Showing posts with label golden eagle. Show all posts
Showing posts with label golden eagle. Show all posts

Tuesday 19 July 2016

Honeysuckle Eyrie



The Golden Eagle breeding season is almost over, with most of the chicks fledging soon or having already left their nest. This one was jumping about and exploring its surroundings, taking very short flights between the nest and an adjacent ledge. It hadn't yet taken its first full flight a few days ago, but it might have done so by now as I write this.

This bird has been reared in one of my favourite eagle eyries, set below a deep overhang with a lush growth of honeysuckle which was in full bloom. How did the honeysuckle get there? Perhaps the eagles brought in sprigs to add to the eyrie and seeds came with them. The plant is certainly vigorous, probably a result of fertilisation from the droppings and prey remains in the eyrie.


This the first time I have seen a chick fledge from that nest since I first knew it in 1982. The birds have alternative nests on nearby cliffs and last year they raised a chick in one of those, which is very high and rather inaccessible. In the past, the birds' breeding efforts usually failed if they tried to nest on this relatively low and accessible crag. Disturbance was the most likely cause for their failure as they were usually successful if they nested on the big cliff. This territory is on ground once used for sheep rearing, and now that sheep numbers have been greatly reduced in that area and in the Highlands in general, there seems to be less disturbance.

There was a heavy mist when I checked the eyrie, some would call it rain, but the chick was well sheltered by the overhang. I was soaked through. The chick had a lovely big nest to play about in, and the view from the cliff is quite dramatic. What a wonderful eyrie to grow up in.



Thursday 16 June 2016

Eagle nests are large

A typical Golden Eagle eyrie site in Scotland
set on a broad vegetated ledge behind an old Rowan tree 
The golden eagle Aquila chrysaetos chicks are now large enough to ring and I visited this nest a few days ago with Adam Ritchie, a fellow eagle researcher. Simon Cherriman, a friend and another eagle researcher - mostly of wedge-tailed eagles in Australia - helped and gained experience of how things are done in Scotland.

The chick is about 30 cm long and 20 cm broad, so this is a deep wide eyrie 


It was good that Simon came to this eyrie, for as the two of us roped down to the nest I was reminded of the size of these nests. I don't always appreciate that when alone. But with another person on the nest the scale became clear. The nest was huge.

Simon measures the length of the chick's head and bill
there is room for two people and the chick on the nest 


The chick was ringed and measured within minutes, a minimal intrusion when the adult birds are often away from the nest for hours when the chicks are this age or older - this chick was about four weeks old. Although I am sure the adult birds would have been watching us from a distance all the time.

The trailing edge on the foreground of the nest is the birds' landing platform, they don't flop down
 onto the nest but glide and stall onto the lower edge, then walk up onto the platform.
It also shows how easily the birds can launch themselves out onto the air straight from the eyrie
- there is a lot of space below

Thursday 23 July 2015

Wild Assynt

The jagged ridge of Stac Pollaidh
While surveying birds in the Highlands, one the extra joys is the magnificent hillwalking that, well just has to be done in such stunning scenery.

Pillars abound in these sandstone hills
I was in the Assynt hills last week and grabbed the best day of the summer for a great walk over one of these relatively small hills. They might be small, but each hill in the area has its own particular character and they pack an amazing variety of landforms into this quiet corner of the north west Highlands.

Sgurr an Fhidhleir points high into the sky
There is so much to explore, around every corner or over every bluff that I don't need to describe where I went. It's all great fun. One of the best experiences in walking these hills is to discover their secrets for oneself. There are landscape-scale features such as the impressive peaks, but take time to look at the finer lines, the hills are covered with little details which mirror the grander features.

A golden eagle added its shadow to the landscape
Then to add cream to the scene; I was walking along a ridge, carefully watching my feet, when a shadow drew over my path. I knew straight away that there was an eagle above, what else could have cast such a shape. And sure enough, I looked up and there was an adult male eagle displaying in deep dives as it cruised along the updraught from the ridge.

The day was already one of my best in the hills this year, now it was probably the best.

Suilven in the evening light
I stayed in the hills til evening, watching the rocks change colour in the sinking west coast light, until I had to finally turn my back on them til next time.

As ever, the trick to any good day is to be there, be out there, do something, do anything, then every once in a while a special day comes.

A wild west sunset

Friday 17 July 2015

Golden Eagles Fledging

A Golden Eagle Aquila chrysaetos eyrie set in a large Scots Pine
It is now time for golden eagle chicks to leave their nests and I have been checking several sites to monitor their breeding success. The birds usually fledge in their tenth week, which is a long time for any bird to sit out as it slowly grows, filling in the hours, days and weeks watching the world go by between occasional feeds and long sleeps as it develops from a tiny downy chick to a sturdy eagle.

The adults began nesting in March, laid their eggs at the end of that month, incubated them for six weeks, and now will have to still provide food for the fledglings for a few months. So most of an adult golden eagle's year is filled by rearing young.

This eyrie was built in a multiple fork in the tree, a massive tree with a wide trunk and a magnificent spreading crown
- a true forest giant  
The fledglings' first flight can be a wobbly affair, and this bird will likely take a short one to a neighbouring tree branch. I was surprised that it hadn't taken that step as it was so well developed, but is was raining that day, so perhaps it was waiting for the best flight conditions for that important stage of life. Other birds I have checked lately have left the nest, one twin had gone off around a corner and was nearly a kilometre away from the nest, yet it's sibling was still in the nest - but testing its wings with big strong thrusts and hopping about the nest.

There will be young eagles jumping from trees and cliffs all over the Highlands this week, what a thought, but they will have testing times ahead.

This eyrie was a few metres wide and although the bird is fully grown size-wise, it can be distinguished as a chick by the bright yellow cere and base to its bill. Adults have less bright bills, they are more generally grey-coloured.

Sunday 27 July 2014

Scottish summer summary

Walking over the tops - ptarmigan and dotterel habitat

It's now late July and I am back at the desk after my annual working tour of Scotland. Time to catch up with write ups and organise photographs. This was a quiet season for me as I had pinched a nerve in my spine in January and the sciatica is still hurting, curtailing any climbing, running and jumping. Fortunately a friend, Simon Cherriman, from Western Australia was also over in Scotland while I was there so we teamed up and I showed him around a few places and some of the special wildlife that abounds in such a small country.

While up on the high ground looking for ptarmigan we came across this Mountain Leveret

First of all we went and surveyed my long-term study site up in the hills for Ptarmigan. Their numbers vary between years following a cyclic pattern, and this year their numbers were low with only three pairs in the core area. But there were numerous Mountain Hares which was a welcome surprise. For these animals are being relentlessly killed on some estates managed for red grouse shooting in the belief that they carry parasite and act as a vector for disease in grouse, leading to fewer grouse to shoot. Such a selfish attitude at the cost of these animals which the majority of people visiting the Highlands in search of wildlife would so much like to see.

These three leverets were hiding in one form,
unusual behaviour as the mother usually leaves them in separate forms for safety 

A visit to the bird cliffs is always a tremendous experience
 - Simon rather enjoyed himself

Our next day passed quickly when we went to the sea-cliffs. The smell of guano mixed with the scent of Thrift had to be smelt to be appreciated, so so, different from anything else. 2014 was a splendid year for blossom of all sorts, but for now I'll concentrate on the animals. That day was definitely for the birds, thousands all around us and we must have fired off thousands of shots between us trying to capture the perfect shot of the birds in flight.

A Fulmar cruising past, most shots were out of focus, out of frame or wrongly exposed - hundreds of them


Simon adds colour-rings to a Redshank chick with Raymond Duncan

We spent most of our time based in the north-east and much of the field time ringing wader chicks with members of the Grampian Ringing Group, mainly with my brother Skitts, Ewan Weston and Raymond Duncan. Simon is a trainee ringer/bander in Australia, but has no experience of ringing wader chicks, or any other chicks for that matter. So he gained full-on intensive training from some of the most experienced bird ringers, not only in Scotland but the world.

A colour-ringed Lapwing chick

One of the jobs I had to do was find and fit Greenshank with geolocators as part of a study of their migration being organised by the Highland Ringing group. So we spent a couple of weeks in the far north doing that with Nick Christian and Brian Etheridge. That wasn't all we did there though, as there were so many other birds around us in that stunning landscape, but that has been covered in previous posts. And it would take too long to tell here.

Simon photographing newly hatched Greenshank chicks

The same Greenshank chicks

We ringed various birds during our travels, and as it was springtime most were chicks. They ranged from tiny Willow Warbler nestlings, Redstarts, Skylarks, Meadow Pipits, Pied wagtails, Common and Black-headed Gulls, Kestrels and Common Buzzards, etc. One rather different brood we ringed were Barn Owls which were in a nest in the roof space of an old ruined cottage. 

Simon checking the old cottage for the Barn Owl nest, and Jackdaws

There were five owlets squeezed between the ceiling and the roof

But it was when we had trees to climb that Simon earned his living. As I had hurt my back I was reluctant to climb some of the trees to reach various nests, but Simon is a superb tree-climber, probably the best I have seen. He had timed his trip to Scotland perfectly. I helped him and he helped me - all happy.

Predator in his natural habitat
 - a similarity noted by Mick Marquiss as Simon skipped up a tree
 so like the film character with his dreadlocks and camouflaged gear

Simon, like all of us who climb these trees, really enjoyed the thrill
 and atmosphere of climbing ancient Scots Pines

We helped Skitts and Ewan ring Golden Eagle chicks at various nest sites which they monitor annually. Ewan and Simon would climb the trees, lower the chicks in a bag down to the ground, where they were ringed and measured safely, then they we would pass them back up. Some of these nests are over a hundred years old, in trees that are several hundred if not thousands of years old. And some of these eyries are big, really big. Who wouldn't be impressed by such an experience.

Simon nears a Golden Eagle eyrie in the crown of a Scots Pine
- even he, at two metres tall was dwarfed by the eyrie

Simon studies Wedge-tailed Eagles in Western Australia, so he was perfectly at home and adept at handling the Golden Eaglets. Although they can be big strong birds and they can be in a potentially precarious setting, mixing tender careful handling with confidence ensured slick procedure.


Talking to eaglets always helps - it might not calm the the birds,
but it does calm the handler and helps the work go efficiently 

And that was what I did in Scotland 2014, well a little bit of it, there were also Arctic Terns, Golden Plover, Dunlin, Woodcock, Sparrowhawks and....  Thanks for all the help Simon.


Tuesday 10 June 2014

Ringing Golden Eagle chicks

Golden Eagle habitat in ancient pinewood of the eastern Highlands

As it is now the second week of June, the Golden Eagles chicks in Scotland are well grown, between three and five weeks old. So it is time to ring them while they can be handled easily and safely, for the birds' sake, more than ours.

I was out helping Ewan Weston ring the chicks in some of the nests which he monitors and in three that we checked, all had twins. This is a sign of plenty food and fair weather, and now that they have reached this age, they should all fledge. His study area is in the eastern Highlands and all three nests were in Scots Pines, magnificent old trees


An eyrie set on the upper branches of one of the pines

The adult birds gave a silent fly-past as we approached the nest tree, then they slinked off to watch us from a distant perch. Meanwhile the chicks remained silent too, lying flat and inconspicuous in the eyrie until Ewan came within reach and showed his head over the edge of the nest. He then gently placed them into a bag and lowered them down to be ringed and measured on the ground.

One eaglet sits up on the nest while the other lies low on the far side

In each of the three nests, there was one male and one female chick - the females recognisable by their larger size, especially that of their feet, legs and head. The flight feathers on Golden Eaglets begin to show dark against the white down when the chicks are about four weeks old, and the birds generally lie quietly when laid in the heather below the eyrie while they are ringed. When older, some will strike out with their talons, and hiss, but they seldom snap with their bills.

The chicks were lowered down the tree in a bag for safe processing on the ground

Simon Cherriman from Perth, Australia, who is visiting Scotland with me at the moment came along to learn how we ringed eagles and Jenny Lennon, Ewan's partner, helped guide him through the process. Although the chicks were docile, the rings need to be extra-strong, so that the birds cannot open them and take them off once fully grown. And so, the rings are especially tough to fit and close securely.

Ringing one of the chicks

Each bird was fitted with a standard ring issued by the British Trust for Ornithology, and a colour-ring on the other leg which can be more easily read if the birds venture into the line of view of many of the remote cameras which are being set up throughout the Highlands. This will help to inform us on how much interaction there might be between Golden Eagle home-ranges. Anyone visiting eagle eyries or ringing of eagle chicks must have a licence from Scottish Natural heritage to do so and we were all covered for the work we were doing.

Each bird was fitted with an individually numbered colour ring 

It only took a few minutes to ring the chicks then they were measured to ensure that even if it looked like the larger birds were female they did in fact fit the criteria.  

Several measurements were taken to determine which sex the chicks were, here the hind claw

These young birds already had large talons and bills, but wait until they are fully grown. Then they are really impressive.

And their heads were measured

Ewan, Jenny and I have ringed lots of eaglets the years, so all was done most efficiently and the birds were passed back up the tree. Then we were gone. The chicks lay quietly in their nest and the adults would soon return - as quietly as they left.

And the birds were all set to be returned to the eyrie

Thursday 13 June 2013

Golden Eagle prey
Some of the prey items below the eagle eyrie
Whenever we visit a Golden Eagle eyrie, we always search around below the nest for pieces of prey dropped from the nest, and whoever climbs to the nest also has a good rummage through the nest lining for any more pieces.

Yesterday, while at the eyrie described in the previous post, we found remains of a Red Deer calf, a Roe Deer calf, a hen Rock Ptarmigan, a Red Grouse and what seemed to be feathers from a Common Gull in a pellet.

Both the deer were new-born calves, distinguishable by the unbroken cuticles on the soles of their hooves as seen in the photograph below.

The hoof of a Red Deer calf on the left, and a Roe Deer calf on the right. Very similar, but that of the Roe is smaller. A Golden Eagle can easily lift a Roe Deer calf, although a Red Deer calf must be a bit heavy to carry very far. Hence, both calves had been dismembered before they were carried to the chick in the eyrie, which might have been several kilometres from the place they were found.

Ringing a Golden Eagle chick
A four-week old Golden Eagle chick with a wonderful view from its eyrie. What an entrance to the world.
Yesterday I was up helping members of the Highland Raptor Study Group ring a Golden Eagle chick in an eyrie which I found a few days before. The eyrie was in an old Scots Pine, set about twelve metres up on the main stem where the branches split into a multi-fork. This presented a bit of difficulty in climbing up to the nest, but Brian Etheridge rose to the challenge.

Brian negotiates a route up over the eyrie
The eyrie was about two metres deep and two metres wide
Adam with the chick, a strong, well-fed male. 
For safety, the chick was lowered from the tree in a bag and ringed on the ground. Adam Ritchie ringed it as he had only done a a couple before, and putting on the extra-strong rings takes a bit of practice. The chick was a strong, healthy male, readily sexed by his relatively small feet and quiet nature. Females are larger with big strong legs and feet, and they are usually much more aggressive.
 

Sunday 2 June 2013

Golden Eagle hatching
A Golden eagle eyrie set on a cliff
While out on a moor watching Greenshanks, in the northern Highlands, I noticed a pair of Golden Eagles rise from a cliff about a mile away. I knew that to be a historical eyrie site and wondered why a pair should be soaring over it? If they had eggs or small young one of them should have been on the nest. So I went over to check.

I soon found an actively-used eyrie and I quickly climbed up to look into the nest from the cliff top. There was a day-old chick and an unhatched egg in the eyrie. This seems negligent of the adults, but I am sure they were watching from up high, so I left the area completely as quickly as I could. I have seen this behaviour before. Perhaps the chicks are not as vulnerable as we would think, and the weather was warm and sunny that day after several days of cold, rain and snow. Maybe the adult female simply needed to get off the nest after seven weeks incubating and the male is less inclined to brood young than to cover eggs while she is off.

The soft down of an eaglet can just be seen above the fine warm nest lining of dried grass. An unhatched egg lies behind.