At the start of last month we were asking "Where are all the ospreys?" There were fears that many would not return.
Well things changed in early April and there was a rush of ospreys arriving.
On 2nd April there was great joy when EJ arrived, a bit late but looking magnificent. Then very unusually early on 6th April Odin arrived in the dark something I do not think we have seen before. Then they were off for another breeding season which initially went smoothly except for a pine marten having dug a hole in the nest.
However late in the month the coupled have been plagued by intruders who have made life difficult for them. The last time that EJ suffered a really bad intrusion was 2004 when she was fiercely attacked each morning. This came to an end with an egg being broken. Fortunately history has not repeated itself yet.
The new female at Loch of the Lowes produced a few surprises and quite a few people were convinced that she was Lady. However with time it became clear that she was most likely to be the female who occupied the nest for a week in 2013.
At Dyfi Blue 24 put in an appearance on April 7. To the great delight of his fans Monty arrived later in the day. Monty was not so keen to entertain Blue 24 this year and when Glesni arrived early on April 9 Blue 24 was seen off quickly.
Glaslyn has been rather sad this year. It is now clear that the legendary 11 (98) is not coming back. The Glaslyn female has had a succession males (including her son Blue 80) but none of them have stayed long. Remarkably she has laid three eggs but it has all been rather strange.
At Kielder the news has been excellent. Three successful nests so far and one (nest 2) is a four egg nest. The two tracked Kielder birds continue to do well.
On 6th April there was the most amazing news from Manton Bay, Rutland. Both Maya and Blue 33 returned. Maya was nearly three weeks late compared to 2014 and many people were very worried for her.
Then later in the month there was news from site B Rutland that the grandson of 3 (97) had attempted to evict grandpa. Well grandpa managed to hold on to his nest but the first clutch of eggs were broken. Remarkably a second clutch has now been laid. A very rare occurrence.
The tracked birds Blue XD, Green J and Beatrice all made it home safely.
The Bassenthwaite chick White 14 has started his migration north. Still no sign that Breagha will do the same but surely he must be on his way soon.
So a greatly transformed situation with lots to look forward to in the coming months.
Tiger Signature
The question of when is the last date for laying osprey eggs?Well I have decided to work it out the other way around. viz. How old does an osprey chick have to be to migrate? Well I would say around 80 days old.If you add 37 days for incubation that makes 117 days.
Assuming at 30th September is the very last time that a young osprey could migrate.
Now there 30 days in September, 31 days in August, 31 days in July and 30 days in June a total of 120 days.
So it would seem that 31 May is the very latest that an egg could be laid and there be any realistic prospect of the chick having a successful migration.
That's an interesting analysis TIGER. I don't think I've seen such a late date suggested before, but it makes complete sense!
Do you know of any eggs laid around the end of May and chicks which successfully fledged?
Birdie's DU Summaries 2018 https://www.imagicat.com/
SheilaFE said: That's an interesting analysis TIGER. I don't think I've seen such a late date suggested before, but it makes complete sense! Do you know of any eggs laid around the end of May and chicks which successfully fledged?
We know the chicks at Threave in 2012 were late but we do not really know when the eggs were laid as there is not a cam on that nest.
Rothiemurchus was the oldest chick of one of the latest broods ever ringed by Roy Dennis. Ringed on Aug 10th, fledged Aug 18th, migrated Sep 6th. Allowing 38 days for hatching and 53 days to fledging that would give a laying date of c. May 20th, hatching on June 27th and migration at 71 days.
Hilary J
In 2012 the first Threave chick fledged on 25th August & the second had fledged by the 30th, the Father & young Ospreys were last seen together on the nest on 6th Oct 2012.
I also suspect that with milder weather Ospreys could potentially migrate later from Rutland than a more northern or Scottish nest
The very latest brood that we have exact statistics for is Dyfi 2013
There egg #1 was laid on 22 May and egg #2 on May 25
Unknown said: In 2012 the first Threave chick fledged on 25th August & the second had fledged by the 30th, the Father & young Ospreys were last seen together on the nest on 6th Oct 2012. I also suspect that with milder weather Ospreys could potentially migrate later from Rutland than a more northern or Scottish nest
It does seem that this brood was running a week behind the Dyfi 2013 brood.
HilaryJ said: Rothiemurchus was the oldest chick of one of the latest broods ever ringed by Roy Dennis. Ringed on Aug 10th, fledged Aug 18th, migrated Sep 6th. Allowing 38 days for hatching and 53 days to fledging that would give a laying date of c. May 20th, hatching on June 27th and migration at 71 days.
Rothiemurchus must have migrated very early. Some of Logie's chicks migrated very early but they did not get to Africa.
Hazel b said: In 2012 the first Threave chick fledged on 25th August & the second had fledged by the 30th, the Father & young Ospreys were last seen together on the nest on 6th Oct 2012. I also suspect that with milder weather Ospreys could potentially migrate later from Rutland than a more northern or Scottish nest
[/quote]Threave blog from 9/8/12: "The birds showed signs that eggs had been laid around the 30/31 May. We believe the chicks hatched on the 5th July."
So fits in with your above dates for latest egg laying dates.
I would think that if 30(05) and 28(10) at Rutland do produce eggs they're going to be running to a similar timeline to Dyfi in 2013. No worries there.
Our herring gulls are red listed birds. Think about that the next time you hear some flaming idiot calling for a cull of them.