The novelty of carrying out much of the incubation of her eggs by herself has worn off for our resident female osprey. We suspect that she is a young, possibly even first time breeder and she was so pleased with her fine clutch of eggs that initially, she was resistant to allowing white leg SS, to take a turn to incubate. Well a few weeks of the endless sitting and nothing much happening, must have played a part in changing her mind, as she is now taking extended breaks and leaving a bemused SS alone to incubate.
On Monday 18th, male SS was alone in the nest and sitting on the eggs for most of the day, he was there when the cameras came on and he did not get relieved from his duty until 3.15pm.
The next day, once again, white SS was on incubation duty for most of the morning until just before midday he flew off and she returned within a couple of minutes of him leaving and took over. She had just settled down after turning the eggs and rearranging some nesting material when an almighty hail shower burst. A very fed up looking osprey could be seen hunkered down low with hail stones literally bouncing off her back.
They have a few more weeks to go yet before hatching time. The earliest likely date for hatching would be from 3rd June to 7th June.
Now that the pair are established this season, there seems to be a more settled atmosphere at the main nest site and although we have seen an occasional alarm calling and the shadow of an intruder bird flying over the nest, most of the time they seem to be left in peace.
It is thought that intruder birds played a part in the downfall of the previous female which led to her leaving the three young chicks to die in the nest last year, as there were certainly other birds about and the new female wasted no time to move into the nest site, the very next day after she had gone.
Other osprey sites around the country have not been so lucky this year with eggs being kicked out of the nest at Loch Garten by an intruder male bird and Kielder nest sites have had multiple intruder birds harassing the resident pairs. Luckily their eggs have not been damaged. One of the intruder birds causing mischief was a Kielder returning youngster.
When intruder ospreys check out nesting pairs they possibly assess the situation and size up the competition. They may be seizing upon the chance that one of the pair may be a weaker or aged bird that can be displaced to make way for them to move in on a nest site with a resident bird in breeding condition that holds a territory. It has certainly worked for our new Mrs osprey and it would seem that another bird is trying to push out Odin the male at Loch Garten in a similar fashion.
When ospreys fail to breed they often build another nest close by (known as a frustration nest), we do not really understand the purpose of this nest. Is it a ‘back up’ nest in case they lose the territory of the one they hold and they intend to use it themselves, or is it to perhaps distract intruders away from their site and hope that they may take that nest instead?
The number of intruder osprey incidents causing nest upsets and failures is perhaps a good argument for putting up some more artificial nesting platforms to provide an opportunity for a pair in breeding readiness to move straight in.
However, some healthy competition for nest sites may be of benefit to the breeding population too, in a way that osprey breeding success comes from the strongest and best birds in their prime, as the weaker ones are driven off site. Survival of the fittest ensures that the weaker, sickly birds do not get to breed and therefore the offspring are perhaps born to only the best of the osprey stock.
Tweed Valley returner
A Tweed Valley osprey has been reported to have been seen at Esthwaite Water in the Lake District this spring. It is a ringed bird, CK2 which is one of the birds which fledged from our main nest in 2012. Great news that CK2 has made it back to the UK successfully and has been seen and we are waiting to hear more news about whether the bird was just passing through or if it is nesting there.
Bird box news
Blue tits have had a slow spring due to the weather but the pair that have moved into the nest box at Kailzie now have seven eggs and another box which we had assumed had been abandoned had some new nesting material today, so it looks like a pair of late breeders are ready to move in.
Sparrows have moved into the sparrow box on the outside of the osprey centre building, these birds like to nest communally and at least two pairs have moved in.
At Glentress the house martins have been very busy near to the pond area outside the Wildlife Watch room and they are taking advantage of the rainy weather causing messy puddles where they are gathering beakfuls of mud to build their mud cup nests which must be in the houses below Glentress judging by the direction the birds are flying off to.
Thanks for reading,