Friday 25 July 2014

Red-necked phalaropes

An adult male Red-necked Phalarope in breeding plumage - and out of water
For the past few years I have been taking part in a study of arctic-breeding waders in northern Norway. This has been organised by my brother Robert Rae and the local ornithologist Karl-Birger Strann. And there have been numerous other helpers as it is a long-term study.

One of the wader species which breed in the area is the Red-Necked Phalarope Phalaropus lobatus, and when I photographed a bird walking over dry land I could not remember the last time I had seen this behaviour. For Red-necked Phalaropes spend most of their lives on water, whether on oceans during the non-breeding period, or while spinning around catching mosquitoes in tundra bog pools where they breed.

Sedge-lined pools in the arctic tundra - Red-necked Phalarope breeding habitat
We have caught numerous phalaropes over the years, to ring as part of the long-term study on the population and their movements. They are a reverse sexual dimorphic species, where the female is the larger brighter bird which does most of the sexual displaying, and the males are less boldly marked as they do all the incubation and care of the chicks. Although there are some well-marked males and some dull females, so telling their sex in the field can be trickier than suggested in some literature.

An adult male Red-necked Phalarope - a well marked bird
When holding phalaropes in the hand after catching them, one is given a rare chance to see their lobed toes. Their scientific name Phalaropus means coot foot-like and the lobatus emphasizes the reference to their lobed toes. A feature seldom visible when seen in the field.

The lobed toes of a Red-necked Phalarope
The bird I photographed on land was walking a few metres back to its nest after feeding on a nearby pool. Most Red-necked Phalarope nests are set in wet sites, amongst sedges which fringe the pools where they forage, often in extensive beds of sedge on larger pool systems. The birds build a tiny platform of dry sedge stems, just enough to keep the eggs dry above the waterline.

A typical 'wet' nest site - a platform built above water amongst sedges
Some birds select a dry nest site on the edge of a bank next to a pool, or as in this case on top of a dry hummock amongst scattered pools. The nest was right on top of the hummock, tucked beneath a clump of cotton grass and below a dwarf birch.

A dry phalarope nest site on top of a hummock

A closer view of the same dry nest site
As with most waders, Red-necked Phalaropes usually lay four eggs in a clutch, and again like most wader eggs, they are very well coloured and marked for camouflage, to conceal them while the incubating bird is off feeding.

The eggs are well camouflaged to avoid detection by visually-clued predators such as ravens
When the adult bird is on the nest, the whole is even more hidden as the male's dull plumage colouring blends softly with the surrounding vegetation.

The adult bird is also well concealed when sitting on the nest
Phalaropes might be unusual waders in their habit of being mostly swimmers that rarely walk, but the opposite also occurs. I have seen several species of wader swim, usually just to cross a narrow creek or section of deep water, such as Dunlin or Purple Sandpiper in their winter coastal habitats or Spotted Redshank, another species of wader which breeds in the Norwegian tundra next to the phalaropes.

A non-lobed-toe wader swimming - Spotted redshank crossing a deep section of a feeding pool

Saturday 5 July 2014

North Norway


I have recently returned from a trip to north Norway, well within the arctic circle, but still within the northern treeline. The higher hills are above the altitudinal treeline have long-lying snowbeds and where the snow has melted are covered with heath.The lower ground is largely covered with birch forest, only a few metres tall, with other areas covered with dwarf birch and willow scrub less than a metre tall.  The dominant ground cover in the heath and forest floor is lichen, often referred to collectively as reindeer lichen as that is the traditional food of the vast herds of semi-domestic reindeer that are held the there.  


The landscape as a whole is a complex mosaic of birch woodland, scrub, heath, mires and lakes. The winter snow is late to thaw and a cold north wind held the spring growth back this year.


The sky was often grey, but carried very little rain, most of it falling as showers, the clouds lit pink in the low midnight sun.


And midnight rainbows ran over the horizon.


Then as the wind turned to the south the air warmed and cleared, and the low sun cast soft backlight through the birches.


Although much of the lichen-heath has been heavily grazed by reindeer, there are still some carpets of reasonable size and depth, and they give a hint of the thick intricate growth of numerous species of lichen which should cover most of the dry ground.


The lichens are fragile, and crunch when trodden upon, it seems tragic to destroy so much art.


But the lichens are prolific and do grow back, to spread over twigs, leaves, branches and cast reindeer antlers.


Even a reindeer skull.

So when, or if ever, the reindeer herds are reduced enough, the lichens will return their former glory.


However, attractive as the woodlands and lichens are, I was there to study birds like this male Bar-tailed Godwit and other species of wader which come to these lands for a few months each year to raise their young. More of which I shall describe in further posts.

Sunday 29 June 2014

Auks

A Guillemot stands between three Razorbills
Following on from the previous post on seabirds, I thought I should add a page on the guillemots and razorbills, two species of auk, often overshadowed by their more famous related species, the puffin. Yet, these two species have a special appeal of their own, if one just spends time watching them.

These shots were all taken on a recent visit to the Scottish coast where seabirds nest in the thousands during May/June/July.

Guillemots stand in a crowd on a slab below the breeding cliff
I avoid disturbing these birds on their nest or rather egg ledges (they do not build a nest, but simply lay their single eggs on bare rock ledges), I prefer to capture shots of them on points of rock or slabs where they congregate away from the dense breeding ledges. The guillemots gather on slabs below the cliffs, where when seen from above they look like a busy human street scene, all coming and going, and interacting in individual ways.

The sleek head and bill of a Guillemot, perfect for swimming quickly underwater
By lying quietly on a viewpoint, I could easily catch images of the birds which show their basic black and white plumage is not as featureless as at first perceived. The guillemots have wonderfully sleek feathering on their heads and necks, they are as smooth as skin, probably smoother. It has to be for the birds to dive deep and chase fish underwater.

Beads of water cling to the belly feathers of a Guillemot fresh out of the water
Those feathers are also well oiled (from the oil gland at the base of their tail and spread all over by the bird with its bill) and as they fly up from the water, most the water is rapidly shaken off. When they land, hundreds of tiny water droplets cling to the birds, giving them a luxurious sheen, but they too are quickly shed.

Adult Razorbills have grooved and striped bills, and subtle chocolate colouring on the throat
 - not black like that on the upperparts of their body
Razorbills mostly lay their eggs in niches large enough for only one pair, and they tend to be dotted over the cliffs rather than clumped in large ledges like the guillemots. When seen close up, they too have gorgeous feathering. The white eye-stripe is a stunning feature as are the stripe and grooves on their bill. They have very dark eyes and their dark brown throat feathers can only be seen in their true colour under favourable light.  It pays to take time to take a good long look at these characterful birds.

A pair of Razorbills in full copulation - his tail is tucked under hers, both birds are relaxed with wings and bills closed. Birds are often shown in photographs of them copulating with wings and bills flapping and gaping. Those are incomplete mating attempts, or pre-copulation positions
I especially like to watch seabirds, such as the auks for their behaviour. As there are so many birds in view at any time, there is usually something going on somewhere in the colony; display, calling, mating or aggression in tight spaces. There really is never a dull moment, nor a finer way to spend a few hours of a summer day.

A Razorbill sky-points, a formal display posture often adopted high on a cliff edge

Sunday 22 June 2014

Seabird flight

Two Kittiwakes soaring over the sea
While visiting some seabird colonies on the Scottish coast recently I took a few images of the birds in flight to capture their comparative morphology and technique. For each has its own, which fits the species' life.

Herring Gulls have a heavy appearance 
Herring Gulls, like most gulls are more land birds than seabirds, for they forage onshore, often well inland, as much as at sea. Even when at sea they mostly inhabit coastal waters. So these birds have a generalist type of flight; they can soar and they can flap with deep strokes. They are recognisable by their strong, bulky body and thick set appearance.

Kittiwakes have a straight edged tail and bent wings even when gliding
Kittiwakes are true oceanic gulls. They are light buoyant fliers, only coming ashore to rest or nest. Most of their lives are spent foraging out at sea, where they glide, flutter and dip into the surface waters for food. These are delicate gulls, recognisable by their slender build. It is not so much their colouring or markings that identify them, but their agility and knack of switching from a long oceanic gliding flight to a tern-like fluttering dance, with their legs hanging down as they dip for food.

Fulmars have rounded tails and their wings are held rigid most of the time when flying
Fulmars are true seabirds. They spend most of their life on the wing, gliding on stiffly-held wings as they flip low over the waves. And they seem to fly more easily the stronger the wind. They might be clumsy on land when they come ashore to nest, waddling on their short weak legs as they scrabble onto their nest ledges. But those short legs are suffice for their purpose, when out at sea, they are an advantage, as they are tucked into the body feathers and never hinder the birds' aerodynamics. The whole bird is a slick flying form, using the wind for lift and thrust, and they are a delight to watch as they wheel around and around the airspace off the nesting cliffs.

Fulmars, like all petrels and albatrosses are true masters of oceanic flight
I have not mentioned the auks or shags which also breed on the Scottish coast, for they are more swimmers that fly, than flier that swim like the birds listed above. The auks' and shags' forte is their diving ability - they swim underwater.

Monday 16 June 2014

Precocial and Altricial young

Birds in Scotland are busy hatching and rearing their young at the moment, with June being the month when most species have dependent young at some age. I have been ringing, with other members of the Grampian Ringing Group, various species of chicks from common and tiny Willow Warblers to large and rare Golden Eagles, and all sorts between. While doing so, I have as ever been impressed by how well each species has adapted the best method of post-egg development to suit its lifestyle.
 
Common Gull eggs, with cracklines and holes - the chicks are beginning to hatch

I have been ringing gull and wader chicks and took a sequence of photographs at one Common Gull colony to show the development of their chicks. The typical clutch size is three eggs and the chicks hatch one after another, over about two days. The first chick to hatch stays in the next and are brooded by the adult birds until the last chick hatches and dries. Then they all begin to wander from the nest, usually set on the ground, and hide beneath the surrounding vegetation.

One dry chick, one wet chick and one still on its way out

Gull chicks have cryptically-coloured down which keeps them concealed from predators and warm. They can walk sand run strongly and are known as precocial young.

A fully dry Common Gull chick - two days old and now three metres from the nest

Or rather, gull chicks are better described as Semi-Precocial young, those which are downy and can walk and can leave the nest soon after hatching. e.g. in the case of terns and gulls, although they still rely on their parents for heat and nourishment.

True fully precocial, self-dependent young would be such as Mallee Fowl which find their own food without even guidance from either parent.

This is so different from the familiar nestling birds, which are Altricial - where the young are naked, blind, weak-limbed at hatch and rely totally on their parents for food and heat.

Semi-altricial young such as raptors are downy at hatch, but weak and rely on their parents for heat and food.

Four Skylark chicks in their nest











Two other terms which are used to describe young birds are; Nidifugous - those that leave the nest soon after hatching, generally once the whole brood has hatched and their down dried, and Nidicolous - those which remain in the nest for several days or weeks after hatching.

A three-day old Skylark chick, still partially naked and blind

The nestling stage is a very vulnerable period for young birds and the variety of concealment and protection methods taken by the parent birds is, to me even more fascinating. From secretive single nests to noisy colonies, each works for the protection of different species. But more on that later.

Five kestrel chicks - ranging from about one to two weeks old