i’ve done a new time-lapse project on frog spawn, because i spotted some in my pond.
the first post about this can be found here.
it would be too hard to record a pollywog’s growth in time-lapse – too much effort and clearly not ethical.
you’d have to give them tiny living space so they wouldn’t jet around all the time, or even slow them down somehow. there would have to be a special (=unnatural) way of feeding. water cleanness and oxygen problems would arise, and of course plants etc. would give them unwanted hiding places…
and i don’t presume to do that. (the environmentalist is shining through again ;-))
anyway, i did some internet research and found out the duration of my project would be about 2 weeks. in springlike-pond-climates, of course. it turns out, at room-temperature those little creatures leave their gelatinous eggs in less than 2 days!
the eggs would float around a lot, so i needed to fixate them somehow.
i had the idea of using single-hair-loops, because they’re thinner than any thread i could find, and they were there, sitting right next to me.
- i remembered a glimpse of the “lord of the rings, special extended version” audio commentary, where john rhys-davies (playing gimli) mentioned problems with the scene in lothlorien where gimli asks for three hairs from galadriel. the issue was that you couln’t really see a single hair on a tv screen (that’s why they didn’t show that particular scene and made up a little flashback-storytelling dialog).
sandra kindly played along and gave me three of her hairs, which were perfect because they’re long and blond (almost elvish ;-)) if you look closely you can see one of them in the bottom-right third of the image (on the very left part of that third).
the setting was a little different, this time:
- i used continuous artificial lighting this time, to ensure brightness constance (because i was only using my dlink dsc-350 webcam >> lower level of light sensitivity).
- i didn’t cover the whole window with soft tissue, but instead built up a little screen with double-layered tissue, so there would (hopefully) only be very scattered light and no shadows (i didn’t even want soft ones).
what’s that, you want a time-table? there you go!
|2005-03-23 17:00||noticed frog spawn on the ground of my pond *|
|2005-03-28 22:00||took about 1/4 of the egg-cluster and set everything up in my room. eggs still perfectly globated|
|2005-03-29 08:00||two poles (different in size) are clearly noticeable|
|2005-03-29 11:00||“black blobs” start wiggling, still elongating; head and tail ends are distinguishable|
|2005-03-30 04:00||pollywogs now have their typical shape|
|2005-03-30 11:00||wiggling at full speed, real-time watchable|
|2005-03-30 15:00||first individuals hatch out|
|2005-03-30 20:00||most pollywogs have emerged, staying close to the cluster|
* the pond had been ice free for at most 5 days then, so the spawn couldn’t have been very old.
also note the worm that was roaming the upper left portion from 13:00 to 23:00 on day 1.
the pollywogs that “grew naturally” in my pond hatched close to april 5th, so the 2-week breeding-time does apparently apply in natural conditions.
|mpeg4/xvid – one pass: quality – 20 fps – qual: 85% (get the codec | help)|
|x 4500 (1 second in the video equals 75 minutes in real-time)|
update: you might want to see this one, too:
new time-lapse video of frog spawn in higher quality