August is the month when we've seen the Loch Arkaig ospreys depart on their journey south. We've enjoyed watching them this year - the wonderful parenting skills of Aila and Louis, and the antics of their 3 chicks, Captain, Vera and Doddie.
Mary GK did an absolutely wonderful video summarising the 2020 season. Thank you so much Mary! And here is Geemeff's great compilation, thank you!
2020 last dates:
Doddie JJ6 was last seen at the nest on Saturday 15th August 2020
Aila was last seen on Saturday 22nd August 2020
Captain JJ7 was last seen on Sunday 23rd August 2020
Vera JJ8 was last seen on Saturday 5 September.
An unidentified osprey was seen off camera on Sunday 6 September eating a fish. This could well have been Louis, having arrived and found no Vera around to feed.
Doddie JJ6 was videod and photographed fishing for over a fortnight at Avalon Marshes in Somerset
Link to July 2020 thread
Link to Youtube channel
Link to Woodland Trust Loch Arkaig page/webcam feed
I wonder if JJ7 dropped the fish Ian - as those fly by's were so fast, but definitely by a fishless osprey
EJ's Memorial Balgavies Loch Ospreys 2023
Geemeff said:
MaryGK said: I don't think it is that word Ian, I am sure I heard Emyr @ DYFI mention it once a while back.
I don't think it is that word Ian, I am sure I heard Emyr @ DYFI mention it once a while back.
Triangulation
"If you watch a bird of prey long enough, you will probably see it bob its head from side to side, move its head around in circles, or even turn its head almost completely upside down. This isn’t some kind of strange dance. Raptors do this to triangulate an object and better determine how far away it is."
https://peregrinefund.org/keen-vision
No that is not the word I am thinking of Geemeff it has a more scientific type sounding name
Mary, I don't know about Geemeff but I am admitting defeat in attempting to identify your "bobbing & weaving" name. I have tried searches involving osprey, owls and birds in general but can find nothing that would match. Ian
Thanks very much Ian for doing that, I have been Googling like mad, and search the DYFI website to see if I could find the word I am thinking of to no avail.
MaryGK said:Thanks very much Ian for doing that, I have been Googling like mad, and search the DYFI website to see if I could find the word I am thinking of to no avail.
No bother, it wasn't wasted time, I now just need to find excuses to squeeze the terms "sclerotic rings" and "double fovea" into my posts without anyone noticing. Ian
Ian S said:
MaryGK said: Thanks very much Ian for doing that, I have been Googling like mad, and search the DYFI website to see if I could find the word I am thinking of to no avail.
Ian, I'll see your sclerotic rings and raise you a pecten oculi.. Mary, like Ian I think it time well spent although I didn't come up with a suitably scientific term for triangulation either - I love the wonderful pathways google and wikipedia take me down!
Two non-fish delivery videos from today: Captain in the mist, and Vera packing up the furnishings ready to move out
Vera packing up 10.25 (direct link here: https://youtu.be/W1MXcuMt0uk in case the other link is still weird, see Ian's post 20/8)
Captain looms up out of the mist 06.49
And now for the really boring, sorry, i mean interesting stuff, about bird eyes and their head moving.
Most species of birds have 2 foveas, the temporal fovea and the central fovea.
Temporal fovea, which is like ours in the sense that it looks straight ahead and offers binocular vision (i.e. the temporal foveas of both eyes point in the same direction).
But birds also have a central fovea, which points sideways and is, obviously, monocular (i.e., the central foveas of both eyes look in opposite directions).
So the bird has a choice of which fovea it wants to look through.
It can look straight ahead with its temporal foveas, to the left with the central fovea of its left eye, or to the right with the central fovea of its right eye.
And this is not a hypothetical possibility: Birds actually do switch between foveas all the time! This is why they tend to swing their heads erratically in turns of about 90°
Richard B