Baldfaced hornet nest: Nature's architectural marvel

It wasn't the Great Pyramid of Giza, but the nest outside my office window was an architectural wonder.

I marveled at this structure from its incipient stages last July until its untimely demise last week. This spectacular building was the nest of a baldfaced hornet colony.

The word "hornet" elicits an immediate reaction in most people - usually fear.

Go one step further and say, "There's a hornet nest," and you'll raise ire, usually followed by a declaration of war and a dash for the weapon of mass destruction: the spray can of wasp-killer. And for good measure, pruning shears to chop off the branch and get rid of the nest.

Herein I plead mercy for the builders of this masterpiece and petition for preservation of the architectural wonder that is their nest.

Baldfaced hornet nests provide food and shelter for the colony in the summer and fall, and even when the colony has died, the nest provides food and shelter for other wildlife in the leanest months of winter. Leaving these nests in the trees will benefit lots of wildlife.

Plus, it allows us to admire an ever-changing work of art throughout the year.

Like all good construction, the creation of a baldfaced hornet nest is the concerted effort of many partners over a period of time. The blueprints are drawn by the queen. She has survived the winter buried under a log or tucked under some bark in the woods. In spring she emerges to search for good real estate among the tree branches.

When she finds a suitable spot, she gets to work. First, she gathers the raw materials for construction: cellulose from weathered wood. The queen mixes this with her saliva to produce paper pulp. She attaches a small disc of pulp to a branch. Next she builds a pedicel. On top of this she constructs the nursery: a flat layer of cells.

The queen lays eggs in these brood cells and envelopes the whole affair in multi-layer "wallpaper," leaving an opening at the bottom for ingress and egress.

The firstborn females are workers, and they can waste no time getting to work. When they do, the queen hangs up her hard hat. Her construction days are over, and her offspring will carry on with the plans from here on out. Her job is to sit tight in her master suite, produce more eggs, and rule the colony.

Phase 2 of the construction project is the enlargement of the nest to accommodate an ever-increasing number of offspring. The workers remove the inner layers of the wall paper to expand the interior, and then they build a new exterior layer. All the while they are making multiple tiers of new cells for new eggs inside the structure.

This is pretty cool, but cooler still is the fact that the workers are doing this in the dark - upside-down, no less. According to one source, each worker determines the dimensions and thickness of a cell by keeping one antennae in one cell and one outside, and one mandible inside, one out. The computers in their brains do the calculating.

By early July, a baldfaced hornet nest may approach the size of a volleyball. It was at this stage that I noticed the nest in the tree outside my window.

Despite its size, it was well hidden in the leaves, and you had to know right where to look to see it. The multicolored layers of new paper revealed the variety of wood that the wasps used to make their construction paper. It blended in both color and texture with the host tree. Very tasteful decorating, in more ways than one!

There was constant activity at the nest in July and August. Rush hour was any time on a hot, sunny day. There were continual outgoing sorties for food, and continual incoming deliveries of food. Secret communiqués were passed in brief exchanges between the pilots.

Meanwhile, the workers on indoor-duty were building apace to keep up with the burgeoning colony.

Like other architectural wonders of the world, this one drew tourists. I set up binoculars, a tripod and a camera at the window, so people could take turns admiring the nest and noting the activity each month. (OK, the tourists were my co-workers.)

Down on the ground, the naturalists made the nest a stop on their guided hikes with school and family groups. This piece of animal architecture had a lot to offer on all fronts.

In late summer and early fall, there can be as many as 300 individuals in a baldfaced hornet nest. (I didn't count mine, but I have it on good authority.) The nests can be as big as a beach ball - albeit a lopsided one.

It's at this stage that many people first notice the nest, and usually determine it must go. This is unfortunate, because the nest has not yet completed its purpose.

The final construction phase in early autumn is a time of frenzied building. They're up against a deadline: frost.

Sensing a change in daylight, the workers build larger cells and the queen lays larger, fertile female offspring. For good measure, she produces a few males as well. The new males and females do their thing, and then the young, fertilized females fly off to find a good wintering spot under a log.

The rest of the colony - the old queen, her hundreds of workers, and the handful of males - die inside the nest with the onset of cold weather.

The architectural marvel outside my window had passed its glory days at Thanksgiving, but it held up well in the first winter storms - a testament to its solid construction.

One subzero day in January, I watched with rapt amazement as a female red-bellied woodpecker probed the cells of the nest with her long bill. She methodically pulled out protein treats for hours.

The next week, a male red-bellied came to dine. Next up in February was a black-capped chickadee, who hunkered down on the lee side of the nest. His rapid-fire digging was proof that there was still nutritious food inside.

One morning in late February, I arrived at my office and, as was my habit, checked messages, took a sip of coffee, and looked outside the window at the nest. Only there was no nest.

I looked down at the ground but it hadn't fallen. I looked up in the tree again and couldn't even find the branch. Then, I saw the cut. It was a clean, fresh, round cut, leaking sap.

I learned that someone had complained that the nest was dangerous. Perhaps they felt it was an eyesore. It could be argued the nest wasn't dangerous even in its prime activity last summer, given the fact that none of the hundreds of passers-by had gotten stung. It certainly wasn't dangerous in late February. It was an asset for wildlife when pickings were slim at the tail-end of winter. And, for some of us, it was an element of beauty in the stark, bare branches of the tree.

The take-home lesson is that there's lots to be fearful of in life, but much of that fear is unfounded. And, one person's architectural wonder is a another's monstrosity. (I'm reminded of the Picasso in Chicago!)

I cherished our baldfaced hornet nest as an architectural and ecological masterpiece. The opportunity to see it through its final cycle was cut short, but the opportunity to teach goes on.

It's good to know that a young queen is out in the woods and will soon emerge to create a new chef-d'oeuvre - hopefully with a building permit, so we can enjoy her work for an entire year.

• Valerie Blaine is the environmental education manager for the Forest Preserve District of Kane County. You can reach her at blainevalerie@kaneforest.com.