Bumblebee colonies die in late Summer early Autumn leaving only mated Queens to hibernate over Winter and emerge in Spring to start up new colonies – at least that’s what the books say! Over the last few years more and more bumblebees have been seen flying around in the depths of winter. So what’s going on????
Queen Bombus terrestris – Buff Tailed Bumblebee (Photo: by me)
I had an email recently from my friend Stuart at the Bees, Wasps and Ants Recording Society (BWARS) asking me to look out for “winter active bumbles”, I thought you might like to have a look as well?
Why’s it happening?
It seems that some queens are starting new colonies in the Autumn instead of going into hibernation. It’s these queens that are sometimes seen, and their workers that are actively foraging on mostly non-native flowering plants (in peoples gardens). Due to warmer winters?
Others suggests that Bombus terrestris (Buff tailed bumblebee) colonies, that are being raised in nest-boxes “year round” and placed in glasshouses to pollinate commercially grown tomatoes, are starting to lose their hibernating instinct. When some escape it seems only natural that they might turn up in our winter gardens.
Queen (?) Bombus cryptarum (Photo: from Wikipedia)
Where are they?
For the last few years sightings have been mainly in the South of England, along the Western Coast and South Wales but now they are being spotted in London (a colony has been seen in the Wildlife Garden at the Natural History Museum… under the noses of some of the top entomologists!), in Shropshire, Leicestershire and last winter in North Wales.
Soggy Queen Bombus terrestris – Buff Tailed Bumblebee (Photo: by me)
How’s it possible?
I didn’t realise this but bumbles are apparently able to fly at quite low air temperatures. As long as it’s about 9 or 10 degrees Celsius they can be very active flying and foraging for food. I’m told that even in temperatures just above freezing, there still seems to be considerable activity
Although it’s blimin cold at the moment there have been plenty of days this warm in November in Southern England, the South West, the Central Southern Regions and the Midlands.
This got me thinking about previous years, so I got onto the Met Office website and had a look at the actual average temperature highs (daytime) for last winter and the one before. I thought you might like to see what I found… so I’ve made you a couple of really lovely line graphs (yes, I know I’m very, very sad – but stick with me!!).
Winter 2006/2007 (Dec, Jan, Feb)
In 06/07 England SE & Central S, England SW & Wales S and East Anglia were in the 9-10 degree Celsius “bumble zone” all three months. While even the Midlands nipped into the zone in January 07 and England E & NE and England NW & N Wales were only a degree away!
Winter 2007/2008 (Dec, Jan, Feb)
Last Winter we started with a cold December but England SE & Central S, England SW & Wales S, the Midlands and East Anglia were all in the “bumble zone” in January and February 08.
NB. Sorry Scotland you were just toooooo cold to get on the graphs!
So where should I look?
If you walk a specific path on a regular basis that would be a great place to start. If not your garden, neighbours garden, parks… anywhere really that you can see some flowers.
There has been some analysis of the winter flowers they seem to like. I’ve put together a “top 14 winter bumble flowers”:
- Mahonia cultivars (prickly leaves, yellow spikes of flowers)
- Erica cultivars (heathers)
- Rhododendron pachysanthum
- Ulex europaeus (Common gorse)
- Hedera helix (Common Ivy)
- Viola cultivars
- Senecio (Daisy family ie ragworts, groundsels)
- Antirrhinum majus (Snapdragon)
- Clematis cirrhosa
- CyclamenJasminum (Jasmine)
- Lonicera (Honeysuckle)
- Rosmarinus officinalis (Rosemary)
So go in search of any of these plants and you might just spot a bumble and as the winter progresses, it’s very likely the choice of forage plants will shift as new ones become available, and others go over.
Bombus terrestris – Buff Tailed Bumblebee (Photo: From wikipedia)
What Species am I looking for?
In the main it seems to be Bombus terrestris (Buff tailed bumblebee) that are being spotted, and a few Bombus pratorum (Early bumblebee) see picture below.
Bombus terrestris queens have a buff brown band of colour at the end of the abdomen. (See pictures above.)
If you look really carefully, terrestris workers have really dark “old-gold” banding, a whitish tail, with a hint of buff at the point where the white hairs join with the black hairs (if you can get that near!).
Bombus pratorum – Early bumblebee (Photo: from Wikipedia)
What do I do if I see one?
Really simple.. first scream, run around trying to find your camera and jump up and down a lot (sorry that’s just me!) you should try to record the following (or as much as you possible can):
- species of bumblebee
- whether a queen (big) or a worker bee (small)
- where you saw it (postcode, grid reference or village/town would be great)
- date you saw it
- the recorders name
- name of person identifying the bee (if different from recorder)
- a photograph (if possible) as it really helps verification
- the flower(s) being visited (if you can ID them)
- a note of whether the bee was carrying pollen (yellow on it’s legs)
Then you can either leave the information in the comments section below or email it to me at jane(at)naturewatched.org or send it straight to Stuart Roberts, BWARS at firstname.lastname@example.org
Me? I’m going out to buy a bright yellow blousey Mahonia this weekend with my Christmas money! Here come the Bumbles!