Yesterday we got the amazing news that Seasca was missing in action presumed dead. Now she may well be but I find myself really very puzzled by it all as the more I think about it the less convinced I am that the evidence shows this.
At the second last update I had no worries whatsoever. A well fed juvenile osprey on her first migration what could go wrong. Well unfortunately lots can often go wrong but there are usually clues as to the reason.
If I had one concern it was that she was losing out in the fish war on the nest. However Mallachie in 2009 was losing out in the fish war and she got to Africa no trouble.
In times like this people are usually only too willing to blame the tracker. I am very reluctant to blame the tracker but in this case it may well be the only explanation.
Firstly it may be delayed data. We know that can and does happen. So on Thursday the missing data may turn up. Not as unlikely as you might think.
So if no data does turn up then it is time to look to other reasons.
In November 2012 Blue 44 was an incredibly well fed bird heading toward Africa when he simply disappeared without trace. Now that seems the closest parallel with the present case. Again not a hint of an explanation why. Was it a tracker problem or did Blue 44 come to catastrophic harm?
Well that has got this started and see what parallels we can come up with.
Tiger Signature
scylla, Loch Garten's tracking does not give any times on Google Earth - the only ones available are in the blogs. Seasca left LG at about 13.00 on the 19th.
Regarding patily's question, I agree with scylla. To quote Richard "The last recorded data point we had last Thursday was at 21.00 GMT 21 August when she was flying at an altitude of 110m over the Bay of Biscay" . To me, this and the course shown on GE, indicate that there was probably nothing wrong, up to and including that point. However in the transmitter's pre-programmed schedule, it also marked the start of a 3-day window of silence, before the transmitter next tried to send data to the satellite, which was due to happen on the evening of the 24th. If something catastrophic happened during that time, we will only be able to pinpoint when/where it happened if there is a further signal, or Seasca is found.
At the last point, Seasca had flown 500 km in about 14 hours from Bodmin, and at the same rate of progress, had about 300 km and 9 hours flying left, in order to reach the Spanish coast around dawn. To me, Richard seems excessively nervous of the Bay of Biscay; other tracked juveniles have made similar or even longer crossings successfully (Alba, Rothiemurchus, Blue YD, Blue YZ, Einion, Ceulan) and I can think of no others who have attempted the BoB since 2007, who have failed.
What, then could have happened with Seasca, given that the weather seemed OK? At the last point, it had just got dark, and I note Roberto's comment on another thread about the lack of moon, maybe causing her to get disoriented.
Something else I've noticed is that compared with LG juveniles from previous years, Millicent and Seasca had done relatively little exploring, while still at LG. This is the two of them, compared with Breagha (Seasca = blue, Millicent = mauve, Breagha = red). Whatever the reason for this, would it make them more likely to get disoriented or exhausted, once on migration?
patily said: I am certainly no expert and so far have no experience of birds being lost across the Bay but what I keep pondering is why the data suddenly stopped If Seasca became exhausted, wouldn't the data show her slowing down and losing altitude?
I am certainly no expert and so far have no experience of birds being lost across the Bay but what I keep pondering is why the data suddenly stopped If Seasca became exhausted, wouldn't the data show her slowing down and losing altitude?
With the case of Deshar we had download every hour so saw this kind of trend of slowing and loosing altitude. This was rather expensive and so they switched to a 4 day download.
With regard to What happened - I find it strange but would only be speculating as what may have happened - If we do not hear anything at next download will just have to assume Lost at Sea - where - when - how - do not know and we will never know or another talk of "Failed Tracker"
I do like SUE C thesus of the failing light and getting disorientated - it does sound the most prospective.
(Sent from Blackberry on EE Network).
SueC - I was very struck by how close to home the two tracked juvies stayed this year.
Keith - This may be a knee-jerk reaction from a person still very tender from the wound of Seasca's possible loss - and I don't quite know how to put it...
"They" are being half-hearted with this tracking lark if they deem it too expensive to do anything but record a bird's travels so sketchily that its performance (allowing for route, terrain, weather conditions*) cannot be monitored. All they know is where they go, how long it takes them to get there, and whether the tracker keeps working, and if they're lucky there's a signal to pick up the tracker of a perished bird to use it again.
*Plus the conditions of its life from egg up to the point of first migration. Am getting carried away now ;-)
IMAGICAT
Thank you, Sue C for the reminder of how satellite tracking downloads work. I, for one, was being rather blinkered. Since Seasca was following a track very similar to Alba's, she then could have been lost anywhere over water between her last point and Africa. If she had gone through Spain or Portugal, it could have happened there. Does anyone know what the weather conditions were like further south in the Atlantic on the following 3 days?
Lots of interesting points on here - and it only goes to show how little we know!! So we have a lot more to learn about their migration.
I'd like to think that just the tracker is faulty: she was making such good progress and is a healthy well fed bird.
At this stage I'd go for either the tracker or the satellite malfunctioning.
Birdies LG DU update.
One hazard that Seasca did face was being mobbed by gulls as she approached the north coast of Spain. This is a hazard that all migrating raptors face and is not usually too much of a problem for ospreys. However a very tired young osprey might just have fallen victim to them.
Tiger
Are you thinking of this "anecdotal" report from the Rutland project - or have you seen other information about gull mobbing?
In the linked case above, the signals continued for a while - though this would depend on the transmitter being on the surface of the sea, and right side up.
Not experienced enough to submit any theories, just want to remain optimistic about Seasca!
2013 photos & vids here
eff37 on Flickr
Would flying in the dark affect the data points that the satellite can pick up from Seasca's backpack?