2014 National Peregrine Survey: preliminary results show decline from grouse moors

2014 National Peregrine Survey

Bowland-Peregrines-in-nest

A ground nest containing 3 peregrine chicks in the Forest of Bowland 2009. This territory is one of at least 16 known to have been abandoned following persecution of raptors throughout this region.

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 undertaken 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.

peregrine-survey-2014-prelim-results-copy

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].

Below we have added an abstract from an important scientific paper  which has just been published on the status of breeding peregrines in NE Scotland: There are restrictions of publishing the full details contained within this paper, however  if anyone wishes to read the full paper you can either 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

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.

Here is the abstract text:

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:

Peregrines NE Scotland 2014_NERSG - Copy

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

Forest of Bowland Grouse Moors-Peregrine Population Crash in just the last 5 years.

Here in Northern England evidence collated by the North West Raptor Group has shown that peregrine numbers in this small moorland region of Lancashire in north west England have declined dramatically since 2010, a result of persecution.

peregrine dead embrio -1

One of three peregrine nests each found in the same season in Bowland containing dead embryos 

In 2009, twenty five Bowland peregrine territories were examined by licensed members of the NWRG. Seventeen territories were found occupied, 6 of these sites failed following the disappearance of eggs and chicks. A total of eleven territories were productive fledging twenty four young. This result was considered by the NWRG to have been a very poor breeding season.

This year (2015) only 6 breeding attempts were recorded in Bowland, only a single nesting pair was successful after one nest were found destroyed, adult birds disappeared and several clutches of eggs vanished. These figures graphically highlight the current trend of raptor persecution still taking place upon moorland in northern England where red grouse are shot. In the last 5 years no less than 16 peregrine territories formally establishing within the Forest of Bowland prior to 2009 have either been destroyed completely, rendering their future use impossible, or are currently known to have been abandoned.

Although the 2014 peregrine survey does show an increased population for peregrine numbers in England overall, this situation has been brought about by more peregrines establishing new territories inside our city centres or on a variety of man made structures away from grouse moors. A good example of this new trend has been the establishment of at least 25 territorial pairs of peregrines inside London well away from grouse moors. A figure which exceeds all the known occupied territories on grouse moors in the whole of the north west England. A shocking statistic.

Related Peregrine Article

The Final Solution – A peregrine holocaust looms on England’s northern uplands

 

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