Forest Homes by Tom Seeley.

Introduction.

Welcome to all you lovely new subscribers who joined us this month, and thank you to everyone who generously donated towards the blog maintenance and site security. I must also say thank you to Iain (my admin support in Australia) for trouble shooting the series of problems with getting the blog out to you over the past few weeks. I appreciate your patience and persistence, Iain. And also to you the readers for letting me know about them and sticking by.

It’s been a busy month on the blog with the highest number of recorded viewers reading about Tom Seeley’s new book coming out in a couple of days.  A consignment arrived at Northern Bee Books and they stocked the shelves this week so it’s all systems go.

We decided to treat you to another excerpt this week, and here is part of the story from Chapter 2 about forest homes. You can read the rest when your book arrives. Thank you so much, Tom, for sharing this story with us here on the blog.

Forest homes is very apt really as swarm season is winding up to take off and bees all over the land will be searching for new accommodation. We have had snow here this week but swarms are part of the conversation. I was asked to comment on Scottish national radio last week on the swarm interrupting the tennis match in the US. That was a bit of a surprise given the call came just over an hour before the show went live, and I don’t have a TV so hadn’t seen the drama. I had to swot up quickly via the link I was sent and hope for the best. The following day, Radio Berkshire in the south of England phoned up asking me to come on Brigitte Tatteh’s show as their “expert” to talk about bees for 10 minutes. That was good fun because the presenter Brigitte is so relaxed, friendly, and good at her job.

It’s over to Tom now.

Excerpts from Chapter 2 in my new book, Piping Hot Bees and Boisterous Buzz-Runners.

Because nearly every colony of honey bees that one sees these days is living in a manufactured hive, it is easy to think that honey bees are domesticated.  But this is not so.  A swarm of honey bees that escapes a beekeeper’s hive can move into a hollow tree and live there all on its own for many years. 

Let’s take a brief look at what is known about the homes of free-living honey bee colonies.  This is something that Roger A. Morse (“Doc”), the Professor of Apiculture at Cornell University, and I studied in the summer of 1974.  This was a first step toward understanding what the nest-site scouts in a swarm seek when they go about choosing the future dwelling place for their colony.   Working with a friend, Herb Nelson, who had worked as a logger in the State of Maine, I would go a bee tree, photograph it, and then measure and record several details about its entrance:  its size, shape, height and compass direction.

The first bee tree whose nest I dissected.  It was a 120-year-old sugar maple tree that was nearly dead.  The knothole in the left fork was the bees’ nest entrance.

Then, Herb and I felled the tree, cut out the section that housed the bees’ nest, wrestled it onto a truck, and brought it to the Dyce Laboratory for Honey Bee Studies at Cornell University, where I split it open to expose the nest.  Then I carefully took it apart, comb by comb.  It was fascinating to dissect the nest of a wild colony and thereby discover its secrets.  It was also sobering, because I had killed the colony—very quickly, using cyanide gas—before sunrise on the day we felled its tree.  I did this so Herb and I could collect these nests without getting heavily stung, and so I could count how many workers and drones were in each colony.  Even after 50 years, these awkward memories still elbow themselves to the front of my mind when I think about bee trees.  No beekeeper likes to harm, let alone kill, honey bees.

The nest inside the bee tree shown above.  The nest entrance is on the left side, about two thirds of the way up the cavity.

This investigation revealed many striking differences between the forest homes of free-living colonies and the apiary homes of managed colonies.  Besides the obvious difference of home spacing—far apart in the woods vs. close together in apiaries—there were many differences in in home design:  size and height of nest entrance, size and shape of nest cavity, thickness of cavity’s walls, and many more (see Table).  These glaring differences began to open my eyes to the many ways that conventional beekeeping practices alter the lives of honey bees in ways that benefit us but can harm the bees:  more risk from disease (by crowding colonies in apiaries), more energetically costly nest thermoregulation (by using thin-walled hives), and less reproductive success (by inhibiting swarming and drone rearing), to mention just a few.

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Looking back, I see that this study of the natural homes of honey bee was an early stage in my thinking about how to be a bee-friendly beekeeper.  For example, I now use hives whose walls are well insulated with foam board.  This raises the walls’ R-value from 1 (that of standard hive made with 3/4-inch /1.9-cm pine boards) to about 8 (that of a tree cavity whose walls are 6 inches/15 cm) thick.  And this means that, summer or winter, heat passes through the walls of my hives 8 times more slowly than before.

      The work of describing the natural nests of honey bees showed us what their homes are like when they live out in the woods around Ithaca, but it did not tell us which features of their homesites are important to them and which ones are incidental to living in hollow trees.  For example, it might be that their nest entrances tend to be smallish openings because the nest-site scouts in swarms instinctively choose nesting sites with small entrances so their homes are snug and easily defended.  On the other hand, a tall and cylindrical nest cavity may be the norm simply because this is the most common shape of cavities in tree trunks.  So, Doc and I needed to ask the bees about their nest-site preferences.

       Our plan for doing so came from something that we knew about beekeeping in East Africa and South Africa.  Beekeepers in these places acquire swarms by hanging hives—often hollowed-out logs—in trees and waiting for swarms to occupy them.  Birdwatchers the world over do something similar:  putting out bird houses to attract cavity-nesting birds. 

I had not heard or read of beekeepers in North America putting out bait hives to catch swarms.  But I supposed that this might work, and that if it did then Doc and I could ask the bees about their housing preferences by putting up groups of two or three bait hives (nest boxes), with the boxes in each group identical except for one property, such as entrance size.  If swarms found our boxes, and if they consistently occupied those with certain attributes, then they would reveal to us their housing preferences. 

Painting of a log hive occupied by bees, with Maasai watching the bees.  Purchased by Roger A. Morse in 1972 in a market in Kenya.  The artist is unknown.

This study plan worked surprisingly well.  Each summer, for the next three years (1975-1977), Doc and I mounted some 250 nest boxes along roads in the countryside around Ithaca.  We deployed them in groups of two boxes spaced about 30 feet (10 meters) apart, and in each summer over half of these nest-box groups had a swarm occupy one of its boxes.  In each group of nest boxes, there was one box whose properties (entrance area, cavity volume, etc.) matched those of a typical nest site in nature, and another box that was identical to the first except in one property, the value of which was atypical for a natural nest site.  This experimental design enabled us to test for a preference in the property that differed between the boxes in a group.

Our hard work was well rewarded.  We captured 124 swarms in our nest boxes in the summers of 1975, 1976, and 1977.   These nest box occupations showed us that nest-site scouts have preferences regarding six properties of their new homesites (A>B means option A was preferred to option B:)

1.  entrance area (2 sq. inches > 12.5 sq. inches)

2.  entrance height above ground (15 feet > 3 feet)

3.  position of entrance (bottom > top of cavity)

4.  entrance direction (south > north)

5. cavity volume (1.4 cubic feet > 0.35 cubic feet)

6. preexisting combs from another colony (with > without)

We also learned that nest boxes that we had rendered drafty (by drilling small holes in their walls) or damp (by dumping waterlogged sawdust in them) were perfectly acceptable to nest-site scouts.  This is because worker bees can remedy these two shortcomings.  Every swarm that moved into a drafty box made its new home draft-free by plugging the holes in its walls with blobs of propolis.  Likewise, every swarm that moved into one of the damp boxes rendered its new home perfectly dry by removing all the soggy sawdust.  Lesson learned:  honey bee swarms will accept fixer-uppers, and they are willing to do repair work.