A hen ptarmigan sits on her nest, quite relaxed - confident but watchful |
I have been surveying rock ptarmigan on the hilltops in the far north-west of the Scottish Highlands over the past few weeks and they are now incubating their eggs. The eggs will take about three weeks to hatch, so the birds have to select their nest sites carefully if they are to gain shelter from the type of wild wind and rain they have had to endure recently.
I found this hen ptarmigan soon after finding her mate, who was about a hundred metres uphill watching over her. As I approached him, he flew off then landed about two hundred metres away, giving a brief croaking alarm to the hen. I knew by his behaviour that he would have a hen on a nest somewhere nearby. Although there was a seemingly endless choice of places where she could have been hiding, with years of experience, I took a look over the area and checked what I considered the most likely place where she might be. It helps to think like a ptarmigan and reason why a bird would choose what features to nest near. And there she was, quietly sitting on her nest as I approached, relying on her camouflage to conceal her in the the short vegetation, which was only about seven centimetres tall.
She was nesting in the short Arctic-alpine heath on the summit plateau of a hill |
Unlike red grouse, a closely related species which hide and nest in or under the taller heather on the lower moorland, ptarmigan live successfully on the short Arctic-alpine heath which is seldom tall enough for them to hide beneath. They rely heavily on boulders or exposed bedrock for shelter and concealment. Their plumage colouring matches both the heath plants and the lichen-covered rock. Rock ptarmigan are never far from rock of some kind, hence their name.
She had placed her nest close into the lee of a large boulder |
I hadn't taken my main camera or lenses with me that day as I had to walk over twenty kilometres of wet heath and bog, climb the hill, and walk into a strong wind. So I only took the binoculars and telescope, and my mobile phone, which was all I had to photograph the ptarmigan with. No problem though, as I always talk to any ptarmigan I approach, for what predator talks to their prey before pouncing on them? I sat down slowly and gently a few metres from her and began to chat. Initially, she had been holding her head low and I could see her breathing deeply. Then, after a minute or so, she had accepted me, lifted her head and began breathing more slowly. I inched towards her and took a few shots, explaining what I was doing all the time and telling her how much I appreciated her life on the high tops. I don't think she understood a word I said, but there was some form of understanding between us and I am sure that she was confident all the while that if I approached too close, she could jump off and fly away unharmed. If any animal uses camouflage for concealment, it needs to be confident in its effectiveness, and evolution needs to have honed the animal's cryptic colouring to perfection. I think this applied to that ptarmigan as a few hundred metres away there was a large cliff and half-way down that cliff there was a pair of golden eagles with a hungry chick. I left the ptarmigan and wished her luck.
From an eagle's eye-view,she was well concealed, as her cryptic plumage matched the colours of the heath |
Beautiful bird. Lovely story.
ReplyDeleteThanks, they are wonderful. I have paper in the current issue of Bird Study on ptarmigan nest placement.See attached link:
ReplyDeletehttp://www.tandfonline.com/doi/full/10.1080/00063657.2015.1006163
or follow the link in publications page of my website:
http://sites.stuartrae.com/publications