Starving on the fringes

Streaked in brown, female Hen Harriers look very different from pale grey males Ground nesting Hen Harriers are always vulnerable Harriers lay four to five eggs in late spring and raise chicks for up to 42 days. Nesting on the ground, they are, naturally, vulnerable to Foxes, and, less naturally, human predation. In Britain, our birds remain here year-round, moving from upland breeding sites to lowland saltmarshes or heathlands to winter. Harriers have declined across Europe – in countries from Finland to France – and degradation of vole-rich grasslands is the key cause. Outside of Britain, persecution is rarely a major issue. Starvation, as for most birds, is driving the continental decline. In the early years of the 19th Century, Hen Harriers had a patchy and localised distribution across southern England. By 1900, however, a startling change had taken place. The lowland population was largely wiped from Britain by habitat change, especially drainage, and harriers retreated to the uplands. But from the 1830s, written accounts detail the killing of harriers on a massive scale. From 1850 to 1854, as many as 351 harriers were killed in Ayrshire – giving some example of the onetime abundance of this moorland raptor, and, of course, the industrial scale of its removal. Where grouse hunters went, harriers vanished. This was ironic. Many observers, including the impartial BTO, make the point that the abundance of prime habitat, and Fox removal, on grouse moors can lead to excellent food supplies and nesting success for harriers. It would have taken so little for this to happen – but it didn’t. The harrier was clinically removed from Ayrshire – then from Britain. By 1900, harriers were effectively wiped out on the British mainland, persisting only on the Outer Hebrides, Orkney and Arran – outposts that would eventually recolonise Britain. Two World Wars later, the same abandonment of intensive land practices that led Snipe to surge back into southern England allowed harriers a reversal of fortunes. Between 1939 and 1970, Hen Harriers returned to recolonise large areas of Scotland, some areas of Wales and very small areas of the English uplands. Driven grouse shooting exists largely across northern England and southern and eastern Scotland. It does not occur on Shetland, Orkney, the Hebrides, much of Argyll and northern Highland or the Isle of Man, and is a much smaller concern in Wales. So harrier declines in these areas have other causes. Understanding this is not only useful for these populations. History has