RSPB Conservation Scientist, Jonathan Groom, writes about fieldwork in the Perthshire hills. 4:00am starts, black grouse, hen harriers and more.
Native upland woodland expansion survey
Field work has its ups and downs. The 4:00am start so that I can be at my first survey point and ready to go at 06:00am is certainly a shock to the system. But not long after arriving at my survey site on one particular morning I was greeted by the amazing sight of three Black Grouse leks all happening simultaneously on the moorland outside my study plot. The sight of up to 20 stunning male grouse prancing and strutting with their amorous cooing calls punctuated by sharp ‘swishes’, echoing through the early morning air is one like no other. They were some distance away, as of course I did not want to disturb their display . Sadly, as much as I'd like to spend time watching them, I had surveying to do.
Two hours later and I was feeling the downside again - I had seen and heard little and this particular patch certainly seemed light on birds. Then all of a sudden I heard a sharp cry and turned to catch two large birds in my binoculars in flight over a distant hillside. It was a pair of Hen Harriers and the female was calling to the male! This is a bird that I hadn’t really expected to see here, let alone a pair of them. As the stunning pale grey male drifted out of sight over a ridge leaving the female briefly perched atop a young Scots Pine, I couldn’t help but punch the air. With a big smile on my face, I resumed my survey and finished off my last couple of hours with renewed vigour. The ups definitely more than make up for the downs!
So what am I doing up here in Highland Perthshire that gives me the opportunity for such incredible sightings? My study sites are all areas that have been used for replanting or regeneration of native woodland over the last 10-20 years under various Woodland Grant Schemes. Recent studies have shown that Black Grouse, a threatened species with a stronghold in Perthshire, prefer wooded areas that have yet to reach maturity so that there is a rich shrub layer providing food, nest sites and cover for them. Long running surveys of Black Grouse leks in Perthshire have also demonstrated an increase in numbers during the last few years, and we are interested in whether these increases are linked to the availability of these new native woodland plots. So my task is to collect data from these areas, which vary considerably in size, age and location, to assess the habitat structure and quality and to get an idea of what other breeding birds are using these plots. I will not be surveying the grouse directly, unless they happen to appear during one of my counts, as the annual lek counts are well covered by a dedicated local volunteer group.
I have been carrying out bird surveys for nearly two weeks now and despite the very changeable weather and late appearance of many of our summer migrant birds, it has been an interesting and often exciting experience. The plots have all been enclosed with deer fences to allow the young trees to survive and enable the shrub layer to regenerate without being grazed down by the large herds of Red Deer that roam the surrounding moorland (those pesky Roe Deer still seem to manage to get in somehow). The effect is clear – the heather is deep and thick and shrubs like Bilberry and Crowberry grow in deep, thick patches. It will be interesting to compare my habitat data to the areas outside the fenced woodland plots. It’s a little early to make any statements about the birdlife as I have another month and a half of surveys yet to do – but the grouse are certainly abundant and widespread and I have had regular Hen Harrier sightings from different areas. I am hoping for maybe a Short-eared Owl or a Merlin at some point and I am looking forward to the arrival of our summer visitors to see which species might use these plots –Blackcap and Redstart are newly arrived in the area so hopefully things are about to pick up! And its not just birds of course – I was lucky enough to come across this beautiful newly emerged Emperor Moth a few days ago.
And, like my fellow blogger, Nick, I have had my first adder sighting of this lovely female today on the 1st of May.
The early morning sunrises aren’t bad either!
Find out more about the native upland woodland expansion survey here.