Using Google Earth to plot Peregrine persecution

New research by the RSPB and the Northern England Raptor Forum has revealed the apparent extent of persecution of Peregrine Falcons that attempt to nest on England's grouse moors. The paper — "Linking nest histories, remotely sensed land data and wildlife crime records to explore the impact of grouse moor management on peregrine falcon populations" — is published in the international scientific journal Biological Conservation. The study used Google Earth to map the characteristic 'strip burning' that is typical of moorland managed for intensive grouse shooting. This map was then combined with nearly three decades of nest monitoring information that had been collected by teams of dedicated volunteer monitors from raptor groups across the north of England. Comparisons of the fortunes of Peregrine Falcons breeding on grouse moors with those breeding in other habitats in northern England revealed that breeding success for birds on grouse moors was half that of birds in other habitats. Only a third of nests on grouse moors produced young.

Dr Arjun Amar of the FitzPatrick Institute for Ornithology — formerly an RSPB scientist — is the paper's lead author. He said: "I was shocked at just how low the bird's breeding output was on grouse moors; they were significantly less likely to lay eggs or fledge young. The few birds that did lay eggs or fledge young on grouse moors did just as well as those breeding off grouse moors, which suggests that a shortage of food supplies can be ruled out of the equation."

Peregrine Falcon, undisclosed site, Powys (Photo: Mike Warburton)

In the 1950s and 1960s, the global population collapse of the Peregrine alerted the world to the long-term effects of pesticides such as DDT that built up in the food chain and caused the Peregrine to lay eggs with dangerously thin shells. Fortunately, the UK's Peregrine population recovered after these pesticides were withdrawn and ultimately banned. However, increases in Peregrine numbers have not been uniform, and their recovery has been particularly slow in some areas where intensive management for grouse shooting is the dominant land use. Red Grouse can form part of the Peregrine's diet, which has led to historical persecution of the Peregrine on grouse moors.

Although Peregrines have been fully protected by law since 1954, there have been numerous confirmed persecution incidents on land managed for grouse shooting over the years. The study looked at the distribution of confirmed and probable incidents of Peregrine persecution between 1990 and 2006 across the study areas in northern England. It found that these incidents occurred far more frequently on grouse moors than on other habitats, despite there being more pairs breeding away from grouse moors. The higher levels of breeding failure meant that Peregrine populations on grouse moors were not self-sustaining and regional extinction was only prevented by more productive birds nesting in sites away from grouse moors.

Paul Irving, chair of the Northern England Raptor Forum, added: "To people who visit and live in the uplands of northern England, the Peregrine should be a familiar bird in an iconic landscape. However, the guilty few deny the pleasure of many."

In recent years, Peregrines have started to breed in the centres of many cities, enabling more people than ever to experience the thrill of seeing these magnificent birds close up. Martin Harper added: "The fact that Peregrine Falcons are nesting in cities highlights the stark contrast between urban areas and areas of suitable habitat in the English uplands where the species is largely absent."

Peregrine Falcon, Rochdale, Greater Manchester (Photo: Ivan Ellison)

Last year, 134,000 people enjoyed seeing Peregrine Falcons with the RSPB's Date With Nature viewing scheme at 11 sites across England and Wales. Six of the sites were urban, including Manchester city centre, and five were rural, including Malham in the Yorkshire Dales. Martin Harper added: "The results of this study suggest that without the highly productive birds in other habitats, the Peregrine could go extinct on driven grouse moors. To me it is unacceptable that a few lawbreakers are removing a species which has lived in our uplands for thousands of years. The shooting industry has repeatedly assured us that the illegal killing of birds of prey is not tolerated on moors, and we hope they will be quick to act to improve prospects for Peregrines on upland shooting estates."

The RSPB launched its latest annual Birdcrime report on Thursday 3 November, which again highlighted the persecution of birds of prey, including Peregrines. The report identified a series of areas where Government needs to step up to address illegal persecution of birds of prey and secure the future of our raptors.