13 - 21 September 2021

Not the most imaginative title for a post, I'll admit, but this one encompasses several topics, including the mysterious deaths of many seabirds on the north and east coasts of the UK and a day spent surveying for signs of Orkney Voles, as well as also featuring a day's birding in Deerness and several ambles around the bay at Houton.

Let's begin with the strange case of the auk 'wreck'. Every Winter, usually after a severe storm in the North Sea, many dead seabirds (often juveniles) wash up on the east and north coasts of the UK. It's depressingly normal, but it's nature, and something that the species involved cope with by their breeding strategies. Recently, many auks have been seen inshore at a time when they're expected to be out in the North Sea. These birds seem to have come back to the coast looking for food, and they have been weirdly confiding, a sure sign that all is not well. Many of them have died and been washed up on beaches. Without a North Sea storm as the source of the problem, scientists have been puzzling over what the cause could be: bird flu; poisoning from an algal bloom; lack of food due to either climate change or overfishing, or something else?

A couple of surveys of local beaches confirmed what was being seen elsewhere. On the 13th, a dead Guillemot was found washed up in Orphir Bay, with another moribund individual seen offshore. On the 17th, in Houton Bay, we counted about fifty Guillemots and Razorbills feeding close to shore, as well as four dead Guillemots washed up on the tideline.

Bird flu has now been discounted as the cause, but research is continuing to find the real reason behind the loss of so many seabirds.

Guillemot

Guillemots and Razorbills feeding (plus a Long-tailed Duck)

On the 18th, the day was spent birding around Deerness in East Mainland, although strangely most of my photographs were of insects. In the shelter of an abandoned quarry, Red Admiral butterflies were nectaring on various flowering shrubs, and I found the bizarre-looking caterpillar of a Pebble Prominent moth on a willow. Also seen at this site was a new moth species for me, a Redline Quaker.

Red Admiral

Caterpillar of a Pebble Prominent moth

Redline Quaker

Flies congregating on 'fruit'

In the willows behind the dunes of Sandside Bay, several more moth caterpillars were seen.

Ruby Tiger caterpillar

View south along the coast

Early instar of a Garden Tiger caterpillar

At another plantation, again on willows, another Poplar Hawk-moth caterpillar was spied. I seem to be getting my eye in!

Poplar Hawk-moth caterpillar

A few nights later, an amble around Houton bay at dusk allowed some time to play with camera settings. Admittedly, a small hand-held compact was never going to produce amazing results, but here's the best of a bad bunch, showing the piers, an almost full moon and Jupiter (top right).

The next day, walking the same route whilst it was still light, gave a splendid view of a family of Stonechats. Though only a short distance from home, we think these are a different set of birds to the ones which frequent our garden.

Dad, Mum and two of three youngsters

And finally, on the 21st, it was our second monitoring session of the year for the Orkney Native Wildlife Project, surveying for signs of Orkney Voles. Two transects were walked, each a kilometre (and not, you may note, 0.8 miles) long, with twenty five sample points along each transect. At each sample point, we looked for evidence of vole activity in the form of runs, grass clippings or vole poo. Now, even without the deleterious effects of a non-native invasive predator, vole numbers can differ wildly year to year, so it is not possible to draw any conclusions from a single session. However, that said, this was our most 'productive' monitoring day by a long chalk (if I can use that phrase on an island dominated by Old Red Sandstone), with prodigious amounts of poo discovered. Anecdotally, 2021 has also been a good year for the voles' natural predator, the Short-eared Owl, which makes sense from an ecological point of view.

Vole poo, yay!

A group of Twite seemed quite interested in what we were up to

Our office for the day

Lunchtime view, and yes, we did wash our hands very carefully

Through the day, we had plentiful sightings of Hen Harriers, quartering the land or occasionally being mobbed by Hooded Crows, although we suspect it was probably repeated views of two birds. And as it is Autumn, there were small flocks of Golden Plover present too, which are always a delight to see and hear.