What a great idea! Forget the persecution of your species and head to where the grass is green or better still full of voles! First of all you have to find these areas and how do you do that? Fly around looking for tell tale signs. Follow other harriers, Kestrels or Short eared Owls who hunt the voles as well? Nobody knows how they do it but Wendy has struck gold on Mull.
Wendy was born on a military site north of Glasgow and satellite tagged to follow her movements once she left the nesting area. Every year most tagged harriers end up dead on Red Grouse moors. The amazing thing is that by killing all the ground predators and birds of prey the vole population explodes encouraging wondering harriers and Short eared Owls to move onto these moors to catch voles not Red Grouse!
Sure harriers can catch Red Grouse especially females which are bigger than males but why waste time trying to catch such a big prey when lots of voles are running around in the day time and so easy to catch. Recent evidence shows large numbers of birds of prey being shot on these Red Grouse moors. Derek Ratcliffe in his book’ Galloway in the Borders’ showed a figure of 300 birds of prey killed in a year. These included Hen Harriers, Golden Eagles, Goshawks and many Short eared Owls. Pub talk in recent times showed a figure of 250 birds of prey on one Cumbria Red Grouse moor.
So keen are these shoots to pump up the Red Grouse numbers that even the sheep are dosed with a ‘tick’ killer on their backs to stop the ticks killing large numbers of Red Grouse. This tick insect uses blood to feed a female tick to produce large numbers of young and create a disease in the Red Grouse and sheep called ‘louping ill’. This chemical again helps the voles as they are prayed on by these ticks and in some years the ticks must reduce the population to low levels effecting the number of birds of prey that can feed on them. Recent work at The Langholm Project showed Short eared Owl dropping from 42 pairs to 0 in 2 years due to lack of voles but harriers changed their diet to birds changing from 12 females to 7 in 2 years.
Wendy so easily could have headed south or east to land on one of these shooting estates but unlike other harriers moved north west over the water to Mull. Once settled she found an area of rewilding where 2000 sheep had been removed and a large number of Red Deer leaving the voles to be the main grazer. The area will have ticks but it seems so far, the voles are flourishing.
Rewilding is a big question these days as so many upland areas have been stripped of their trees and more natural vegetation. We know from Roman digs that even around Hadrian’s Wall that few heather areas were found by the lack of Red Grouse. Only 1 Red grouse has turned up in the area while Black Grouse were described ‘ as common as chicken bones in the digs’! Black grouse need a different habitat to Red Grouse and are not reliant on heather as are Red Grouse. So rewilding could add many more species then our present uplands often offer.
One area of rewilding has seen a surge in breeding Hen Harriers. This can only be good for the species with so many birds being killed around Britain by shooting estates. It is suggested that with Brexit and a trade deal with New Zealand and Australia that the home market will be flooded with sheep products making the prospect of sales of sheep products here under server pressure. This in turn could lead to more areas of rewilding in our uplands helping the population of Hen Harriers.
On a sunny February day with snow on most of the tops of Mull we stood for 2 ½ hours scanning the area where Wendy was living seeing several Golden and White tailed Eagles as well as Buzzards, Divers and a female harrier on the mainland. We had 2 sightings of the bird we thought was Wendy in the rewilding area and left with the feeling of utter jubilation that at least one of the satellite tracked harriers was doing well. Long may it last.
A New Year
February 4, 2019
Wildlife of Madeira and the Canary Islands by John Bowler