Strange Hornet's nest.

[nomad]

This an unusually sited and large hornet's nest in a local country park. Vespa crabro have built their nest around a bird box. 



Here is a worker hornet cleaning itself on a late summer's day, a few years ago.

[trehopr1]

Indeed, a very odd location. Funny that it was still functional after the damage it incurred. Under such instances, the nest ceases to exist very much longer as the adults find it impossible to defend against enemies such as various flies, other wasps, and spiders. Also, without the protection of an enveloping envelope from the elements; the wasps find it likewise impossible to regulate the temperature of the nest so the larvae will soon die off from excessive heat, cold, or fungal spores.
Here in the Midwest states our Bald-faced hornet does make some impressive aerial nests. Large, well developed colonies can over the coarse of 4 months make a nest the height of two basketballs (placed on top of one another); and of similar width. On very rare occasions, they mistakenly develope a nest directly on a house near an attic vent or eave which may also happen to have a window just below it.
Before, the home owner even even takes notice the nest covers a portion of the window and the whole activity of the nest and it's inner workings can be observed in relative safety (from the inside of the home).
Insect architecture is one of my side interests so, I have a collection of wasp nests numbering around 30. They are all perfectly intact as I only want the good ones I do see and it represents about 20 or so years of searching. I've probably seen twice as many tatty ones during the same time period.

[nomad]

Interesting details. I am not sure how the damage happened to the nest. We have had some strong winds lately. It is also in a public area, with a noticed advertising that it is there that mentions consider an alternative route. As least with the damage you can see some social behaviour inside the nest, probably rarely viewed. I expect the nest will soon be empty and the young queens will find a place to hibernate through the winter.

[trehopr1]

V. crabro was accidentally introduced to the states a long time ago (probably in the 1800's). The farthest north it reaches as far as I know is Southern Illinois, Indiana, Michigan etc., pretty much the freeze line of the upper Midwest. I have collected it in S. Illinois and in West Virginia but, have never seen a nest. I've read that they nest in tree hollows and in the spaces between building walls where they have access to the outside via a small opening.
Much like our native Yellowjackets and our introduced ones (V. germanica); it is secretive in it's habits and is really only noticed by people when the colonies reach a substantial size and their activity is obvious. Would love to get my hands on a nice example of one of their nests !

[nomad]

I have never seen a Vespa crabro nest out in the open until this one. The only ones I have seen have been in hollows in trees. Once I found an old yew tree, Taxus baccata on a ridge in Hants, I wanted to measure it, as I suspected this yew was at least two thousand years old. It was hollow with a split where you could fit inside. Once inside I was confronted with a large hornet nest. While measuring the tree, the hornet soldiers started to become very agitated with the vibrations and we moved off. Certainly not a tree to hug. Nearby was an Iron age hillfort, and I suspect both the much younger yew stood here and hornets were in this area when the Durotriges Celts stood on the ramparts.