Sea Eagle Management Scheme - Summary Report on Enhanced Shepherding 2021

Published: 2022

Report prepared by: Andrew Kent, NatureScot Sea Eagle Management Team

Introduction

The purpose of this summary report is to provide an overview of the work delivered in 2021 under the enhanced shepherding measure, supported by the Sea Eagle Management Scheme (SEMS).  In 2021, eight holdings across Argyll and Skye delivered enhanced shepherding and background information on this collaborative measure is available on the NatureScot website.

Five of the holdings participating in this measure in 2021 also participated in 2020 and this report sets out some of the key findings from the eight participating holdings and includes feedback and suggestions from those delivering and co-ordinating the measure.

Overview of participating holdings

The eight holdings delivering this work in 2021 all comprise significant areas of extensive open hill, with ewes lambed either on the hill, or ewes and lambs turned out there shortly after lambing indoors, in-bye or in hill parks. For the purposes of this report, two farms in Argyll are considered as one larger unit, Farms A, with the labour involved in this work shared.

Table 1 below provides an overview of the extent of the participating holdings, the flock size and the lambing locations of each in 2021. Figure 1 below provides an overview of some of the areas of the holdings in Argyll and Skye where shepherds delivered this work in 2021.

Table 1: Overview of holdings participating in enhanced shepherding in 2021

Holding	Holding Size (ha)	Flock Numbers	Lambing location
Farms A	1620 ha	916 breeding ewes and gimmers	In-bye and hill parks
SSC A	1338 ha	1077 breeding ewes and gimmers	Hill
Farm B	1283 ha	787 breeding ewes and gimmers	In-bye and hill
SSC B	1800 ha	811 breeding ewes and gimmers	Indoor, hill parks and hill
Farm C	800 ha	550 breeding ewes and gimmers	In-bye and hill
Farm D	400 ha	450 breeding ewes and gimmers	In-bye
Farm E	4600 ha	1145 breeding ewes and gimmers	In-bye and hill

 

Whilst the individual management systems on each of these areas are not identical, all of the participating holdings comprise traditional hefted flocks, which rely on the recruitment of suitable replacement stock from within the flock.  The majority of holdings have been involved in the SEMS for a number of years and have reported ongoing predation of lambs from white-tailed eagles (WTEs).

The levels of reported loss from WTE on each of these areas and in individual years differs. However, all have reported that the presence of WTE has resulted in additional lamb losses, over and above expected levels.  This is having a negative impact on the availability of replacement stock, which each of these holdings rely on.

In 2021, the SEMS supported twelve shepherds to gather more detailed information on WTE interactions with sheep flocks on these holdings as well as trying to provide a scaring element through their presence on the hill.  A summary of the key findings from these holdings in 2021 is detailed in section four.

Weather

Unlike in 2020, when weather conditions during lambing were very favourable, the weather at lambing in 2021 was more challenging.  May 2021 in western Scotland was cooler than average with the mean temperature for the month 1.2°C below the long-term average.  There were more frosts than average, but below average rainfall in the west (MetOffice, 2021).  On SSC B, there were some hill lamb losses to exposure reported because of the cold start to May. Vegetation growth on the hills and in-bye across many areas was limited due to the unseasonably cold weather. This is evident in Figure 2 below, with this photograph taken on the 3rd of May 2021 showing the limited growth on the hill on Farm B. Because of the unseasonably cold conditions, supplementary feeding of ewes had to be extended across the holdings delivering enhanced shepherding.    

After the cold start to spring, the weather improved during summer, providing good grass growing conditions that continued into early autumn. 

Those delivering enhanced shepherding recorded visibility and general weather conditions each day.  The highest number of days where work was not possible due to poor visibility and/or weather conditions on the hill was seven at Farm B.  

Key findings

WTE Activity

Shepherds delivering the measure recorded observations of WTE on their holdings and where possible, recorded information on the age class of birds observed, whether they were alone or part of a group and any behaviours of note or interactions with their flocks. 

In 2021, there were 291 observations of WTE recorded across the participating holdings.   The highest number of observations were again recorded at SSC A (108) followed by Farm B (89).  The observations at Farm B included those recorded by NatureScot’s observer team, who were supporting the enhanced shepherding work here and at Farms A. The number of recorded observations at the remaining holdings ranged between 6 and 37.

In May alone at SSC A, the shepherd there recorded 56 observations of WTE, which is higher than the total observations recorded at five of the other participating holdings in 2021. As in 2020, the majority of observations recorded were of juvenile or sub-adult WTE (154).

A key aim of the enhanced shepherding work was to determine whether the shepherd’s presence on the hill acted as a deterrent to WTE interaction with the flock. 

In 2021, at SSC A, as in 2020, the shepherd there recorded occasions where his presence could be considered as deterring further WTE interaction with the flock.  On the afternoon of the 3rd of June, the shepherd observed from a distance, a group of four immature WTE harassing a group of sheep and lambs, which stopped when he arrived in the area that this was occurring.  On the morning of 17th June, the shepherd observed similar WTE behaviour from a distance, this time a group of seven immature birds observed diving low over sheep along the cliff tops. This again stopped when the shepherd arrived in the area. There were also a couple of occasions at Farms A in Argyll where the presence of one of the shepherds on the hill there seemed to alter the direction of travel of WTE. 

At Farm C, it was felt that the presence of the additional shepherd there was very useful and combined with the additional presence of walkers on the Farm post Covid; this greatly helped to reduce the predation levels in comparison to previous seasons.  Farm C also employed the use of two bird scarers on their in-bye ground and this combined with the enhanced shepherding work, could have resulted in fewer WTE observations and levels of lamb predation on the Farm.  

However, shepherds at all holdings delivering the work in 2021 did not record this potential scaring effect and influence on WTE activity levels. At SSC B, one shepherd observed predation of lambs by adult WTE in one of the hill parks, with WTE there reluctant to move away from the area until shepherds were very close.  This is in contrast to the feedback from SSC B in 2020, where shepherds reported that the enhanced shepherding work helped to reduce lamb losses, with less WTE activity also reported. 

At Farm B, where enhanced shepherding did not seem to have the desired effect in 2020, there was an additional 379 hours of observation from NatureScot’s observer team across the season to support the work of the shepherd there. Initially this additional support seemed to have the desired effect, with feedback from the shepherd at Farm B that lambing early on appeared good, predominately on the area where observers were present, indicating this possibly made a difference in this area. However, by marking time, the numbers of lambs present did not reflect this early observation, with 249 lambs expected from scanning results not present at marking.

Other predator and prey species

Shepherds recorded other potential predators of lambs and their signs when delivering this measure as well as recording observations of other potential WTE prey species. Across the participating holdings, shepherds recorded observations of foxes, golden eagle, ravens, hooded crows and great black-backed gulls, with records of known losses to foxes kept for some of the holdings. Fox control is practiced at all of the participating holdings, with the majority of holdings also controlling hooded crows to mitigate predation of lambs from these species.

As well as being predators of lambs - corvids, gulls and foxes are all potential prey species for WTE.  Other potential prey species observed and recorded on one or more of the participating holdings included rabbits, red grouse, black grouse, duck and wader sp., red deer calves and roe deer kids.  The total number of observations of each of these potential WTE prey species varied between holdings.  At two holdings, rabbits, which were historically present, are now absent and shepherds at Farms A, Farm B and SSC A have all previously commented that natural prey species abundance on the hill has decreased over time. As referenced in the 2020 report, this factor could be influencing reported levels of WTE predation on these holdings. 

Lamb predation signs

As in 2020, shepherds recorded any lamb carcasses and possible signs of predation observed on the hill and where possible, photographed these sites. In 2021, across the holdings delivering this work, there were 124 sites recorded where lamb remains were present.  The largest number of recorded lamb remains were at Farms A, one of two holdings that had additional support from the NatureScot observer team, who also recorded this information.  Between April and July, there were 45 sites recorded at Farms A where lamb remains were present. At the remaining participating holdings, the number of recorded sites where lamb remains were present varied from zero to 21.

The remains found at each of the 124 sites differed. At some sites, a whole carcass was present and at others, only part of the carcass was present, with evidence of predation and/or scavenging in some cases.  At some sites, only legs, tail, fragments of bone or areas of plucked wool were recorded, with no other material present.  This made it difficult to establish the cause of lamb mortality.

In 2021, there were 18 sites recorded where the cause of lamb mortality was reported as not due to predation.  The suspected cause of lamb mortality at each of these sites varied, with some losses reported due to exposure, because of the cold snap in May and others due to asphyxiation during labour, misadventure, or miss mothering.

At the majority of sites, a suggestion of the cause of lamb mortality was not recorded by shepherds, often due to the lack of remains found at sites, or their state at the time of finding. 

In 2021, there were direct observations of WTE predating lambs at SSC B. On the 26th of April, one of the shepherds at SSC B observed an adult WTE predating the lamb photographed in Figure 4 below.  This incident took place in one of the hill parks at SSC B, where there were further observations of adult WTE predation of lambs in 2021.

One of the shepherds at SSC B recorded a few occasions of observing a ewe beginning to lamb but by the time he arrived to assist, an adult WTE had taken the lamb. Initially these observations were restricted to one of the hill parks where ewes were lambing. 

In an attempt to mitigate the issue ewes in this area were moved to another park however, the problems persisted.  Shepherds at SSC B frequently observed adult WTE perching close to these areas, with WTE reluctant to move off until shepherds were very close.  The shepherd at SSC A also observed perching by WTE in areas close to newborn lambs, although the two sub-adult birds observed on this occasion seemed to move away more readily due to the shepherd’s presence.

Interaction between predators and lambs at SSC B, who lamb their flock across a combination of sheds, hill parks and hill, was not restricted to the hill parks. On the morning of 26^th April, one of the shepherding team found the lamb photographed in Figure 5 below on one of the hill hefts.

The shepherd disturbed a golden eagle from feeding on the lamb photographed in Figure 5 above, which had sustained injuries to the top of the head.  The shepherd also observed a WTE overhead the carcass and it was not possible to say which species had inflicted the injuries visible on the lamb.

The shepherd at Farm B also recorded an observation of a golden eagle attending a lamb carcass. On the morning of 29th April, the shepherd there observed a golden eagle attempting to take off with a lamb or part of a lamb carcass, with the eagle eventually flying off in the direction of the nest site on this holding with the remains of the lamb. It was not possible to determine whether predation or scavenging of this lamb had taken place.

Shepherds at three holdings, Farms A, B and C, all recorded observations of WTE leaving lamb carcasses.  The condition of these carcasses varied, but in the cases of Farms A and Farm B, some of these showed signs of predation, in the form of fresh blood, which are shown in Figures 6 and 7 below:

One of the shepherds at Farms A had observed the lamb photographed in Figure 6 alive on the evening of the 1^st of May, but on his return to this area of the hill forty five minutes later, an adult WTE was observed lifting from this lamb, flying to a nearby tree, before heading further away on to a knoll.  There was fresh blood found at the side of the lamb, which would have been three weeks old at most based on the lambing start date at Farms A in 2021.

The shepherd at Farm B photographed the lamb in Figure 7 above after finding this carcass on the morning of 7^th May. The shepherd observed a juvenile WTE leaving this carcass when he approached, with fresh blood evident and scattered plucked wool in the area immediately surrounding the carcass. Based on the timing of lambing at Farm B, this lamb would be at most, three weeks old too.

At some lamb remains sites, it was possible to identify signs that pointed to predation and/or scavenging by other predators, such as foxes and corvids. Examples of these are detailed in Figure 8 below:

The images of the lambs in the top left and bottom of Figure 8 above, recorded on Farms A were examined by one of the NatureScot call off contractor team with experience in considering potential predation injuries. In both cases, there was likely fox involvement, with the image in the bottom of Figure 8 confirmed as likely fox predation. In addition to likely fox involvement in the image in the top left of Figure 8, there was also raven involvement with birds observed leaving the carcass. It was not possible to identify the cause of death of this lamb, with large parts of the lamb, including the internal organs missing.

The lamb in the top right of Figure 8 was found and photographed on SSC B’s hill ground and showed signs typically associated with corvid damage with the eye area targeted. There was fresh blood present around the eye area and abdomen, indicating a potential predation incident. Although the injuries to the eye are typically associated with corvid predation or scavenging, it was not possible to identify what other predators could have been present at this carcass in addition to corvids. 

At other recorded sites in 2021, only plucked wool was present. Examples of these sites that shepherds at Farms A recorded and photographed are detailed in Figure 9 below:

One of the shepherds at Farms A recorded the image in the top left of Figure 9 on the 26th of May in one of the hill parks, with only two lamb’s legs found along with the large area of plucked wool.  Another shepherd at Farms A recorded the top right image of Figure 9 on the 17th of May.  There were no bones or other remains found at this site, with only the large area of wool and attached skin found.

The two images on the bottom row of Figure 9 were recorded on the 12th of June in another hill park at Farms A, with the image on the left showing a closer angle of the wool which was also photographed from a distance and shown in the bottom right image of Figure 9.  Blue marker spray was evident on this wool, as can be seen in the bottom left image, indicating that this lamb was born in-bye and there was blood staining in the wool, which is evident in this same image.  The shepherd also found a few WTE down feathers at this same site.

Levels of lamb loss in 2021

One of the requirements of the enhanced shepherding measure is the completion of an end of season report that gathers information on key aspects of the lambing season. One of the aspects of the end of season report is the collation of 2021 lambing data from those Farms and SSCs who participated.  Table 2 below provides a summary of lambing performance and losses between key stages in 2021 across the holdings delivering enhanced shepherding:

Table 2: Lambing Performance and Loss Levels on Enhanced Shepherding Areas in 2021

Holding	Expected lambs from scanning	Lambs present at marking (% age loss scanning -marking)	Lambs weaned (% age loss marking – weaning)
Farms A	908 ¹	657 (27.6%)	671 ²
SSC A	N/A	928	842 (9.2%)
Farm B	717	487 (32%)	458 (5.9%)
SSC B	844	603 (28.5%)	550 (8.7%)
Farm C	N/A	455	436 (4.1%)
Farm D	N/A	549	539 (1.8%)
Farm E	N/A	929	806 (13.2%)

¹ There were 39 ewes missed at the scanning gather at Farms A which are not included in this figure.
² There were ewes and lambs missed at the marking gather hence why the lambs weaned figure is higher than the number of lambs present at marking.

Pregnancy scanning provides an indicative figure of lambs expected to give birth and whilst it cannot be definitively said how many lambs of the expected lambs were born at those holdings who scan, in the absence of actual counts, it provides a useful indication.  From Table 2 it is clear that lamb losses on both Farm B and SSC B were significantly higher in the scanning to marking period than the marking to weaning period.  This is to be expected, given that lambs in the period from birth to marking are more susceptible to the range of factors affecting loss. 

At SSC B, end of season feedback from shepherds reported the colder weather as an influencing factor in the increase in percentage losses observed in the scanning to weaning period between 2020 (32%) and 2021 (34.8%).

There was also an increase in WTE activity observed at SSC B in 2021 compared to 2020, with an increase in activity adjacent to hill park areas during lambing. Shepherds observed WTE predating lambs in 2021 - something not observed in the previous year.  This could be another factor influencing the increase in percentage losses observed between 2020 and 2021.

The levels of lamb loss between marking and weaning at SSC B in 2020 (9.1%) and 2021 (8.7%) are very similar, despite the weather at lambing being considerably different in each year.  This demonstrates that despite the different starts to life, the majority of lambs that survive the pre-marking period will go on to thrive. 

Understanding the causes of lamb loss in the marking-weaning period, when lambs are stronger and more mobile, could help to mitigate some of the percentage losses between scanning and marking and is perhaps easier to address, with lambs in the birth-marking period more vulnerable to a range of factors.

At Farm B, there was a reduction in the levels of loss observed between marking and weaning from 10.1% in 2020 to 5.9% in 2021. There was also a slight reduction in the losses recorded between scanning and marking from 35.2% in 2020 to 32% in 2021. This reduction in level of loss between years could be because of the presence of additional observers on the Farm supporting enhanced shepherding work; however, this is difficult to measure.

Despite the reduction in levels of lamb loss between 2020 and 2021, the losses observed at Farm B are still significantly above the levels expected and achieved by the Farm before the first observations of WTE over the Farm in 2013, with the Farm expecting on average lamb losses of 10-15%. Figures 10 below provides an overview of the numbers of lambs marked and weaned on Farms B between 2010 and 2021 and the equivalent percentage losses between marking and weaning during this same timeframe:

Figure 10 demonstrates the general decline in the number of lambs marked and weaned on Farm B from a high in 2011. The “Beast from the East” influenced the low point in 2018 within this timeframe and the recent upturn in the number of lambs marked and weaned could have been because of the additional presence on the ground, with shepherds and NatureScot observers working collaboratively.

The first year of WTE observations of the Farms (2013) coincides with a trebling in the percentage losses between marking and weaning evident in Figure 9, with the trend in increased lamb loss in this period continuing to a high of 22% in 2017.  The levels of loss observed on Farm B are not sustainable for a closed hill flock, reliant on replacements from within the flock, which are hefted to that ground. There are knock on effects from this level of loss, with changes to the flock age structure and the inability to sell ewe lambs or cast ewes.  NatureScot continues to work with Farm B to better understand the role of WTE in these losses and how these can be addressed going forward.

At Farm C, which was participating in the enhanced shepherding measure for the first time, the weaning percentage achieved in 2021 (79.3%), was the highest achieved in the period 2016-2021. The combination of enhanced shepherding, additional presence of walkers on the ground and use of scaring equipment were reported as factors in the reduction of overall losses and losses associated with predation by shepherds there. 

At Farm D, lambing takes place in-bye with a count of lambs recorded when ewes and lambs are turned out to the hill. In 2021, there were 17 lambs lost between turn out and weaning. There was some early WTE activity recorded in the pre-shepherding period; however, activity was much lower, in comparison to previous years when there was an active WTE territory adjacent to the Farm. In the years when WTE were nesting adjacent to the Farm’s hill ground, average lamb losses of 26 lambs were recorded in the period between turn out and weaning, with 45 lambs lost in 2018. Prior to WTE establishment in the area, average lamb losses were in the region of five lambs per year in the same turnout to weaning period. Farm D have reported that since the relocation of WTE from their nesting area immediately adjacent to the Farm, loss figures have started to return to a more acceptable and expected level.

At Farm E, levels of lamb loss recorded on the hill were highest in the area closest to the WTE nest adjacent to this holding, which failed in May due to poor weather.  There were frequent sightings of WTE in 2021, but unlike in previous years, there was no observed lamb attacks or signs of predation.  There were higher lamb losses on the hill in 2021 between clipping and weaning, however end of season reporting indicated that this could be partially attributed to higher levels of mortality associated with ticks.

At Farms A, the weaning percentage in 2021 was 69.8%, down from the 74.4% achieved in 2020. Feedback from shepherds at Farms A reported increased WTE activity in 2021, with shepherds feeling that additional WTE pairs were active over the Farm and predating lambs. Shepherds at Farms A indicated that the enhanced shepherding, delivered in collaboration with the NatureScot observer team, was useful and had this not been in place, losses might well have been greater.

Feedback and conclusions

The end of season reporting requirements for the enhanced shepherding work also provide an opportunity for participating shepherds to feedback their thoughts on the measure and areas for improvement.  In 2021, as in 2020 there was mixed feedback on the effectiveness of the measure and the feedback from Farms A below reflects on some of the logistical challenges of shepherding in a large area and also their feelings that WTE predation pressure on their flock increased in 2021:

“The Enhanced shepherding funding was very useful this season and helped fund the extra time (but did not cover it) involved. However, on our farm the extra time involved in having presence on all the hirsels to keep WTE’s away due to the geographic spread of hirsels would make it uneconomic to pay for unless it was fully funded by NatureScot.

If we did not have this extra payment for the enhanced shepherding the lamb losses would have been even greater. The birds have definitely adapted their habits from the start of the project but regardless of all the good work from observers and shepherds alike they continue to kill and this is not sustainable.

I feel that we have the local pair that are predating lambs but also other birds to the eastern parts of the farm potentially travelling, alongside another potential pair to the south, which would compound the issue.”

At Farms C and D, who both delivered the measure for the first time in 2021, feedback on the measure was positive:
 

“We feel the additional shepherding presence was very useful as well as the extra folk walking (post Covid). Both greatly helped to reduce the predation levels. We also employed the use of two bird scarers, which may have helped. We would consider this measure in future years should funding be available.”

“The enhanced shepherding was useful, as we feel more human activity on the hill parks was a deterrent to the bird. We would be interested in doing this again.”

At SSC B, where enhanced shepherding was not as effective in 2021 as in 2020, there were some wider benefits reported with SSC B engaging local community groups, schools and colleges in this work and discussion on this wildlife management conflict.

“We have been trying to involve more people from different backgrounds in the scheme and have had University Rural Skills students out for some VP surveying, as well as a High School crofting class and young person’s group.”

“By discussing the impact of WTE and the role of hill farming in crofting communities we hope to give a better picture of the rural landscape and the politics surrounding it. Folk better understand something if they are involved with it and can take part and have a say.”

Another wider benefit of the enhanced shepherding measure reported at SSC B is that it has helped to support rural local employment as highlighted in the feedback below:

“We are happy to be working with NatureScot again; being in the Sea Eagle Management Scheme gives extra funds that are put back into the local community employing folk close by to be out on the hill and better looking after the sheep. We are seeing this in the sales and endeavour to keep better figures and continually improve management.”

It is clear that on some holdings in 2021, enhanced shepherding had a positive impact in deterring WTE presence and potential predation of lambs. On others, this was not the case and work continues with shepherds on those holdings to adapt and explore other measures that might help to reduce levels of lamb loss and WTE interaction with flocks.

WTE predation of livestock is a complex wildlife management issue and in writing this report, the views and feedback of some farmers and crofters experiencing WTE predation have been reflected. 

NatureScot recognises the concern and seriousness of this issue to some farmers and crofters across parts of Scotland and continues to work closely with stakeholders at a local and national level to find solutions.

Acknowledgements

NatureScot acknowledges and thanks the shepherds, SSC clerks and farmers delivering and co-ordinating this work for their contributions and communication throughout and after the shepherding period. Thanks also go to the NatureScot call off contractors and observers for providing advice and assistance in the delivery of this work, including associated monitoring and liaison work.

Glossary

• Heft/Hirsel – An area of the hill where a flock of sheep graze and return to following gathers. Hefting is the sheep’s natural instinct to return to and use that area which it learns from its mother and is passed on through the generations.
• Hill Park – A fenced area of grazing on the hill, adjacent to a larger area of fenced or unfenced rough grazing. Hill parks are often the interface between the in-bye and open hill.
• In-bye – Enclosed improved fields that are often used for lambing or silage production.
• Marking – This usually takes place when lambs are 4-6 weeks old. The ewes and lambs will be gathered and marked so that ownership can be identified in areas where there are open marches with other holdings. Lambs will be earmarked to identify each individual in the flock with relevant flock treatments also applied at this time.
• Scanning – Ultra-sound scanning of ewes to determine pregnancy status that allows separation of the flock into different groups and areas and a calculation of the number of expected lambs. Scanning usually takes place in February or early March depending on the timing of lambing.
• Weaning – The separation of lambs from ewes. The flock is gathered usually in August or September and lambs will be separated and sorted, with individuals that are to be retained for future breeding identified.