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A future for the Hen Harrier in England?

A future for the Hen Harrier in England? 1 ♤

Introduction

The Hen Harrier breeds widely across Eurasia persecution. Once breeding locally on both and North America. About 800 pairs nest in upland and lowland heathlands, in wetlands the UK and Isle of Man, with most in Scotland. and on downlands and other rough grasslands However, the species’ current English range is a throughout the UK, nesting birds gradually fraction of that in historic times, with nearly all became restricted to Orkney during the early of the relatively few recent nesting attempts in decades of the twentieth century. Following the northern uplands. a considerable recovery in both range and numbers during and after the 1939-45 war, The species has an unfavourable conservation breeding birds returned to England in 1968. status in Europe, is a red-listed UK Bird of They have remained scarce breeders here, Conservation Concern and appears on however, despite the availability of much government’s section 41 list of priority species. apparently suitable habitat. It is also listed on Annex 1 of the EU Directive on the Conservation of Wild Birds (1979) and This report provides a summary of information Schedule 1 of the Wildlife and Countryside gathered during an intensive Hen Harrier Act (1981). Breeding Hen Harriers are interest Recovery Project carried out by Natural features of both the North Pennines and England and its predecessors between the Bowland Fells SPAs and several of their 2002 and 2008. We report on the numbers, constituent SSSIs, although they no longer distribution and breeding success of Hen regularly breed in the North Pennines SPA. Harriers in England during this period and information on the very different rates of The UK Hen Harrier population has long failure that are occurring outside of the species’ A future for the been adversely affected by habitat loss and core breeding sites. Hen Harrier in England? The Hen Harrier in the breeding season

The charismatic and spectacular Hen Harrier is a rare breeding bird in England. We provide a summary of the species’ recent status here and evidence that illegal Hen Harriers are birds of open landscapes, persecution continues to thwart the efforts of the conservation community to usually avoiding closed-canopy woodland, restore its former range and numbers. conurbations and high mountain tops. Within England they currently nest on the ground almost exclusively in mature heather. Breeding Summary activity generally commences with the appearance of adult males which prospect for Since 2002 Natural England’s Hen Harrier Recovery Project has monitored the numbers of potential nest sites and attempt to attract a breeding Hen Harriers in England. For the first time, new tracking technologies have been used to mate during spectacular aerial displays known monitor the fate of Hen Harriers during the non-breeding season. The key findings are: as sky-dances. The females normally lay four to six eggs between April and the end of May. The The English Hen Harrier population remains There is compelling evidence that chicks fledge some 28-38 days after hatching. perilously small, with no more than 23 persecution continues, both during and Both parents continue to provide food for nesting attempts in any one year in the following the breeding season. their dependent young. Pairs often breed period 2002-2008. Persecution continues to limit Hen Harrier semi-colonially and occasionally a male may Productivity from successful nests is high, recovery in England. mate with, and provide food for, more than but very few nesting attempts are successful one female. Hen Harriers feed mainly on birds on grouse moors. and rodents, especially voles, with the larger females tending to take larger prey.

2 A future for the Hen Harrier in EnglanEnglandd?? A future for the Hen Harrier in England? 3 Hen Harrier monitoring in England The numbers of Hen Harriers breeding in England 2002–2008 The data used in this report have been collated We take as evidence of a proven breeding from the following sources: attempt any of the following: Hen Harriers attempted to breed in England each year (Figure 1) varied between 10 attempts Natural England Hen Harrier Recovery Food pass between two adults in each of the seven breeding seasons in the in 2004 and 23 in both 2003 and 2007. There Project staff (a project officer and up to 4 Adult carrying prey period 2002-2008. We recorded a total of 127 was no significant overall trend in numbers field assistants) who have annually searched nesting attempts in the period, an average of with time. for Hen Harrier activity in areas with a recent Used nest or eggshells found 18.14 nesting attempts per year. The numbers history of occupancy. Nest with eggs Natural England Hen Harrier Recovery Nest with young Project volunteers. Recently fledged young Natural England and RSPB reserve staff who have reported Hen Harrier activity to HHRP Seven different causes of nest failure have staff for follow-up. been recorded, as described in Table 1. Figure 1: Nesting Hen Harriers in England 2002–2008 Licensed raptor enthusiasts and raptor study

groups. 90

80

Table 1: 70 Reasons for Hen Harrier breeding failure in England 2002–2008 60 Failure reason Definitions/qualifiers 50 Persecution (i) Bird or birds settle in an area and build a nest then leave the area/disappear or settle elsewhere 40

(ii) Nest built then destroyed, birds in area 30

(iii) Eggs/Chicks destroyed/removed 20

Fire Active nest sites burned 10 Weather Nests washed out, deserted nests, parents in area 0

Predation Tangible evidence of natural nest predation such as tooth/mandible marks in 2002 2003 2004 2005 2006 2007 2008 smashed eggs, dead chicks

Lack of Female not provisioned well by male, deserted eggs, lack of male sightings (food percentage of successful attempts from all attempts per year provisioning passes) female away from nest for long periods number of chicks fledged per year

Infertility Eggs fail to hatch despite full incubation and subsequent analysis results number of attempts per year

Unknown Instances where no hard evidence was found at an empty nest that was once active number of chicks fledged per successful nest per year

4 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 5 Figure 2: The distribution of Hen Harrier nesting Hen Harrier known breeding sites in England 2002–2008

attempts in England 2002–2008 Sites shown below from north to south 2002 – Kielder, Geltsdale, Yorkshire Dales, Bowland, Cornwall 2003 – Kielder, Geltsdale, Yorkshire Dales, Bowland, Goyt Valley, Wiltshire The 127 nesting attempts identified in the we refer to nesting attempts in Kielder Forest period were very unequally distributed (Northumberland), Ridsdale (Northumberland), 2004 – Bowland between 12 localities. We recorded just two Cheviots (Northumberland), Geltsdale RSPB 2005 – Geltsdale, Cumbria (unspecified), Northern Pennines, Yorkshire Dales, Bowland attempts in the lowlands; one on the Lizard reserve (Cumbria), Cumbria (unspecified), 2006 – Kielder, Ridsdale, Geltsdale, Cumbria (unspecified), Yorkshire Dales, Bowland, Upper peninsula in Cornwall and one on Salisbury Northern Pennines (County Durham), Yorkshire Derwent Valley* Plain in Wiltshire. The remaining 125 attempts Dales, Bowland Fells, Goyt Valley (Peak District), 2007 – Cheviots, Ridsdale, Cumbria (unspecified), Yorkshire Dales*, Bowland were all in the un-enclosed northern uplands. Upper Derwent Valley (Peak District), Wiltshire A remarkable two-thirds of all the upland and Cornwall. 2008 – Ridsdale, Cumbria (unspecified), Bowland, Upper Derwent Valley attempts (a total of 83 of the 125) were made in the Bowland Fells. The remaining 42 upland The Bowland Fells was the only area in which * supplementary fed due to missing male parent attempts took place in a total of 9 separate breeding attempts took place in all years: geographical areas widely spread along nesting attempts were identified in 6 areas the Pennines from the Goyt Valley in the away from the Bowland Fells in 2006, the Peak District in the south, to the Cheviots in maximum number of geographical areas Key Northumberland in the north (Figure 2). occupied in any one year, but attempts were 1–5 breeding attempts known from just three areas in 2008 and no 6–10 breeding attempts In order to avoid drawing undue attention to attempts were known outside of the Bowland nesting Hen Harriers, we refrain from making Fells in 2004. Neither the number of areas 11–15 breeding attempts reference to the exact locations of nest sites. occupied nor the range of the Hen Harrier However, in order to provide further insight overall has shown any tendency to increase into the distribution of Hen Harriers in England, over the period. 2002 2003

6 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 7 Figure 2 continued: Hen Harrier known breeding sites in England 2002–2008 2004 2005

2006 2007

The success of Hen Harrier nesting attempts in England 2002–2008

A total of 72 nesting attempts were successful was no evidence of a consistent pattern of in the period, just over half (56.69%) of the total change in breeding success over time. Whilst number of known attempts. The successful the productivity per successful nest compares 2008 pairs produced a total of 225 fledged young, favourably with that recorded elsewhere in the at a rate of 3.23 fledged chicks per successful UK, productivity overall is comparatively low attempt and 1.57 per attempt overall. There (Table 2).

Table 2: Key Hen Harrier productivity elsewhere in the UK 1–5 breeding attempts Productivity Author Year Place of study 6–10 breeding attempts Per successful nest Per attempt 11–15 breeding attempts Balfour, E. 1959 Orkney 2.4 1.58 Watson, D. 1977 Scotland (SW) moorland 3.1 1.2 Watson, D. 1977 Scotland (SW) forestry 2.6 2.1 Watson, D. 1977 Scotland (SW) combined 2.8 1.6 O’Donoghue, B. 2008 Ireland 2.5 1.63 Whitfield, P. 2008 Wales 3.3 1.85

8 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 9 It is evident from the table that relatively few away from the Bowland Fells, the birds which Variation in the success of Hen Harrier of the Hen Harrier nesting attempts on grouse did manage a successful attempt here raised moors were successful away from the Bowland more young per successful attempt than those nesting attempts by land use in Fells (26% compared to 55-65 % on the other in any other class. This strongly suggests that upland land classes). Notwithstanding the grouse moors provide good quality habitat for England 2002–2008 overall poor level of success on grouse moors those pairs which are successful.

The geographical distribution of nesting Away from the Bowland Fells, birds also breed attempts offers some scope for further on land managed as driven grouse shoots Table 3: exploration of the data concerning nesting as well as on other land. Table 2 provides a A summary of Hen Harrier breeding statistics by land class in England 2002–2008 success. Both of the lowland nesting attempts summary of the data by each of these five ‘land were successful, resulting in the production classes’. Away from the lowlands (with very Land Class Number Mean (SD) Number Number Number Mean (SD) Mean Mean of 4 fledged young from a nest in Cornwall few) and the land managed by United Utilities of number of (%) of (%) of of chicks number number number in 2002 and of 4 fledged young from a nest (with a majority), the numbers of nesting breeding breeding successful breeding fledged of chicks of chicks of chicks in Wiltshire in 2003. We have already seen attempts were distributed approximately attempts attempts breeding attempts fledged fledged fledged that the upland nesting attempts were very equally between the three other classes. per year attempts failed per year per per unevenly distributed, with a surprisingly large successful breeding number in the Bowland Fells. Interestingly, breeding attempt the attempts within this area were also very attempt unevenly distributed. Over three quarters (78.31%) of the nesting attempts here were on Bowland 65 9.28 (2.62) 42 (64.62) 23 (35.38) 128 18.29 (7.38) 3.04 1.96 an area of land owned and managed by a water Fells company, United Utilities. The remainder were United widely spread in the area but all were on land Utilities managed as driven grouse shoots. Bowland 18 2.57 (1.13) 10 (55.56) 8 (44.44) 22 2.85 (1.34) 2.20 1.22 Fells This highly skewed distribution of nesting grouse attempts might be taken to suggest that moors either there is something rather special (for Uplands 23 3.28 (2.21) 13 (56.52) 10 (43.48) 48 6.57 (5.16) 3.69 2.08 Hen Harriers, at least) about that part of the elsewhere: Bowland Fells managed by United Utilities or, non- grouse conversely, that the rest of England is far less moors suitable for nesting Hen Harriers. Note that the 1 2 land managed by United Utilities is only some Uplands 19 2.71 (2.28) 5 (26.32) 14 (73.68) 20 2.86 (2.97) 4.00 1.05 elsewhere: 10,500 ha: there is some 2.2 million ha (land grouse in Less Favoured Areas which closely follows moors the extent of the uplands (Backshall, Manley & Lowland 2 0.28 2 (100) 0 (0) 7 1 3.50 3.50 Rebane 2001)), which support exceedingly few nesting Hen Harriers. Totals 127 18.14 72 (56.69) 55 (43.3) 225 32.14 3.23 (0.79) 1.57 (0.51) (3.36) (6.99)

1 Includes nesting attempts where females were artificially fed following disappearance of male birds (presumed shot) and would have failed under normal circumstances. 2 Excluding juveniles fledged following artificial feeding.

10 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 11 The causes of Hen Harrier breeding The frequency with which Hen failure in England 2002–2008 Harriers disappeared whilst breeding

We identified the cause of failure in 45 of It is evident that the main causes of failure An unusual feature of some of the Hen Harrier killing Hen Harriers where the species’ ranges the 55 failed attempts. For convenience, we differ between land classes. Persecution breeding attempts was the disappearance overlap, but records of adult Hen Harriers have allocated each failure to one of seven accounted for the failure of nearly all failed of one, or occasionally both, of the adult being predated away from the nest are categories of cause (for definitions see Table 1), attempts on driven grouse moors away from birds. Considering the amount of persecution virtually non-existent and cannot account for with the largest three categories; persecution, the Bowland Fells. It was a much less important recorded overall, the proportion of persecution the frequency of disappearances in England, predation and unknown, respectively factor on grouse moors in the Bowland Fells incidents reported at nests was surprisingly not least because of the virtual absence of accounting for 29.1%, 23.6% and 18.1% of and on other moorlands and absent as a cause low, possibly reflecting the monitoring Golden Eagles from the country. Three radio- failures overall (Figure 3). of failure on land managed by United Utilities. presence. However, we noted that the number tracked juvenile Hen Harriers were assumed By contrast, failures due to predators were of birds that disappeared whilst foraging away to be predated in Northumberland when the relative high away from grouse moors. from these nests was high (Figure 4). carcasses were found near a Peregrine’s eyrie.

Lack of provisioning by an adult male Hen In the Bowland Fells, where Peregrines were Harrier has occasionally been recorded as a numerous, none of the 83 breeding attempts natural cause of breeding failure, especially recorded since 2002 failed as a result of Figure 3: where an adult male has more than one nesting disappearing adult Hen Harriers. Furthermore, Proportional reasons for Hen Harrier nest failures in different land classes in female and is infrequently attendant upon Peregrines were absent from some of the England 2002–2008 (n55) one of them. We have thus only recorded areas where Hen Harriers were recorded the disappearance of an adult as a cause of disappearing whilst breeding. A pair of Eagle nest failure when we are sure that the male is Owls in the Bowland Fells, the only known pair 100% not attending to more than one female. Our in the vicinity of Hen Harrier nests, predated observations on the number and regularity of an adult Hen Harrier in 2007. Neither of these 90% food passes made by males which disappeared instances resulted in breeding failure. often allowed us to confirm that they were 80% able to exploit a plentiful food supply and The only other avian predator capable of 70% made regular visits to the nest which stopped killing a Hen Harrier foraging away from the abruptly with no further sightings. We nest is a Goshawk. This species was present 60% conclude that in these cases, the disappearing in the same area of the Peak District within male Hen Harriers were dead. which Hen Harriers disappeared in 2006, yet 50% the Goshawks were also disappearing with The only natural cause of death in a healthy proven evidence that these birds were being 40% adult Hen Harrier is predation by another persecuted. predator. Golden Eagles have been noted 30%

20%

10%

0% All land classes (n55) United Utilities (n23) Bowland grouse Other moors (n10) Grouse moors moors (n8) outside Bowland (n14)

Fire Persecution Unknown Predation Lack of provisioning Weather Infertile

12 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 13 Figure 4: The % of breeding attempts failing as a result of adult Hen Harriers disappearing, by land class The Hen Harrier in England outside the breeding season

70%

Hen Harriers which breed in continental distances. We have, for example, found birds 60% Europe are largely migratory, moving hundreds of kilometres from their breeding southwards and westwards to winter in grounds, on mainland Europe, in Ireland and in areas where weather and prey availability Denmark. These individuals have proved to be 50% allows them to hunt efficiently. Many over exceptional, however, and a majority remain winter in England, frequenting agricultural much closer to home. land, downland, lowland heathland, raised 40% mires, reed swamps, grazing marshes and The general pattern is that during the first saltmarshes, particularly in the south and east few months after fledging, virtually all the 30% of the country. individuals monitored, including those which go on to make a long-distance movement, The preliminary results from our own remain in the vicinity of their breeding areas. 20% intensive study of the movements made by Some move away from their breeding areas in 106 English-born Hen Harriers, each of which November, but the great majority remain in the has been fitted with a radio or a satellite northern uplands of England all winter, before 10% transmitter, indicates that some individuals, a return to their breeding areas in spring. like their continental counterparts, travel large

0% Bowland Fells Bowland Fells Uplands elsewhere: Uplands elsewhere: Lowland United Utilities grouse moors non-grouse moors grouse moors

14 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 15 Population spread The nature of confirmed and suspected persecution incidents Although virtually all recent Hen Harrier nesting Hen Harriers, in common with many other attempts in England have been in the uplands, bird species, are also site faithful and tend to involving Hen Harriers in England the species is not, in fact, an obligate upland return to the area in which they were born or bird. We have seen that birds have nested close to it to breed themselves. Such behaviour successfully in lowland England and we know is unlikely to facilitate rapid colonisation of they were widespread here in the past. They areas away from the existing heartland. We During the course of our on the ground about their ultimate fate. We have, for instance, also nest in lowland areas across continental believe that the re-colonisation of England monitoring work, we have operated exclusively been looking into the disappearance of six Hen Europe. However, whilst our breeding birds will be a gradual process, if persecution on public land or on private land with the Harriers at an autumn roost known to us in produce insufficient recruits to populate even ceases, with nesting densities first increasing permission of owners. the northern uplands. The anecdotal evidence the moorlands adjacent to the current breeding in the existing heartlands, followed by slow of deliberate persecution given to us in areas and whilst they continue to be killed both expansion into neighbouring moorlands We have nevertheless found direct evidence confidence by a local land manager correlates within and away from protected areas, the where the habitat is similar. Eventually, some that Hen Harriers have been persecuted. In with the information provided by the last prospects of a return to lowland haunts looks individuals may break the mould and nest in three incidents nests had been destroyed by known location of a number of birds that were distant indeed. other habitats and/or at some distance from illegal burning and we have come across two being radio-tracked by project staff. the current area of importance. more where nests of eggs had been removed. In other incidents territorial Hen Harriers In the same way, a number of birds, including disappeared during breeding attempts, six birds fitted with satellite transmitters have 12 of which have been under suspicious been tracked from the Bowland Fells into parts circumstances. of the North Pennines managed principally Table 4: as driven grouse moors, and have not been Hen Harrier nesting densities in key upland areas In other instances we have observed masked recorded subsequently. and/or armed individuals in the vicinity of nest and roost sites and recorded activities likely Site Average number pairs Area (ha)3 Hen Harrier density (km2 per nest) to disturb birds at or near their nests. We have (2002–2008) also come across eight instances where other birds of prey have been shot, poisoned or Bowland 11.86 16,002 13.5 disappeared on sites where Hen Harriers have South Pennines 0.71 20,937 293.1 been observed.

North Pennines 2.43 147,246 606.3 We believe that we underestimate the numbers of these incidents because many others both in the remote uplands and the under-watched lowlands will go undetected.

Our studies of the movements of satellite- tagged birds are continuing, as they are yielding much useful information on the movements, habitat use, and ecology of Hen Harriers. But they are also raising questions Young female fitted with transmitter

3 Figures based on size of equivalent Special Protection Areas

16 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 17 ♤

References

Amar, A. & Redpath, S.M. 2002. Determining Picozzi, N. 1978. Dispersion, breeding and prey the cause of the hen harrier decline on the of the hen harrier Circus cyaneus in Glen Dye, Orkney Islands: an experimental test of two Kincardineshire. Ibis 120: 498–509. hypotheses. Anim. Conserv. 5: 21–28. Potts, G.R. 1998. Global dispersion of nesting Amar, A., Redpath, S.M. & Thirgood, S.J. 2003. Hen Harriers Circus cyaneus; implications for Evidence for food limitation in the declining grouse moors in the UK. Ibis 140: 76–88. hen harrier population on the Orkney Islands, Scotland. Biol. Conserv. 111: 377–384. Redpath, S.M. & Thirgood, S.J. 1997. Birds of Prey and Red Grouse. Stationery Office, Backshall, J., Manley, J. and Rebane, M. (eds.). London. 2001. The Upland Management Handbook. . English Nature, Peterborough. Redpath, S.M. 1991. The impact of hen harriers on red grouse breeding success. J. Appl. Ecol. Balfour, E. 1962. The nest and eggs of the hen 28: 659–671. harrier in Orkney, Bird Notes 30: 69–73. Sim, I.M.W., Dillon, I.A., Eaton, M.A, Etheridge, Female with chick Brown, A., Grice, P. and Nurney, D. 2005. Birds B.,Lindley, P., Riley, H., Saunders, R., Sharpe, C. in England. Poyser, London. & Tickner, M. (2007). Status of the hen harrier Circus cyaneus in the UK and the Isle of Man in Etheridge, B., Summers, R.W. & Green, 2004, and a comparison with the 1988/89 and R.E. 1997. The effects of illegal killing and 1998 surveys. Bird Study 54, 256–267. The future of the Hen Harrier as a destruction of nests by humans on the population dynamics of the Hen Harrier Circus Stott, M. 1998. Hen harrier breeding success breeding bird in England cyaneus in Scotland. J. Appl. Ecol. 34: 1081–1105. on English grouse moors. British Birds 91 (3): 107–108. Holmes, J., Walker, D., Davies, P. & Carter, I. 2000. The Illegal Persecution of Raptors in Watson, D. 1977. The Hen Harrier. Poyser, Of all birds of prey, the Hen Harrier is the most to be a widespread activity both in this and in England. Research Report No. 343. English Berkhamsted. heavily persecuted in relation to population neighbouring countries, the prospects for the Nature, Peterborough. size in the UK. The significance of persecution Hen Harrier’s return to its former range and Whitfield, D. P., Fielding, A. H. and Whitehead, for Hen Harrier populations is well-established: numbers unaided are slight. Madders, M. 2000. Habitat selection and S. 2008. Long-term increase in the fecundity of populations in Scotland have been proven foraging success of Hen Harriers Circus hen harriers in Wales is explained by reduced to be limited by persecution (Redpath & Our studies of the critically small English Hen cyaneus in west Scotland. Bird Study 47: 32–40. human interference and warmer weather. Thirgood 1997); and models suggest that in the Harrier population will continue and we will Animal Conservation (in prep.). absence of persecution, numbers in Scotland redouble our efforts to help the police stamp Newton, I. 1979. Population ecology of raptors. would rapidly recover (Etheridge et al. 1997). out illegal persecution. We intend to reveal Poyser, London. Potts (1998) estimated that in the absence of both the true beauty and the plight of The Hen persecution the English uplands would support Harrier to a much wider audience in an attempt O’Donoghue, B. In prep. PhD Thesis. University 232 territorial females. to encourage more land managers to place a College Cork. greater value on Hen Harriers live than dead. Whilst evidence of persecution is irrefutable, We will also be examining the feasibility of it should be noted there is no proof linking re-introducing Hen Harriers to the lowland part incidents to particular individuals, as proven of their former range, but public attitudes and by the lack of successful prosecutions. This likely levels of illegal killing here will be critical in no way diminishes the effect of criminality. in making our decisions. We believe that whilst illegal killing continues

18 A future for the Hen Harrier in England? A future for the Hen Harrier in England? 19 Cover and page 9 photographs: © R. Saunders Page 17 photograph: © Professor W. G. Hale Page 18 photograph: © Phil Curtis All other photographs: © Natural England/Stephen Murphy

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