In this guest blog, RSPB Conservation Scientist Lucy Mason talks about our work at Otmoor to protect lapwing numbers and cut down red kite predation using free meals as a distraction.
Diversionary feeding of birds of prey, where substitute carrion is placed at certain locations, has already enjoyed success as an effective way of reducing red grouse predation by hen harriers and little tern predation by kestrels. So, looking at its potential in other areas, we are embarking on a two-year scientific study to test the efficacy of using this technique to reduce red kite predation of wader chicks, especially lapwing, in Oxfordshire, near our Otmoor reserve.
Before describing our diversionary feeding project in more detail, it is worthwhile taking a brief history lesson. Lapwing and other waders were once widespread as nesting birds across lowland England. But changes in the countryside, largely driven by modern farming policy, have squeezed these birds out of the wider landscape to a point where sites like Otmoor are one of the few areas where these birds can flourish. Before the Otmoor nature reserve was established in 1997, drainage and arable cultivation had eroded the wildlife value of the site to a point where only a remnant of the once widespread wader population survived. Subsequent large-scale restoration of wet grassland has enabled the recovery of many wetland species, including lapwing.
Our efforts combined with the ongoing decline of waders means that Otmoor is now the most important site for breeding waders in central England. Eighty years ago, the red kite was a truly rare bird in Britain with only 10 pairs, all confined to the hanging oak woodlands of mid Wales. The red kite was reintroduced to the Chilterns in 1989 with the first breeding taking place in 1992; at a time when the lapwing was already an extremely localised bird in central England. We believe, the red kite’s recovery is one of the greatest conservation successes of recent times.
We trust that the habitat work that we have completed at Otmoor for the benefit of waders will encourage these birds to re-colonise the surrounding Upper Thames river valleys. The biggest single factor affecting lapwing is the lack of suitable wet grassland habitat in the surrounding landscape.
As populations of waders have become concentrated in fewer and fewer sites, the risk of predation increases in these honey-pot sites. We have undertaken a lot of work to reduce predation by mammals, such as foxes. The installation of anti-predator fences has stopped mammalian predation, but it has concentrated nesting waders into a smaller area, which at times can attract the attention of red kites.
We will use the trial to see whether targeted diversionary feeding during the wader breeding season can reduce predation rates in the fenced areas of the site; and to assess whether reductions in predation rates by red kites result in more wader chicks being recruited into the adult population. Overall we will be testing whether red kite diversionary feeding could be a practical, publically-acceptable and cost-effective management tool to boost lapwing numbers on Otmoor.
We encourage the public not to feed red kites and it is important that we highlight the difference in our view between diversionary feeding and supplementary feeding. The trial will provide diversionary food in a controlled way which aims to lower red kite predation of wader chicks – so we will only undertake this targeted measure during the limited period when waders have chicks. Supplementary feeding of red kites, which has become an important issue in the Chilterns, is done by those people who want to encourage these birds year round into gardens so they can obtain better views of these magnificent raptors. We understand the desire to see these raptors – we like to watch them too – but supplementary feeding of red kites is detrimental to red kites as it doesn’t encourage them to forage and disperse and it doesn’t provide the diet these birds need: red kites are used to quite a poor diet of carrion, so strings of prime sausages –albeit well-meant - don’t provide the roughage these birds need in their diet.
We look forward to the start of this project, which we hope will help improve understanding of this non-lethal method of reducing predation of conservation-dependent species by birds of prey.
What happened to Mark and Madge, the Montagu's harriers we were tracking on their migration from the UK to Africa? Ben Koks and Almut Schlaich, from the Dutch Montagu's Harrier Foundation, have exciting news...
Tracking birds with satellite transmitters is still bringing us new insights in wildlife ecology. In 2014, the RSPB and the Dutch Montagu's Harrier Foundation organised the tagging of three adult Montagu's harriers in the UK.
The main objective of this particular part of our work is not only to find out more about the migration of Montagu's harriers, but to gain a better understanding of where they 'stopover' and spend winter. For this reason, we started doing fieldwork in countries like Niger, Mali, Burkina Faso and Senegal in 2006. We also visited eastern Morocco, an important stopover site, four times in 2010 and 2011.
We wanted to see with our own eyes what happened to 'our' birds. Rather than waiting for the satellite coordinates, we went and found the birds! This combination of high-tech and old-fashioned fieldwork is necessary to understand Montagu's harriers in greater detail. Another major objective was to find out where deaths occur. Without satellite tagging, this would have been impossible.
When we received an enthusiastic invitation from Mark Thomas of the RSPB to be part of an exciting workshop about the conservation of Montagu's harriers in the UK, we replied in a split second with a thrilled 'Yes'. Later in 2014, together with Mark and some of the other dedicated British Monty's fieldworkers, we caught and tagged three adult birds. One male ('Mark') and two females ('Mo' and 'Madge'), all funded by Mark Constantine at Lush.
We know that Mo did not even start her migration because in August she died in circumstances that sadly suggest illegal persecution. We knew about the killing of hen harriers in the UK but we were not aware that Montagu's are under pressure because of illegal persecution here, too!
After their departure from the UK, Mark and Madge started their autumn migration in the last week of August, and on the RSPB website people can follow their journeys.
It's always exciting to see how they do it. Madge reached Senegal on 23 October. Mark arrived in his first wintering area in Mali on 4 October, then headed to Senegal on 7 November and finally reached his second wintering area on 10 December. So far so good.
Both birds seemed to stay in their wintering areas, but just before Christmas we saw that though Madge's transmitter was still sending data, she was not moving anymore. In other words, Madge died at that time.
During our fieldwork in Senegal we visited the wintering areas of Mark and Madge. We arrived in Madge's area, near the village of Ndiaouara, on 29 January. Not far away from the Gambian border, at Madge's last-known location, we found a small roost of six Montagu's and six marsh harriers. This is a typical type of wintering habitat of many Monty's in western Africa.
We saw during our regular grasshopper counts that there was plenty of food in this area, so this could not be the cause of Madge's death. It's possible she was killed by a jackal or Verreaux's eagle-owl - these are both predators of Montagu's harriers and were present in the area where Madge died.
Madge was already an 'old lady' during her last breeding. We spent almost a day trying to find Madge and her satellite tag with the help of local boys, but we were unsuccessful. The vegetation was too high and too dense to find a tiny, 12g device in an area of one squarekilometre. We left our contact details in the hope the transmitter will be found by someone in the future. Fingers crossed we get some news when we return to Senegal again in March.
Looking for Mark was totally different. First of all, we knew that this male was still alive but we had to tackle at least one problem. We knew that he was roosting on a small island called Gaye, but we had to organise a safe trip there. Using our contacts we made our way to a small village called Ndiol and found a fisherman with a good motor on his pirogue (fishing boat) to take us to the place where we thought our British hero was roosting regularly!
We found a roost of at least six harriers there on the evening of 5 February and planned a trip the next day. On the 6th we had enough time to visit the rich and beautiful island, collect more than 70 regurgitated pellets (with an average of 10 prey items per pellet). And, best of all, we counted a total of 26 Montagu's harriers at Mark's roost! Unfortunately, we didn't see him, but we were still very satisfied with our work - with the bonus of five magnificent short-eared owls hiding under a small tree.
Going back to our own roost, after eating dinner we checked our photos and discovered to our great joy that we had photographed Mark! He had been too far away for us to see his tag's antenna, but the camera caught this most important evidence. We had found Mark in his main wintering site, he was safely surrounded by water and we once again had a new piece of the puzzle of harrier ecology on two continents.
We have just arrived back home in Holland: we collected information about at least 7,000 prey items from 12 roosts, counted the biggest harrier roost ever (4,000+ Montagu's harriers), proved again that wintering short-eared owls are quite regular in the Sahel, met a lot of people, kept our four-wheel drive running. And we learned a lot about 'our' migrant birds and their place in rapidly-changing landscapes in this part of the world.
Satellite transmitters connect these worlds to each other and we hope to report more results from further fieldwork in this stunning region of our globe very soon.
Guest blog by RSPB Senior Conservation Scientist Dr Steffen Oppel
Four vulture species breed in Europe, and the smallest species, the Egyptian Vulture, is the one with the most precarious conservation status. Just how desperate the population status of Egyptian Vultures is in eastern Europe was recently revealed by a study published in the journal Bird Conservation International.
Egyptian Vulture decline of about 7% per year
A large group of collaborators from Bulgaria, Greece, Serbia, Albania, Turkey, and the former Yugoslav Republic of Macedonia compiled all survey data from the Balkan peninsula from 1980 until 2013. The team, led by Metodija Velevski of the Macedonian Ecological Society (MES), and supported by RSPB Conservation Scientist Steffen Oppel, found that the population had declined from almost 600 pairs in 1980 to less than 100 pairs in 2013 – a decline of about 7% per year! That is the equivalent of the UK losing the human population of a city the size of Brighton, Leicester or Cardiff every year!
Egyptian vulture (Neophron percnopterus) by Béotien Lambda
Disappearing from regions and countries
During this period, Egyptian Vultures not only declined in numbers, they also disappeared from entire regions and countries. The documented declines are however just the tail end of a decline that began many decades ago – before anybody tried to systematically count vultures. Egyptian Vultures no longer occur in the Ukraine, Romania, Croatia, Bosnia and Herzegovina, Montenegro, or Serbia, and the few remaining pairs in Greece and Albania are struggling to hold on.
Why are Egyptian Vultures in desperate trouble?
A large project in Bulgaria and Greece is currently trying to understand the causes of population declines. Because Egyptian Vultures migrate to Africa every year, they are exposed to a wide variety of threats both in Europe, along the flyway, and in Africa. Many birds get killed accidentally by consuming poisoned carcasses that were intended for other animals, by landing on poorly insulated power lines that electrocute birds, or by being shot for pleasure or market trade in Africa. Some progress has been made in the project, for example a dangerous power line in Sudan, which killed hundreds of vultures over decades, has recently been disconnected.
Calling for a ban of vulture killing drug in Europe
Despite conservationists working intensely to understand and reverse population declines of Egyptian Vultures, conditions are not necessarily improving: the EU has recently allowed a veterinary drug that his killed millions of vultures in India and Nepal (and has been banned in these countries!) to be used for cattle in Europe – despite repeated warnings by scientists. You can help vultures by telling the EU to ban this lethal drug and hopefully avoid yet another threat that will accelerate the decline of vulture populations in Europe.
How you can help:
Sign the Diclofenac petition