It’s certain that there are a lot of niches for insects and other small invertebrates. The hot springs at Banff in the Rocky Mountains have their own endemic species of snail, found nowhere else in the world. For that reason, visitors are forbidden to dip their fingers into the pools lining the old baths—sweat, hand lotion, or insect repellent might harm these unique, “left-handed” snails.
(Photo by Mark & Leslie Degner)
And then there are washroom flies. I once lived in a house where little purple flies with orange wings appeared in the bathroom each spring. And when I worked in one of Toronto’s downtown office buildings, the 10th-floor washroom had its own flies. The flies were only about 3 or 4 mm long, perhaps just larger than a fruit fly. They were rather handsome: neat, black flies with loop-shaped wings, neither pointed nor blunt. The wings were clear with black veins. Their legs or antennae were like tiny pipe-cleaners with alternate bands of grey and black velvet. There were never more than a few and I suppose that the cleaning staff waged war on them.
At first I thought that the flies had somehow blundered inside.But now I think that these flies probably came down a ventilation pipe from the outer air to live in the damp overflow drains of the sinks.
Another day, another contract—evenually I moved on, leaving the flies to their fate. But one day I was in the Niagara Peninsula, at a restaurant… and in the washroom, there was a tiny fly: my old friend the washroom fly! But with differences. Its wings were more elongated and its pipestem legs: were they red and black?
So here’s my question: are there a few well-known species of flies that make their home in convenient washrooms? Or does each washroom evolve its own species of fly? I’d be happy to hear from an entomologist or anyone who can enlighten me.
It’s amazing what a little research will do: apparently they were “bathroom flies,” Clogmia albipunctata, of the moth fly family (Psychodidae). (I found them on “What’s That Bug?”, whence I stole this picture.) But my question still stands: do they speciate in different washrooms?
Sunday, 29 January 2006 at 19:53
When monado & I went to Banff (in 2001) we saw a family dip their hands into these snails’ pool, right in front of the signs begging them not to. (This may be the same functional illiteracy as exhibited by the students at the community college where I once worked, smoking madly next to the NO SMOKING signs above the compressed-gas cannisters. :-)
But by far the most interesting nature observation from that trip monado has never posted. I’ll give her a clue: corvids.
Monday, 30 January 2006 at 01:45
` I LOVSES CORVIDS! YEEE!!!
` Hey, that’s interesting about washroom flies. Good thing to ask an entemologist!!
` I’ve recently been talking to someone who believes in intelligent design. If the small populations under pressure do evolve into different species, it would be an interesting thing to tell her!
Monday, 30 January 2006 at 18:35
There are many examples of local speciation. There’s a meromictic lake (no streams in or out, no spring & fall turnover of the water) in the Gatineau Hills where live sticklebacks that are apparently descendents of marine sticklebacks from before the last ice age. As far as I know, they are unique.
If you throw fish into a lake with varying depths, in short order—like 60 or 70 years—there will be a deep-water and a shallow-water form. Check out Fishing for clues about evolution.
Lake Tanganyika is swarming with unique species of chichlids.
And Darwin pointed out that caves contain cave-adapted relatives of the surface fauna, not some “ideal” cave critter dropped in from the heavens.