Non-random orientation of hornets' nests in trees

The leaves have been off the trees for many months now and abandoned hornets’ nest are a common sight. Still, whenever I see one, I am always drawn to it. There is just something about them that I find, well, compelling.

It is quite obvious that the nests are not randomly placed on the tree branches. Invariably, they are towards the periphery. More interesting, and what I can’t understand is that the nests seem to always be closer to the street than to the house. In other words, if there is a tree between a house and the street (a common arrangment around where I live), the nest is always on the street side of the tree. Why is that?

I thought it might have something to do with catching sunshine, but there seems to be no east/west or north/south preference. The only thing that seems to matter, regardless of the direction in which the street runs, is that the nest is on the street side of the tree, furthest from the house.

                   O   tree
                                                         (nest always [SIZE=4]on this side of tree)

=============================================== street

Can you enlighten me, please?

Nope. That needs some looking in to.
Meanwhile, consider this: Last year, after the leaves fell, I noticed an honest to god, wild-type beehive hanging from a lower branch on a large oak located between a house and the street. The hive was on the side of the tree nearest the house.

My WAG would be that the average altitude of a hornet flight is lower than the top of the house. The further the house is from the nest, the less of an obstruction it is.

Continuing with this logic, if we assume from a hornet’s perspective that an ideal nest will have 360° of open flight paths, almost any nest will have the disadvantage of a big ass tree trunk blocking maybe 20 or 30° of that. Various branches will collectively block another chunk of that. The way to maximize approaches is to get as much open space as possible on the remaining side.

Furthermore, it’s not just the house that gets in the way - most houses will also have smaller trees and shrubs hugging the sides, and possibly more big trees behind. Although at that distance, you probably have to worry about the same thing on the opposite side of the street.

On the other hand, they may be practicing feng shui.

This is interesting and I hope someone that really knows will chime in. How far away from the house are these nests? The only things I can think of have to do with shadows from the house or perhaps the tree blocks some of the air turbulance that the house might cause when the wind blows around it.

Thanks. Very interesting hypotheses.

While there’s always variation, I’d say that the typical arrangement in this neighbourhood is having the tree about 20 to 30 feet in front of the house. I should also say that this is a pretty modest area in terms of house size. They are not big, “monster homes”. Not even close. Mostly two-story brick with 35 to 50 feet frontage.

Per the other post I think it would be mainly sunlight related. Further from the house = more light = more warmth.

Damn wasps always build their nests right on my house!

Actually, it’s a Gaussian distribution.

One thing you’re not considering is that the distribution may not be natural. If I were a homeowner looking out my window and I saw a hornet’s nest abuilding in one of my trees, I’d be out there with the Raid, doing my best to knock it out of the tree. And likely, the nests on the house side would be more visible.

Very clever, and possibly true. Still, when leaves are present you’d be hard pressed to notice the hive.

Coming back from the store today, I deliberately took a different route than usual in order to increase my sample size. I counted four hornets’ nests. All of them were on tree branches essentially overhanging the street (and were thus as far away as possible from the house).

dqa’s idea was most intriguing. I realize now, though, that in many, perhaps most, cases the hive is actually quite close to the tree from the house across the street (with the two trees’ most peripheral branches, typically where the hives are situated, are almost touching). To me, this seems counter to the idea that unobscured flight paths back to the nest are the underlying explanation.



                   O   tree
                                                         (nest always on this side of tree)

=============================================== street

O tree across the road

gHOUSE across the road

Suppose the hornets have a preference for the size or type of trees lining the street. When part of a hive splits off to found a new hive in a nearby tree, the nearest part of a tree on the other side of the street will be the street side. Over time, this would skew the distribution of nests to the street side of the trees.