An Interesting Redpoll - Well Aren’t They All?

There’s no birding or bird ringing for a day or two with both rain and wind preventing activities. 

However, there came an interesting if slightly puzzling recovery of Lesser Redpoll AJD6136. 

Lesser Redpoll

 

We caught and ringed redpoll AJD6136 at Oakenclough on the morning of 1st October 2018. The  morning produced a catch of 6 Lesser Redpolls, 4 Goldfinch, singles of Chaffinch and Meadow Pipit, plus a couple of Great and Blue titmice; a typical if not over large mix of early October local and migrant species. 

At this time of year many Lesser Redpolls from Northern England and Scotland are on their way south to winter in France and the hotspot of Belgium, the latter a country with a special attraction to the species. A Belgian winter landscape holds a redpoll's preferred seeds in abundance and the ambient temperatures are certainly preferable to those of Scotland.

Lesser Redpoll from BTO Migration Atlas

“Most recovery data of Lesser Redpolls comes via North and North West European ringing regions. Most populations follow on average a North to South or North West to West/South East axis, with recoveries as far as N Kazakhstan, up to China. There are two recoveries at more than 4000 km, mostly less than 2000 km.”  BTO.

Only this week did we learn that the same Lesser Redpoll AJD6136 was recaptured by Belgian ringers 44 days later at Maubray, Hainaut, Belgium on 18th October 2018. Yes, that’s right; it took four years for the information to reach us that AJD6136 was recaptured in the centre of the Belgium hotspot pictured above. 

Lesser Redpoll AJD6136 - Lancashire to Belgium

 

A likely but only partial explanation for the four year delay is that the Belgian end of the recovery noted the ring as AJO6136 rather than AJD6136, transposing the letter “D” as “O”. 

This simple error would cause confusion plus double checking and detective work in both the BTO UK and Bruxelles, Belgium end of operations with an exchange of emails and phone calls until the true number could be confirmed. The number AJO6136, if it existed and in circulation, would probably refer to a different species, perhaps one that was highly unlikely to be found in Belgium in the month of November. 

All’s well that ends well but the lesson is that once a ringed migratory bird is released it is unlikely to be caught again so the utmost care should be taken with ring numbers and sequences that are not recognised. 

Our own procedure, after first identifying the species and realising that the bird has an unfamiliar ring, is that the ring number, letters, plus country code if applicable, are read and double checked by two people.  One can never be quite sure where that bird was ringed!

European Bee-eater

I just double checked the weather forecasts for the week ahead again. It’s not good news for anyone who likes to be out and about. 

Keep watching for a window of opportunity and news, views and photographs here on Another Bird Blog. 

 

Six Of The Best

The early starts aren’t too much of a problem when there’s a break with a day off to relax. Thursday became something of a lie in, sitting in the afternoon sun and then afterwards cutting the grass while recharging my solar panels in readiness for Friday’s trip to Oakenclough. 

Friday’s mist over inland mosses signified a fine day ahead as the drying bales lay in wait of the tractor day ahead. 

Morning Bales

 

Another 0630 start saw Andy, Will and Yours Truly set up the ringing shop in the shade of the Mountain Ash trees now glowing red with early berries. The berries, a source of food for autumn birds, are not especially plentiful this year, perhaps  below average and in not enough quantity to sustain hungry Redwings and Fieldfares for more than a few days.   

Rowan berries

There is a belief that a bountiful rowan crop signifies a hard winter ahead, a belief that varies from place to place, country to country. We shall see, but for now and after a terribly cold spring, we are experiencing that rarity, an English Summer like the ones I recall of years 1976 and 2003. 

It is possible that people of more recent generations than I might be nudged into thinking that this summer is alarming, frightening, even catastrophic rather than simply a display of variation and periodic weather changes to which the Earth and solar system is subject. I digress, but suffice to say that not everyone is a follower of The New Religion and its absurd doom laden offshoots. 

The morning brought goodies in the form of visible migration of pipits and over 50 Swallows. Some of the pipits we caught, the Swallows we saw. 

We caught 18 new birds of just five species - 8 Willow Warbler, 6 Tree Pipit, 2 Wren, 1 Goldcrest and 1 Robin. 

We partly expected to see and hear “trepis” with the timing right coupled to clear overhead conditions suited to a notable diurnal migrant like the Tree Pipit. 

Many migratory bird species fly mainly during the night (nocturnal migrants), others during daytime (diurnal migrants) and still others during both night and day. 

The Tree Pipit is a splendid bird with its bright pink legs and fine-streaked yellowish breast. Dare I say it is a little more beautiful than its close cousin the Meadow Pipit? 

All six trepis were juveniles of the year whereby the species’ long-distance migration to Central and Southern Africa has begun in earnest in numbers that may signify a decent breeding season north of Lancashire. 

Tree Pipit

Tree Pipit

In contrast, the Willow Warbler is mainly, perhaps almost exclusively a night migrant. The new ones we caught on Friday had probably arrived overnight and then settled in to feed up in readiness for the next leg of their journeys to Africa. Likewise, all eight Willow Warblers were seen to be juveniles of this season. 

Willow Warbler

Other birds noted – Sparrowhawk, 2 Raven, 6 Pied Wagtail. 

We packed in at 1130 and although we had not ringed too many birds it’s always exciting to see migration in action. 

Linking this weekend to Eileen's Saturday Blog and Anni, Birding in Texas.

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.

Sunnier Days

Sorry to disappoint regular readers but following at least 48 hours of solid rain rather than showery migrant bearing showers, birding would be rather pointless and unproductive at the moent, so apologies for the lack of bird news. 

On Monday evening I and many other bird enthusiasts went along to an event entitled “Bird Migration”, an illustrated talk given by Professor Ian Newton and arranged by the Lancaster and District Birdwatching Society. 

Bird Migration by Ian Newton

Professor Newton is one of the world's leading ornithologists, currently chairman of the British Trust for Ornithology and also the author of several essential-reading bird books. These volumes include a couple of my own favourites, “Finches” and “The Sparrowhawk”, the latter a book which many consider to be the most detailed study ever of any population of raptors. 

The evening proved a great success as Professor Ian Newton described to the packed audience some of the mysteries of bird migration, its evolution, and how it is changing under the influence of climate change. His presentation included explanations of some the many challenges that birds face on their immense travels around the globe, together with the remarkable physical adaptations that enable them to take such demanding journeys. For any blog readers who get the chance to go along to one of Professor Newton’s talks I would urge you to do so. In my case it was rainy evening well spent. 

For today I trawled through the PC archives to find a few pictures from sunnier days and sunnier places so as to keep the blog alive and well. 

Kingfisher

Cattle Egret

Bee Eater

My recent picture of Pilling at high tide was shown as a background to the BBC North West weather forecast last night. They must have decided to use it as illustrating lots of water rather than a sunny day.

A Sunnier Day

As soon as it stops raining or brightens up I’ll be out birding and then report in to readers of Another Bird Blog, so tune in again soon because it can’t rain forever can it? 

This post is linking with I'd Rather B Birding and Stewart's Photo Gallery.