Tag Archives: science

Bee comb

This week I took advantage of what may be the last warm, sunny days of the season to tidy up the bee hives for winter. I removed unneeded boxes of frames from the tops of the hives and shuffled frames within the boxes to keep as much honey in the hive as possible. Thus prepared, winter hives are less likely to blow over in storms and, more important, all the honey is gathered into one place within the hive. In cold winters, bees huddle in a ball around their honey stores, slowly eating the honey as fuel to keep them warm (the center of the hive is as warm as human body temperature). If honey is thinly dispersed, the balmy bee ball cannot form.

I had forgotten just how beautiful the wax combs of honeybees are. The near-perfect six-sided geometry, repeated hundreds of times is a fabulous piece of natural architecture.

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The wax is secreted from chinks in the abdominal exoskeleton of worker bees. The bees then mold the wax into the six-sided pattern using chewed wax particles. This task falls to middle-aged (2-3 week old bees) worker bees. Younger workers look after the brood; older workers leave the hive and forage.

This weekend marks the 153rd anniversary of the publication of On The Origin of Species. It is therefore fitting to include here Mr. Darwin’s thoughts on the wonders of beeswax.

He must be a dull man who can examine the exquisite structure of a comb, so beautifully adapted to its end, without enthusiastic admiration. We hear from mathematicians that bees have practically solved a recondite problem, and have made their cells of the proper shape to hold the greatest possible amount of honey, with the least possible consumption of precious wax in their construction. It has been remarked that a skilful workman, with fitting tools and measures, would find it very difficult to make cells of wax of the true form, though this is perfectly effected by a crowd of bees working in a dark hive. Grant whatever instincts you please, and it seems at first quite inconceivable how they can make all the necessary angles and planes, or even perceive when they are correctly made. But the difficulty is not nearly so great as it at first appears: all this beautiful work can be shown, I think, to follow from a few very simple instincts. (First edition, Chapter VII, page 224).

He elaborated these thoughts with a series of calculations and experiments, summarized in a recent essay at the Darwin Correspondence Project. As you might expect, Darwin concluded that natural mechanisms could explain the structure of bee comb and that sophisticated combs could have evolved from simple beginnings.

This naturalistic view contrasts with the opinions of Darwin’s contemporaries. After reading Darwin’s passage, I pulled down Langstroth’s Hive and the Honey-bee, an important review of bee biology and bee-keeping published in 1859 (the 4th edition, 1878, is the one that I have on hand; post-Darwinian for sure, although Darwin is not mentioned). Langstroth writes of comb:

To an intelligent and candid mind, the smallest piece of honey-comb is a perfect demonstration that there is a “GREAT FIRST CAUSE.”

These enraptured references to the Divine are peppered throughout his work.

Langstroth was a priest, but depression kept him from many of the usual priestly duties. Instead, he studied insects, especially honey bees. Although his theology seems unsophisticated to modern ears, his entomology was not. His careful studies of bee behavior transformed bee-keeping. In particular, these studies led to him a new design of bee hive, a design that is still the preferred hive for most bee-keepers, especially in North America. Unless you’re eating honey from wild nests, you can almost guarantee that the honey in your kitchen came from a Langstroth hive. I use a modified design: Langstroth in the upper portion (from which come the photos in this post) and open in the lower part (no photos — I never open this part, leaving it for the bees to do as they will).

Winter birds

This afternoon, I heard the querulous call of my first yellow-bellied sapsucker of the season. This migratory woodpecker breeds in mixed coniferous woodlands in the northern forests, then winters in the southern U. S. and in Mexico. Unlike their woodpecker cousins, sapsuckers prefer to feed on live trees. They take a delicate approach to drilling, making horizontal lines of holes from which they drink sap and eat sap-tippling insects. With the sapsucker’s arrival, Sewanee’s woodpecker count is up to seven species. The others are: pileated, hairy, downy, red-bellied, red-headed, and northern flicker. (The endangered red-cockaded woopecker used to breed in Savage Gulf, just north of here, but has been extirpated from Tennessee for more than thirty years.)

So far, this has been a good year for sightings of winter birds. Pine siskins have been quite abundant and I saw a pair of red-breasted nuthatches in early October. In some winters both these species are rare or absent. All this good birding for southerners results from hard times for the birds up north. When pine and hardwood seed crops are poor in Canada and the Northeast, birds are driven south by hunger.

According to Ron Pittaway of the Ontario Field Ornithologists, this will be a bad year for northern seed crops. His “bird forecast” focuses on Ontario, but what happens up north will be reflected in bird life across the country.

Humans add an interesting overlay to this natural year-to-year variation in food supply. As I note in The Forest Unseen, our love of birds results in the transport of millions of tons of sunflower seeds from the former prairies into bird feeders all over the country. This makes life easier for many birds, causing some of them to expand their winter ranges northward. Bird-hunting hawks therefore also linger in the northern woods. Our bribes have shifted the calculus of migration.

We know surprisingly little about how feeders affect the day-to-day behavior and ecology of birds. New technology, deployed (appropriately enough) at Sapsucker Woods where the Cornell Lab of Ornithology is located, is starting to shed some light into these questions. Least we humans feel left out, the same technology is being used to study our own “day-to-day behavior and ecology” and, like the birds, as long as the sunflower seeds keep coming, we’re happy to play along.