Icons of Migration – How White Storks Have Inspired the Study of Migration for Centuries

Even in a place so packed full of natural migratory wonder as The Straits of Gibraltar, there are few sights as wow-inducing as a flock of hundreds – if not thousands – of migrating White Storks.  As they move along the coast in huge, glittering black and white columns, tracing the patterns of the thermals they ride, they really are the epitome of visible migration!

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White Storks heading to Africa – July 2020 © Inglorious Bustards

These flamboyant voyagers capture the imagination and curiosity, and have been inspiring research into migration for hundreds of years.  Back in 1822, a White Stork turned up in the German village of Klütz with what was clearly an exotic spear lodged through its neck.  It turned out to be from central Africa.  At a time when it was still commonly believed that Barn Swallows spent the winter hibernating in the bottom of muddy ponds, this Pfeilstorch – ‘Arrow Stork’ – opened our eyes to the possibility of incredible avian journeys, and migration science was born!

Their great size, conspicuous presence and predictable return to nest sites makes White Storks fantastic candidates for study, and extensive ringing (banding) programmes were already underway as early as 1906.  From then until the onset of the Second World War, about 100,000 mainly juvenile birds were ringed, resulting in over 2,000 long-distance recoveries of birds reported between 1908 and 1954.  To this day, this wealth of information is arguably the foundation of what we know about where they travel and the routes they take.

White Storks breed extensively across Europe.  Almost like a watershed, there is a line that runs right through the middle of Germany, along which the westward-flyers separate from the eastward-flyers.  The eastern route leads over the Balkans, the Gulf of Iskenderun, the countries of the Middle East over to East, Central and South Africa.  The White Storks we see here, crossing over The Straits in such spectacular fashion have come from west of that line, their migration leading them down through France and the Iberian Peninsula to concentrate at this point.

For a bird with such a large wing span, flapping flight uses around 23 times more energy than gliding.  Since there are no thermals over the sea, they are driven to seek out the very shortest distance between land masses.  That means that, in an average autumn season, 150,000 White Storks of all ages – pretty much the entire western European population – are pushed towards this one point, looking for their moment to cross the 14 km (9 miles) of sea to Africa.  This gives rise to the spectacle of these huge gatherings, spiralling upwards on rising warm air until they emerge up to 1500 m above the ground and then gliding out into the blue.

From here they continue their journey south into Morocco, across the Sahara and down to their wintering grounds in central Africa.  In fact, having cheered them on in The Straits, we often get to see them again when we travel to The Gambia each December!

In the 90’s came satellite-tagging technology, a new way of gathering information about birds that was set to change the way we understand so many things.  Technology tends to be larger when new and unrefined – some of the earliest tags were the size of a brick!  Since a tag is required to be below 3% of a bird’s bodyweight to avoid hindering it, these gigantic nomads with their fascinating journeys presented the ideal species to take this new toy out for a spin!

This opened up the opportunity to study a whole new world of detail not just about migratory routes, but about migratory behaviour.  White Storks usually migrate in mixed groups of both adults and younger birds.  A number of studies have followed the fortunes of young Storks making their first migration without adults to follow, in order to look at the innate-ness – or not – of the journey plan.

Although their in-born sense of direction takes them vaguely in a south-westerly direction, if displaced by weather conditions they are unable to orientate themselves with any precision and many never fully migrate.  This is very different to small passerines, which migrate more-or-less alone, often by night, following an inherited map and with no guidance from adults.

The high importance of this social inheritance makes a great deal of sense.  As a day-flying, soaring bird, the efficiency of their route is heavily reliant on thermals generated by local topography.  They follow adults to learn an exact route – a kind of thermal highway – which on future travels they will be able to recognise visually and be sure of the optimum journey.

Tags also give us more information on the temporal nature of migration in these birds.  It turns out they treat it rather like a nine-to-five, flying for around 8-10 hours every day when the air is warmest, before resting until the following morning.  They barely take a day off, covering the 4,000 km (2,700 mile) journey from northern breeding grounds to sub-saharan Africa in two to three weeks.  Rather than feeding up before migration like some birds, Storks evidently snack en route only to meet their immediate needs, and lose weight on the journey.  Presumably when you’re reliant on literally being lighter than air, every invertebrate over-indulgence counts!

As satellite tags become lighter, cheaper and more precise, the insights they give us become ever-more fascinating.  In 2018 a project set out to explore how White Storks navigate thermals as a group by analysing individual high-resolution GPS trajectories of individual Storks during circling events.

A thermal is a complex, drifting, constantly changing column of air.  To thermal efficiently, birds need to adjust their flight speed and circling radius to find, and remain close to, the centre of the thermal where updraft is highest. Thanks to the precision of the data obtained from the tags, we are able to see that Storks navigate the thermal based not only on their own perception of the airflow in their immediate surroundings, but also on a complex series of social interactions, reacting to the movement changes of Storks within their nearby subgroup, as well as the leaders of the group at the highest vertical point in the thermal.

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Collective flight trajectories and synchronization in circling direction. (a),(b) Flock trajectories of migrating storks showing different flight types (circling and gliding). Grey arrows show flight direction. Tracks are colour-coded based on horizontal path curvature. The thermal is drifting with the wind resulting in distorted trajectories even if the bird flies in a perfect circle relative to the moving air (c) Curvature against time for each individual. Arrows at the top depict time delays between switches relative to first individual. (d) Horizontal trajectories of birds that switched their circling direction.

How amazing to think that each Stork is effectively acting as an individual sensor, such that the whole flock becomes a distributed sensory array.  In this way, they explore and gather information on the thermal as a group, effectively mapping its structure and enabling them to use the optimal airflow within it.

From solving ancient mysteries to changing our perception of collective movement, to simply turning a good day into an amazing one, these really are inspirational birds.  And they are pouring over our heads at the moment here in The Straits!  We’re thrilled to be assisting as always our conservation partners, Fundación Migres, with the annual autumn migration count – to date over 38,000 of them have made the crossing, and we look forward to many more inspirational moments in coming weeks!

Get some migration inspiration in your life!  Get in touch for day trips or bespoke tours this autumn, or give yourself a trip to look forward to, taking in Migration and Cetaceans in 2021 or beyond…

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The group reach optimal height and reach for Africa © Inglorious Bustards

 

 

 

 

Safe travel to The Straits is back!

As COVID-19 remains under control in Spain and cases continue to dwindle, we are extremely pleased that we can now begin to safely deliver our day trips and tours!  With the announcement of Europe-wide “air bridges” on 4 July, international travel to Spain from many countries is now available with stringent health precautions en route but no self-quarantine measures at either end of the trip.

This spring in The Straits of Gibraltar, one of the world’s most breath-taking migratory spectacles passed by almost unobserved.  But whilst we were all sequestered away, Nature carried on regardless, and now these same birds that passed by so spectacularly unseen are preparing to make their journey to their sub-Saharan wintering grounds, new offspring in tow!

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Honey Buzzard © Inglorious Bustards

We’re thrilled that, this autumn, we’ll be able bring you right to your front row seats at Nature’s greatest show either for a day or bespoke trip, or as part of a scheduled departure tour.

The Strait of Gibraltar is the point at which Africa and Europe are at their closest, and is the epicentre for one of the world’s most spectacular bird migrations.  Every year, millions of birds make the 14 km sea crossing, making use of uplifts and thermals rising off the Rock of Gibraltar and the stunning Moroccan peak of Jebel Musa. An estimated 300,000 raptors and other soaring birds pass over this rugged terrain during autumn, as well as untold thousands of other journeying passerines and seabirds.

As well as the star attraction, a boat trip into the Straits itself will let you get close and personal with our resident cetacean species – Common, Bottlenose and Striped Dolphins and Long-finned Pilot Whale.  Even migrating Fin, Sperm Whales and Orca are possible here.

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Long-finned Pilot Whale © Inglorious Bustards

There’s plenty more to explore among the area’s superb habitats, which include salt pans, intertidal areas, freshwater wetlands, low intensity farmland, Mediterranean scrub, precipitous rock faces and the woodlands of Los Alcornocales Natural Park, Europe’s largest Cork Oak forest.  The diversity and wealth of avian and other wildlife in this beautifully unspoilt area of Spain really is astounding!

Couple this with tranquil accommodation in an eco-lodge at the edge of the Natural Park itself, the chance to enjoy the picturesque streets and Moorish fortifications of the Old Town of Tarifa, and of course the chance to sample some of Andalucía’s best local sustainably-produced food and wine, and you really do have a trip that’s Strait-up fantastic!

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Short-toed Eagle © Inglorious Bustards

We can’t stress enough that the health and safety of our clients and avoiding the spread of coronavirus in wider society have been and always will be our top priorities.  We are proud to have been awarded a badge of approval for our COVID-19 Risk Prevention Protocol from both the Spanish Ministry for Industry, Commerce & Tourism, and by the local Junta de Andalucía for both tourism and “active tourism” specifically.Guía Visual Por Un Turismo Seguro con SARS-CoV2

 

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These badges mean you can book with confidence that we are fully compliant with official guidance set out by these organisations, and have in place a stringent COVID-19 Risk Prevention Protocol.

Additionally, we receive training and take advice from our independent risk prevention consultants, Quirón Prevención.

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Upon booking and arrival, you will receive a comprehensive guide on measures taken and your own responsibilities.  Here’s a summary of the measures we’re currently taking to protect you and others, which we´ll update periodically:

  • When we meet you, we’ll go over our COVID-19 Risk Prevention Protocol in detail, and introduce you to the whereabouts of hand-sanitiser and thermometer. Sadly, there’ll be no hugging!
  • You can expect our minibus to have been thoroughly cleaned using recommended virucidal products before the start of the trip, and at the end of each day, and to display clear signage about hygiene, self-protection and distance guidelines.
  • We ourselves will also be thoroughly scrubbed and wearing clean clothes that have been washed at >60ºC.
  • Only two seats per row in the minibus will be occupied, meaning you’ll be sharing with a maximum of five other people. Wearing of facemasks will be mandatory during journeys.  You’ll always have the same seat.
  • If you have your own vehicle, you may use it to follow us if you’d prefer.
  • Thanks to the nature of our passion, we’ll be mostly outside and away from crowds! Group sizes will be also be small. In the event that we can’t maintain appropriate social distance, facemasks will be worn.
  • We’ll encourage you to bring your own protective masks and hand sanitiser for frequent use, but we’ll always have a stock of these available for your use.
  • We’ll encourage you to bring your own optical equipment and not share this. We can however still lend out disinfected binoculars for your personal use during the trip.  Although we cannot share scopes, we have digi-scoping equipment that will allow you to see without coming into contact with the scope.  As always, we will have field guides with us, which we can show.
  • We have stringent procedures in place should anyone – including us – fall ill during the trip.
  • Any accommodation used or hostelry establishments visited are known and trusted, and verified to also have a COVID-19 Risk Prevention Protocol in place.
  • Our legendary picnic lunch will be provided as usual – hygienically prepared, served on disinfected reusable crockery to avoid plastic waste and stuffed full of locally sourced, sustainably produced and delicious ingredients!

We are also keeping a close eye on international travel advice from the World Health Organisation, Spanish government and relevant Foreign Offices.

We hope that with everyone’s collaboration this situation will continue to improve and we will see you soon in The Straits and beyond to enjoy the best of #FlywayBirding.

We still have limited availability remaining on our Straits of Gibraltar – Bird Migration & Cetaceans scheduled departure tour, 26th August – 1st September 2020.  We also have selected availability for day tours or bespoke trips throughout the Autumn migration season!  We are happy to take no-financial-obligation provisional bookings for future tours – just contact us to register your interest and talk further.

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Black Kite © Inglorious Bustards

 

They’re coming! – a spring migration spectacular!

Our Strait Birding & Cetaceans spring migration spectacular is coming soon, and there are still spaces available! Here´s a flavour of what happened last time…

“The clouds were low and moody, and the winds pretty strong, but the intrepid Black Kites had decided, “Stuff it! This will do!”.  One by one, and then by the dozen, they started to appear out of the clouds, wings beating like crazy and some barely making land!  We watched, hearts in mouths as two individuals struggled right in front of us, so close we could almost have dragged them in with a well-flung lasso!

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Black Kite © Inglorious Bustards

There are no thermals over the sea, which is what makes crossing it so treacherous for soaring birds.  Though barely metres from land, they were having to use the diagonal wind to gain lift, increasing the length of their journey many times. Then, after what seemed like an age they hit land and instantly found a thermal, taking them from a couple of metres above the sea to a couple of hundred metres above the land within seconds!  We cheered them on with a massive amount of relief!

“Exhilarated, we headed down to the village for a coffee.  But our break was not to be an uneventful one!  Suddenly a break appeared between two large clouds over Punta Carnero and Gibraltar, effectively creating a sunlit channel of warm air which stretched right from the coast of Morocco to just above our heads!

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White Storks and inter-mingling Black Kites © Inglorious Bustards

This was the moment they – and we – had been waiting for!   Necking our coffee we took up position by the sea wall as they began to arrive.  Over the next hour or so we witnessed an immense river of raptors and storks arriving from Africa.  Three hundred Black Kites, twenty Griffon Vultures, three hundred Short-toed Eagles, over a hundred Booted Eagles, 38 Black Storks, thirty or more Western Marsh Harriers and a sprinkling of Egyptian Vultures, Montagu´s Harriers, Eurasian Sparrowhawks and Lesser Kestrels poured over us in one of Nature´s most uplifting and vibrant spectacles.  We abandoned all plans and ate our picnic right there, barely finding a quiet moment between migratory waves to grab a plate of food!”

This trip, running 28th March  – 3rd April 2020, is not to be missed!  Check out further information on our website here for your ringside seat to the greatest show on Earth…

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Short-toed Eagle © Inglorious Bustards
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The Spring 2018 team – check out the new found Raptor watching skills!
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Booted Eagle © Inglorious Bustards
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White Storks © Inglorious Bustards
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Long-finned Pilot Whales © Inglorious Bustards