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
After a few days of pondering what I do really think, here it is. I am basing my view on what information has been provided and what I have gleaned by watching the nest over the past few weeks.
Firstly, as others have said, Seasca was a very well fed chick. To put this in perspective, she was heavier than the heaviest chick they have ever recorded in Wales. There is only one day, to my knowledge, that she didn't have a fish - the rainy day - and she afterwards ate copiously to make up for it before departing. Her reserves would have been top notch.
She had two overnight stops on her way through the UK. It was reported she may have refuelled in the south of Scotland. Throughout, she flew at between 24 and 94 metres in altitude (she obviously flies low) and at 11 to 42kph. Her last reading at 21.00hrs on the 21st was at 110 metres (the highest she had flown) and at 25 kph, which is average for her. This does not suggest she was flagging.
The transmitter then switched off to resume in three days, which it didn't.
I doubt if she just dropped into the ocean from her 'record' height. Either the transmitter failed to switch on again after the three days or something happened to her during those three days. Three days could have seen her in or near Africa. In years gone by, LG would have said 'missing in action'. I think this would have been more appropriate.
I really like your analysis deveronside. I agree that Seasca should be classified as "missing in action".
I do not believe that young ospreys do any fishing until they reach their first stopover.
Interestingly the Kielder osprey Blue VV is being tracked just now with a new GSM transmitter. This is showing us that she has not fished so far.
Hazel b said:Interestingly the Kielder osprey Blue VV is being tracked just now with a new GSM transmitter. This is showing us that she has not fished so far.
It seems unlikely that she has fished, Tiger, but she did spend a long time near the Cherwell and a tributary on her second day and data downloads weren't as frequent, 20-40mins apart, so we can't be absolutely sure. But there is no evidence she fished!
Deveronside. Thank you for that comprehensive study. I think many will draw comfort from it,particularly the 'didn't switch back on'bit. I have always felt her demise was too readily accepted. We may have to wait a long time but we have to for those without trackers anyway.
Birdies LG DU update.
Claire
'Has any research found that the eggs of a first clutch grow progressively weaker as each one appears?'
Later eggs tend to be smaller and the younger chicks miss out when food is short. 4th eggs are so uncommon that there is unlikely to enough data to draw conclusions about the fitness of surviving 4th chicks.
Hilary J
Just heartbroken
"Birds are, quite simply, little miracles - and as such they require care and consideration."
Magnus Ullman
My Flickr account is here
Don't despair L, there is a glimmer of hope!
2013 photos & vids here
eff37 on Flickr
HilaryJ said:Later eggs tend to be smaller and the younger chicks miss out when food is short. 4th eggs are so uncommon that there is unlikely to enough data to draw conclusions about the fitness of surviving 4th chicks.
Our herring gulls are red listed birds. Think about that the next time you hear some flaming idiot calling for a cull of them.
deveronside said:After a few days of pondering what I do really think, here it is... In years gone by, LG would have said 'missing in action'. I think this would have been more appropriate.
Well thought out and well worth waiting for, DEVERONSIDE :-)
IMAGICAT
From a science perspective: When birds disappear, the cause should be recorded as "Unknown" unless and until evidence is produced to support a conclusion. Without evidence, any conclusion is purely speculation. It may be an educated guess -- based on projected mortality rates -- but guesses and conjecture have no place in scientific data collection. If tracking is done to create a body of research, then the scientific method should be followed.