the wood block was you used? I intend to DIY my beehotels this year. Thanks.

[@davegoulson6831]

It is about 15 cm deep. Deeper would be better.

[@VC57UK]

So, will you be looking at optimum (or at least minimum) *depths* of holes next? That might help those of us with access to timber that's not so deep to decide whether it's worth trying?

[@patrickdelvisohopkins]

Great work! I was looking forward to this video, and it didn't disappoint. I'll try this experiment next year in my garden 😀 You may be interested in launching a global experiment with your subscribers running this same experiment and report results to you! You'll end up with plenty of data and information of bees and wasps nests in the UK, Europe, the World... 😁

[@kevinpowell7948]

Great, thanks. Does anyone know which is best,a North,East, South or West facing wall to hang bee hotel on. I live in London. Cheers 🍻

[@juliacheetham6854]

I was wondering the same!

[@montym9814]

Dave. Does it matter which direction the holes in the bee hotel face? Eg I’ve heard they should face south if possible?

[@aurorawalker7952]

Yes South if possible!

[@FYHBettan]

I'm wondering, does it matter what type of wood you use? I've heard that pine isn't a good choice.

[@michaelday6870]

Would you consider getting onto BWARS for a wider-reaching citizen science project?

[@Theedappa]

Do you think they would nest in clay? thinking of making a block like that with holes in the clay. i feel like they might like it if it bakes in the sun or maybe thats just me haha

[@bearhustler]

I know people who have used clay blocks successfully.

[@alisonburgess345]

Looks like no-one went for the bamboo stacks?

[@mm-dz2pm]

Are bamboo sticks also good? Or rather wood blocks?