Hive Density - When are there too many?

[North End Bees]

No not true 1 instance I can think of was a coral cliff face in the middle no where that had many different colonies. As for limited sites in a man made environment, rubbish man made structures provide a multitude of voids/cavities. Bees have developed to take at vantage of cavities, it doesn’t mean they only like trees

A multitude of cavities available in towns, yes, but all in close proximity. I didn't say they only liked trees!

I don't know about the particular cliff faces you mentioned. If it was in the middle of nowhere, perhaps there weren't a huge amount of viable alternatives?

 

[North End Bees]

European honey bees are an invasive species in North America. Different forests. Does the same density apply here? Will have to read the book again, he may have referenced similar studies in The Old World idk. ?

Introduced species not invasive. Invasive infers that they had a negative impact on the invaded territory.

The forests in Europe will have different species of tree dominating but the density will be similar.

 

[Parsonage Bees]

Introduced species not invasive. Invasive infers that they had a negative impact on the invaded territory.

The forests in Europe will have different species of tree dominating but the density will be similar.

Saw an explanation somewhere of why the ecosystem of North America is more diverse than Northern Europe. Something about the east-west mountain ranges of Europe restricting the return of species after the last ice age. I wonder what native species of pollinator they compete with in North America since they've elbowed their way into the ecosystem.

 

[Ian123]

A multitude of cavities available in towns, yes, but all in close proximity. I didn't say they only liked trees!
I don't know about the particular cliff faces you mentioned. If it was in the middle of nowhere, perhaps there weren't a huge amount of viable alternatives?

.......... Really don’t you think the bloke 3 miles away has a hole in his soffit as well! why do you say lack of alternatives as a negative they are perfectly happy and productive.

 

[North End Bees]

Saw an explanation somewhere of why the ecosystem of North America is more diverse than Northern Europe. Something about the east-west mountain ranges of Europe restricting the return of species after the last ice age. I wonder what native species of pollinator they compete with in North America since they've elbowed their way into the ecosystem.

The ice barrier in Europe was responsible for the differentiation of species, for example Apis mellifera iberiensis on one side and A. mellifera carnica on the other, as the barrier/retreat followed the mountain ranges.

In N. America native pollinators will have to compete for resources with managed colonies, same as they do here.

 

[North End Bees]

why do you say lack of alternatives as a negative they are perfectly happy and productive.

But hugely more prone to disease transmission.

 

[Ian123]

Your changing the goal posts what’s that got to do with bees choice for a distance. As for disease I would suggest they are still likely to rob a dead out or weak colony 1km up the road as the neighbour if they find it that is. Also this lot happened to be living and coping with varroa far better than anything we have here however well spaced.

 

[user 6228]

There have been no detailed studies on whether bees have a distance based nest selection behaviour. However, the known nest selection behaviours point strongly to trees. But the man made environment has reduced the tree hollows dramatically, so the bees find cavities that appear to fit their behaviours, even though they prove to be sub optimal and totally unlike a tree. Those nest selecting behaviours also allow poorer fit to the behaviours nests to be selected as well. Mating drives in honey bees probably do not make the colonies group close together as Drone collection areas do have drones from distances of several kilometres
However, not only are there mating and bee selection behaviours, there is colony survival influences, from disease spread and foraging. Thus there is definite pressure for colonies to spread out, but detecting whether this is expressed as behaviour rather than a result of nest availibility and colony survival pressure, will require a very carefully designed experiment.

 

[North End Bees]

Your changing the goal posts what’s that got to do with bees choice for a distance. As for disease I would suggest they are still likely to rob a dead out or weak colony 1km up the road as the neighbour if they find it that is.

No moving of goal posts. Low disease transmission is integral to long-term colony survival. It's not forage availability alone. Otherwise you could site fifty colonies next to the waste skips of a confectionary factory and see how they survive long-term. Without disease management they would infect/infest eachother and be dead within no time, regardless of unlimited forage.

The Tom Seeley reference to 1km distances was for both disease and forage. His data shows that the weak colony 1km up the road is not likely to be robbed out. Presumably because prospective robbers are not as likely to find it as they would the weak colony 50 yards up the road.

 

[Ian123]

But did Seeley find limited long term survival of an individual colony but numbers density remaining similar.? Still no answer to the question of bees choice though?

 

[Boston Bees]

But did Seeley find limited long term survival of an individual colony

Depends what you mean by "individual colony"

I believe that none of the nests inhabited at the start of the study were inhabited at the end of the study (this is normal I guess - they abandon the nest to wax moth when it gets too "black").

The colonies existing at the end of the study were presumed to descend from one or more of those there at the start, given that the Arnott Forest is a closed environment (in theory - though not sure how varroa got in there in the first place if so). No DNA testing was done to confirm this though.

Bees will naturally subdivide and scatter over time, if possible, as you know. And mate with drones from other colonies. So the term "long term survival of an individual colony" is a bit of an oxymoron when it comes to wild colonies, no? It's something that some people try to achieve in managed hives, but that's different.

 

[North End Bees]

But did Seeley find limited long term survival of an individual colony but numbers density remaining similar.?

The original study was in 1978 and showed colony density of 1 per km2.
He repeated the study in 2002 and found exactly the same population density.
A particularly pertinent point is that the 1978 study was pre-varroa. He proposed that the maintenance of colony numbers was due to optimal spacing.
According to his data, colonies lived on average 5 years.

 

[Michael ECB's]

Well, in my neck of the woods it's different, very very different.
Hive / colony density depends on many factors and I doubt any formula could be used... Very often 2 "wild" colonies in the same building or within meters of each other. This is a common occurrence in high value forage areas.
My opinion, bees are foragers, so they should be compared to foraging livestock.
(Some times to be considered as cannibalistic livestock when robbing starts) - another topic...

How many cows or sheep can you run on 1000 sqm ? - depends on what is available to eat...
Spring = 10,,,,,,, summer = 8,,,,, winter =4 etc etc etc
If you over stock you will need to supplement feed during times of need... if this is not an option simply move your stock to another camp/apiary during the tougher/leaner times.
Wild colonies.
If the going is good, bees will make a plan to move in somewhere.... some long term huge colony builders and some limited for space that just cast swarm after swarm almost as if destined to do so...... Nature left alone has a way of thriving....
Disease
Firstly, Im very fortunate here, so this is based on my little protected piece of the world I call home.
Another point was so many colonies close together may/could be a risk with regards to disease.... Another way of looking at it is natures way of keeping them healthy and apart from other diseased colonies...

See below pics, (Pls excuse other lines drawn through pics, they are for measuring distance when moving caught swarms)
6 colonies within 100m of each other and another 2 very large colonies perhaps 70 meters away. (All within 1sqkm)
4 colonies also within 100 sqm of each other.

 

[Ian123]

Surely not they want to be a km apart it’s natural How many colonies do you find in cavities other than trees inc the ground pls Michael.

 

[Michael ECB's]

Surely not they want to be a km apart it’s natural How many colonies do you find in cavities other than trees inc the ground.

Trees are not very common, with the limited space these usually offer I believe colonies dont have enough space to build sufficient reserves to see them through.
Ground hives are also usually short lived, predators, weather conditions etc etc usually lead to absconding or die out...
Most popular is parts of dwellings or man made rubbish discarded, old vehicles, fridge, tyres, bales of hay, even under septic tank covers....
By far the best, structures like sheds, workshops, storerooms, under old wooden floors etc etc....
Where there is a will, a Bee will find a way.

 

[North End Bees]

Surely not they want to be a km apart it’s natural

Where does nature come into it? Multiple swarms from colonies originally placed in an artificial environment where the only subsequent nest sites available are part of the same managed environment. They can only fly so far in their search for the optimal site.
The original premise was that bees choose to nest at distances from each other.
If the availability of nest sites is artificially constrained then they have to make do.
Making do is far from optimal.

 

[user 20297]

Evidently, managed bees can thrive at a very high density of colonies. Feral or wild bees probably won't be using a tape measure for spacing, and will settle wherever they find the right spot. This all relates back to "natural selection". Bees probably aren't actively looking to find a new house a long way from their nearest neighbours. But where a wild colony decides on a well-spaced location and ends up with a fairly exclusive food supply and an absence of robbers bringing along parasites and pathogens, that colony and its genes are likely to survive to produce further generations.

But I would have thought that most people could already accept the simple fact surmised by the originator of this thread, that the more closely colonies are spaced, the more likely it is that they will struggle to all find sufficient forage for their needs.

 

[Newbeeneil]

From what I remember of talks by Tom Seely the Arnot Forrest isn't the most productive area for forage etc so probably the Colonies probably find it easier if spaced out.

Regarding spacing colonies in this areas, in 2019 several of us removed 4 colonies from 2 sides of a small barn. They were all within 20' of each other. 9 years ago there were 5 colonies removed from the same barn.

 

[North End Bees]

So at the end of the day it all comes down to what we already knew anyway.

Given the choice bees will choose nest sites away from other bees.

But if bees are located (by the beekeeper) in an artificial environment, then when they swarm they have to stay within that environment. They can't catch a lift to somewhere more suitable.

Natural selection won't weed them out because every swarm every year perpetuates the genes in the built environment. Increasing numbers of swarms, with each colony living just long enough to send out another generation into the overcrowded sheds and soffits. And beekeepers can relocate them and say, "How marvelous, half a dozen colonies in one 20' shed, they must be doing alright."

 

[Boston Bees]

If the availability of nest sites is artificially constrained then they have to make do.

How is it constrained though? The average town contains many times more potential nest sites than the average woodland does.