[New post] Monitoring the not-so-common Common Crane in North East Scotland
NatureScot posted: " Today, we welcome back guest blogger and ace photographer Ron Macdonald, who takes us on an amazing visual and auditory journey following common cranes in North East Scotland, as he volunteers for RSPB to help monitor and understand this recovering speci" Scotland's Nature
Today, we welcome back guest blogger and ace photographer Ron Macdonald, who takes us on an amazing visual and auditory journey following common cranes in North East Scotland, as he volunteers for RSPB to help monitor and understand this recovering species.
In Scotland, the Eurasian Common crane was once a widespread and common species. As in most of western Europe, it became extinct by the 16th century. However, since the 1950s, the population has recovered and recolonised areas of the UK. The first recorded breeding of cranes in Scotland was in 2012, in North Aberdeenshire, where today the population is thought to be around a minimum of five to six breeding pairs and up to 20 non-breeding adults. It's hopefully on the cusp of a significant expansion in range and numbers.
So this is where I come in as a volunteer for the RSPB, monitoring crane numbers, distribution and behaviour in the NE of Scotland. I am part of a small team of half a dozen volunteers led by Hywel and Amanda. From early March through to the end of September/early October, we take it in turns to be on the look-out for cranes in the areas we know they use as breeding and feeding sites, using vantage points in the landscape to scour the fields. For such a large bird, you'd be surprised how difficult they can be to locate! For me, a crane-watching day usually lasts a morning or afternoon, using a pre-defined car route.
If you stay in your vehicle, cranes are approachable, but they're easily spooked if you approach on foot. It gives me the excuse, if I need any, to use my camera and long lens to capture as much of their daily lives as I can. So this blog is really a pot pourri of my observations on crane biology and behaviour, supplemented by images, sounds and videos undertaken during the 2021 breeding season.
Breeding pairs are the first to appear back in their breeding grounds in early March with the non-breeding birds arriving much later in spring or indeed summer. They favour recently sown or tilled fields where presumably the availability of invertebrates is high.
I'm struck how large the birds are, particularly the males, who when standing upright as they sometimes do as part of their display, are over four feet in height. There's something primeval in their appearance – maybe they're vaguely Pterodactyl in their flight silhouette or it's the intensity of their stare from their ruby red or amber eyes.
I spent a lot of time with one pair, P2, as they are known by our monitoring group, studying their behaviour before the female laid her eggs and started incubating . The female lost her previous mate in 2016 and for the remainder of the breeding season she could be heard calling, trying to attract a new mate.
She paired up with her current mate the following year. There are subtle differences in their appearance: she has ruby red eyes, is smaller and her grey plumage is slightly darker. Not surprisingly, I called her Ruby. The male has amber eyes which are striking when you see him close-up. He's appreciably taller than Ruby and yes, I called him Amber.
The pair spent a lot of time in a field that I think was in stubble and then harrowed and spread with manure in readiness for a new cereal crop. The birds fed mostly on earthworms, with occasional short flights to the nest site within an adjacent conifer plantation. This is the same site they used in previous years which contains a small flooded area. This period is termed the pre-settlement stage and usually lasts through March into early April before the breeding birds settle to lay eggs and the female begins to incubate.
The pair usually fed amongst a mixed flock of rooks and jackdaws, but it's easy to see who was boss around here with the cranes frequently scaring off the crows if they approached too close or appeared to have found a good feeding area.
Amber and Ruby soon became accustomed to the presence of my car and I was able to watch them within 20-25 metres, as shown in the photo below, when they drank from the water-filled trenches created by the farmer's tractor.
During the pre-settlement phase, displaying and dancing took place several times during the day. In the photo below, the male is adopting a tall stance, raising his head and neck and walking slowly and rigidly pointing to the sky. I've seen this also occur when another 'unknown' crane approaches a pair, almost as if it is a threat display.
The dancing varied from static wing flapping and co-ordinated jumping up and down to one bird, usually the male, running around the field - which seemed to impress the female no end! In the video below, it's the female who decides to pick up the remnant of a tuber and to peck it and throw it in the air, with the clearly impressed male looking on!
Come late spring, the P2 female disappeared to lay and incubate her clutch and I only ever saw the male feeding not far from the nest. It was not until late May that I came across young cranes, this time further north close to the nest site of another pair. This is the time when the young, and sometimes also the adults, are vulnerable to predation from the likes of foxes who have been recorded taking young cranes.
It was not until early mid-July that I once again came across the P2 pair that I had watched in March. I was surprised that they had two free-flying young feeding in a cut silage field. This was the most successful the pair had been in the four seasons they were together.
However, delight soon turned to concern when just a couple of weeks later, only the male and the two fledged young were observed. Something had happened to Ruby- maybe she had succumbed to predation? In previous years, Hywel had seen adults defending their young from foxes, so perhaps she had succumbed.
So fast forward to this March and around the middle of the month three cranes, two adults and an immature crane, were reported within the breeding territory of P2. Was it possible that Ruby had returned? In late March, I finally managed to catch up with the threesome and to photograph them. I think that's Amber on the left with his lighter plumage and of course his bright amber eyes? But who is the other adult bird? It also has amber eyes so it can't be Ruby. It's probably a new mate for Amber, plus one of his young from 2021.
Once the pair settle down to nest, they will no longer tolerate the young bird and it will likely join the wandering non-breeding flock of 15 -20 birds.
As I write, for the crane monitoring team, it's the start of another busy season trying to track the birds. We have two new volunteers on board who will concentrate searches of raised bog sites where either cranes have been seen on or have suitable habitat. Increasingly, the focus of conservation effort is restoring the degraded raised bogs in the area. If we get the habitat right and continue to have the support of the farming community, which is fully behind efforts to conserve the cranes, there's every chance that the crane population will increase and expand its range to other parts of Scotland.
My thanks to members of the Crane Monitoring team, particularly Amanda and Hywel for your support and allowing me the opportunity to contribute to the work of the project. Also, thanks to Howorth Hodgkinson for allowing me to use his recording of trumpeting cranes in the blog, and last but not least, to the Aberdeenshire farmers who allow us to monitor the cranes on their land.
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