Arkaig ospreys: your questions answered

When will the ospreys return to Loch Arkaig?

Both birds returned early this year - Louis on 28 March and Dorcha on 30 March.

How many cameras are you running?

We began with just one nest camera in 2017, but after Louis followed his new mate Dorcha to a different tree in 2021, we set up a second camera to cover that location too.

Camera One covers the original nest occupied by Louis and Aila from 2017 to 2020. It hasn't had permanent residents since then but has attracted interest from young ospreys in the last couple of seasons, so we hope it might be used by a breeding pair again – perhaps in 2024.

Camera Two, several kilometres away from Camera One, covers the nest occupied by Louis and Dorcha since 2021.

Will I see the ospreys if I visit Loch Arkaig?

Loch Arkaig Pine Forest is a wonderful place to visit, but as far as the ospreys are concerned, the camera livestream is the best place to watch them.

How were names chosen for the Loch Arkaig ospreys?

When Camera One first went live in 2017 a young male bird took up residence and began waiting for a suitable mate. He was on his own for three weeks, so Woodland Trust staff nicknamed him 'Lonesome Louis' – pronounced Loo-ee. When a female finally did pair up with him we dropped the Lonesome.

The female was named 'Aila' – a name found in several different languages. It is the Finnish equivalent of Helga or Olga, meaning 'bringer of light'. In Scottish Gaelic, it means 'from the strong place'.

The pair's first chick, hatched in 2017, was named 'Lachlan' by camera viewers. The name means 'from the land of the lakes'.

During the 2019 season we asked camera viewers for suggestions to name the two chicks and put them to a vote. One chick was named 'Mallie' after Glen Mallie where the nest is located. The other was named 'Rannoch' to honour our volunteer Liz Bracken who lives at Loch Arkaig. There was already an osprey elsewhere named 'Bracken', so we used the Gaelic equivalent – 'Rannoch'.

During the 2020 season 10,000 people voted to name the chicks in honour of figures in the news during the year. Doddie was named for Doddie Weir; Vera was named for Dame Vera Lynn; and Captain for Captain Tom Moore.

In 2021 Louis had a new mate whose colouring inspired viewers to name her Dorcha, which means ‘dark’ in Gaelic. The chicks were named Aspen and Alder after the tree species.

A new young male bird seen on the nest was referred to at first as “The Young Pretender” which was a name used for Bonnie Prince Charlie in the 18th century. Eventually we settled on just Prince. He attracted the attentions of a female whose ring number (152) revealed she had fledged at nearby Glen Affric, so we called her Affric.

Our 2022 chicks were named Willow after the native tree species, and Sarafina – an African name to reflect the other end of the birds’ migrant lives.

Our 2023 chick was named Ludo – a combination of his parents’ names.

How can I tell male and female ospreys apart?

Female ospreys are larger with darker patterns on their chest. Males are smaller with pale chest markings. Osprey chest markings are sometimes referred to as necklaces. Our osprey ID blog goes into more detail.

How do osprey parents divide up the work?

The male osprey brings in most of the food during the nesting season. The female does most of the egg and chick sitting, but the male usually takes over once a day to give her a short break. 

When the nest is threatened it is generally up to the female to defend. Viewers are often aghast the male doesn’t help, but even the tiniest injury could stop him fishing and threaten the whole family’s future.

Do ospreys need to mate only once before eggs arrive?

No, frequent mating is required to stimulate the female to produce an egg. The egg likely won't be fertilised until the last few days before laying so repeated mating is required for success.

More experienced pairs lay multiple eggs, usually around two days apart. Louis and Aila produced 12 eggs between 2017 and 2020, from which six chicks successfully fledged.

Why doesn't the female fish for herself before the eggs arrive?

Female ospreys don't normally fish for themselves during the breeding season. As part of courtship, the male brings in food to impress the female with his fishing skills. That way she knows he is able to provide for their offspring.

Where does Louis fish?

Louis doesn’t have any favoured spots on Loch Arkaig so might hunt anywhere along its 12 mile length. He is also seen heading in the direction of Loch Lochy which lies off to the right of the view from Camera One.

He brings in saltwater fish so we know he must be hunting at sea too, probably in Loch Eil. This is only slightly further away from the nest than the Western end of Loch Arkaig itself.

What fish are the Arkaig ospreys eating?

Identifying fish species at the nest can be tricky because our view is limited and the fish are often bashed around and sometimes headless by the time Louis brings them in. But by far the biggest item on the menu is brown trout.

Saltwater flatfish also make a regular appearance as the season progresses. We generally assume these are flounder but it is possible some could be dab or plaice which look similar. In summer huge shoals of mackerel mass all around the British coast and it is quite common for Louis to appear at the nest with these too.

Migratory salmon pass through the loch as they head from the sea to their spawning burns. Most salmon are too big for an osprey to manage, but a few return after just one winter and are well within Louis’ capabilities. These yearling salmon are known as grilse. Just to complicate matters, some brown trout also go to sea and return to the loch to spawn. These are called sea trout. Louis generally brings in a few grilse and sea trout each year.

Deep in the loch there are shoals of Arctic charr which are normally out of reach of a diving osprey. If they do come to the surface they can be taken and we believe Louis has brought in two or three of these fish in the past, but it is a real rarity. It can be difficult to tell brown trout, grilse, sea trout and charr apart on our camera view. If in doubt it is probably a trout! Very occasionally we have seen saltwater species like pollock or coley which look quite similar to each other.

Loch Arkaig contains pike which can grow to be huge. Smaller 'jack pike' might be catchable for an osprey. Pike have a very distinctive shape and fin profile and so are quite easy to identify.

Louis frequently catches four or more fish a day, though this varies depending on the weather; when visibility is poor, fishing is more difficult. If the weather is wild when chicks are young and in need of food, it can be a worrying time for viewers. This variability is however completely natural.

How many fish do the ospreys eat?

In 2020 we counted all the fish that came into the nest. There were 579 in total. Louis brought 553 of these, while Aila brought 26 late in the season. The species breakdown was: 459 trout, 64 flat fish, 34 mackerel, 11 sea trout and grilse, 7 Arctic charr and 4 pike.

In 2022 we counted 546 fish – 545 brought by Louis and one by Dorcha. The species breakdown was: 491 trout, 16 flatfish, 24 mackerel, 14 sea trout and grilse and one we couldn’t ID.

In 2023 we counted 396 fish – 395 brought by Louis and one by Dorcha. The species breakdown was: 340 brown trout, 21 flatfish, 20 mackerel, 3 pike, and 12 sea trout and grilse.

Do ospreys ever eat anything other than fish?

In West Africa ospreys occasionally catch swimming snakes or lizards, which they probably mistake for fish. Ospreys in the UK had only ever been observed hunting and eating fish – but in 2022 a small bird called a grebe was brought into a nest in the Cairngorms. This was likely mistaken for a fish as it dived underwater. Ospreys certainly seem to intend to only catch and eat fish, but very occasionally make mistakes!

Where does the male sleep when the female is on the nest?

It is actually quite uncomfortable for ospreys to stand on a flat surface, so both the male and female prefer to roost on one of several nearby branches at night time. When eggs and small chicks are present, the female will sleep on the nest with them through the night.

Where do the Loch Arkaig ospreys spend the winter?

Most Scottish ospreys migrate to the wetlands and estuaries of West African countries such as Senegal and The Gambia, but birds seem to be increasingly spending time in Spain and Portugal too. One of our 2019 chicks has been spotted in Senegal.

Does the osprey family travel together when they migrate?

Ospreys migrate individually. The female tends to leave first. The male will wait until the chicks have all left before setting off himself. The pair won't meet up again until next year at the nest. The chicks don't intentionally meet up again with each other or Mum and Dad. Our livestream covers the entirety of their time together as a family. 

Are the Loch Arkaig ospreys ringed?

A licensed raptor expert from the Highland Raptor Study Group records and rings chicks at our nests and others in the area. Scottish ospreys have a metal British Trust for Ornithology (BTO) ring fitted to their right leg and a plastic blue Darvic ring on their left leg.

The Darvic ring has unique letters and numbers which allow the bird to be identified from a distance. English and Welsh ospreys have the Darvic ring on their right leg.

What are the Loch Arkaig chicks' ring numbers?

JH4 – Lachlan, male, fledged in 2017
JJ0 – Mallie, female, fledged in 2019
JJ2 – Rannoch, female, fledged in 2019
JJ6 – Doddie, male, fledged in 2020
JJ8 – Vera, female, fledged in 2020
JJ7 – Captain, male, fledged in 2020
LW3 – Aspen, male, fledged in 2021
LW4 – Alder, male, fledged in 2021
LW5 – Willow, female, fledged in 2022
LW6 – Sarafina, female, fledged in 2022
LY7 – Ludo, male, fledged in 2023

Have there been any sightings of the Loch Arkaig ospreys elsewhere?

Doddie was spotted in Somerset in autumn 2020 as he stopped off during his first migration south. He was filmed and photographed by birdwatchers for over a fortnight. He was spotted again in Shetland in May 2022.

Rannoch was spotted in Senegal by an ornithologist in January 2022.

In September 2022, Willow was spotted by a birdwatcher in France.

In September 2023, Ludo was spotted by numerous birdwatchers in France.

Why don’t you satellite track the Loch Arkaig ospreys?

We believe satellite tracking is only appropriate as part of scientific studies with clearly stated aims to benefit the species concerned. Woodland Trust Scotland is a woodland conservation charity and we share the nest camera with you as a slice of wild forest life. Osprey research is outside our remit. We don’t feel it would be right to add satellite tags to the birds just to satisfy viewer curiosity.

Are the ospreys from the nest male or female?

The only members of our osprey family whose gender we can be sure of are the breeding adults. Based on various measurements taken when they were ringed we can estimate that Lachlan, Doddie, Captain, Aspen, Alder and Ludo are male, and that Mallie, Rannoch, Vera, Willow and Sarafina are female. We will only know for sure if they are observed nesting in future.

Will the chicks come back to Loch Arkaig?

To avoid in-breeding, male ospreys tend to return to nest in the area where they fledged, while females tend to travel elsewhere. There have so far been no sightings of any of the chicks back in the vicinity of Loch Arkaig.

Where is Loch Arkaig in relation to the view on nest Camera One?

Loch Arkaig lies in a dip near the top of the view from Camera One and runs off several miles to the left. The eastern end of the Loch is just off the screen view to the right. Everything above the yellow line is on the north bank. Everything below the yellow line is south of the Loch.

Are the nests protected against pine martens?

Pine marten predation of eggs or chicks is as natural as osprey predation of fish. As we have invested in the camera equipment and hope to show everyone a full season of osprey activity, we think it is reasonable for the nests to benefit from some protection. This tips the odds in favour of the ospreys but doesn’t guarantee there will never be a raid.

Lower branches have been removed from each tree so there are no jumping-on points. We have applied a slick collar to each trunk to stop martens being able to find purchase. This replaces the greased sleeve previously at the base of the original tree. The new wrapping is slicker, longer and higher up the trunk.

What were the notable dates in each season?

2017

10 April – Louis arrived 
28 April – Aila arrived 

10 May – first egg laid
13 May – second egg laid
16 May – third egg laid

17 June – first egg hatched
18 June – second egg hatched
21 June – third egg hatched

23 July – Lachlan ringed

9 August – Lachlan fledged

1 September – Aila last seen
8 September – Louis and Lachlan last seen 

2018

6 April – Louis arrived
6 April – Aila arrived

23 April – first egg laid
26 April – second egg laid
29 April – third egg laid

11 May – eggs taken by pine marten

2019

4 April – Louis arrived
4 April - Aila arrived

23 April – first egg laid
26 April – second egg laid
29 April – third egg laid

1 June – first egg hatched (Mallie)
4 June – second egg hatched (Rannoch)

4 July – Mallie and Rannoch ringed

20 July – Mallie fledged
27 July – Rannoch fledged

13 August – Aila last seen
20 August – Mallie last seen
5 September – Louis last seen
6 September – Rannoch last seen

2020

5 April – Louis arrived
6 April – Aila arrived

23 April – first egg laid
26 April – second egg laid
29 April – third egg laid

29 May – first egg hatched (Doddie)
1 June – second egg hatched (Vera)
3 June – third egg hatched (Captain)

2 July – Doddie, Vera and Captain ringed

18 July – Doddie fledged
24 July – Vera and Captain fledged

15 August – Doddie last seen
22 August – Aila last seen
23 August – Captain last seen
5 September – Louis last seen
6 September – Vera last seen

2021

11 April – Louis arrived at Nest One

14 July – Aspen and Alder ringed at Nest Two

2022

11 April – Louis and Dorcha returned

24 April – first egg laid
27 April – second egg laid
1 May – third egg laid

31 May – first egg hatched
2 June – second egg hatched
5 June – third egg hatched

12 July – Willow and Sarafina ringed

25 July – Willow fledged
31 July – Sarafina fledged

18 August – Dorcha last seen
28 August – Willow last seen
8 September – Louis last seen
9 September – Sarafina last seen

2023

April 2 – Louis returned
April 9 – Dorcha returned

21 April – first egg laid
24 April – second egg laid
27 April – third egg laid

23 May – egg lost in owl attack

31 May – egg hatched

8 July – Ludo ringed

19 July – Ludo fledged

17 August – Dorcha last seen
24 August – Louis last seen
25 August – Ludo last seen

2024

28 March – Louis returned
30 March – Dorcha returned

14 April – first egg laid
17 April – second egg laid
20 April – third egg laid

22 May – first and second egg hatched
24 May – third egg hatched