bee-fly

 

31-03-26

The bee-fly is not a bee. It is a bee-mimic with long legs and an even longer proboscis. I am always keen to see them around now as they signify the start of Spring, or that it's under way. Usually the orange tip butterflies are not far behind either. Also they are super cute and don't sting or bite. I went along to the botanics, not to see them, but butterflies. However it was (again) a little cold for butterflies and when checking the pulmonaria I found this bee-fly. Next best thing. 

lots of trees in blossom currently
and more each time I visit

possibly Clarke's mining bee

hoverflies in the rock garden near the flowering gorse

probably ID as below

Eristalis pertinax - Tapered drone fly

hairy-footed flower bee (male)

lots of magnolias around the garden in bloom

bullfinch (m)

after the recent clocks forward an hour
the sundial was within 30mins of accurate
(I think my watch said 2.45)

highlight of the day - a dark-edged bee-fly (f) on the pulmonaria

you can tell it is a female from the position of the eyes (apart)

a still taken from the video (below)

I was looking at the hairy-footed flower bees on the pulmonaria when I noticed the bee-fly. I'd been hoping to see one and this was a gift. It was flying gently between the flowers and often doing a row of flowers one after the other. I switched the camera to slo-mo remembering last year that in that high speed frame rate, when video-ing very quick wing beats, there can be a bit of rolling shutter. In normal frame rate the wings of a bee-fly are a blur. In 120fps you can see the wings more clearly but there is distortion and it sometimes looks like they bend. Rolling shutter is due to each frame being recorded top to bottom and that the wing is moving so fast it is in a slightly different position through each frame being recorded.

You get the same distortion if you film a propellor on an aircraft. My camera is very good for limiting this effect and it was only filming bee-flies and humming-bird hawk-moths in slo-mo that I came across some of the results glitching slightly. You appear to see the wing in 2 places at the same time or it has a bend to it. In the video below there is less of this than last year's video (linked here) which was filmed using the macro lens. I'm not sure if that increases the rolling shutter. The video below was made with the 100~400mm and seems less affected.

Interesting to note that when filmed with wings parallel to the lens plane the wings beat in unison. When there is an angle to the plane of the wings (one towards the camera, the other pointing away from) they appear to beat alternatively. Again this suggests rolling shutter or frame rate interference.

Anticipating such results I filmed a couple of clips at 100fps rather than 120fps to see if the results favour one speed over another. There was no point in looking at the results through the camera evf or on the camera screen as the frame rate of the editing software and monitor screen would determine the outcome, not the frame rate of the evf in the camera. It is all still work in progress and also luck. I'm sure the flies change their wing-beat rate as they hover and land or to match the wind and that there are likely too many different factors (do individual specimens have slightly different wing-beat rates?) to accurately improve the videos with confidence. So back to just hit and hope, and see what works, occasionally just getting lucky.

In the video towards the end you can see the fly (a female) land on the ground and do a sort of bum-shuffle. It is filling a wee bum-bag on its back end with sand and grit which attaches to its eggs, which it then flicks into the nest holes of other flies and insects, where they will then parasitise the larvae of other species. Which seems underhand or sly compared to standard predation but results in much the same outcome, so I don't think can be judged more harshly on the moral map. Or maybe just a little? Discuss! I kind of forgive them because they are cute and I like to video them, and it's not my children.

I was thrilled the camera focussed on this tiny fly rather than 
the background foliage. (Bird eye detection on.)

Talking of the morel maze (groan) the Botanics must be reading my blog (photo 6 of 32) and saw my post of the False morel, brain-like fungus I photo-ed among the pulmonaria. They have since put a sign up to advertise it, after which time it has been broken in half and looks a bit worse for wear (as above.) Maybe someone took a bit home to put in their partners soup? Ah some handy poison, just what I've been looking for!

if you want something trampled, put up a sign

While in the pulmon-area I had a wee scout about for the handfeeders. Mr Scruff was there as per usual. He is reluctant to sit on a hand but knows I have food and that I usually get bored and throw him some if he sits there long enough, defying the urge to come to papa. He has a sidekick who is smaller and bolder. Either a partner or offspring as robins are not social and do not tolerate competition. A while back I was trying to coax the reluctant one from where he sat high up a tree. I was looking upwards when the interloper (pictured below and now known as Eyebrows) flew in and landed on my outstretched hand and, not expecting it, I shout FUCK and jumped 4 inches off the ground.

Eyebrows happy to pose up close
and sit on my hand for treats

squirrel dealing with the overspill

And that was about that,
I hurried home to edit the bee-fly video.