Feral Cat

A feral cat lies dead on a road in Namadgi National Park

While driving through Namadgi National Park yesterday I came across a dead cat lying in the road. It was still in good condition, although had been killed probably during the previous night. On closer inspection I was struck at how these feral pests have reverted towards their original type pelage of brown stripes on a grey base.

Considering how there has long-been a fashion for boldly marked cats within the pet market, such as black and white, or long or short-coated, and these are the source of many feral cats, such colourations are seldom seen in the wild. Not by me anyway. The last cat I saw in the wild was also in Namadgi and it was of similar colour and size. One driving force is likely selective predation by, for example eagles. I have not seen feral cats killed by eagles in Australia, but in Scotland where I have done much more study of eagle prey, I have found the remains of pie-bald cats, but none of type-coloured animals. Any boldly marked cats are more likely to be seen and killed first. Evolution in action, a second time around.

The markings are feint, but true of type.

This animal is close to the true European subspecies of the wildcat Felis silvestris silvestris, with the generally striped body and ringed tail, although the disruption of the stripes into spots are indicative of domestic cat Felis catus. As the tail is quite thickly haired, it does not fit the form of any warmer climate sub-species such as African (Felis silvestris libyca) from which the domestic cat is considered to have originated, or Asian Felis silvestris ornata, which have slender tails. Nor is the tail really thick and club-shaped with thick continuous dark rings as in the Scottish Wildcat. So, I would conclude that this cat's ancestry originates from a mixed European domestic stock.

The thick, ringed tail is indicative of a European wildcat type

Kookaburra bill

Birds often develop deformed bills and I wonder why they occur, accident or disease. I met this Kookaburra in the bush yesterday, and I recognised it by its distinctive bill shape from last year. It was in the same area and probably the same family group's home range as it was displaying with another bird. So although it appears that it might have difficulty feeding with such a long upper mandible compared with the lower one, it must be successful. Kookaburras catch most of their prey by pouncing down on them from a perch and snatching them with their bills. Typically, they catch anything from insects to small reptiles, so they need to be quick and efficient.

Camouflage

Which bird attracts the eye first, least, the sunlit or shadowed one?

Tawny Frogmouths are well known for their ability to blend into their background, yet they repeatedly impress me with their exhibits of just how well they do so. Here are some shots of birds roosting in the daytime close to their nest trees as they enter their breeding season for 2013.

The male sits on the outside, as in about 90% of cases of pairs roosting together

A short stubby branch of the main trunk is a favourite perch

Another bird in the neighbouring territory sat alone, basking in the late winter sunshine. The freckles on her breast merging so well with the dappled shadows.

Easy to see once we know where to look

Tawny  Frogmouth nest-building

A possum investigates the camera

The birds'  breeding season has begun in south-east Australia and the Tawny Frogmouths have started to build their nests. I set the camera trap up at a nest last night and a short version of the results can be seen here on the this video link: Nest building .

The male bird was perched next to the nest when I set up the camera just after dusk, and he sat and watched me quietly with no sense of alarm. Then all was quiet until near midnight, when a Brush-tailed Possum came and sniffed at the camera. No birds came to the nest until six-o'-clock the nest morning, when the male brought in some fresh twigs or fronds and added them to the basic nest. And that was it for the night. Dawn was not far away.

Then at nine in the morning, An Australian Magpie came and investigated the nest, then jumped over to check out the camera.  A quiet but unexpected sequence of events. But Spring is here.

Northern wader habitat

A road meanders north through the extensive birch woodlands and mires

There are few human settlements or other intrusions to the landscape of the region in northern Norway where we go to study waders and the potential breeding grounds for these birds is vast. The forests and mires form a massive extensive mosaic of birch woodland and sedge-filled mires, with many open stretches of water in the form of tiny to wide lakes and formidable fast-flowing rivers.

A typical mire with open water in the centre surrounded by a floating carpet of mosses and sedges, and the whole encircled by willow/birch scrub and birch forest

Waders such as Wood Tringa glareola and Broad-billed Sandpipers Limicola falcinellus, Jack Snipe Lymnocryptes minimus, Red-necked Phalarope Phalaropus lobatus and Reeve Philomachus pugnax nest in the mires, while species such as Whimbrel Numenius phaeopus, Spotted Redshank Tringa erythropus and Greenshank Tringa nebularia nest in the scrub and woodland.

Numerous other northern breeding birds live in the these habitats, mostly summer migrants which go there to breed, then return south to over-winter. One resident species is the Willow Ptarmigan Lagopus lagopus which nests in the forest understorey. These birds can live there throughout the winter because they feed on the leaf and flower buds of the birch and willow which protrude above the blanket of snow that covers all the ground all winter.

A hen Willow Ptarmigan sits on her nest in juniper scrub

The ptarmigan's eggs are cryptically coloured to conceal them while she leaves the nest, perhaps once a day, to feed.

Arctic waders

Adult Wood Sandpiper

Here are a few photographs of waders and their chicks which I was studying recently in northern Norway. Part of the work, which is organised by my brother Rab, involves finding and catching both adults and chicks to ring them in order to help discover such information as where they live in the non-breeding period, whether they return to nesting or natal sites, and how long they live.

A pair of wood sandpipers, ringed and ready for release

The most abundant wader species in the tundra mires is the Wood Sandpiper Tringa glareola and the Broad-billed Sandpiper Limicola falcinellus is one the less common and seldom seen species. Most of the waders live in extensive mires, hidden by lush growth of sedges and other marsh plants.

An adult Broad-billed Sandpiper is measured -  the sexes are similar in plumage, but can be differentiated by size

Wader nests and chicks are notoriously difficult to find due their cryptic plumage and seclusive behaviour, arctic-breeding species are especially so. Wood and Broad-billed Sandpipers nest in the mires and it takes very specialized skills and a very very keen eye to find them.

A Broad-billed Sandpiper nest and chicks lie hidden in a mire

Broad-billed Sandpiper chicks in the nest

Four Wood Sandpiper chicks, a typical brood size

A single Wood sandpiper chick is extremely difficult to see when creeping through the sedge

Scotland 2013

Ben Loyal

Spring in Scotland seems a long time ago now as I have been looking through and cataloging the photographs from then, when I was in the Highlands studying birds and exploring the hills. Most of my time was spent in the far north-west in Sutherland where I was studying greenshank, golden eagles and ptarmigan.

I seem to recall that the weather was cold with a north wind blowing most of the time and lots of low cloud on the hills, with much late-lying snow. However, I reckon that there is always something to photograph in the Highlands, whatever the weather. It all adds atmosphere and reality to the images.

I have posted a short portfolio to my website, just follow the link on the right.

Cape Wrath sunset

Lichen article

Lecanora campestris grows on an old headstone

While I have been away in the field studying waders and eagles, I missed the publication of one of my articles on lichens in the May edition of the Leopard magazine. This is such a wide topic with thousands of species in the UK alone, so I focused on readily accessible species which people can find growing on gravestones.

Lichens can be difficult to identify, partly because some need to be keyed out to microscopic or chemical characteristics, but also because so few have common names. Scientific double nomenclature can put people off, and in the case of lichens seem overwhelming. I am a scientist, but I do not like aloofness, I like to share my knowledge and experiences of wildlife with people. And the more I share, the more I find I learn. Perhaps if more people were to become interested in lichens more of them would gain common names? Do not be afraid of scientific snobbery, get out there and enjoy the variety of colour and shapes which abound in the wild outdoors 

Xanthoria parietina grows on a gravestone where bird-droppings enrich the surface

Red-spotted Bluethroat

Adult male Red-spotted Bluethroat

While in Norway studying the waders in the marshes, we were constantly surrounded by the songs of local passerines. The main species were Willow Warbler Phylloscopus trochilus, Mealy Redpoll Carduelis flammea flammea and Red-spotted Bluethroat  Luscinia svecica svecica. As there are few ornithologists working in the field in northern Norway, to help discover the wintering ranges of these birds, we ringed any passerine chicks we came across and caught adults in mist nests. The warblers and redpolls do not vary much in plumage between breeding and wintering periods, but the Bluethroats were spectacular in full breeding plumage, especially the males.

The blue throat

The blue-throat of these birds is truly stunning, being of a metallic hue. It is so bright and obvious when seen in the filed, however, when in the hand and viewed face-on, these birds exhibit a clear and bright yellow gape. The yellow line complements the blue and red tones so well, it must have a purpose in the bird's display.

The abundance of waders and passerines in the Arctic is largely attributable to the supper-abundance of mosquitoes. They can be a pest for field-workers, with their incessant buzzing and biting, but without them the mires would not be such a tremendous breeding ground for birds - so many species are dependent on them for rearing their young.

Mosquitoes are ever-present in the Arctic scrub

Broad-billed Sandpiper

A Broad-billed Sandpiper in breeding plumage

I have recently returned from a trip to Norway where I have been helping my brother Rab on a long-term study of the birds in the norther marshes, including the breeding biology of Broad-billed Sandpipers Limicola falcinellus. Typically of Arctic-breeding waders, these birds fly north to nest as soon as the snow melts and their breeding grounds are clear enough for them to feed and build a simple nest on the floating mires. The main function of their journey is to find a nursery area for rearing their chicks, and the whole breeding period from egg-laying to fledging is over in a matter of weeks, Then the birds fly south to their wintering grounds, which to date are unknown for the Norwegian population. To help answer this question we began tagging birds with geo-locators, and plan to re-catch the birds next year to download data which should indicate where the birds have spent the non-breeding period, the longest part of their lives.

The broad bill

One of the individual characteristics of wader species is the specific bill shape, and the broad bill of these sandpipers is not usually appreciated when seen in the field in profile. However, when the bird is in the hand, it is obvious. As these birds spend most of their time in their winter quarters, it is likely that their bill is adapted for catching certain prey there, giving them advantage over other species for a specific food source. The bill is not only broad, but has delicate flutings along its length, which suggest that the bill is a very tactile and maneuverable organ, not just a simple horny probe.

The not-so-simple bill of a Broad-billed Sandpiper

Cuckoo chick

The birds' breeding season in Scotland is now well drawing to a close with many species feeding fledglings. This is tough enough when feeding their own young, but feeding that of a Cuckoo Cuculus canorus must be especially demanding for the adult birds which have been so duped.

A young cuckoo sits in a meadow pipit nest, well camouflaged under heather

Young Cuckoos can be very noisy when begging for food, but the go silent when approached. Then they rely on their cryptic plumage to hide them in the understorey of the heather moor where their foster parents, Meadow Pipits Anthus pratensis have their nest.

Young Cuckoo giving a defensive threat display

Once they know they have been detected, the young Cuckoos adopt a threatening posture, and flash their orange gape.

The young Cuckoo looks down from a fluffed-up posture

When relaxed they often take on a round, puffed out posture, holding their head back and extending a bulge of throat feathers, so typical of cuckoo species.

Young cuckoos have a bright orange gape

Their bright orange gape acts as an exaggerated stimulus for their foster parents to supply the extra amount of food required by the young Cuckoo above the demands of a normal brood of four smaller chicks.

The empty nest after the bird had fledged

Once the bird has left the nest, it is recognisable as having held a young Cuckoo by the widened and flattened shape of the nest cup.

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.