The latest Annual Bulletin of the Société Jersiaise includes a paper on the current status of the birds of Jersey’s north coast with details of trends in their populations over 30 years, 1985-2014.
The north coast of Jersey is one of the most important areas for birds on the Island and will be included in the Jersey Coastal National Park. The cliffs have traditionally held large numbers of breeding seabirds including iconic species like the Atlantic puffin and raptors like the peregrine. A wide variety of vegetation types on the upper slopes of the cliffs and marginal, mixed farmland on the cliff tops have been strongholds for many songbirds including stonechat, meadow pipit and linnet, birds typical of Jersey’s coastline and now found only rarely elsewhere on the Island. Jersey’s now extinct yellowhammer population was previously restricted to the north coast.
In recent years, however, changes in agricultural practices locally, notably the abandonment of many marginal cliff-top fields and encroachment by bracken, threats of widespread development and increase in leisure activities have led to growing concern for the Island’s coastline. Long-term monitoring of the bird populations is a powerful tool, showing in part what is happening to Jersey’s wildlife at the start of the 21st Century.
Jersey’s north coast cliff path runs from L’Étacq to Rozel. The majority of the path (typically from L’Étacq to Les Platons) was walked west to east on one day each year (typically during June) by Glyn Young and others. All birds of every species except herring and lesser black-backed gulls seen or heard at any distance either side of the path were recorded. The two gull species were not counted because, nesting on the cliffs, they are present at all times and difficult to count with this method. These gulls are, however, included in other Island-wide surveys.
There are many variables inherent in this methodology (date, weather on the day, onset or delay in spring etc. and even exact finishing point); however, the spread of 30 years data will exhibit robust trends in populations despite this.
A total of 87 bird species were recorded. While the number of species seen each year stays similar (at around 50 each year), the overall number of individual birds seen each year shows an alarming downward trend.
Gains and losses
The fluidity of the north coast’s bird fauna can be seen by changes in the species composition since 1985. Species recorded in at least 10 consecutive years from 1985 and not seen for more than five years until 2014 can be considered lost. Species that were first recorded since 1985 and seen in more than five consecutive years up to 2014 are considered gains.
The species gained (three diurnal raptors and a corvid) are typically those that have been persecuted, if not in Jersey, certainly elsewhere, and that have seen increases in continental and UK populations following statutory protection. In contrast the losses (three songbirds and a dove) are species likely to have declined through a more varied and often unclear combination of causes within and outside of Jersey including widespread habitat modification and loss, especially in farmland and marginal land, and global climate change. This is of concern as whereas simply protection may have helped restore populations of some, often high profile, species, we are seeing serious declines of formerly common species despite ongoing protection.
Jersey has nine breeding seabird species, of which seven nest on the north coast. Of these, six are threatened with extinction locally (see our Red List here). The north coast population of shag was described as very stable in 1996. It has proved quite the opposite since then with the causes of this decline not yet determined. In contrast, perhaps, the situation with Atlantic puffin was more expected with a longer history of decline. The razorbill, in contrast, remains scarce but may be relatively stable with less than 10 pairs. The great black-backed gull population fluctuates annually but is stable or increasing slightly while the colonisation by fulmar (it first nested in Jersey in 1974) appears to have ended: the 75-100 pairs reported in 1996 have not increased or spread from the north coast.
Numbers of diurnal raptors (here two unrelated groups, hawks and falcons) recorded on the north coast have increased dramatically since 1985. Only kestrel was recorded in 1985 with occasional sparrowhawk (now resident) and migratory hobby adding to the figures in the next few years. Peregrine was first recorded in 1994 but has been seen annually since it returned to Jersey to breed in 2000 after an absence of 42 years. Marsh harrier and common buzzard were first recorded in 2006 and 2012 respectively four and five years after each species was first recorded nesting in Jersey. The kestrel is the only raptor to have been recorded in every year of the survey and, while numbers recorded each year have fluctuated (from five to 22), the population appears fairly stable.
Pigeons and dove
Pigeons and doves (columbids)recorded on the north coast, have shown varied fortunes over the period of study. While only the feral population of rock dove (there are both naturalised, breeding, birds and those possibly still involved in a human activity (‘racing pigeons’) present) can be considered truly cliff nesters, the closely related stock dove and wood pigeon were recorded both on the cliffs and in the cliff-top fields. Two smaller species, the doves, turtle dove and collared dove, are birds of farmland, the latter typically in close association with human dwellings.
Rock dove appears to have a stable, although fluctuating, population whereas each of the other species has declined. Wood pigeon and stock dove are very common in other areas of the Island, seeming, in recent years, to simply shun the cliffs. Stock dove was considered (in 1996) to nest widely on the cliffs but now does so only rarely. While the decline of the turtle dove throughout Western Europe is mirrored in Jersey (it may now no longer breed on the Island) the decline of collared dove is more interesting. Collared doves are common in urban and sub-urban areas but increasingly scarce in farmland where the return of the predatory sparrowhawk and peregrine may have influenced their habitat choice. Similarly, the reduction in stock dove on the cliffs may have followed the return of the columbid-feeding peregrine, the doves choosing to nest inland in safer sites.
Meadow pipit and linnet are birds of the coast in Jersey, preferring too relatively undisturbed areas. These two species probably now breed predominantly on the north coast. Although the decline of the linnet is dramatic, the much reduced population does at least appear to have stabilised since 2005. Jersey’s breeding population of meadow pipit is not high but it too does appear fairly stable on the north coast. The stonechat is another species in steep decline locally with no more than five pairs breeding some years. It is likely that the north coast holds the majority of breeding pairs although even here the population fluctuates.
Two further species, starling and house sparrow are worthy of note. These two birds, formerly considered abundant in Jersey, have declined alarmingly on the north coast. Although both these species are often associated with human dwellings, at least when nesting, it is perhaps a sign of the state of the former farmland on the north coast that both species are doing so badly here.
It is very clear even from this single annual survey that the bird populations on Jersey’s north coast are not faring well. It is clear too that some species and some groups of species are faring particularly badly while some others are apparently stable or even increasing. Although the causes of the declines are not clear and complex, the rise of raptor numbers shows the benefit of widescale, targeted, species-based conservation initiatives while the decline of seabirds and those species dependent on farmland and marginal land shows larger, possibly even global, concerns that will be much harder to redress. Birds On The Edge aims to restore Jersey’s declining coastland birds and return those species now locally extinct.
I am very grateful to Roger Long and the Société Jersiaise for allowing use of the graphs in this piece.