Our last two Ospreys have left

PP1 and PP4 on aviary 9 September 2015On September 19, our last two young Ospreys of the 2015 reintroduction season left for Africa.  The project team were watching PP1 and PP4 (named after the code on their colour ring) when the female suddenly spiralled high into the sky before heading south. A few hours later PP4 did the same. The photo above shows the difference in size between PP1,  the female (to the left), and PP4, the male, on top of their release aviary. Since September 19 we waited several days to be absolutely sure that they had really left. It is common that young ospreys first make a  “false departure”, which might last up to 2 or 3 days, before returning to the reintroduction site for more food before they finally decide to set off. Now that we are sure that PP1 and PP4 have really left we wish them a safe journey, hoping that they will avoid the numerous risks that all Ospreys face from the moment they are born.

Three young Ospreys on the same nest

Three Ospreys on Nest 1 3 September 2015The photo above was taken shortly before PP5 (bird to the left) departed on migration on September 11. We built two nests in front of the aviaries so that the young Ospreys could get used to seeing them. We were delighted when they started to perch on the nests.

Osprey nest 1 aerial view
Bird’s-eye view from the top of the nest.

In the wild Osprey nests are of course much larger and with many more branches than these. However, we built these nests during the peak of the July 2015 heatwave, which limited how much work we could do. We will do better for 2016!

Thanks go to Michel Beaud and Pascal Rapin for their help in building these nests with Wendy Strahm and Denis Landenbergue, as well as to the Etablissements de Bellechasse who built and installed the platforms.

Building nest1 Michel Beaud and Wendy Strahm
Nest-building in 40° heat.
Pascal Rapin nest2 building
Pascal’s-eye view from the bottom of the nest.

Our first young Ospreys take flight

Five recently released Ospreys at the release site 15 August 2015On August 8 and 11 we released our six Ospreys that had been cared for around the clock inside the specially built aviaries. Some, like PP6,  took an hour to realise they were free before making their first flight, while others were content to sit inside the aviary for almost the entire day before taking the big step, or should we say jump. For example, we had begun to think that PP4 would never leave until at 18:30 he suddenly made a perfect take-off, spiralling high in the sky before making a fine landing on top of the aviary. It was as if he had been considering his first flight for the entire day and was determined to make a good job of it. The birds are now being fed twice a day, with fish being put out for them once before dawn, and then once in the afternoon. They are very susceptible to disturbance so the project team is watching them non-stop. It is very important that they are not frightened by anything and that they remain in the release area. Three dead trees were “planted” in front of the aviary and above is a unique photo when we had five young altogether, perched on two of the dead trees.

How we identify our birds

Metal and colour Osprey ringsEach bird has a metal ring on the left leg and a plastic colour ring on the right leg. The rings do not hurt the birds nor do they worry them in any way. Rings are only allowed to be put on birds by licensed ringers, which for our project are Michel Beaud, Adrian Aebischer and Roy Dennis. The metal ring on the left leg is provided by the Swiss Ornithological Station (SOS) at Sempach and has a unique number. If someone finds a ringed bird they can inform the SOS who will then tell us that someone has seen the bird.

Osprey rings
Osprey rings.

To be able to read the metal ring you usually need to have captured the bird. However, on the right leg we put a larger plastic colour ring which can be read more easily when the bird if flying or perched, usually with a telescope or a telephoto camera lens. Each bird has a unique code and in 2015 we put blue rings with the white letters PP followed by a number (PP1, PP2, up to PP6) on the right leg. These rings were already placed on the birds in Scotland so that they were identifiable when they were brought into Switzerland, and the numbers were included on their CITES export and import permits.

Note that  blue colour rings are also used for Ospreys in the UK, but these have different combinations of letters and numbers and are placed on the left leg. Therefore, if anyone sees an Osprey with a blue ring on its right leg, it is an Osprey that has been reintroduced to Switzerland. The birds are named after the letters and numbers on their blue plastic ring.

Launching www.ospreys.ch

Osprey portrait Sylvain Larzillière

After four years of preparing the Osprey reintroduction project in  Switzerland (one century after it became extinct), we are happy to launch www.ospreys.ch.

The main objective of this website is to document the various stages of this project, while at the same time reporting on  other conservation activities or research on this species taking place elsewhere. Our first release of Osprey chicks in Switzerland is planned for the  summer of 2015.

What makes an Osprey unique?

Balbuzard pêchant par Michel Jaussi

  • It is the only diurnal raptor that feeds only on fish.

  • Ospreys are the only species belonging to the genus (Pandion) and family (Pandionidae), meaning that they are taxonomically very distinct.

  • Along with owls, they are the only raptors with a reversible outer toe, meaning that they can grasp their prey with two toes in front and two toes behind. Once caught, the fish don’t stand a chance.

  • The global distribution of a same species of raptor in every continent (apart from Antarctica) is exceptional, with only the Peregrine Falcon having a wider distribution amongst diurnal raptors. But yes, taxonomy is the opinion of the scientist. It is possible that what has up to now been considered the same species (but different subspecies) living on different continents may at some stage become separate species.  But even if science decides that there are different species of Osprey on different continents, this doesn’t change the fact that all Ospreys look very similar and have the same ecology throughout the world. They live at the top of the food chain and are excellent indicators of the health of aquatic ecosystems.



Ospreys can start breeding at the age of 3 years (except for a few exceptional cases), with the average age of first breeding recorded at 3.8 years in France. The more  territories that are available in the region where the birds were born, the earlier they start to breed. However, if the best nests are already occupied by other Ospreys, young adults prefer to delay breeding rather than go further afield to seek new territories elsewhere. Continue reading Breeding

Remarkable fishers

Osprey rings by Wendy Strahm

Osprey carrying fish by Sylvain Larzillière
Osprey carrying a Chub (Squalius cephalus) in its talons.

Ospreys are the only diurnal raptor to feed almost entirely on live fish, and their fishing skills are legion. Flying or hovering high in the sky, they make spectacular dives into the water once a potential prey is spotted. With luck they will then snatch their fish with their enormous talons, firmly gripping it with their reversible toe. They generally take fish that either live in shallow water or at the top 10-20 cm of the water column, for example chub or roach.  Unlike species like cormorants or grebes, Ospreys do not dive and swim underwater.

At times it seems that the fish is too large for the bird to carry, and there are even reports of an Osprey being unable to release a fish that is too heavy, causing the bird to drown. There are no documented cases of this actually happening, but the story is repeated in many places.  We will believe it when we see it!

A fantastic video of an Osprey fishing can be seen here, showing the North American subspecies, which is not the same as the subspecies found in Europe (see taxonomy).


Where are Ospreys found today?

Osprey distribution
Distribution map and population status of Osprey Pandion haliaetus populations in Europe. Adapted from BirdLife Intl (2004) and modified with data from Schmidt, Dennis & Saurola (2014). The green “R” indicate where Osprey reintroduction projects have or are being undertaken.

The Osprey, a cosmopolitan species subdivided into four sub-species, occurs in the Palearctic, North America, the Caribbean and Australia (see taxonomy). It is a migratory species which can be found on every continent except Antarctica. Nowadays the Palearctic sub-species has an irregular distribution, mainly occurring from Scotland to the west to the Kamchatka Peninsula and Japan to the east. While its European population is fairly large (with an estimate of about 10,000 pairs), this population is quite fragmented and has undergone strong declines and extinctions in the relatively recent past. Continue reading Where are Ospreys found today?

The Osprey in Switzerland