A crane lifts the flatcar from down the bank
Yesterday afternoon, I was watching the last of the C.P.R. wreck saga: the lifting of the flatcar that had jumped the tracks and slid down the bank towards the Lake. That story has been told through a number of postings: train wreck, wreck stage one √ , wreck Sunday, drowned excavator, excavator out. The only job remaining was the extraction of the flatcar from the bank. This was done yesterday.
While watching this exciting event (life here is insouciant), I saw a bumble bee fly by and abruptly ignored the C.P.R.’s travails. Heavens, that looked as if it might be a Bombus occidentalis: that is, a rare sighting of the ill-fated Western Bumble Bee. Switching lenses, I set out on a wild-bee chase. Soon I had managed to photograph two different bumble bees, behind each of which lay a fascinating story.
Bombus occidentalis
The Western Bumble Bee was once common across western North America. It was last seen in California a half-dozen years ago, and a survey in the Okanagan a couple of years ago found only two. I saw one around Kootenay Lake in 2009 and another in 2010, but none last year. In former times, hundreds or thousands might be seen during a summer. The backstory of the virtual extirpation of this once-significant local pollinator is involved. The tale combines elements of: bumble bee navigation, commercial greenhouse pollination, breeding techniques, international marketing, and (the lack of) trade regulations. Suffice to say, I was delighted to see one in my yard this afternoon. The Western Bumble Bee is easily identified by its white-tipped abdomen. This female (probably a queen) is collecting nectar from a Pieris japonica.
Bombus melanopygus
As far as I know, this bee is not threatened, so it wasn’t its conservation status that attracted my attention. Rather it was its thorax—I had never seen such a thorax. It is covered with bumps. I suspected the bumps were mites and that the bee was doomed. I sent both pictures to Robbin Thorp of UC Davis. He confirmed that my first picture did indeed show a Bombus occidentalis, and that the second was a Bombus melanopygus carrying mites on its thorax. Then came the surprise. These mites were merely hitchhiking from one colony to another aboard a queen. They are likely to be beneficial because they then feed on harmful fungi found in the nest. The queen is thus bringing her own house-cleaning staff along with her. My Bombus melanopygus and its offspring are probably going to do rather well by those mites.
The bee season is well underway.
Interesting and fascinating information Alistair to accompany these incredible images! I need to pay much more attention to our pollinators, and not just the colour of their abdomen.
marlene
Thanks very much for the info on the mites. Who would have guessed?
Hi Alistair;
Excellent post, very interesting stories and superb photography, not to mention your keen observation.
cheers, Paul
There’s something that makes you sigh with relief when you see the bumble bees again. I don’t know if she had just crawled out of the ground or was looking for somewhere to make a nest. We plant lavender and grow cardoons and alliums specifically for the bees every year.
What a beautiful and informative post. I wouldn’t have known now to positively identify Bombus occidentalis. And I would have suspected negative consequences with mites, as well.
Great post about bumble bees. E-Fauna BC (efauna.bc.ca) has atlas pages with maps showing the distribution of these two species in BC. See http://linnet.geog.ubc.ca/efauna/Atlas/Atlas.aspx?sciname=Bombus%20melanopygus&ilifeform=172 and http://linnet.geog.ubc.ca/efauna/Atlas/Atlas.aspx?sciname=Bombus%20occidentalis&ilifeform=172. However, they have no photo of occidentalis.
Alice, thank you for the information on e-fauna. The offerings have expanded greatly since I was last on the site. It is interesting that the listed observations of B. occidentalis are all quite old. And while the page displayed no picture of this species, in the list of species for which images are sought, B. occidentalis was not included.
I was always able to distinguish honeybees from bumble bees… but prior to this post, I had never really noticed what kind of bumblebee was visiting. Today I noticed a Bombus melanopygus on my apricot blossoms here in Cranbrook!
Carolyne, we have quite a few different species of bumble bees around here. I have seen maybe four different species in the last few days. I have a page showing some pictures of social bees I have seen here.
Alistair, I just spent a lovely twenty minutes or so with the “social bees” link. That is, after I shared with a friend your amusing line about the queen bee “carrying her own house-cleaning staff with her”.
You must have been an amazing professor. Waiting lists to get a seat in your classes?
And now, others have the good fortune of being able follow this site, to see the natural world through your eyes and the lens of your camera. (One of my favourite of your riffs was the one about the camera bringing its leash and wagging its tail hopefully to tempt you to take it for a walk!)