I remember that, shortly after the Hawk and Owl reserve at Sculthorpe Moor had been opened, Roger Clarke, who was our Scientific Officer and accountant, made an appeal for volunteers to help monitor Hen Harriers that were roosting on Roydon Common from October through to March, Roger organised a meeting in an upstairs room in a nearby pub and gave us a lecture on Hen Harriers at roost sites. He told us that most of the birds we’d see would be “ringtails” which were either immature males or females or adult females. If we were lucky we might see a beautiful silver-grey cock Hen Harrier.
It was about three o’clock when we arrived at the common. Roger led us to a good “watch point” and, binoculars poised, we settled down to wait. There was plenty of time for a good look round. We were sitting on a hill looking out over the common which was enclosed by silver birch on the east side and by a mixture of silver birch and conifers to the south. There was a copse to the north where we had parked. It was open behind us. The common itself was largely covered by heather. In the centre was a damp, paler area dominated by molinia grass and sphagnum moss. There were one or two stands of gorse. The whole area was dotted with silver birch seedlings.
Roger directed us to watch the skyline above the silver birch to the east. That’s the area from which the harriers would appear. Sure enough, about ten minutes later, a “ringtail” appeared and started flying to and fro along the tree line checking that the roost was safe. In no time at all it was joined by four others. Re-assured, one by one, the harriers dropped down to fly backwards and forwards, lower and lower, over the pale damp area. The light was dying but one could still follow the action.
Now and then, a harrier would drop into its familiar roost site in the sphagnum moss. Once there was a commotion as a harrier dropped into a site already occupied. Both birds sprang in the air. There was a bit of a kerfuffle before the offender, probably a newcomer, went off to settle elsewhere.
Hen Harrier sketch by Bruce Pearson from a photograph taken by Andy Thompson
That was the first of many visits to Roydon. Nigel Middleton and I decided to revive Roger Clarke’s call for volunteers to watch Hen Harriers at their winter roost sites. At the end of January 2016 Nigel, Neil Chadwick and I went on a roost watch. It was a perfect day for watching, gin clear. We were in position by 3 p.m. and at about 3.30 the first “ringtail” appeared. It flew low S-N up the reserve, passed very close to us. It was in perfect condition, crisp chocolate-brown plumage with a pure white splodge at the base of its tail. There was no doubt that it was an adult female. It flew up and down before pitching in to land in the damp area.
Three other “ringtails” dropped in. Their arrival put up the original “ringtail” and there was some flying up and down, checking everything out, before they all dropped into their usual roosting spots.
Finally, about a quarter of an hour later, two silver-grey cock birds broke the skyline at the south end of the common. As they dropped down they showed up well against the conifers. One of them was a full adult, the other a sub-adult, still with dirty brown patches on his wing coverts. It had been a superb afternoon’s watching.
Another visit at the end of March drew a blank. The warden at Roydon told us that the middle of March was the last time she’d seen a Hen Harrier. Any birds destined to breed in the UK would have left at the beginning of the month. The majority of the birds roosting at Roydon, those that delayed their departure until later in March, would be Scandinavian birds waiting for warmer weather to set in on their traditional breeding grounds in the sub- arctic.
The sketch of the Hen Harrier is by Bruce Pearson from a photograph taken by Andy Thompson.