This thread is a total experiment! I thought of it because a few nights ago, a lot of of useful information about ospreys was being posted in the LG Diary comments, but because of the blog format, it will be out of sight once a new blog is posted, and easily forgotten.
The idea for this thread:
· To provide a place for people to ask questions about ospreys at Loch Garten, or ospreys in general, which members of the Forum will answer to the best of their ability. NB Questions directed to the team at Loch Garten, should still be posted in the Comments area of the Loch Garten Osprey Diary.
· To preserve the answers for future reference
Asking Questions
For clarity, please only ask one question at a time.
Replying to Questions
Try to be specific, giving links to the relevant information where possible, or quote your sources. If you are giving your own opinions, recollections or theories, please make that clear.
If the question you are answering is not the last post in the thread, please use the Quote facility to include the question in your answer.
General
To make it easier to search for the topic in the future, use the Tags field. For example, if your question is “Is Odin really Scandinavian?” enter “Odin” in Tags.
It is obviously very hard to prove whether ospreys stash fish or not. Yes I think we have seen some evidence over the years that ospreys have been known to stash fish. It would take a bit of research to find actual examples but I do think they exist.
Tiger Signature
Thanks Tiger, for your answer.
I wonder if you have any theories on why dropped fish are never retrieved, even if it would be an easy thing for the osprey to do ( e.g. fallen on grass )?
A thing of beauty is a joy forever.
Properly a stupid question, but in that heat, don't the Ospreys need to drink water?? My garden birds drink more than eat or so it seems.
FISH, The ospreys get there fluid from the fish. You may catch an adult osprey drinking on the lake/ loch though
A thought that has occurred - a number of bloggers have commented on the Size difference between the 3 young on the LG nest this year. Assuming the largest two keep stuffing themselves whilst the youngest's growth remains slow; does this reduce the already small window available for ringing & tagging (& in LG tradition - Naming) this years youngsters?
Vespa - I doubt it. Isn't it just for tagging that the window is really tight, as the birds have to be as nearly full-grown as possible, and yet not in danger of fledging prematurely? As I remember the discussions 2 years ago, the tagging window is only about 2 weeks. If they are just ringing, they can do that when the birds are much smaller, before fledging is anywhere near.
In the past, they have tagged the 2 largest of 3 chicks. This year, there isn't a lot of doubt which two that will be. So whatever happens, #3 will only be ringed, in which case being smaller than his siblings won't be a problem.
The way this "summer" is developing so far, the weather may be the real issue anyway. If they are going to tag as well as ring (and hence have to wait for the smaller window when #1 & #2 are big enough), I won't be at all surprised to see a repeat of 2010 with neither being possible.
Rach, some ospreys do retrieve fish they have dropped. Monty at Dyfi definitely does as Nora is apparently always dropping them from the perch. I never saw any of the LG adults retrieve a fish a juvie had dropped though, even when they were easy to spot. Maybe it's just a 'personal' thing - some do, some don't. Watching osprey fish at Spey Bay earlier this year, one dropped a fish and then went back to it on the beach as it was in full sight and crows were approaching - guess who won?! And for the record, I disagree with Tiger with regards to the stashing of fish. Having viewed Odin bring some very 'stiff' fish back to the nest last season that looked as if they had been caught quite some time ago, the view there was he'd been lounging around with them for some time after catching them - as in hours rather than days!
Thanks Sparrow! It seems crazy if they don't, though obviously they're just not able to retrieve them from some places; but when they're dropped in the open, why wouldn't they? Nice to know you've actually seen it happen too. I've never seen an osprey fish, it's definitely on my wish list!
It is stated on the LotL thread that the adult Osprey mortality rate is 10%.
Is the overall juvenile mortality rate known in terms of percentages?
"The road of excess leads to the palace of wisdom" - Wlliam Blake
ClaireM said: It is stated on the LotL thread that the adult Osprey mortality rate is 10%. Is the overall juvenile mortality rate known in terms of percentages?
It is thought to be about 80% but for some reason the ospreys born at Rutland seem to do rather better than that.