Welcome to the latest news and updates from the Orkney Native Wildlife Project.
New to our blog and want to find out more about the project, how to volunteer with us, or have a question? Visit our Facebook page, our website or email us at stoatsightings@rspb.org.uk
Monitoring Orkney's native wildlife
A belated Happy New Year everyone! We hope you are enjoying nature's gifts as much as possible in these challenging times.
In our last issue, we introduced our monitoring programme, what it does, and why. This work surveying the Orkney wildlife expected to be affected by the threat posed by the invasive non-native stoat is huge and varied. In Snippet 95 we explained what we do each year to assess our native wildlife populations of the Orkney vole, skylarks, meadow pipits, curlew, lapwing, oystercatcher, redshank, and snipe.
It doesn’t stop there. We also analyse data with the valuable help of the Orkney Raptor Study Group (ORSG) and the RSPB Scotland.
The productivity of each species is determined by calculating the nest successes from the samples found during the breeding season. From that we estimate the overall number of species in an area to have a better idea of their population by area. By knowing what birds are in an area we are surveying, we can estimate their productivity. We consider a nest is successful if any of the clutches of eggs have hatched.
Seabirds - Fulmar, shag, kittiwake, guillemot and razorbill
Seabird productivity is monitored annually at four sites across Orkney Mainland by the RSPB Scotland staff and their enthusiastic volunteers.
At the end of the project, productivity will be compared between three periods; pre-stoat arrival, pre-eradication, and post-eradication. This will be compared with Fair Isle as it is a stoat-free island around 40 km northeast of Orkney with large, annually monitored seabird colonies. It is also where seabirds are likely to experience similar levels of food availability as found in Orkney.
The results from the 2019 season showed breeding success was higher than the long-term average for at least three seabird species – fulmar (pictured in flight copyright RSPB images), kittiwake, and guillemot.
Productivity has generally been poor in recent years, having declined before the arrival of stoats and mainly driven by a lack of food linked to climate change. Our continuing analysis will assess whether any local variation in productivity could be due to stoats, which potentially have access to some nesting ledges.
Hen harrier and short-eared owl
Orkney is famous for its landscape, its history, its culture, and its wildlife. Despite the combined land area of Orkney’s 70 islands accounting for less than one percent of the UK, these islands are home to nearly a fifth of the UK’s breeding hen harriers. We are extremely grateful to the ORSG and the RSPB Scotland, for kindly sharing their data with us from their own annual surveys of these species.
Hen Harrier in flight (RSPB images)
The majestic short-eared owl is very difficult to monitor and there is currently no standard method. Consequently, we will assess the short-eared owl population size through a combination of community sightings and because of the generosity of the ORSG, which kindly shares their survey data with us.
Anyone who spots a short-eared owl can record the information on the dedicated short-eared owls in Orkney FaceBook page.
Thanks to the community effort, 211 sightings were recorded in 2019, and these are extremely helpful to our study programme.
Red-throated diver (Gavia stellate)
The productivity of the elusive red-throated diver nests will be compared between three periods;
This will be from a sample of annually monitored red-throated diver nests. We use data provided by the RSPB Scotland surveyed at four of their reserves - two sites on Orkney Mainland, one in Hoy and one in Rousay. In 2019, 39 pairs were found, fledging 28 chicks.
Join us
Last month we mentioned we are advertising for seasonal research field workers for the project monitoring programme advertised online here. The closing date for applications is imminent, 18th January 2021, with interviews scheduled for early February.