By Harriet Clark
The last few months at Sorel have been a busy time not only for the choughs, but also their neighbours; the resident flock of Manx Loaghtan sheep. The sheep play a vital role in the restoration of Jersey’s coastline, as their extensive grazing helps prevent the spread of invasive scrub and bracken, opening up areas for more sensitive plants to grow, which allows a mosaic of heathland vegetation to develop. The habitat created by the sheep supports a wider variety of wildlife, particularly specialist invertebrates and birds, and, therefore, helps restore biodiversity (see Grazing for background). The conservation grazing project is a partnership between The Reserve and the National Trust for Jersey.
Manx Loaghtan are extremely hardy sheep which thrive on coastal cliff tops, so are very well suited to their important job of grazing the area of coastline between Sorel and Devil’s Hole. They were introduced to the north coast by the National Trust for Jersey in 2008, and since then the flock has increased in number from 20 to 231, and the habitat where they are found has visibly improved, with bracken much less dominant in the areas they frequently trample.
The flock is managed by local shepherds Aaron le Couteur and Sam Hilton (CS Conservation), not forgetting of course their sheepdog Mist. Every day of the year the shepherds do a head count and visual health check of the entire flock; this can be a very time consuming job as the sheep are somewhat adventurous and are often found scrambling along the steep cliff sides or grazing at the very bottom of the cliffs close to the shore. The adult rams are kept off site for safety, except for the less boisterous wether “Buck” who acts as the flock guardian. Despite common thought, the number of horns is not an indication of sex, with both ewes and rams having 1, 2 or even 3 sets of horns.
The sheep breeding season begins in October, when the breeding ewes are taken from Sorel to the farm to meet the rams and, all going well, fall pregnant shortly after. The first and last months of pregnancy are very sensitive times, so the ewes are kept at the farm for monitoring, but in the interim the pregnant ewes often graze further ecologically important sites. After a five month gestation period lambing begins, with roughly half of the ewes giving birth to one lamb, and half to twins, which have a dark brown fleece that gradually lightens to a mousy brown. As with all sheep, Loaghtan ewes can occasionally have problems at lambing, so a few orphaned lambs were hand-reared by the shepherds this spring; an extremely intensive job as the lambs initially require 24-hour care and bottle feeding.
This year 121 lambs were raised, and after 3-4 months on the farm, they were moved up to Sorel with their mothers. Although the lush grassland of the farm may look ideal for the lambs, they are actually much better adapted to grazing on rough coastal scrub. Work for the shepherds doesn’t stop there though, as a couple of weeks later the ewes and lambs were rounded up for their vaccinations. After a just a few hours all 231 sheep were herded into the fenced off aviary field so that they could be checked and vaccinated, all the while observed by the choughs perched on the aviary roof, apparently quite interested in the spectacle!
Shearing is the next job, and the exact date depends on the weather conditions; Loaghtan wool is very high in lanolin wax, and in warm weather it becomes more viscous which makes shearing a much easier and faster job. The huge amount of wool produced is sold locally, creating extra revenue and reconnecting islanders with Jersey’s traditional knitting industry. Throughout the 16th-19th centuries the Island was an important exporter of knitted goods, so much so that the word “jersey”, describing a woollen sweater, is derived from the Island’s historical trade.
The final job for the shepherds during the busy summer period is weaning the lambs. When the lambs first arrived at Sorel in June they were still suckling, but once they reach over 12 weeks old they naturally begin the weaning process, ready for the ewes to be dried off. The lambs are, therefore, rounded up one more time and moved into aviary field for about two weeks, where they are out of sight of their mothers. Separating the sheep in this way allows the ewes’ milk to dry up and for them to put some weight back on, and the lambs to break the suckling habit in the least stressful way possible.
In addition to providing an extremely efficient habitat management service, the sheep also help produce essential feeding opportunities for the reintroduced choughs. Their grazing and trampling maintains short grass swards which the birds depend on for access to surface-active and soil invertebrates, and the sheep dung provides an important food source of beetle and fly larvae. Dung invertebrates might be particularly important for the choughs in spring and autumn when other insects are less abundant, or during dry periods when the ground is too hard for the birds to successfully probe into (see study by David McCracken here).
The maintenance of low intensity pastoralism is hugely important for the conservation of red-billed choughs throughout Europe, with several studies in the UK showing a significant relationship between sheep and chough populations.
Research on Ramsey Island, Bardsey and the Isle of Man (see IOM paper here) supports this link; in each case, reduced sheep grazing coincided with declines in the numbers of breeding choughs, and when grazing was resumed, the breeding chough populations began to recover. The choughs at Sorel certainly seem to show an affinity to the sheep, and can often be seen feeding in close proximity to the grazing sheep.
Please, therefore, respect the sheep and the important service they provide to our wildlife when visiting the area, and remember if you have a dog, to always keep it under control.
