Montagu's harriers are the rarest breeding bird of prey in the UK, with just five nests in 2015.
This nomadic species currently breeds on agricultural land in three locations in the UK, and widely across Europe, from Spain to Belarus. But the survival of the UK population is dependent on positive partnerships between farmers and conservationists.
The UK breeding population has always been small and prone to fluctuations in success, as elsewhere across the European range. The RSPB and its partners have been protecting UK Montagu's harrier nests since 1982.
In order to understand the factors that control our small population and to protect Montagu's harriers during migration and on their wintering grounds, we also need to understand how and where they migrate and where our birds winter. This information, supported by research in the UK and West Africa, is crucial to developing a plan to help Montagu's harriers in all parts of their range, including the UK.
Satellite tagging provides these answers. The project, licensed by the BTO, will provide detailed information on the daily movements, migration routes and wintering locations for each bird.
In late July 2014, experts from the Dutch Montagu's Harrier Foundation fitted three adult Montagu’s harriers with small, lightweight satellite tags in the UK.
The satellite tagging project continued in 2015 in conjunction with the RSPB, with funding again provided by The Sound Approach.
Three new birds were satellite tagged in July, and were all adults breeding in East Anglia.
What happened to Mark and Madge, the Montagu's harriers we tracked on their migration from the UK to Africa? Ben Koks and Almut Schlaich, from the Dutch Montagu's Harrier Foundation, have exciting news... More...
Mo was a third-year female from the east of England. In 2014 she successfully raised four juveniles with a polygamous male - meaning he was also paired to another female nearby.
Mo is named after Mo Constantine, who kindly sponsored this tag.
Mo remained around her nest area in East Anglia before her tag unexpectedly stopped working early on the morning of 8 August, 2014. The tag had been working well and had given an accurate fix on her roosting position that evening. Investigations continue and anyone with information is asked to call Norfolk Police on 101 or RSPB Investigations on 01767 680551.
Mark is a five-year-old adult male who was tagged in the south-west last year and returned to nest at the same site this year.
He didn't breed in 2014, instead attaching himself to another pair of Montagu's harriers who had four youngsters, regularly providing food for the female, Madge, and her chicks. This behaviour, called polyandry, is unusual and had never previously been exhibited by a Montagu's harrier in the UK.
Last year, Mark began his autumn migration on August 18. He travelled through France and then onto Spain. After stopping off in Morocco, he flew over Mauritania before reaching his final destination, Senegal.
Mark is named after Mark Constantine, who kindly sponsored this tag.
Madge was a seven year-old female with startlingly pale eyes.
She was from south-west England and successfully raised four juveniles in 2014. She was paired with a mature adult male but later in the season also benefited from the attentions of another younger male (Mark), who also brought food for her chicks.
As an experienced adult we expected her migration route to be the most efficient.
In late December 2014, Madge stopped moving about, though her tag continued transmitting. We concluded that she died in Senegal, possibly as a result of predation by a jackal or Verreaux's eagle-owl.
Click the name of a bird to view their route.
As you can see we've started the birds' migration in London. This is due to the sensitivity around the birds actual breeding grounds.
The Montagu's harrier is a slim, medium-sized, long-winged bird of prey. It has a long tail, is smaller than a buzzard, and has more pointed wings than the similar hen harrier. The male is grey above.... More...
More information on all RSPB work on migrant birds
Our migrant birds are disappearing at an alarming rate. Please help save our summer visitors by donating today. More...
Montagu's harriers are migratory, spending just a few months of the year on their breeding grounds and wintering in sub-Saharan West Africa.
Many of our migrant birds are in trouble – UK breeding populations of long-distance, trans-Saharan migrant birds have declined sharply since the 1970s.
By protecting migratory birds during their whole lifecycle in the UK, Europe and Africa – on their breeding grounds, during migration and on their wintering grounds – we can help prevent the loss of our summer migrants, including Montagu's harriers.
In order to protect Montagu's harriers during migration and on their wintering grounds we first need to understand how and where they migrate and where our birds spend winter. This information, supported by more research in the UK and West Africa, is crucial to developing a plan to help Montagu's harriers in all parts of their range.
The project, licensed by the BTO, will provide detailed information on the daily movements, migration routes and wintering locations for each bird.
When the birds return to Europe in April 2016 we’ll be able to locate their breeding sites and monitor nesting success. Although the breeding locations will not be shared publicly, updates will be provided.
This project wouldn't be possible without the generous support of all the volunteers and farmers and the following organisations: