swarming

An open-air colony in a pear tree

I have an open-air colony in my backyard, something I never expected to see. Ever. But why a swarm of bees on the wet coast of Washington would elect to build a home in a tree is inconceivable. It’s also kind of hare-brained, I think.

One month ago, at the end of May, I wrote about a colony that threw three swarms in a week. One landed in a Douglas-fir and the next two selected opposite sides of a nearby pear tree. After a few days of bad weather, all the swarms sorted themselves out. Two ended up sharing one top-bar hive, and I managed to capture the third swarm and place it in a Langstroth.

Not the end of the story

Fast forward to one week later. I was working on my computer when I heard the familiar sound of a swarm on the run. When I got outside, a fourth swarm was issuing from the same hive that delivered the first three. Crazy, right? And, of course, the swarm choose the same pear tree that had been so popular the week prior.

The swarm was high—as they always are—and this one was quite a distance from the trunk of the tree, out where the limbs are skinny. It also wasn’t very big, which isn’t surprising considering it was the fourth swarm from one hive. I watched it settle, tried to photograph it, but I didn’t pay much attention over the next few days because of the weather.

You can just barely see the comb under the nascent colony of bees. The bees are high up and far from the tree trunk.
You can just barely see the comb under the nascent colony of bees. The bees are high up and far from the tree trunk.

Swinging in the wind

Rain and wind pelted those poor bees for a whole week. I didn’t think it unusual because nearly every year I have a swarm in a tree for a week of rain. It seems like standard operating procedure.

On the first sunny afternoon—day eight—I was clearing lunch dishes when I announced my intention to check on those bees. Just as I walked through the back door, the swarm rose from the tree and began heading south in the direction of two bait hives I had placed up the hill. I watched for a while, hoping to follow them, but they stalled over the garden, milling and cavorting but not going anywhere. I waited impatiently for them to do something, but finally I had to leave the house on an errand.

A colony in a pear tree

When I returned, the bees were in the process of re-grouping in the pear tree. That was when I noticed a small snow-white comb hanging from the branch where they had spent the last week. From my vantage point, it seems like there was some type of disagreement, as if the bees couldn’t decide what to do. Either that, or the queen decided not to follow the swarm. In truth, I have no idea why, but they were slowly—reluctantly, it seemed—coalescing on the little bit of comb they had built.

That was three weeks ago and the bees are still there today. They have built much more comb and seem to have settled in. Still, I think they won’t last much longer. The knot of bees is much smaller than it was and the weather has not been great. I can’t see very well, even with binoculars, but I do know that more comb is showing because there are fewer bees to cover it.

A numbers game

In a small swarm like that, the numbers are brutal. They spent a week in the tree before they tried to leave, and now it’s been three more weeks—a whole month. If they had a queen, I don’t know if she managed to mate. If she did, I don’t know if she laid eggs. And meanwhile, natural attrition is eating away at the small colony. I keep hoping they will recover, but I know their chances are slim.

In the meantime, the mother colony doesn’t seem strong either. There is a fair amount of activity at the entrance, but nothing like my other colonies. I shouldn’t be surprised since I split the colony in the weeks before it lost the four swarms, nevertheless I was hoping for a quicker recovery. Still, the split and the other swarms are doing great, so it’s been a net gain.

The longer I keep bees, the less I understand them. What a humbling experience they are.

Rusty
Honey Bee Suite

Open-air colony in a pear tree after about four weeks. You can see more comb but fewer bees.
This is the colony after about four weeks in the tree. More comb is showing, but there are fewer bees every day.

19 Comments

  • Hi Rusty

    Nice story. One time I was at a Tom Seeley book signing and he described the decision making process a swarm goes through while “bivouacked” like this. When there is a unanimous choice of a home, they break cluster and go. I asked him if it was possible that a swarm stuck on a branch like this simply couldn’t break a tie between two good sites. Yes, he said, that is possible! (Grinning slightly).

    Pete 🐝

    • Pete,

      That’s so interesting! Now I feel vindicated. They really did seem “confused” about what to do, and they loitered over the garden for more than an hour, but I didn’t know what to make of it. It’s too bad really. I would have loved them to choose one of my bait hives or at least go somewhere safe.

      • Rusty, since our hives are in the burbs, we have hung as many as 5 bait lures around our hives, trying not to have neighbors upset with us. Three were identical, made of flower pot material, and rather small in volume. Two others were Mr. Seeley’s ideal volume, equivalent to a 10 frame deep. This year, one small flower pot lure attracted one swarm (yay). But we lost 3 other swarms, two to parts unknown, and 1 to a tree behind a neighbor’s house (which they’re now cool with). My question is this: does having too many great options confuse the scouts? Especially if 3 are identical domiciles? Maybe they’d choose one good option instead, more of the time…

        • Dave,

          I’ve wondered the same thing. I, too, have many bait hives set up and I often wonder if I’ve made the decision that much harder.

    • Tom Seeley talks about this in “Honeybee Democracy.” That book taught me so much about swarms! I felt like a pro after reading it. And, with each new swarm that I catch/fail to catch, the bees teach me how far away I am from being a pro 🙂

      Thanks for sharing, Rusty!! Very interesting.

  • Great story. On May 19 I had a prime swarm from one of my over-wintered “condos”. They took flight as yours did into a tall tree at the far back of our yard. They were out of reach, but for a moment thought of getting out the climbing gear and going to shake them loose. Just then down falls 1/3rd of the swarm. The cluster hits the top of a neighbors carport. I scramble and successfully gather virtually all of them using a bait hive near the fallen cluster. I placed those bees in a queenless cell starter I had been using for queen cell grafting. Bees put away my attention then focused on the remaining swarm. One day followed another and then another – for a week! I could see bits of white growing leading me to ask just what survival mechanisms were being played out. As you did I started the count-down becoming more concerned as each day passed. Then on Day 8, the swarm left. It was a huge relief. I re-queened the hive with a new 2020 queen plus all bees. Checking on her a few days later I found the newspaper mostly torn-up. Thinking all was OK I walked away. Later that afternoon what happens but a second-swarm. I freaked thinking our new queen absconded – but no, she was still in the hive nicely hidden away in a honey super. Incredible. Was the second swarm from a virgin queen missed seeing? I checked every frame in that hive. Who knows? Could it have been a mated queen, perhaps the first swarm left with a virgin queen? I’ll never know. Today the hive is still thriving – it has yielded 35 pounds of honey so far this spring and 1.5 supers are filled with newly capped honey.

  • Every year I put out about a dozen swarm traps. A mix of box and flower pot types. This year on three different occasions the swarm settled on the outside of the box or pot. Each time it was on the bottom and front edge of the trap and covering the entrance. Very few bees inside the trap. All three had started building comb under the trap. I did manage to get them into hives. In my 8 years of beekeeping, I have only seen this once before.

    • We had a small, late season swarm start up under such a flower pot hive. But since it was hot (July in Tennessee), they seemed to want to stay underneath, as yours did, and eventually got robbed out. Since then I added a screened ventilation hole near the top of the lures. We’ve caught 3 swarms since then, and all moved in properly. Maybe that would help. Good luck!

  • Hi Rusty, a similar situation last year; we saw a hive in the process of swarming, way up high, grabbed a metal bird feeder and started banging; incredibly the bees started flying back down towards our loud tanging and landed on a branch where we were able to catch and re-hive them. A WOW moment for us. We had another swarm and again, we were there, and tanged again, but this time drove them away from the noise into a very, very tall tree. They bivouacked there for a week, through rain, wind, thunderstorms, etc., even starting a hive there with drawn wax. This impressed me, thinking how much I worry about my bees, and they can survive easily. They eventually left, and we now have a cool bee tree in our old maple in the front yard, which I am not surprised, survived the winter. They ignored traps, empty hives, etc.

  • A lovely story. I don’t keep bees or know very much about their habits I am gradually picking up tips though and I find it is so interesting. I am lucky that we often find a comb on our small farm I think possibly that is the way it is here as I don’t know many people who keep bees 🙂

  • Exposed comb. Bees building comb outside an enclosure, why? One possibility, often the exposed comb is constructed in fairly deep shade In such a case for the bees, the darkness is equal to some degree of being in an enclosed cavity.

    In another possibility.the bees swarm, then cluster, the following 2 or 3 days is heavily overcast and/or raining, the bees under reduced light levels commence comb construction. Once the weather improves the bees remain wedded to the comb, begin storing nectar, the queen begins laying. This is another possibility.

    • Thank you, Al. I think both those scenarios were at work here. After the swarm landed, it rained for about eight days. And while the days were dark and gloomy, the little swarm was covered in multiple layers of pear leaves. Thanks for the insight!

  • My husband got too close to one of the hives with the lawnmower last week and some of them swarmed into the pear tree right next to the hive. I baited a nuc with lemongrass oil but they didn’t care. Happened to be taking honey off the other hive that day, so I put a frame of empty comb in the “trap”. Also didn’t work. I ended up putting that in a honey super on that hive which they haven’t drawn any comb on yet. The swarm then disappeared and we weren’t there to see which way they went! I checked today and they have cleaned up that comb, but not drawn anything else or out honey in the super. They are super-aggressive now – there seems like there is a fair number in there. Do you think it’s possible they swarmed because of the lawnmower and then just decided to go home?

    • Jenn,

      No, I don’t think they swarmed because of the lawnmower. The decision to swarm is made weeks in advance and is determined by the needs of the colony rather than an occasional disturbance.

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