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
Unknown said:Are you thinking of this "anecdotal" report from the Rutland project - or have you seen other information about gull mobbing?
No I was citing someone who observed it for themselves admittedly not in northern Spain but on another migration point.
I find it hard to believe that Seasca just fell from the sky after the last recorded reading. Surely we should have got others of her slowing in flight and lowering in height before contact with water - if she is gone.
Unknown said: Would flying in the dark affect the data points that the satellite can pick up from Seasca's backpack?
Would flying in the dark affect the data points that the satellite can pick up from Seasca's backpack?
The backpack does not normally record points in the dark. The last point tends to be about 9pm and then no more points until the morning.
Thanks Tiger, that answers my second question also in that she could have got into difficulty during the night but we wouldn't get recorded points on that.
Unknown said: I find it hard to believe that Seasca just fell from the sky after the last recorded reading. Surely we should have got others of her slowing in flight and lowering in height before contact with water - if she is gone.
lmac
See my post at 8.11 today on the previous page - I think this answers your query.
Thanks for the answers to my questions. I have no theories but just trying to get all the data straight in my own head. Unfortunately the analysis of which leads me to feel more pessimistic than optimistic - sorry :(
Hazel b said: Would flying in the dark affect the data points that the satellite can pick up from Seasca's backpack?
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I don't believe the dark affects the ability of the tracker to sample points, technical wise. I agree with Tiger that points seem not usually collected during the night, it might be because the bird is assumed to be roosting most of the time and battery can be saved when it cannot be recharged in sunlight, with appropriate schedule.
It was definitely already dark when the last sample was taken (11 PM in France/Spain, but we can keep 10 PM in UK as a valid and even more realistic reference to judge what the light was). Just mind that in summer lower latitudes mean shorter days, it was a bit darker than in Scotland. At that time we know that Seasca was flying, but most of the night was still ahead of her. I also remind that other birds made a similar and even longer journey over the sea in moonless nights before, so they do have the ability to keep proper altitude while seeing almost nothing - we humans would be scared to death in similar conditions - it adds something to the challenge though.
There is only one osprey flight at night that I am aware of that was by choice and that was by Nimrod in 2008 when he took advantage of the full moon to fly from France to Africa in 35 hours. See Nimrod jets into Africa
So it does seem that ospreys prefer to have the light of the moon to fly by.
SUE Thank you for explaining about the tracker I had misunderstood how it works. Having said that I agree with SCYLLA...almost "What's the point?" I don't understand what new data and insight is being gained
Hazel b said: See Nimrod jets into Africa
See Nimrod jets into Africa
I believe many other cases can be found of ospreys successfully overflying the sea (Nimrod overflew Spain in the night and got over the Atlantic the next morning, actually) with and without moonlight help, but we probably cannot give them statistical significance to tell what's the safety margin added, if any. I expect moonlight reflection to be more visible and useful over the sea than over land, in my personal judgment Nimrod did something really brave in not stopping to roost. On the other side, roosting was not an option for Seasca and she was forced to continue - as many ospreys had to do in the past and many will need to do in the future - that's the only thing we can be sure of. The concerning thing is that we did not receive further data and this is the reason why we are holding our breath.