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.
 

Tracking Greenshanks

A colour-ringed and geolocator-tagged Greenshank

This year, 2013, we (Me, Nick Christian, Brian Etheridge and Ron Summers) caught several Greenshank and marked them with individual colour ring combinations. The orange ring on each also held a tiny, less than 1 gram, geolocator. The Greenshank weighed about 200 gm. This is a device which can determine the birds' approximate location to within 100 km, by analysing the relative daylight length with Greenwich Mean Time. The information on where they have been is stored in the device's memory and downloaded on subsequent recapture of the birds.

We retrieved two geolocators which had been put on birds last year. And the preliminary results suggest that Greenshank which breed in northern Scotland over-winter in southern England, Wales and Ireland.

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.

Greenshanks

Double-red back on his feeding-lochan

I have spent the past few weeks studying Greenshank in Sutherland, in the northern Scottish Highlands, where I soon found the bird colour-ringed with double red, which was caught three years ago at the same site. He has also been seen since on the same wintering grounds in Suffolk. So he is very site fathfull for breeding and over-wintering.

This study is a cooperative voluntary one, done by a few members of Grampian and Highland Ringing Groups, with the aim to determine where Greenshank which breed in northern Scotland overwinter. But first we have to find the birds on their breeding grounds by searching the lochs for feeding birds and the moors for nesting birds. They are notoriously difficult to find.

A Greenshank lies low on its nest as I passed by - so easy to miss

Long-tailed Tit nest

A Long-tailed Tit nest set in a fork of a birch tree

It has been a long cold spring in the Scottish Highlands this year, with the trees late in coming into leaf. Any birds which nest early, therefore need to be crafty in concealing their nests from predators. Long-tailed Tits, are masters of this. They build their domed nest with mosses and then dapple the surface with flecks of lichens gathered from the branches of neighbouring trees. The finished surface then blends in almost imperceptibly with the lichen-covered nest branch.

A well concealed Long-tailed Tit nest

Here an incubating bird watches from the entrance hole to the nest, set high on the right side. Even her face seems to merge with the colours of the lichen on the branch. In all, a marvellous example of camouflage.

A Long-tailed Tit looks out from its nest hole.

Spring at last

Birch catkins and fresh leaf buds

I have been in Scotland for over two weeks, and at last Spring has arrived, about four weeks late.

Rowan leaves open as last years berries wither

There have been cold northerly winds most of the previous weeks, with some strong westerlies bringing in wild rainy weather. Then after a particularly heavy downpour yesterday, today woke up to still, quiet skies and later a warm sunny afternoon. The leaf buds and catkins on the trees responded to the warmth, bringing bright green foliage into the landscape.

Tiny flies such nectar from rain-washed willow catkins

Wall Flowers

The front cover of the current edition of the Leopard magazine is of one of my images from a feature inside written and illustrated by me on urban plants: describing how they colonise various niches in our cities, adding colour to otherwise drab decay. 

Autumn Frogmouths

Tawny Frogmouths can be very difficult to see when roosting quietly up in the branches

We are well into autumn in Canberra now and the Tawny Frogmouths are even more tricky to find than in spring or summer. They can be anywhere in their home ranges, but this adult male and juvenile were still within a hundred metres of last year's nest. I couldn't find the adult female. I had expected the youngsters to have left their family groups by now, as this is often the time of year when resident birds establish or confirm their pair-bonds and territories. I thought I would find the birds in their favourite winter roost by now, the ones which are better exposed to morning sun and out of the cold south-west wind. This branch was in the sun, but higher up, about 15 m,  and more hidden than the winter roost.

The adult male, on the left, sits comfortably, partially fluffed up as he basks in the sun, while the young bird is a bit more secretive, taking on a partial branch-pose for camouflage. The adult bird has seen me many times before, so is probably less afraid of me.


The young bird is identified as such by her scruffy moustache and eyebrows, and her nasal bristles are not as finely developed as those of a bird in full adult plumage. She is definitely a  female as she has taken on a rusty colouring to her wing coverts. Males are more uniform grey.

Red Wattlebird

It is autumn now and the our local garden Red Wattlebird Anthochaera carunculata is re-affirming his ownership of the nectar-bearing plants, especially the grevilleas. This will be his main food supply throughout autumn and winter and whenever he sees another bird in one of these bushes he chases them well away. This the largest mainland honeyeater measuring up to 360mm in length, and when in pursuit of smaller birds, with determination in their eye, they look very like a sparrowhawk. Their name derives from the pairs of red wattles which hang from their cheeks, and they also have a splendid lemon-yellow belly. As with all honeyeaters they have specially adapted brush-tipped tongues for lapping up nectar and they are important pollinators in Australia.

Being large and heavy does have some drawbacks though, and they do have to stretch to reach the farthest flowerheads. Like this one outside the office window.

'a refreshing and fascinating book' 

The British Trust for Ornithology have just published a review of my book Eagle Days in their monthly newsletter, BTO News. This seems a long time since its publication, but I have no problem with that as it is yet another very favourable review. Once again I am fascinated by the details which each reviewer has chosen to highlight. This reviewer, anonymous, picked up on the poetic aspect of both the text and photographs, using such phrases as:

`has a quality which brings colour and life to the broader landscape in which the eagles are to be found'

`well illustrated by Stuart's own photographs'

while they still picked up the core message:

`the need for such fieldwork to be undertaken'

Young pigeons

A first year Common Bronzewing Phaps chalcoptera

On the weekend I was out mist-netting birds at Charcoal Tank Nature Reserve, NSW, helping Mark Clayton with a long term cooperative bird banding study. As it is now late summer almost autumn, the birds there have all finished breeding and the birds caught were a mix of adult and birds of the year. I am in the process of putting together an online guide to aging and sexing woodland birds of South-east Australia, based on photographs taken of birds in the hand, prior to release after banding them. And this trip provided a chance to photograph young pigeons as we caught examples of Common Bronzewing and Peaceful Dove.  

The young bronzewing, which would have hatched last spring, differs from the adult in still  having a soft bill, especially the cere above the nostrils. This is a residual feature of squabs, young pigeons,which have large wide and soft bills. An adult bronzewing has a hard bill and the cere is less spongy. This young bird was probably a male as there are some chestnut coloured feathers growing into the sides of the crown - adult females do not have such well coloured heads. The adult male also has a bright pale forehead and there seems to be signs of such growing into the young birds head.

An adult male Common Bronzewing

A first year Peaceful Dove Geopelia placida

The young Peaceful Dove was instantly recognisable by its generally dull plumage compared with that of an adult, which cannot be sexed on plumage. The adult bird has a smart blue-grey forehead, chin and cheeks, and boldly marked black and white bars on its breast. The young bird has a white/buff speckled head, and the barring is of brown, buff-tipped feathers.Also, the young bird has only a faint blue ring of bare skin around its eye, while that of the adult is bright, together with the prominent blue cere and irides. Again, the young bird has a soft bill, especially the cere, and the adult has a a hard, worn and flaky appearance, through wear and tear after years of foraging.  

An adult Peaceful Dove

The Nature Conservancy
Australia

I have added a link to The Nature Conservancy, Australia to the list of associated websites on the right of this column. Please click on  http://www.natureaustralia.org.au/ and have a read though to see just what they are doing and needs to be done to secure a future for wildlife and wildplaces in Australia.

Sulphur-crested Cockatoos

The fruit in the garden has now all passed, the last of the apricots were eaten by the Red Wattlebirds, Crimson and Eastern Rosellas. But all is not over yet. The Suphur-crested Cockatoos have moved in to eat the apricot kernels which the other smaller birds could not open and eat. They only ate the soft flesh like we do. A carpet of split shells now lies below the apricot trees.

Great flying at the cricket 

The Foxcopter hovers over Manuka Oval

As part of their TV coverage of the Prime Minister's XI v West Indies cricket match at the Manuka Oval, Canberra yesterday, Fox Sports were flying their new Foxcopter. This is an eight-rotor helicopter drone which carries an HD camera, and the whole is controlled to line up overhead pictures of the game. What a wonderful machine it is, it was very competently and safely controlled - and it produced great pictures.

When the machine first took off for a tour around the ground airspace during the afternoon session, an Australian Hobby Falco longipennis gave it a fly-past, probably to investigate this strange new flyer in its territory. There was never any danger of conflict or collision however as the bird was never closer than about 70-100m. 

Later, when the sky darkened, the new stadium lights were switched on and moths soon fluttered around them as it became darker. Then just as it became truly dark, a Hobby, probably the same bird, began hawking moths from in front of the lights. It disappeared into the shadows behind to eat its prey, and this was repeated several times, with the vast majority of the crowd unaware of the wildlife flying display above them.

Tawny Frogmouth breeding success

An average brood size of two Tawny Frogmouth chicks

I have been monitoring the breeding success of Tawny Frogmouths Podargus strigoides in Canberra, Australia, for several years and have found that the pattern is fairly constant. About half the breeding pairs rear two young to fledging; a few rear three in any year and about a quarter rear one chick. The proportion of pairs which fail to rear any chicks is about 24% on average over the years, ranging from 17 – 34% (Figure 1). I do not disturb the birds to record clutch size, but it is known to range from 1-3.

Figure 1: The number of young reared per breeding pair of Tawny Frogmouths in 2006 - 2012.

In recent years I had thought that more birds were failing to rear young, but this is just the impression gained as I have added more pairs to the study in the past few years. Although I have been recording more failures, this has been in proportion with larger sample sizes, there is no statistical difference (χ² = 3.8, df = 6, P = 0.43). The main causes of failure, which are usually the loss of whole clutches or broods, are predation by unknown species, but likely Brush-tailed Possum or Brown Goshawk. One male was taken off the nest by a feral cat. A few nests have been blown out of their trees by strong winds.

Figure 2: The number of Tawny Frogmouth pairs which failed to rear any young in any year is proportional  c24%, to the number studied (r = 0.899, P = 0.003).

Further study will aim to determine whether there are any differences between the breeding success of frogmouths in grassy woodland, dry sclerophyll forest or suburban remnant woodland; or if there is any difference between years of drought and high rainfall. Fortunately the study has already covered these criteria.

A male Tawny Frogmouth protects his chick

Another cover shot

I received a copy of this book through the post a few days ago and it features another of my images on the front cover. The book has been written mostly by Adam Watson who has used his old notes on birds in his native north-east of Scotland from as far back as the 1940's for comparison with bird numbers in the same area today.

One of the largest differences has been the deep and widespread decline of the Capercailie, featured here on the cover: a magnificent bird, the largest grouse, one of those species which exudes character, and is indeed part of the character of the pinewoods.

The book is full of details on species, which give an insight to how different species have reacted to changes in the landscape, mostly man-made. Not all have declined, some have increased, and possible reasons are dicsussed in the book. Above all, these notes come from a time when there were very few ornithologists recording such data. There is no substitute for original notes made at the time

Cheese-plant   Monsteria deliciosa

The cheese-plant in the garden is flowering with several blooms. Hopefully they will develop into fruit and I can have a taste of the delicious custard apple /pineapple type flesh. The plant has thrived since we cast it out of the veranda when it became too big. Now it lives happily in its frost-free rain-forest under an evergreen canopy by the pond.

By-catch

The stick insect climbs onto Terry's hat

When mist-netting birds last weekend I came across this little beauty in one of the nets:

A Pink-winged Phasma Podacanthus typhon.

After I safely took her out of the net and we took a look at her, she instinctively climbed up whatever was near, in this case it was Terry. Then once she had explored around his hat and could not climb any farther, and had not found any green foliage to hide in, she opened her wings and flew off. And what marvelous wings she had - bright pink, wow!

It looked like she was a female as her abdomen was swollen, perhaps gravid. She can lay eggs without mating, by parthenogenesis, and if she does so, the offspring wold be all female. If she did mate the sexes would be mixed.

For further information on stick insects have a look at the following link:
http://www.ozanimals.com/Insect/Pink-winged-Phasma/Podacanthus/typhon.html

She opens her wings to fly off

She merged well with eucalypt leaves

Birds are returning after the drought

Adult female Turquoise Parrot

Last weekend was spent mist-netting birds out at the Weddin Mountains. John Rawsthorne organised the banding and we caught about three-hundred birds, an indication that birds are coming back in numbers a couple of breeding seasons after the drought. We caught several Turquoise parrots, in a mix of adult females and young birds of the year. So they have had a successful breeding season.

Chestnut-rumped Heathwren

We also caught four Chestnut-rumped Heathwrens, which I haven't seen in the area for several years. Two birds were adult and two were young of the year - the one illustrated is a young bird as it has buff tips to its coverts and its tail is all new in uniform length. Adults have no buff tips and they were moulting their tails, the outer feathers being shorter than the central ones.
 

Yellow-tufted Honeyeater

Most of the birds caught were honeyeaters; about a hundred each of White-eared and Yellow-faced, a few Yellow-tufted, Brown-headed and White-plumed, and single Fuscous, Black and Black-chinned. The Black Honeyeater is a bird of the farther west, drier country which had bred in the area earlier in the season but had now moved on. The Yellow-tufted and Black-chinned were evidence that the species were now breeding in the area after being absent for several years. Their food plants have probably been flowering well in surrounding places which have held numbers in refuge during the drought.

Yellow-faced Honeyeater

The flocks of Yellow-faced and White-eared Honeyeaters were largely composed of young birds. Some of these were in early stages of their first post-juvenile plumage moult and others were further on, signifying that there were probably two cohorts of young birds; one from nests initiated early in the breeding season and the other of birds from second broods. So there has been a very successful breeding season in the area in 2012.

Black-chinned Honeyeater

The netting site at the Weddin Mountains is a long-term study site, so it will interesting to see what birds are recruited into the breeding population in 2013.

Happy New year.

10,000 UP

Yeh, the 10,000th visitor has just read this blog. Thank you everyone of you who has checked in for a look. That makes it all worthwhile. It is good to share experiences and news, and it's good fun.

Meanwhile, the other day while sitting on the veranda  I was thinking that I hadn't seen any sparrowhawks, or evidence of their kills, in the garden yet this post-breeding season. And what happened yesterday while I was out talking to the chickens, a beautiful hen Collared Sparrowhawk came swinging in through the shrubbery, over the chickens' heads and grabbed a House Sparrow. She then flipped over and into the neighbours' garden where she mantled her prey.

She stood there for a few minutes with the sparrow in her grasp, ensuring that it was definitely dead before she began to pluck it. Never releasing her grip all that time, she clearly held it tight in a constricting hold, so that it died of suffocation.

She was a stunning full adult, with a slate-blue back and head, rich red collar and belly stripes. The females usually take larger prey  such as Starlings or Common Mynas, and the smaller males take the sparrows and wrens. But, now she knows the sparrows are around the chicken house, where there are always food scraps, she will be back. And others will pass through too I'm sure.