Osprey Diary 23rd April

Our female osprey never ceases to amaze and surprise us- this morning  she was off the nest and  out of sight for over five hours which is highly unusual for her. Luckily the male stuck to his incubation duties like glue and held the fort until her return- what a wee star!

By far the most commonly asked question about our ospreys:

Q: How do I tell the male and female apart on the nest?

A: The female is larger, has paler brown feathers with many ragged edges, and has a much darker chest ‘necklace’ of brown spots. By contrast the male is smaller, sleeker and a darker chocolate brown, and has an almost white chest. He also has very long wingtips which meet past the end of his tail- the females are the same length as her tail. There are also subtle differences in head markings and of course different eye patterns, but the above are the easiest methods to use on the webcam.

Otherwise its been a calm quiet and misty day on the reserve with just one hour of intense excitement- when two Red throated divers were seen on the loch! These beautiful birds ( known in north America as Loons) nest in the far north highlands of Scotland and  artic regions in summer, after wintering at sea. These birds were probably a pair ( they mate for life) heading north to their favourite summer nesting area and just dropped in for a visit.

Library photo of Red throated divers, courtesy of Wild About Britain website.

Library photo of Red throated divers, courtesy of Wild About Britain website

What  lovely visitors though- we will be keeping a sharp eye out for them over the next couple of days in case they hang around- as they sometimes do awaiting better weather to continue their journey north.

Elsewhere today , the ranger and volunteers have been doing some spring botanical monitoring at Keltneyburn reserve, some photographic monitoring of tree regrowth at Balnaguard Glen , and installing mink rafts on our riverside to survey of invasive north American mink- a busy week all round.

Q: Is the nest illuminated at night?  I assumed it was infra red, but having looked and seen the shadows I’m now not so sure. Is it just to deter  humans or does it have other purposes and if so what are they, and is it a common practice?

A: The nest is not illuminated ( there is no visible light) at night. The camera has a small inbuilt infrared lamp that enables it to ‘see’ and record . The birds, like us have extremely poor infrared receptors in their eyes and cannot see the light, and neither can we if we look at the nest directly. You need infrared sensitive night scopes or binoculars or cameras to see the light, so the birds are not disturbed at all. The purpose is to allow us to see the birds at night in order to monitor their behaviour and spot if there are any problems such as human disturbance- this is the same technology uses in most security cameras.

Posted in Diary 2014 |

Osprey Dairy 22nd April

Male Osprey Incubating in the Rain - copyright SWT

Male Osprey Incubating in the Rain – copyright SWT

Our male osprey has been showing his dedication to his nest and mate, incubating a lot of time and being reluctant to let his mate take over despite the rain. On Monday night, he unusually sat on the eggs well into the hours of darkness for over 2 hours, and it was only his mate’s strong insistence that made him get up. This is quite unusual as the female invariably incubates through the night- but no one seems to have told our male!

It is also interesting that he has been bringing in yet more material to shore up the nest – we think this is probably driven by his hormonal response to the site of the eggs.

Q: Why did the 3 eggs fail to hatch last year? Were they found to be infertile?

A: The three eggs were analysed and two were found to be completely infertile, and the third to have a few tiny cells inside which stopped developing after a few days. This means there was no fault in incubation, but that the birds fertility is low, which is most likely due to the female’s age.

Q: The male bird was on duty but was standing on the edge of the nest eating a fishtail and not incubating the eggs.  How long overnight would the eggs be safe?  Is this normal?

A: Eggs can remain uncovered for a varying amount of time depending on the weather conditions. We don’t believe this was long enough to cause any problems it was such a mild night.

Q:  I was wondering what might have happened to the other female who had been nesting with the male prior to lady’s return this year. Have you spotted her, and do you know whether she found another mate or nest, and whether she in fact produced a clutch of eggs?

A: The short answer is: we don’t know. She has not been seen again over the loch or nearby – though it is hard to identify her with any certainty as we did not have a good close view of her. She may have returned to another nest and laid eggs with another partner, or she may still be looking for a nesting opportunity- we hope she found one.

Q: When the chicks get ringed by your qualified staff, do they (the staff!) not get attacked by the parent ospreys when the chicks are removed from the nest?

A: All ospreys are vigilant in defensive of their young and nests, but this is mostly bluff and noise as ospreys are surprisingly docile compared to some other birds.  Some ospreys have been known to fly close to the climber’s heads, but our birds tend to circle overhead, alarm calling, or sit nearby watching carefully. This is one of the reasons we keep the whole process to a minimum of time so the chicks can be returned safely and the time they are separated is kept to a minimum.  

Ranger Emma

Posted in Diary 2014 |

Osprey Diary 21st April

Our ospreys have been basking in glorious sunshine and incubating happily all Easter weekend. There have been no dramatic incidents, which is a blessing- our hearts go out to our friends at Rutland Water osprey project where the nest politics between rival males are rampant on the Manton bay nest, and the future of the eggs there looks uncertain. What this highlights is that so many of our presumptions about ‘normal’ osprey behaviour are being rewritten each year as we get the opportunity to study these birds in such detail.

Osprey with Pheasant wing 20th April- copyright SWTClose up of Pheasants wing

Osprey with Pheasant wing 20th April- copyright SWT

 An interesting new observation from our well-studied nest is that for the first time I can remember, the female osprey has brought in a dead pheasants wing to the nest. She seems to have brought this in as nest decoration rather than food (the wing ends are almost all feathers and no meat and are often discarded by predators) . It has been half-heartedly pecked at by both birds, but not eaten- perhaps she was attracted to it as soft extra padding? For more examples of strange things brought to osprey nests as decorations- see the blogs from earlier this month.

Q: How did the female cope with nearly 24hrs without a fish delivery over the weekend?

A: We believe she may well have fished for herself during one of her spells off the nest, which lasted over an hour, whilst the male incubated. She is of course perfectly capable of doing so, but usually relies on the male it’s his role to support her and the chicks. She really only needs one large or two small fish a day at the moment to eat herself – this will increase massively however, when a chick is hatched.

 Q: Why are the birds panting with their beaks open?

A: They are hot! Believe it or not the glorious warm weather we’ve been having means they birds are warm on top of their tree, which doesn’t have much shade. They cannot sweat so release excess heat this way, much like a dog.

Any other burning questions about ospreys? check our FAQ’s above then if you can’t find the answer, send it to ospreys@swt.org.uk  and I will endeavour to answer it here for all to share.

Ranger Emma

Posted in Diary 2014 |

50th Anniversary Prize Draw


Our winner from our prize draw is Ben from Edinburgh!

Well done Ben! We will be contacting you shortly.

Emma – Visitor Centre Assistant.

Posted in Diary 2010 |

Osprey Diary 19th April

At Lowes today in the beautiful sunshine, we finally got a clear view of the third egg!


Loch of the Lowes (19.04.14 – Copyright E Castle-Smith)

Our famous female and her mate were working well together, taking turns in incubating the eggs.  We are eagerly waiting for potentially a fourth egg.  However the laying of a fourth egg is unusual, with our female only having done this twice in the past.  So keep watching the webcam for another egg!!!  The first egg is due to hatch around the 20th of May.

First glimpse of the 3rd egg


First glimpse of the 3rd egg!!! (Copyright SWT)

3rd egg male Osprey

Our male Osprey arrives to take his turn incubating the three eggs. (Copyright SWT)

Emma – Visitor Centre Assistant

Posted in Diary 2014 | Tagged , , |

An Easter Egg: more great news

We believe our osprey laid her third egg of the season last night around 11.30pm, as she showed all the usual behavioural signs. However, its been difficult to get a good close view as the nest cup is so very deep- we will bring you confirmation and a photograph asap. Just as well the nest is so snug and well insulated- it was well below freezing here last night under a gloriously starry sky.

Three eggs is a  normal ‘full clutch’ for an osprey and more than we dared hope for at our females advanced age- though of course last year she did surprise us with a rare four eggs.  So it look like we now have three chances of having a young osprey hatch this year- start keeping your fingers firmly crossed that the next month of incubation goes smoothly.

Ranger Emma

Posted in Diary 2014 |