Tag: peregrine

Following on from yesterday’s blog about the preliminary National Peregrine Survey results (see here), an important new scientific paper has just been published on the status of breeding peregrines in NE Scotland:

North East Scotland Raptor Study Group (2015). Peregrines in North-East Scotland in 2014 – further decline in the uplands. Scottish Birds 35(3): 202-206.

We’re not permitted to publish the full paper here, but we are able to publish extracts from it. To read the full paper you’ll either need to subscribe to Scottish Birds (published by the Scottish Ornithologists’ Club) or you can email the authors and ask if they’d be willing to provide a copy for personal use: nesrsg@gmail.com

Here is the abstract:

Peregrines in North-east Scotland were surveyed in 2014. Compared with previous studies there was an increase in coastal breeding Peregrines, but a decline in the uplands, trends persistent since 1991. Overall fewer Peregrines were recorded in 2014, but their breeding performance was relatively high. Low occupancy of nesting ranges, with more singletons than pairs, was associated with intensive management for driven grouse shooting. The results document a further decline in the Peregrine breeding population in the eastern Cairngorms National Park.

Here is the table of data:

And here is the discussion section:

The breeding population of Peregrines in the north-east of Scotland has been monitored in detail since 1975 with changes in both numbers and distribution well documented (summarised in Hardey 2011). Together with the earlier studies, the 2014 survey results suggest Peregrines in North-east Scotland have increased further on the coast and continued to decline in the uplands, particularly on intensively managed grouse moor where in 2014 only two pairs and four singletons were found.

Occupancy could be underestimated if not all alternative nesting sites are visited or if breeding attempts fail early and birds abandon the site. In 2014 this was unlikely because nesting ranges were well known, visits were not tardy, and most observers were both experienced and skilled using observations of faeces and prey remains as well as of birds. The survey’s key result involved fieldwork in areas that were easiest to search. Most nesting ranges on moorland were on relatively small rocks which were easily checked for both birds and prey remains. By comparison, birds on the coast were less easy to locate because of the continuous potential breeding habitat, including nesting sites that could not be viewed from above. That said, birds were often obvious as they perched high on sea cliff buttresses, with both droppings and plucked prey remains evident. The change in numbers on the coast might thus be complicated by birds obscurely shifting nest site, but the numbers inland are difficult to dispute. The decline of breeding Peregrines recorded in earlier studies is endorsed; in 2014 there were simply even fewer Peregrines to be found at traditional breeding places in the uplands, particularly on moorland managed for driven grouse shooting.

Both Hardey et al. (2003) and Banks et al. (2010) suggest the decline of breeding Peregrines on grouse moorland is the result of killing by game keepers in a sustained effort to reduce the numbers of grouse predators. It is difficult to argue otherwise. Amongst alternative explanations, for example, a reduction in Peregrine food supply is unlikely because Red Grouse Lagopus l. scotica (the main prey by weight) are superabundant on these intensively managed moors. Indeed, 2014 saw record-breaking grouse bags on many estates (www.shootinguk.co.uk/news/moorsreport-record-grouse-bags-6860). It is possible that some other aspect of management for grouse might be reducing the numbers of Peregrines, such as protracted muirburn or the persistent long term use of anthelminthic drugs (medicated grit), but such speculation lacks rational foundation; the most parsimonious explanation is that, as has been established for other birds of prey (Scottish Raptor Study Groups 1997, Whitfield et al. 2003, Fielding et al. 2011), Peregrines are killed on a broad scale and persistently, as newcomers repeatedly attempt to colonise untenanted breeding sites. Such killing reduces the chance of re-colonisation, and moreover reduces recruitment in nearby less intensively managed upland.

The history of the killing of Peregrines on grouse moors is well documented (Ratcliffe 1993, Hardey 2007) and the decline in breeding pairs since 1991 is well reported, initially published by Scottish Natural Heritage (Hardey et al. 2003) and several times since. Despite previous publication the results from 2014 show further decline. The context and scale of the decline is alone of major concern, but has further significance because the north-east of Scotland forms around 40% of the Cairngorms National Park designated in 2003, and currently claimed to be “a stronghold for Britain’s wildlife” (cairngorms.co.uk, accessed 13 May 2015). The eastern portion of the National Park has 53 known Peregrine nesting ranges and in 2014, 51 of these were visited, but only 17 were occupied, 12 by pairs and five by singletons. In 2014, the North-east Scotland portion of the park held less than a quarter of the number of Peregrines that bred in 1991.

END

This paper, like many before it, presents compelling evidence about the scale of illegal raptor persecution on driven grouse moors, and in this case, notably in the eastern portion of the Cairngorms National Park. We’ve blogged about this notorious raptor-killing hotspot several times before:

In May 2013 we blogged about the launch of ‘Cairngorms Nature‘ – an ambitious five-year action plan to ‘safeguard and enhance the outstanding nature in the Cairngorms National Park’. The proposals for raptor protection were unbelievable – see here.

In May 2014 the Convenor of the Cairngorms National Park Authority complained to the Environment Minister that continued raptor persecution in the area “threatens to undermine the reputation of the National Park as a high quality wildlife tourism destination” (see here). This resulted in a high-level meeting between the Env Minister and various landowners and their representative bodies in January 2015 – lots of talking and ‘partnership working’, natch – see here – but bugger all else.

Almost 45% of the Cairngorms National Park is covered by ‘managed moorland’. And just look at the damage that ‘management’ is causing. Inside a National Park for christ’s sake!

As an aside, on yesterday’s blog somebody asked whether peregrines prey on red grouse. Yes, they do. Below is a photo of a red grouse that was killed by a peregrine on a Scottish grouse moor. We watched the whole spectacular event. It’s what peregrines do and it’s why many grouse moor managers are doing their utmost to eradicate this species, as well as the hen harrier, golden eagle, and anything else with talons, a hooked beak, or sharp teeth that might affect the number of red grouse available to be shot by high-paying customers.

It’s time to ban driven grouse shooting. Please join over 22,000 other voices by signing this e-petition HERE.

Periodically there are synchronised national surveys for a number of raptor species in the UK, which help to build a picture of national and regional population trends. This year it was the national survey of breeding golden eagles, next year it will be hen harriers, and last year it was the peregrine.

The final results of the 2014 National Peregrine Survey are yet to be published – these things can take time, although we’d hope to see a publication in 2016. In the meantime, the project coordinator, Dr Mark Wilson (BTO Scotland) has written a short piece on the preliminary findings:

2014 National Peregrine Survey

The sixth UK breeding survey of Peregrine was carried out in 2014, providing a provisional estimate of 1480 pairs in the UK and Isle of Man. This initial figure indicates that the Peregrine population in the UK has remained largely stable since the last national survey in 2002. However, this overall stability belies marked variation in the trends of Peregrine populations in different parts of these survey areas over the past 12 years.

Peregrines are now distributed more widely and evenly than ever through the UK, due to decreases in Scotland, Wales and Isle of Man, and increases in England and Northern Ireland (see table). For the first time, the estimated number of breeding Peregrines in England is greater than that in Scotland, though these two countries still hold the majority of the UK’s Peregrines.

The country-level changes described above, together with regional trends in peregrine breeding numbers and territory occupancy, suggest that, broadly speaking, Peregrine numbers have decreased in upland areas, remaining stable or increasing in many lowland and coastal areas. The association of Peregrines with wild and remote places in the UK grows increasingly tenuous, as numbers nesting on traditional inland crags decline, and the numbers occupying lowland quarries and man-made structures continue to grow.

This ongoing redistribution of Peregrine numbers across Britain is probably being driven by multiple factors. Food supply is likely to be important; changes in numbers and availability of prey are likely to be having an effect in many areas. Illegal persecution continues to restrict numbers and productivity of breeding Peregrines in some regions, particularly where pigeon racing is practiced and where there is intensive management for red grouse shooting. In contrast, decreases in lowland persecution during the 20th century and the ban on organochlorines have had positive influences on numbers, and allowed Peregrines to expand into many areas where they were previously absent. But more work is needed, particularly on food supply and its role in limiting Peregrine numbers, in order to diagnose the cause of regional declines, and identify measures to halt or reverse them. [Mark Wilson, Research Ecologist, BTO Scotland].

END

So, not many surprises here. It’s been long-established that peregrines are routinely killed on many driven grouse moors but not so much in urban and coastal areas, where they’ve been doing well because, er, they generally aren’t poisoned, shot or trapped there, unless a dodgy pigeon racer happens to live nearby. These latest (preliminary) findings show it’s been business as usual on the grouse moors of northern England and Scotland.

The final sentence of Mark’s article is quite surprising though, and really should have been clarified. Food supply may be an issue for peregrines in some areas but it most definitely is not a limiting factor on driven grouse moors – those moors are heaving with red grouse! A brilliant paper written by Arjun Amar et al (2011 – we blogged about it here) showed pretty conclusively what was happening to peregrines on grouse moors in Northern England and it had absolutely nothing to do with lack of food and everything to do with illegal persecution.

Mark’s suggestion that ‘more research is needed to diagnose the cause of regional declines and identify measures to halt or reverse them’ may be true for some areas but not for areas that are managed as driven grouse moors. Extensive research, over many decades now, has shown exactly what the problem is and it’s high time it was addressed. Here’s the best way to address it – ban driven grouse shooting – please sign the petition here.

Tomorrow we’ll blog about another new paper, just published, that stemmed from the 2014 National Peregrine Survey. It’s about peregrine declines in North East Scotland, particularly in the Cairngorms National Park, and leaves no doubt that grouse moor management is central to the problem.

Peregrine photo by Steve Waterhouse