Science Articles

Where do all the bees go?

Wed, 26th Aug 2015

Where do they disappear to in the colder months?

Felicity Bedford

A sure sign that spring is in the air is the return of bees to your garden but have you ever wondered where the bees have been during the colder months? The answer is more complicated than you might think because there are around 250 species of bee in the UK alone, and the only thing they have in common is that they don't fly south for the winter. This huge group of species act as essential pollinators for many flowers and crops, so it is important that we understand what resources they need to survive.

Honeybees huddle together to keep warm

Honeybees (Apis melifera) are a semi-domesticated species which forms large colonies with up to 60,000 workers. Although usually found in artificial hives managed extensively by beekeepers, they can sometimes form wild colonies in tree cavities and rock crevices. Most of the honeybees that you see today are strains that have been imported from Europe.

Honeybee carrying pollen

Like all other species of bee and most insects, honeybees are ectothermic (taking heat predominately from the environment) for most of the year. However, during the winter honeybee colonies survive by working together to maintain temperature collectively. Clustering together each bee shivers its flight muscles to generate heat. Bees on the outside of the cluster act as insulation for those in the middle where the temperature is maintained at about 35oC. If the body temperature of the bees drops below 8oC they are unable to move their flight muscles and die.

During the summer each worker honeybee will only live 1-2 months. However, honeybees that hatch later in the year are adapted to survive longer, up to 6 months, to get the colony through the winter while no brood is being produced. In the autumn when the temperature drops below 10oC the bees return to the hive only venturing out when temperatures are warmer to dispose of body waste and keep the hive clean.

The population is much smaller during the winter and survives on honey stored from earlier in the year. If the honey supplies run out the colony will starve. The winter cluster of bees stays centrally in the hive and moves gradually upwards through the honey stores. This pattern of minimal movement means that clusters can fail to find honey stores in other parts of the hive and colonies have been known to starve to death surrounded by honey. Losses of honeybee hives over the winter have also been linked to the level of parasitic varroa mites (Varroa destructor) within the hive reducing the average lifespan of the worker bees.

Bumblebees hibernate underground

You may not have noticed but there are many different types of bumblebee across the UK and the queens, males and workers within a species all look different too.

Winter life is lonelier for a bumblebee queen. Although they form colonies in the spring they overwinter alone. After mating in the autumn each bumblebee queen will dig a small home to spend the winter. There has been a lot of interest in bees and their habits lately with concerns about population declines and the loss of valuable pollination services bees provide. However, exactly what a bumblebee looks for in its winter home is still a mystery. The last scientific research was published in 1969 by David Alford when he stumbled upon an area used for hibernation by loads of bees and recorded the characteristics of each queens home.

Bumblebee - Bombus terrestris

The first bumblebees you see in the spring are these queens looking for somewhere to nest. The queens are easily recognised as they are a lot bigger than the workers that appear after colonies have been formed. Most bumblebee species dont make their own nest. They look for holes in the ground vacated by rodents or tree cavities.

The queen lays her first batch of eggs and forages for food. Once this first brood has developed they become workers and help with the foraging allowing the queen to become a full-time egg layer.

At the end of the colony life, new queens and males are produced and go out into the world to mate with bees from other colonies and start the whole cycle again. Typically, the colony, including the original queen and all the males will die leaving only the newly mated queens to start again next spring. However, with climate change and warmer winters some colonies are now surviving the winter. The buff tailed bumblebee, Bombus terrestris, has been recorded foraging on winter flowering plants. The Bee and Wasp Recording Society are collecting data to work out how widespread this phenomenon is and if it is happening in cities because gardeners are providing nectar and pollen from exotic winter flowers.

Solitary bees dont emerge from their brood chambers

A lot of people dont even realise that solitary bees exist; many of the species at least superficially resemble honeybees, bumblebees or wasps. In the UK we have more than 200 species. They make their nests in tunnels in the ground, mortar or dead wood or within hollow stems. Every female makes her own nest cells they dont work together as a colony like bumblebees and honeybees. In the spring the adults emerge and females lay eggs individually, provide a pollen food packet and seal up the chambers.

Solitary Bee

You can put up a bee-house in your garden to support these non-aggressive bees which often lack suitable nest sites. The winter strategies of this large group of bees also vary considerably. Some overwinter as adults while others stay in larval form and pupate in the spring. Common solitary bees you might see include the red mason bees (Osmia rufa) and leaf cutter bees. Mason bees form a cocoon and pupate in the autumn. The fully formed adults remain in their cocoon until the spring. Once emerged each adult will only live a few weeks, just long enough to reproduce and start the cycle again.

Why are bees important?

They may be small but insects make an enormous contribution to the UK economy (over 400 million per annum). Bees are incredibly important pollinators. Many wildflowers can't reproduce at all without insect pollination and the yields of many important crops from beans to apples are dependent on bees. Although honeybees are important to providing pollination services to agriculture, research has shown that crop harvests are even larger when there are several species of bee visiting crops. This makes it important that we understand the habitat requirements and threats to all of our diverse bee species.

Bees are threatened by a variety of factors including disease, pollution and pesticides, invasive species and climate change. The interaction of these threats with land use change (the most important threat to biodiversity) puts a huge strain on already reduced populations. Land use change across the UK as a result of agricultural intensification has reduced the amount of habitat suitable for bees. Neat and tidy farms with few wild spaces have reduced wildflowers to forage on and less sites where bees can find space to nest or overwinter.

Honey bees

As a result of these changes in farming practice, two species of bumblebee and many species of solitary bee have been driven to extinction in the UK. Agri-environmental schemes are now in place that encourage farmers to create more bee friendly habitats but more research is needed to fully understand the importance of different flowering plants, nest sites and overwintering requirements to make these schemes effective.

How can you help bees?

Urban habitats such as parks and gardens are becoming increasingly important for bee species as natural habitats are being lost. Providing plenty of flowers producing nectar and pollen to keep colonies well provisioned is important throughout the year. Bird nest boxes are now sometimes being used by the tree bumblebee (Bombus hypnorum) and solitary bees will take up home in artificial nests increasing the range of bees that you see in your garden.

You can record bees that you see with the Bumblebee Conservation Trust BeeWatch and specific data is being collected on winter foraging bees by the Bees Wasps and Ants Recording Society.

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---- UPDATE MONTHS AFTER THIS POST HERE BELOW WITH A SHORT STORY mid October 2015 ----
Many years in Sydney NSW Australia, in a suburb called mascot industrial district, i found some feral bees, but had never got around to catching and keeping them.
Around a year and a half back i decided i would catch them and bought the pieces for a 10-full-deep Langstrough hive system, built it and set it, but had the difficulty they were in a wall, too again i found an underground wild beehive(Feral European honeybees) around 500 meters away.
So i tried in vain to tempt them into the wooden hive by leaving it beside their entrance. The problem, A. I wasn't generous enough on substances for them to feed internally, but also B. The single 10-full-deep section is under 40 Liters in size. 40 liters is a size scientists have determined is the basic minimum for Feral bees to move into (a full deep "section" is only around 22 liters).
This year 2015, i decided to use a chopped method of catching the bees in the wall while they were swarming by scraping them into a box and taping it shut until i opened it and poured them into the ready hive open top with four frames out of the way, and basically with only 10 stings and running away each time the patrol near the dropped box was sitting for an hour or two, i eventually got it to the hive and poured them in with their queen.
They were absolutely hopping mad for hours until the sun went down, i could see them in the twilight whirling around up to 10 meters above the hive and they attacked people 100 yards from the hive on the footpath as they past bye.
The Monday of the Queens birthday long weekend in October i scraped them from the wall, it's now twelve days since and they are settling in well.

This is the industrial building wall they came from and the four bolt holes is their entrance.
https://www.youtube.com/watch?v=MQdKhhL9NuI

This is twelve days later, i'm handling them without protective clothing.
https://www.youtube.com/watch?v=KrVG2omc8o8



...reply to OP post
They hibernate in their hive i presume, well if they are European or Asian honey bees. I've seen European keepers encase them(domesticated ones) with insulation around the hive.
Feral European and Asian bees i presume simply regulate the hive temperature by blocking the entrance hole alike European wasps, and uncork the hive from inside when the temperature warms up in Spring.
Cambodian giant bees i don't know? they don't have a winter.
Australian micro NATIVE honey bees(...do produce honey) , i don't know much of those (see video list below), but Australia for most "has a winter" until you get into the tropics toward the equator (However at points on days can be similar to North European summer).

Choice Videos (most 720p)!!!

Italian & Australian native bee hives in the same tree
https://www.youtube.com/watch?v=jhU0owIP9_Y


Microchips trail dwindling Australian bees
https://www.youtube.com/watch?v=LjNl8CDwpn8

Stingless Australian native bees
---------------------------------

Part 1: Design of an Australian Native Beehive
https://www.youtube.com/watch?v=hz3YsEDEQOM

Part 4: Extracting Honey from an Australian Native Beehive
https://www.youtube.com/watch?v=WrkO6lhGSh4

Australian Native Bee Hive
https://www.youtube.com/watch?v=SgCpxfvsNf8


Australian Native Bee Hive in Fallen Tree Branch
https://www.youtube.com/watch?v=cGk4Z6NffPY

Native Stingless Bees
https://www.youtube.com/watch?v=jAtVwOqCRqI

Australian stingless bee nests
https://www.youtube.com/watch?v=f7Nn-cuDYlE


Bee Off Topic
----------

Honeybee Queen Grafting from Larvae into DIY Queen Cups
https://www.youtube.com/watch?v=toJK3xTXqXg

Grafting Queen Honey Bees (Queen Rearing)
https://www.youtube.com/watch?v=XpDciR9-OVk

How we make and sale our package bees
https://www.youtube.com/watch?v=AKWVq-bZ9Ok


One thing, Brood disorder foul-brood, It may be caused by re-queening from the same hives alike splitting. It's a continual practice to use the same bees to split into new "Nucs" and alike the opposite effect of "Africanisation" domesticated bee hive are smaller and in some terms by "wild creature" psychology health check are superior by aggressive characteristics.
http://beeaware.org.au/archive-pest/africanised-honey-bee/#ad-image-0  ...."The Africanised honey bees have a much greater aggressive and defensive behaviour than European honey bees and because of this rapid hybridisation, they were quickly able to out-compete the European honey bee. "....
https://en.wikipedia.org/wiki/Africanized_bee

In terms of survival, alike wolves and Canis Familiaris, What's the point of instinctive aggression loss for survival, it makes them in requirement of prosthesis of care!
Moreover, inbreeds are typified usually by size as much condition by being runts(smaller than normal).

The final underlying point of whether a species is a psychopath or sane is whether the aggression has any sensible meaning and it's fears can be allayed such being with "Africanised" bees being able to be kept, they're just a little extra nervous and bitey.
If i were to grab some little bleeder and talk to them with Asperger, they would bleed to death(inbred response), if i did that with someone healthy it would be minutes before the kicked the stink out of me(healthy response)!
It simply shows there is nothing wrong about the Africanised bees in their "wolf template".

So, in effect, to graft bees to queens from your own hives (rather than swapping queens with other keepers 50 - 100Km away that obtained from different bee farms around the country) is a serious mistake in terms of inbreeding genetics.
What is probably needed in each country is a free open forum site with a name such as beelineregistry.org to allow the users profile to show where the bees were acquired and which hives, and help them trade grafted queens in a healthy pattern across the country.
Wild bees do group up in numbers when small breakaway bees leave a colony. The smallest breakaway(European bees) i saw, was in Sydney NSW Australia a few years back contained only 100 or less on a branch in the city, busy making a hive and queen on it.

Any breeder can tell you it's one thing to hold a genetic line but its another to inbreed it!

Another probable bee killer is thermal shock from use of hive heaters. A hive heater should simply be used in massive cold climates to prevent critical levels of temperature drop being reached, not as device to manipulate seasonal climate.
If i remember , during winter in natural European hives, the bees block the hole to a tiny size.
"Beekeeping: How To Wrap Your Bee Hive For Winter" (entrance reducer)
https://www.youtube.com/watch?v=-Cog7eRBP9A

Almost forgot...
One of the biggest killers of species that have aggression are governments!!!
In Australia Africanised bees (simply for point cross bred) are not allowed to be kept.
Many breeds of dog are not allowed to be kept.
All this because they cannot understand aggression in it's correct context for a kept species.
It's also a smart arse about people keeping them, they then totally ban them so they never need face them!!!

You can understand from this following video how endemic by governments , the idea of destroying survival instinct in a species is, "because of the species aggression" !!! Really it cannot be done because it "defies" gravity metaphorically.
(time:  7:06)
"Selection of honey bees for yield and behaviour"
https://www.youtube.com/watch?v=MYtPTt512tE nicephotog, Wed, 16th Sep 2015

....DEPENDS IF THEY REACH WINTER...

About Foulbrood bacteria....  All i've known of bacteria is it can live and reproduce well over a variety of high temperature well unless maximum threshold is reached.
Inversely on the otherhand, higher more complex delicate and simple organisms such as insects (bees) have as described below a threshold maximum much lower than any bacteria.
The majority of commercial hives are kept in the sun and may not have heat shielded lids.
Most lids and hives in the recreational license and by price have only a single tin lid, commercial hives probably have these by economics, which raises temperature within inches of the lid when in strong sunlight in summer to no different than the back of a solar panel such as 50 Celsius - 60 - 70 Celsius and does the fact a "heater bee" itself appears to have the optimum laboratory temperature of 45 Celsius the problem. The larvae themselves are probably suffering cannot have "entrance fanning bees"(coolers) successful at lowering the heat.
Bacteria has the tendancy to increase and accelerate its'growth and breeding in sync with rises of temperature.
The attacking bacteria problem combination environment is there with some types of lids and location together.


http://www.arnia.co.uk/temperature-and-thermoregulation-in-the-beehive/
.....Honey bees maintain the temperature of the brood nest between 32C and optimally 35C
.... a heater bee can hold this position for up to 30 minutes while its thorax is at around 43C


http://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/2.02.03_EUROPEAN_FOULB.pdf
...........This organism is isolated most efficiently by inoculating decimal dilutions of the aqueous suspension into agar that has been maintained molten at 45C and which is then poured into plates. The plates must be incubated anaerobically, such as in McIntosh and Fildes jars in an atmosphere of approximately 510% carbon dioxide (CO2) at 35C. Small white opaque colonies of M. plutonius usually appear within 4 days..............

There is a lid design called a migratory lid that comprises a "flat masonite sheet cover" over the hive super "topmost section", then four edge blocks 1 1/2 inches high to sit under the tin cover with four holes with vent covers to allow slow but able air flow through between the tin (as a multi section lid).
This is what i have over my hive because "nothing in Australia would survive the tin lid temperature" when it were suddenly either or be exposed within two inches of the tin lid on some days !
nicephotog, Tue, 20th Oct 2015

Nice story! chris, Mon, 26th Oct 2015

The bacterial care sheet for the laboratory does seem to show "it can be done" by a poorly heat shielded hive.
Too when more supers are put over the top the collective density of substance below will absorb and hold heat above the higher brood incubation threshold.
The tin lid in direct radiation can only lose by radiating infra red for most so it can reach to the bottom of the stack through the gaps and queen excluder.
Some of my bees were fanning this midday in their single Nuc full deep(has a double layered cover) and it was under 30 degrees Celsius. nicephotog, Thu, 29th Oct 2015

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