Sunday, 28 July 2013

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

Sunday, 21 July 2013

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

Monday, 15 July 2013

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

Thursday, 4 July 2013

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

Wednesday, 3 July 2013

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.