Thursday, August 16, 2018

Up There. Somewhere.

Migration, the regular movement of birds and wildlife from one part of the world to another and back again is one of the wonders of the natural world. It’s a subject often discussed or referred to here on this blog when a post concerns the ringing of birds. 

We know lots about bird migration, most of it gleaned through the ringing of birds, but there is still a great deal to learn. There are techniques developed in recent years which have the potential to add to our knowledge of how, when, where and why birds orientate and navigate. There are new and developing methods like data logging through radio tracking, radar observations or aural (listening). The physiological basis for bird migration has also received considerable attention, particularly the effects of seasonal increases and decreases in daylight and the seasonal rhythms that influence birds’ movements. 

But now a new study shows that small birds migrating from Scandinavia to Africa in the autumn occasionally fly as high as 4,000 metres (about two and a half miles) above sea level - probably adjusting their flight to take advantage of favourable winds and different wind layers.

The study concerns two species I see at migration time each year in Menorca and Greece, May and September respectively – the Great Reed Warbler and the Red-backed Shrike. 

Red-backed Shrike 

This is the first time that researchers have tracked how high small birds fly all the way from Sweden to Africa. Previous studies have successfully logged the flying height of larger migratory birds. 

The aim of the study was to investigate whether the measuring method works on small birds, which involved measuring acceleration, barometric pressure (air pressure) and temperature throughout the flight using a small data logger attached to the bird. 

A data logger was attached to two individuals of different species: Great Reed Warbler and Red-backed Shrike. Among other things, the results show how long it takes for each bird to fly to their destination. The measured barometric pressure showed that Great Reed Warbler occasionally flies at altitudes of up to 3,950 metres, while Red-backed Shrike flies at up to 3,650 metres. Both individuals flew the highest above ground across the Mediterranean Sea and the Sahara, but the shrike also reached high flight altitudes closer to its winter grounds in southern Africa. 

Great Reed Warbler 

Red-backed Shrike 

"We only followed two individuals and two species. The fact that both of them flew so high does surprise me. It's fascinating and it raises new questions about the physiology of birds. How do they cope with the air pressure, thin air and low temperatures at these heights?," says Sissel Sjöberg, biologist at Lund University and the Zoological Museum in Copenhagen. 

Both individuals flew the highest above ground across the Mediterranean Sea and the Sahara, but the shrike reached higher flight altitudes closer to its winter grounds in southern Africa. 

Sissel Sjöberg thinks it is likely that other small birds fly as high, maybe even higher. But there is no evidence of that yet. 

"In this study, we only worked with data collected during the autumn, when the small birds migrate to Africa. There are other studies that indicate that the birds fly even higher when they migrate back in the spring, but we cannot say for sure." 

Great Reed Warbler - photo credit Vitalii Khustochka 

There's one thing for sure. The next time I see those two species, I will think of them in a new light and try to imagine them heading to and from Africa two and a half miles above me. Up there - somewhere in the sky. 

Journal Reference: Barometer logging reveals new dimensions of individual songbird migration. Journal of Avian Biology, 2018.

Linking today to Eileen's Blogspot.



Saturday, August 11, 2018

Shakespeare And Stroganoff

There was no ringing planned today so instead I had a scoot around Cockerham way. It’s guaranteed to produce a good variety of species and sometimes excellent numbers of birds. 

I kicked off at Conder Green, where for an hour or more the place was alive with Swallows and Sand Martins taking breakfast. The cool morning produced a hatch of thousands of insects above the hedgerows and close to the water’s edge. 

The birds took full advantage as many took insects on the wing while others fed on the ground, almost as if they were collecting nesting material.  It was hard to estimate the mass of birds, especially as some perched up in the straggly hedgerow briefly before returning to the bonanza. My best guess was 350 Swallow, 25 Sand Martin and 15 House Martin. 

Some of the House Martins were from across the way where they nest on the sides of at least two buildings close to the tidal creeks, the ditches that provide food and also mud for nest building. 

Swallow 

House Martins 

The House Martins here seem to have enjoyed a very productive year with upwards of 60 in air around the said buildings earlier in the week. Similarly, the colony of House Martins on a single house on our road in Stalmine-with-Staynall have done really well this year with more than 40 individuals on some days. At the end of the season the UK breeding bird stats will make for interesting reading to gauge the effect of the longest, hottest summer for many, some say fifty years. 

Despite the numbers of both swallows, martins and air-borne insect food, I didn't see a single Swift this morning; it would seem that many have now left for Africa. 

The midday tide began to run about 10am where it pushed a good number of mainly Redhanks into the creeks and onto the pool: 280 Redshank, 80 Lapwing, 3 Greenshank, 3 Curlew, 1 Oystercatcher, 3 Little Egret and 1 Grey Heron. 

On the pool otherwise were noted 12 Little Grebe, 6 Common Tern, 5 Greylag and 5 Pied Wagtail. 

Those dabchicks are so elusive. One second it’s there, the next it’s gone, made no splash or noise but slipped into the water as if its plumage were lubricated with WD40. As suddenly as it dived to leave just a ripple of water, so it reappeared, but never in the exact same spot, as if to tease the amateur cameraman. 

Little Grebe 

“A di-dapper peering through a wave, 
Who, being looked on, ducks as quickly in.” 
William Shakespeare 

You must excuse me. I have a beef stroganoff to make and a bottle of wine to uncork. But never fear there’s more soon from Another Bird Blog. 

Stroganoff

See you soon. Cheers.

Linking this post to World Bird Wednesday and Anni's Birding Blog.



Wednesday, August 8, 2018

Low Level Ringing

Oakenclough is very much an autumn and winter ringing site where nothing much happens in the summer except for nest boxes containing Pied Flycatchers. But the autumn/winter and early spring of 2017/18 was so wet and miserable that we never managed to get here until today, our first ringing at the site since November 2017. 

In the meantime we enjoyed our hottest, driest summer for 50+ years with very little rainfall. The nearby reservoir is about one third full and where the typical water level is near the top of the brick towers and covering the immediate bank of stones. 

Low Level Water 

I met Andy at 0630 and we hoped to catch up a little on our lack of visits. We packed in at about 10.30 when the early minimal breeze wind increased to unmanageable levels. But we had a nice mix in the catch of 8 Willow Warbler, 2 Garden Warbler, 3 Goldfinch, 1 Lesser Redpoll, 1 Goldcrest, 1 Treecreeper and 1 Blue Tit. 

The two Garden Warblers, Sylvia borin, were the first ringed here since 2014, when I ringed a nest full of four youngsters. It was soon after that we were forced to abandon the site when out of control rhododendron took over the plantation and made it impossible to work as a ringing site. About four years ago United Utilities employed contractors to clear the site and to then replant in the hope of restoring its former glory. 

Both of the Garden Warblers proved to be adults, one male, one female, with feathering growing over their bellies, a sign of recent breeding. But as we caught only the two adults, there is no way of knowing if they bred on the now suitable site. The plantation now resembles how it looked in the 1980 and 1990s and hopefully some of the missing breeding species like Garden Warbler, Tree Pipit and Lesser Redpoll may reappear. 

Garden Warbler 

Garden Warbler 

All eight Willow Warblers were birds of the year, with six of them caught together in the same net – a flock of Willow Warblers! 

Willow Warbler 

There was no doubt about age and sex of the single Lesser Redpoll caught - adult male. 

 Lesser Redpoll

We don’t catch too many Treecreepers, here or anywhere else. They often accompany roving flocks of titmice and small warblers but not today. 

Treecreeper 

Birding in between ringing was very quiet. Highlights were 3 Great-spotted Woodpeckers, 1 Kestrel, 35 Goldfinch and a thin but noticeable movement of Swallows – about twenty heading due south in three hours.

Linking today to Eileen's Blogspot.



Sunday, August 5, 2018

A Wild Day With Honey

Saturday morning and there was time for a whizz around Conder Green before I met up with Andy at lunchtime. We’d agreed to take part in a “Wild Day” at Cockerham. 

But first. Early doors showed things were pretty tame at Conder Green despite the sight of 380 Lapwings, the most I've seen here this autumn. Mostly the Lapwings stayed on the island or the rough grass beyond and very few ventured close to the viewpoint. 

Lapwing 

Lapwing numbers fluctuate here according to the tidal bore of the River Lune a quarter of a mile away. It’s not unusual to see three or even four thousand Lapwing on the Lune sandbanks in autumn and winter where they often mix closely with flocks of Golden Plovers and Redshanks. 

Waders otherwise numbered 95 Redshank, 10 Curlew, 10 Oystercatcher, 5 Black-tailed Godwit, 4 Common Sandpiper and 2 Snipe. 

It was good to see a brood of 5 young Shelduck and although there were no adults, the young seemed quite independent. In recent years it has become increasingly difficult to find broods of Shelduck along the shores and estuaries that they favour. 

British Trust for Ornithology (BTO) figures suggest that the overall UK and Ireland population of Shelduck is stable.  Maybe it’s a local issue, especially on our shores where disturbance has become very regular and more prolonged.  It’s no longer just a weekend problem with the human disturbance affecting every one of the many species of coastal waders and wildfowl. 

Shelduck 

Shelduck - via British Trust for Ornithology

Shelduck were persecuted in the 19th Century in the sandy areas of Britain because they competed with rabbits for burrows to nest in. While in those days rabbits were good eating, the salty Shelduck was less sought after. 

Nowadays the Shelduck is a protected species that should not be shot. But living as it does in the close company of “game” ducks like Teal, Mallard and Wigeon, the Shelduck is as wary of man as the wildest of waterfowl and is sometimes shot by inexperienced or cowboy shooters. 

Other counts: 10 Little Grebe, 8 Little Egret, 1 Kingfisher and 6 Common Tern. 

Between the six or more regular Common Terns there’s feeding the single youngster taking place but also the presenting of fish by male on female.  It is rather difficult to tell which individuals are involved in what is likely to be late summer courtship displays, a prelude to the same individuals returning here in 2019 where they will find similarly minded birds.  However it is as well to know that Common Terns do not generally breed until their third or even fourth years, and that these courtship rituals may be wishful thinking. 

Common Tern 

Of course the Common Tern is not just a European species. It is the most widespread and familiar North American tern, known and for its long history as a symbol of the conservation movement. The Common Tern was the impetus for the formation of the Audubon societies and other conservation initiatives of North America. The Common Tern was widely sought after in the late 19th century for the millinery trade, in which feathers, wings, or entire stuffed terns were mounted on fashionable women’s hats. 

Slaughter of terns and other seabirds for this purpose peaked in the 1870s and 1880s, and by the end of the century the species was almost lost from the North American Atlantic Coast and many inland areas. Fortunately, the efforts of the burgeoning conservation groups culminated in 1918 with the passage of comprehensive bird protection legislation, the Migratory Bird Treaty between the United States and Canada. 

Back to the present, and on the drive through Cockerham village a Barn Owl crossed the road some distance ahead of the car. By now the road was busy with traffic with nowhere to stop but from old I knew the farm it headed for.  Along Lancaster Road I found 5 Buzzard in the air together and where at least one of them seemed to be a youngster still begging food. 

Buzzard 

The afternoon venue was Moss House Caravan Site at Cockerham where our group of bird ringers had agreed to host a table for the annual “Wild Day”.  The BTO kindly sent a pile of magazines and a host of leaflets covering a wide variety of bird-related subjects: Garden Plants for Birds , Garden Birdwatch, About The BTO, Nest Recording, Feeding Garden Birds, The Sparrowhawks & Garden Birds, Bird Ringing etc,etc. 

Bird Table 

We had two separate slides shows running on laptops. The first one showed birds in the field while the second one consisted of birds in the hand and shots of bird ringers doing their thing. We also had several field guides for people to browse. There was great interest in our display and a number of people stopped to ask questions and to talk about the birds they see in the local area. 

Other participants included RSPB, Bowland Wildlife and The Naturalists Trust plus exhibits of bee keeping with pots of natural honey to buy. For the kids large and small there was “build a bee” and other entertainment by way of goats and miniature pigs brought along by a local farm. 

The afternoon provided an entertaining and valuable exercise in spreading the word about birds. And I came away with a rolled shoulder of goat for the roasting pan together with a jar of real honey.   

Honey

Back soon with more news and views. In the meantime keep those comments coming and I will return your visit very soon.

Linking this post to Stewart's World Bird Wednesday.




Thursday, August 2, 2018

More Dove Destruction

Two weeks ago I shared a story about the Turtle Dove a seriously endangered species of the pigeon and dove family at  Dove Tales

Incredibly, and despite pleas, requests and irrefutable evidence of the species continued decline, the French are about to ensure the Turtle Dove loses another 100,00 of its population this coming autumn. 

This from the LPO (Ligue pour la Protection des Oiseaux). 

“100 000 Tourterelles des bois seront chassées cet automne” - 100,000 Turtle Doves will be hunted this fall.” 

Turtle Dove

“France has until August 30 to suspend hunting for this endangered species as requested by the European Commission. And for good reason, the global workforce of the Turtle Dove has fallen by 74% since 1980 and, for France, by 44% for the last ten years alone. 

The responsibility of our country is engaged since we welcome every year 10% of the world population of the Turtle Doves during the breeding season. And we now know that France is an important stage for the populations of North-West Europe because it is located on the migratory corridor of the species. 

However, around 100,000 Turtle Doves are hunted every year in France during the autumn migration period!. 

Faced with this catastrophic picture of a collapsing species, the European Union has proposed to the Member States a series of measures, including the suspension of its hunt. 

As incredible as it may seem, France has refused ! 

Nicolas Hulot, The Minister of State with Responsibility for Ecology has until August 30 to reverse this incomprehensible and scandalous position of France. 

We invite you to call him on social networks : Facebook and Twitter and to send him a mail  to  secretariat.ministre@ecologique-solidaire.gouv.fr. No insult, it is neither authorized nor relevant.

Thank you for your mobilization.”

Turtle Dove

Please, all bird watchers and bird lovers, home and abroad, share this story on Social Media as requested by our colleagues in LPO.

Let’s get this stopped NOW with people power.

Linking today to Anni's Blog.


Tuesday, July 31, 2018

Demo Time

On Tuesday I joined Andy at Marton Mere Nature Reserve Blackpool to help out with a demonstration of bird ringing. A start time 7 a.m meant a bit of a lie-in. 

Demo Time 

Events like this present a great opportunity for non-ringers to see birds in close-up instead of through a pair of binoculars.  It’s an opportunity to learn a little about how bird ringers’ age and sex birds by using techniques involving the taking of biometric measurements, studying feather wear and moult or by simple but sometimes subtle differences in appearance.  

The morning dawned bright with a few cursory showers but not enough to deter the 12 or so people who initially turned up. A good number of those volunteer at the reserve and give freely of their time and energy to make the nature reserve a better place for visitors and birds alike. 

Maybe the 7am start did not encourage many more to join in but the smaller group allowed everyone to get a close look and for us to answer their many probing questions.. 

Reserve Warden Rick at centre stage 

Ready to go.

After a couple of hours we’d caught 4 Whitethroat, 4 Reed Warbler, 2 Cetti’s Warbler, 1 Sedge Warbler and 1 Blackcap, not a tremendous total but enough birds to allow close examination and explanation for the appreciative visitors. 

Andy holding court

The two Cetti’s Warblers, both adults, a male and a female, proved to be object lessons in how our UK summer warblers moult. The two had quite recently finished breeding and one in particular was in the advanced stages of complete moult of wings, body and tail. Not the prettiest of Cetti's to be sure.

Cetti's Warbler 

Cetti's Warbler

No wonder then that adult warblers hide away during the height of summer when their lack of fully working plumage makes it harder to avoid predators. Cetti's Warblers are secretive at the best of times so our visitors enjoyed seeing the pair we caught as it is a species they mostly hear but rarely if ever see well in the field.

Sedge Warbler 

juvenile Blackcap 

Whitethroat 

Reed Warbler 

A good morning was had by all. And there's more soon from Another Bird Blog - ringing, birding and photos.

Linking today to Eileen's Blog.


Friday, July 27, 2018

Smart Moves

The plan was to meet Andy at the Sand Martin colony at 0630. 

I set off at 0600 as an HGV accident on the M6 near Garstang on Thursday resulted in closure of the motorway overnight, gridlock on the alternative A6 and local congestion on the A588. One accident and the whole of the North West ground to a halt. Luckily, no one was hurt and I heard that one side of the motorway was opened early morning. 

Following our last visit to the colony on 3rd July 2018 I paid a few visits but looked from the road above so as to not directly trouble the nesting birds. The visits were mostly inconclusive but I suspected that after the first broods of June and early July many birds had already left as numbers seemed not to exceed one hundred birds. 

Getting up close this morning showed the numbers present to be about 180 and possibly more as suggested by the catch of 72 Sand Martins. 

Out of that overall total, 52 were new birds and 20 recaptures from this and previous years. The 72 comprised 29 juveniles and 43 adults; it was quite illuminating to find that on this our third visit, we are still catching new adults amongst the expected juveniles. 

Sand Martin 

Sand Martins are members of the swallow tribe, and one of the few British birds that nest in sometimes tight colonies; it’s a type of sociable living afforded to them by their preference for nesting in sandy or gravelly banks. 

But Sand Martins are subject to the whims of nature when they return to a colony each year. The riverine bank or quarry face may erode or disappear completely during the birds’ six-month winter absence. In March and April the early returnees have first choice of existing holes that are in good shape when all they have to do is tidy up last year’s nest and add a few new feathers to protect the eggs from the cold sand and gravel of the tunnel. 

New members of the colony may have to compete to find a suitable excavation, but if they can’t they have to set to and make a home. A Sand Martin has claws adapted for clinging, the beak short, rigid and pointed, the two a useful combination for excavation tasks. They grasp the perpendicular surface of their chosen spot with their claws and steady themselves by means of their tail and then make a small hole with their bills. They gradually enlarge the hole by moving round and round, edging off the sand with the side of their bills. Their progress is slow at first but after they have made room to stand on the excavation they intensify the work and push out the sand and gravel with their feet. Both sexes take their turn at the labour until the hole is three to four inches in diameter and up to three whole feet in depth. 

Sand Martin 

The building work is so expert and practised that the terminal nesting chamber of up to five or six inches is situated above the level of the entrance so that no rain water lodges where the eggs and chicks will be. 

The picture below shows how the holes become worn, damaged and eroded throughout the season but if you look closely (click the pic), there are Sand Martins at hole entrances. 

Sand Martin colony 

Processing 72 birds for age, sex and biometrics kept us rather busy but we managed to see 2 Grey Heron, 6 Linnet, 2 Pied Wagtail and 2 Oystercatcher. 

Pied Wagtail 

Grey Heron 

Take a look soon for more birding, ringing and photos in Another Bird Blog.

Linking today with Anni's Blog  and Eileen's Saturday.

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