Michi wrote: ↑October 22nd, 2019, 11:12 pm
<snip>
Is it really likely that someone took the transmitter? And, if yes, who tells us, that this is not a thief?
(Just a rhetorical question.)
It would be so good if the transmitter again would send a signal and coordinates ...
Changes in magnetic field started at 2019-10-14 15:29:04 and lasted until 2019-10-16 18:04:53 after which the magnetic field record stabilized. Meanwhile the measured direction of the Earth's gravity, relative to transmitter axes changed more random. This period of more than two days may correspond to transport in a vechicle. Who knows why it was taken, if it really was.
Anyhow, from a certain point of view, a bird with digital navigation, acceleration (gravity) and (Earth's) magnetic field record plus telecommunication capabilities in a backpack is comparable to a mechanical airborne robot which measures the same things. In many countries a permission from the authorities is required to make such measurements, especially if foreign. I don't know these licence requirements in Turkey. Although a backpack bird don't establish a security threat in reality, its capture may make controlling organizations curious of the eventual dangers they are keeping eye on. So, if the transmitter was taken, reason may be that someone just was curious or worried of it. Of course somebody may have thought that the device has commercial value and brought it to a bazaar for sale.
As seen by the acceleration (gravity), at first the transmitter was stabile with right side down, like hanging, then it moved irregularly, then it was stabile with left side down, like hanging again, and in it's final transmission it was more or less in a normal position, like on a table. All these four periods corresponded to separate magnetic field strength environment, hence possibly to separate sites and coordinates, too.
The transmitter may have been not capable of receiving signals from the GPS satellites, e.g. because it had been located inside with no direct "visibility" to the sky, where the satellites were. Hence the navigator could not calculate any GPS coordinates. This sensitivity is a specific property of the device, and manufacturer knows it better. Of course it can be tested by a buyer, provided enough time and resources before mounting the transmitter on a bird. Normally, thereis no use of testing, because living BS stay under open sky.
The temperature drop of the tranmitter may have been caused either by death of the bird or because the transmitter was removed. In principle Oru may still be alive somewhere, although wounded. It its a pity, that the workers did not have any observation on it. Before the complete change of the nature of transmitted data record at 2019-10-12 15:27:10, Oru moved close to a strongly magnetic object or many of them, both by flying and walking. This made me think that eventually it followed a field machine, which frightened or uncovered small animals in the field to escape and let a swarm of migratory birds to feed themselves. I may be wrong, because the local people don't have any such observation.
