Now, after losing Tore too, several people have shared their opinions "both for and against" tagging .
Someone suggested we collect the views and "stats" on the survival of tagged birds and bring them to the attention of Roy Dennis at his next talk and ask his opinion
With a separate thread, all the comments will be in one place for whoever speaks to Roy.
Rachel provided some sobering stats yesterday on the survival of tagged juveniles verses the survival of juveniles with just leg rings and I hope she puts those stats here too
Originally I thought the information obtained from the tags would be valuable for insuring the survival of the Osprey.
Now I see that all that is being learned is where they go and that they have perished. :(
They learned that all 2 year olds (Rothes) do not make a complete migration the first time, but is that information worth £3000?
I don't know if the tags are contributing to the death of these birds and I don't want to speculate.
However, the cost to tag them is tremendous . Would the money be used more wisely to train more people who are licensed to attach leg rings so more juveniles would have rings?. Could the money be used to send Roy, Richard and others "more often" to the places where they winter to educate the locals on how to protect them? Maybe they could give pre-addressed postcards to the locals at wintering sites to report leg ring sightings or other news of interest?
Many people here who have vast knowledge of Ospreys have great statistics on many birds "just from their leg rings" .
Perhaps a three year experiment with only legs rings would be helpful to see how many juveniles with "only" leg rings return in 2-3 years
I personally think the leg rings are very valuable
Formerly known as Barbara Jean
Thanks for starting this thread, Barbara. I really like the idea of a three year leg rings only experiment.
Warning! This post contains atrocious spelling, and terrible grammar. Approach with extreme edginess.
I think this extract from the Rutland site might help .
"After fourteen years and 75,000 miles of migration between Rutland and Senegal, he finally had a chick of his own. It is moments like this that make all our years of hard work at Rutland Water, worthwhile. 1998 was my second year on the project, meaning I have known 09 for all but a few months of his life. Having watched his repeated failed attempts to breed and then followed his amazing migration from Senegal, watching him looking down into the nest at his first newly-hatched chick was a very special moment indeed.
Although we do not know how many eggs are in the nest, 09 is likely to increase his fishing effort now his first chick has hatched. We’ll be able to monitor every fishing trip using his satellite transmitter and it will be fascinating to see how the arrival of the chick changes his behavior. We’ll be sure to keep you updated over the course of the summer, but for now just raise a glass… to 09 and success at last! "
The full article mentions the loss of three birds,presumably shot locally, which makes the tagging of this one even more significant.
Birdies LG DU update.
Mike, thanks for the quote from Rutland. I think there is a distinction to be drawn between birds which are tagged as adults and those which are tagged as chicks before they fledge. Both the example you quote above, and birds such as Red8T, Morven, Beatrice and Nimrod tagged by Roy D as adults have provided a lot of data, and there appear to have been fewer casualties among that population. Rutland AW was also tagged and may have been lost but this is a more isolated instance.
The concern I have which is demonstrated very well by Rachel's data relates to the return of juveniles tagged prior to fledging. I now feel very uncomfortable that the rate of loss of these (mainly highland) birds seems greater than the Rutland population which are ringed but not tagged. Rutland have the advantage of one organisation monitoring a group of nests, and they are very good at reading the ring data from intruders to identify returning chicks, so there may also be an impact from the data collection on the apparent return rate. Many people thought the "handsome visitor" at LG a couple of weeks ago may have been an LG chick, but as the 2010 brood were not ringed (for good reasons) we will never know. Both in terms of cost and impact on life expectancy, I do now doubt the overall value of tagging fleglings.
When we talk about juveniles the first thing we need is some statistics on how many go south each year and how many are ever seen again. I doubt that we ever see fifty again othewise the osprey population would be exploding.
Then we lose expeienced adults too. What happened to green 7Y? The Wigtown ospreys and how many others that we do not know about.
Tiger Signature
You're right in that Tiger,
This sort of makes tagging/tracking pretty much a one way street, with an occasional "driver" coming up the wrong way..
A bit of a lottery, then.
All for one and one for all.
I think that the reasons that tagged adults seem to do better than juveniles is that they are a self selecting bunch. They are birds that have managed to find safe areas in Africa. We know that the adults move very little when they reach their winter quarters. Thus if they have found a safe area then they stay safe.
Here are the numbers of ringed young ospreys supplied by the BTO:
2008 148
2009 194
2010 182
2011 164.
How many of these have returned?. Very few I suspect. Tagging or not I think the birds would have perished regardless. There are a lot of dangers in Africa apart from shooting. fishing netting, crocodiles, hyenas etc.
Despite the doom and gloom, overall sightings are up this year particularly for May indicating that there are a lot of young ospreys around looking for nests.
Alan Thanks for that data.
Hello Alan,
Thanks for that info, yes I agree, from the sightings you post of migrating birds it seems that numbers are good.
The doom and gloom is, for me, caused by the trackers.
If Tore and Bynack were not tracked I would be living in blissful ignorance to the fact that these birds were dead. As I am with the "Born Free" Three from LG 2010.
However as I said on the Gab last night, if their demise helps us understand how or why, then it is one up side. Now if we are seeing one particular area of danger for the birds, we may be able to target that area with an educational programme.
There must come a time though that we are learning nothing more from giving birds "schoolbags" to carry.
Yes Alan, it is good news that there are a lot of young ospreys around looking for nests, a lot of un-tagged young ospreys you forebore to add.
I am strongly of the opinion that tagging young birds is unnecessary and probably detrimental interference to their well-being. As Barbara said, tagging is an expensive business and the money could be better spent elsewhere in pursuit of their welfare and conservation.
We have learnt interesting things from being able to follow their migration, but enough to justify the expense in financial terms or to the birds themselves? I think not.
A thing of beauty is a joy forever.