Ancient rocks 

I was up on Arkle last week, a mountain in the the north-west Highlands. This is a land of complex geology and marvellous landforms. The hill is topped by 500 million year old quartzite, laid down in shallow seas. 

Now it is 250m above sea level and forms a hard stony surface, breaking down into screes and coarse nutrient-poor soils - a desert like place.

Few plants can gain hold and find a niche to live on these wind-scoured tops, but here a single bud of Thrift comes into bloom amongst the sharp rocks.

Water has collected on part of the lower plateau forming a lochan which shines blue in the white landscape, due to the nutrient poor water and few plants or animal life that can live in it.

5000 UP


There have now been over 5000 visitors to this blog. It is actually much more but the counter was down for a while.

Thanks to all who have shared.

Stuart

Dead eagle chick

While checking golden eagle breeding success this week Derek Spencer (above) and I found this dead chick in one eyrie. It had died when about three days old, which would perhaps fit with how long it could live off the nutrients held its yolk sac post hatching. Had it died due to insufficient food being brought to it by its parents, or was it a sickly bird from hatch? The body will be analysed for clues to what happened. The chick's head and feet had been eaten, by an adult bird, or some scavenger? 

Several of the eagle nests we checked were empty. There has been a prolonged period of cold, snowy, northerly winds this spring and perhaps this has caused some birds to abandon their breeding attempts for this year. 

Ptarmigan nest sites

Rock Ptarmigan in Scotland usually nest close to boulders, which probably reduces the risk of detection by predators as their cryptically patterned plumage merges well with the colour and form of the lichen-covered rock. It was wet, in low cloud yesterday and this bird's back was covered with pearls of moisture.   

There are few human artifacts in the ptarmigan habitat of the high ground in the Highlands, but one such is the erection of snow-fences at the ski-resorts. And these decay over the years. I have known several ptarmigan nests to be placed near these, presumably for shelter from predators, but possibly also from wind, rain and snow. There are two such nests in my study area this year.One is at the base of an upright but partially broken fence.

Another nest was placed under a section of fallen fence. Both birds sat still, confiding in their camouflage for protection.

Golden Eagle paper

A scientific paper of which I am a co-author has been accepted for publication by the journal Ornis Fennica.

Adam Watson, Stuart Rae & Sandy Payne: Mirrored sequences of colonisation and abandonment by pairs of Golden Eagles Aquila chrysaetos.

As the summary states:
'We report colonisation by extra breeding pairs of Golden Eagles Aquila chrysaetos, and
subsequent abandonments, in part of northeast Scotland during 1895–1985. The number
of pairs rose from three in 1895–1937 to eight by 1948, and then fell to four during 1959–
71 in reverse of the colonisation sequence. This fits the concept of hierarchic quality of
habitat used, or of bird quality. Possible mechanisms to explain this are discussed.'


This is now available for view in the online early page of their website: http://www.ornisfennica.org/ornisfennica.org/early.htm