Natur-al-Andalus

September Feeding Frenzy in the Strait of Gibraltar

2011-09-28T18:26:00.000+02:00

This is the time of year when flying fish are passing through the Strait of Gibraltar. They attract many predators that chase them and catch them below or above the surface of the water. These concentrations provide a unique opportunity to see large concentrations of marine predators. Last Sunday we were able to experience this amazing event. See our blog of 20 September, 2010, for a similar event.

Last year we found them in the Mediterranean, east of Gibraltar, but this time they were in the Strait within view of the mist-covered and imposing Rock. Below are some scenes from this magical event...

Leading the underwater action were Common and Striped Dolphins

On the surface, the main predator was Cory's Shearwater

They wait patiently, and peacefully, in rafts until, that is, the dolphins bring the fish to the surface. Then the squabbling commences!

Just like the smaller vultures at a carcass, the Balearic Shearwaters (below) operate on the fringe as they wait for scraps

Gannets arriving from the Atlantic to winter also join in. Most are juveniles or immatures. There are very few adults right now, most will arrive in October.

These past weeks have been very busy for us in the field, so we need to catch up with a number of stories. So keep visiting our blog!

The Day of the Honey Buzzard

2011-09-04T20:30:00.000+02:00

Late August and early September mark one of the most incredible and impressive of bird migration spectacles - the passage south of the Honey Buzzard Pernis apivorus across the Strait of Gibraltar

Tens of thousands of Honey Buzzards migrate south in the space of a week or so. They come in tight flocks which adds to the air of spectacle. These birds are coming from Scandinavia, western Russia and Western Europe. They are bound for the tropical forests of West Africa.

Their plumage is very variable and we can identify three main plumage types or phases - they are linked to each other by intermediate patterns. The most common phase is the intermediate or barred (above)

This bird is of the light phase

and this one is of the dark morph

In this image we see all three phases together

All the images in today's blog were taken today over the Rock of Gibraltar

Not all were high and some, incredibly, flew low over the town

The passage continues and more species will pass over the next two months...

Activity in the Strait of Gibraltar in mid summer

2011-08-04T18:20:00.000+02:00

The Orca activity in the western end of the Strait at this time of the year is related to the exit of the Red Tuna from the Mediterranean towards the Atlantic. The tuna enter the Mediterranean in April to breed and leave in July and early August. The Strait is very deep, reaching 1000 metres, but in the west a sill rises from the sea bed and the depth is reduced to around 200 metres. Any fish passing this is forced upwards allowing a chance for fishermen (below) and orcas (above) to catch the fast fish.

One interesting aspect is that the highly intelligent orcas have learnt to go for the tuna which have been caught in the fishermen's hooks. It is not unusual for the fishermen to pull up a tuna head, rest of the body missing!

The groups of orcas seem to fuse and split at different times as they hunt for the fish. Here is a pod of females, recognizable by the small, curved, dorsal fins

Male (right) with higher fin than female (left)

Female with young

The Strait is a busy shipping lane so the orcas have to be alert to this danger at all times

Male Orca

Female starting a dive

Male showing the large fin clearly

While watching the orcas we picked up other activity which we illustrate from here down, with images from our own archives, taken in the Strait at other times. Here is a group of Common Dolphins Delphinus delphis

Loggerhead Turtle Caretta caretta

Common Tern Sterna hirundo - steady flow of birds migrating towards the Atlantic

Black Tern Chlidonias niger - The first birds are now moving into the Atlantic

Balearic Shearwaters Puffinus mauretanicus - coming from the western Mediterranean to feed in the rich waters of the Strait

Cory's Shearwaters Calonectris diomedea - also feeding in the upwellings of the Strait

Magical 24 Hours

2011-08-03T19:36:00.000+02:00

The last 24 hours have been magical. Few places can offer what the Strait of Gibraltar can. Here an Orca Orcinus orca off Tangier, Morocco, this morning...Last night 10 thousand Black Kites Milvus migrans and up to 100 thousand Common Swifts Apus apus migrating south over the Rock of Gibraltar (below)

Part of a large flock of Black Kites yesterday

Black Kites against a backdrop of migrating Common Swifts

This is a quick news flash. These stories will be developed in future blogs...

Raptor Migration in late July

2011-07-31T17:11:00.000+02:00

We saw the last Black Kites Milvus migrans migrating north in mid-June. Now they're back, heading south for Africa with this year's youngsters!

For a few days now small groups of Black Kites have been crossing the Strait of Gibraltar as they head for the tropical African savannas

But yesterday evening, around 6pm we saw a big "rush" of birds over the Rock of Gibraltar. My friend Mario Mosquera estimated 1500 birds in the flock, a taste of things to come. With westerly winds these birds drift over Gibraltar from where they gain height to start the crossing. If the wind is too strong some turn back, often having already started over the sea, and try the next day.

Most of yesterday's birds were juveniles, birds that have been born this spring. You can tell them by the pale, rufous, plumage and the fresh wing and tail feathers. Breeding among the Iberian birds is timed to coincide with the spring abundance of food. The Iberian adult Black Kites arrive in February and early March. It is these birds, and their young, that are now leaving to avoid the summer drought. Their arrival in sub-Saharan Africa will coincide with the onset of the summer rains there.

Not everything is leaving after breeding. Eleonora's Falcons Falco eleonorae are just arriving in the area from their wintering grounds on the island of Madagascar. These rare and elegant falcons breed in remote islets and unfrequented coastal sites across the Mediterranean and the Atlantic coast of North Africa. They arrive late for a reason. Their young will hatch in September and will be fed on the millions of small migrating birds that will then be heading for Africa. It is a wonderful example of a perfectly tuned specialised strategy. It's not easy to find these birds on migration so it was a treat to see this female (above and below) yesterday at Europa Point.

Forest animals of Cazorla

2011-07-26T19:51:00.001+02:00

The mountains of Cazorla (above) in south-east Spain are a reservoir of trees, insects and forest animals. It is here that the Guadalquivir River (below) starts its long journey towards the distant Atlantic Ocean.

Spanish Red Deer Cervus elaphus hispanicus (above) and Fallow Deer Dama dama (below) thrive in these forests

Red Squirrels Sciurus vulgaris have a southern European stronghold here as do many forest birds (below). The degree of sub-specific differentiation testifies to the isolated nature of the Iberian Peninsula, a refugium, during glacial times

Iberian Chaffinch Fringilla coelebs balearica

Iberian Nuthatch Sitta europaea hispaniensis

Iberian Long-tailed Tit Aegithalos caudatus irbii

Iberian Crested Tit Parus cristatus weigoldi

Iberian Coal Tit Parus ater vieirae, now in body moult

Iberian Jay Garrulus glandarius fasciatus

Iberian Crossbill Loxia curvirostra balearica

More migration towards the Atlantic

2011-07-16T10:52:00.000+02:00

Audouin's Gulls Ichthyaetus audounii are not the only gulls now leaving the Mediterranean for the rich waters of the Atlantic (post of 10th July). The attractive Mediterranean Gulls Icthyaetus melanocephalus are also on the move.

Many of the birds coming past are adults, with very worn plumage after breeding and already in head moult

Juveniles, noticeably browner and greyer than the adults, follow the adults on migration (above) though often adults also travel without youngsters (below)

Immature birds are also moving. Above is a first summer bird already going into second winter plumage. Below is a second summer bird, looking almost like an adult but with black outer primaries

Also moving out of the Mediterranean are Black-headed Gulls Chroicocephalus ridibundus, and they travel in larger groups, of adults and juveniles.

All this activity does not go unnoticed. Peregrine Falcons Falco peregrinus fly close to the sea (see post of 12th July), ever watchful of an opportunity to take one of these small gulls...

Cattle Egrets of all shapes and sizes

2011-07-14T19:36:00.000+02:00

In our blog of 24th April, Stewart had visited a breeding colony of Cattle Egrets Bubulcus ibis that was starting up. Now he returned to find thousands of birds in a colony in full swing, from incubating birds, to small juveniles, and others recently fledged.

Incubating adult. Going for a second brood or retrying after a first failure?

cute juveniles

feeling the heat - it regularly gets above 40 degrees celsius here!

adult on lookout duties

part of the colony

recently fledged hooligans

adult on guard

Peregrines - the New Generation

2011-07-12T19:29:00.000+02:00

Juvenile Peregrine Falcon Falco peregrinus brookei at Europa Point, Gibraltar - 10th July

It was back on the 22nd February that we got this shot of the adult peregrines mating. We've been following their progress and three weeks ago three youngsters fledged...

The juveniles are largely independent now and are terrorising the neighbourhood! Juveniles of other species that nested on the same cliffs better beware! Here a juvenile peregrine as a go at a young Yellow-legged Gull Larus micahellis which doesn't appreciate the gesture...

...but they have to watch out as mummy doesn't take kindly to their approaches.

This afternnon they had a go at a young, and noisy, Common Kestrel Falco tinnunculus, that managed to get away minus a few tail feathers. The lower peregrine had its crop full so she must have been helping her sister get a snack.

They are rapidly becoming experts at their job

equally at home mover the sea as over land

we'll keep an eye on them in the coming weeks but, for now, they're doing very well, even if their neighbours don't share the sentiment!

We're back !

2011-07-10T21:00:00.000+02:00

After a short break, we're back with the Natur-al-Andalus blog and we hope to provide you with the latest information of what's going on. Gerry and Stewart Finlayson previously contributed to this blog. Now they join us - the complete Finlayson Nature Photography team - so expect even more than before! We will be busy this summer - as usual! In August we'll be excavating at the Neanderthal cave site at Gorham's Cave so watch out for news soon. For now, we start with what's going on right now. The migration of the rare Audouin's Gull Ichthyaetus audouinii is under way...

These birds were very rare before the early 1980s but they have recovered substantially since then although they remain vulnerable as they only breed in a few scattered colonies in the Mediterranean, mostly in Iberia

They are amazingly elegant and beautiful birds and they are now migrating in numbers past Europa Point, Gibraltar, on their way out to spend the non-breeding season in the rich waters of the Atlantic off West Africa

This afternoon, in 3.5 hours of observation, we counted 120 going past Europa Point. Most were adults and their plumage was not as tatty as it usually is at this time of the year. We don't expect so many adults this early and it may be that they've had a bad breeding season and are leaving early. The relatively good condition of the plumage seems to bear this out.

Adult passing Europa Point lighthouse

These birds travel singly, in pairs or loose flocks

Today's blog has been a brief prelude of what is to come. Keep visiting us for more!

In a colony of egrets

2011-04-24T18:35:00.000+02:00

Among the spectacular sights of southern Iberia in the spring is a colony of nesting egrets. Stewart went on a mission to capture the beauty and elegance of the Cattle Egret Bubulcus ibis in full breeding plumage. He caught up with them in a colony on white poplars. The photographs speak for themselves...

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An unexpected visitor

2011-04-13T19:07:00.000+02:00

Last weekend saw an intense passage of raptors across the Strait of Gibraltar and over the Rock. More of that will follow in other posts. The local Peregrines patrolled the airspace by their nesting cliffs searching for tired migrants. Little did we know what would unfold...

From out over the Mediterranean Sea, in the east, came a strange falcon...It was larger than the local Peregrines, with a disticntive shape and plumage pattern. It was a Lanner Falcon, a North African species that occasionally strays onto the European shore at this time of year.

Venturing close to the Peregrine's cliff, it was a matter of time before an aerial combat would unfold, and it did...

the chases went on for over fifteen minutes, the intruder seemingly returning for more of the action. And it gave as good as it got (below)!

We sighted the bird later in the day so it didn't quite get the message instantly!

The bird was in its second spring of life, in other words it was born last spring. It was probably dispersing into new territory and stumbled upon an angry cousin!

We are grateful to Dick Forsman for providing a second opinion on the identification.

A moment in the life of an eagle

2011-04-02T12:54:00.000+02:00

If there is a bird of prey that really struggles across the sea while migrating, it has to be the Short-toed Eagle. Those reaching European shores at the Rock of Gibraltar are exhausted, often panting. But it is not all over. They then have to contend with the attacks of local Yellow-legged Gulls as these images, taken this week, show...

the bird rises on updrafts as it reaches the cliffs, but is the struggle really over?

gulls also use the same updrafts...

there may be trouble ahead...

impact imminent!

soon one gull has become lots of gulls

this eagle has gained sufficient height to make a quick getaway. Others are not so lucky...

Marsh Harriers on the move

2011-03-28T23:45:00.000+02:00

Marsh Harriers are now reaching their peak, the early waves dominated by males.

Today several birds that came over Gibraltar were mobbed by the local gulls, providing opportunities to observe their escape and defence strategies as captured in these images.

One of those mornings!

2011-03-27T17:28:00.000+02:00

After days of cloud and strong easterlies the morning was soon sunny once the early morning cloud had dissipated. The wind was fresh from the north-west so there was a good chance that raptors would come over Gibraltar. Early indications were good - a strong passage of Swallows, House Martins, Goldfinches, Linnets and Serins, all arriving across the Strait of Gibraltar from Morocco. With them were the first Black Kites. But the day belonged to the Booted Eagles (above and below).

These eagles are now hitting their peak passage and many had obviously been waiting to get across

The finches continued to swarm. A flock of ten or so Red-rumped Swallows dashed past a metre away from me and Bee-eaters swarmed as they noisily passed north. If the day was the Booted Eagles', the Sparrowhawks weren't far behind, darting into the trees and having a go at the passing finches. There were many males in today's migration (below).

The range of species was good and included Montagu's and Marsh Harriers.

Male Marsh Harrier overhead

Some Short-toed Eagles are still coming through - their peak was earlier in the month - and the gulls still make them feel unwelcome!

And of course the Black Kites keep on coming, these are now heading for Western and Central Europe

Denizens of the White Water

2011-03-23T18:57:00.000+01:00

The fast-flowing mountain streams of the Iberian Peninsula, from the Pyrenees down to the Betics, are home to specialists at living amidst torrents and cataracts. No species is more at home here than the Dipper.

This amazing bird is widespread across the Palaearctic Region to the Himalayas. To the east it is replaced by the Brown Dipper. The American Dipper is the North American counterpart, reaching south to Central America. Two other species - White-capped and Rufous-throated - take over in South America. And that is it. There are only five species of Dipper in the world!

Dippers are highly specialised and adapted for taking insect larvae and other invertebrates under water. They don't dive for them but instead walk under water to take their prey, a unique behaviour among birds. The images below show this amazing behaviour...

Often associated with similar habitats is the beautiful Grey Wagtail, with its safrron yellow rump and undersides. It is less restricted to fast flowing streams but is usually found wherever there are Dippers.

Also present alongside is the White Wagtail but this species is the least specialised of the three and is often at home in other aquatic habitats too (below)

Perhaps more appropriately grey than the Grey Wagtail the absence of yellow separates this species easily from its cousin (below)

Mass arrivals of Black Kites

2011-03-05T17:58:00.000+01:00

The Black Kite is among the earliest of spring migrants and certainly the most abundant, tens of thousands crossing the Strait of Gibraltar from Morocco into Europe (below). The first ones appear in January and passage is substantial in February, building towards a peak in the first days of March.

View of the Strait of Gibraltar from the north. The mountain on the right is Jebel Musa in Morocco. The Rock of Gibraltar (in Europe) stands out on the left.

Having already undertaken the arduous crossing of the Sahara Desert, these soaring birds have to run the gauntlet of the Strait. It may not be a huge distance (only 14km at the narrowest) but flying over the sea is never good for a soaring bird. Additonally, unpredictable winds add to the hazard.

Travelling in flocks helps with keeping on the right track and offers protection. Flocks descend to roost together at night. But the downside is that wherever they stop there is unlikely to be sufficient food to feed them all. So they tend to fast during the journey, catching prey opportunistically when the chance arises, and simply get on with the migration as quickly as possible.

The early birds are the ones from the south. They will breed in southern Iberia. As the season advances birds heading further north arrive. These may be going all the way to Switzerland, Germany and France. One the breeding adults have passed, a second movement - of immatures - takes place between late April and June. All in all, almost six months of Black Kite migration!

Of Eagles, Rabbits and Partidges

2011-02-18T20:43:00.000+01:00

It is quite remarkable how we often observe the world around us without fully appreciating the depth of time that we are observing. Three species are currently staging a "cat-and-mouse" saga that goes back to the Pleistocene. The game is at least 100 thousand years old!

The "cat" in our game is the majestic Spanish Imperial Eagle, an endangered species which is endemic to the Iberian Peninsula. I watched these birds hunting in the plains of La Janda this week.

There are two "mice" in this story. One is a bird - the Red-legged Partridge (above). The other is a mammal - the Rabbit (below). Both are Iberian endemics too. Hard to believe it may be but the Rabbit evolved within the Iberian Peninsula and has been introduced everywhere else by humans!

The eagle is one among a suite of species (including the endemic Iberian Lynx) that have relied to a large degree on these two prey species. Both reproduce quickly and in large numbers and have been an almost inexhaustible supply of food for these predators.

Rabbits are doing particularly well in La Janda, having recovered from epidemics that have reduced their numbers in recent decades. It is wonderful to see families of them sunning themselves close to their burrows under the cover of wild olives (above). Indeed a millennial sight! Rabbits must have been so numerous that they gave Spain its name. The Roman Hispania was derived from the Carthaginian Ispania which is thought to come from the word Sphan which meant Rabbit. Literally Spain means "Land of Rabbits"!

With the big eagles lurking Rabbits rely on camouflage and keeping still (above) to go by unnoticed. Partridges too are cryptic when seen from above or behind (below).

But Nature generates uncontrollable impulses which can expose prey. Partridges calling out to stake out territories may suddenly become visible (below).

...and the eagles are ready to pounce!

their strategy is to dive from great heights (above) or to approach low with stealth (below)

either way it is a long, tried and tested, method with great rewards...

Above: Spanish Imperial Eagle with Rabbit

It's hard to fathom, watching in awe as these animals play out this game of life an death, that the same sight was seen millennia ago by our Neanderthal cousins. They died out and we have put the eagle's future very much on the balance. How much longer will we allow this millennial game to continue to be played in our skies?

Diary - The Common Crane

2011-02-13T23:41:00.000+01:00

This is the month when the Cranes that have wintered in southern Iberia and Morocco return northwards to their Scandinavian and Russian breeding grounds. The gathering of thousands of Cranes in traditional spots like the old lake of La Janda might convince us that all is healthy with this species. But reading the accounts of the 19th Century naturalists leads us to realise that we are observing a meagre ration of what was once a real spectacle of nature.

One of my favourite accounts of the northward passage of Cranes across the Strait of Gibraltar is Irby's who wrote how: "On the 11^th of that month (March), in 1874, Mr Stark and myself had the pleasure of seeing them (the Cranes) on passage; and a grand and extraordinary sight it weas, as flock after flock passed over at a height of about two hundred yards – some in single line, some in a V-shape, others in a Y-formation, all from time to time trumpeting loudly. We watched them for about half an hour as they passed, during which time we calculated that at least four thousand must have flown by. This was early in the morning, and we were obliged to continue our journey; but when we lost sight of the Vega of Casas Viejas, over which the cranes were passing in a due northerly direction, there appeared to be no diminution of their number, and, as my friend remarked, ‘One would not have believed that there were so many Cranes in all Europe.’"

Thirty years later Verner commented how the passage was as spectacular as in Irby's day and noted how:

"The direction taken by successive flocks, in accordance with observations made by me for me for many years in the same district, is almost invariably the same, namely a line which when plotted on a map passes about 6 miles west of the old town of Tarifa."

It is a danger to highlight the spectacle today as it lulls us into a false expectation that all is well. But the real cause of the decline of the Crane is habitat loss. Places like La Janda, once Spain's largest lake and now sadly drained, and many other wetlands of the Strait of Gibraltar were part of a vast network that supported vast numbers of waterbirds of which the Crane was a spectacular flagship. Even as I write these lines wetlands like the Smir on the Moroccan side of the Strait are being filled to give way to developments. This is particularly ironic as this wetland forms part of an intercontinental UNESCO Biosphere Reserve!

The situation is even sadder. Cranes no longer breed in southern Europe but they did in Irby and Verner's day, la Janda being their last stronghold. Verner (1911) tells us how: "About thirty years ago, considerable numbers of Cranes remained to nest in south-west Andalucia: but constant egging by professional “collectors” has sadly reduced their numbers. In some districts they have ceased to nest altogether while in others where I can recall seeing over thirty pairs in the nesting season there are now hardly half a dozen to be found during the summer months."

So these images are a tribute to a wonderful species and its wetland habitats and a warning: just because we see large flocks of this species (or indeed other animals), it should not be taken to mean that all is well. The wetlands of the Strait of Gibraltar and its birds have been dying a long and lingering death for 150 years. Yet it seems that more emphasis is placed on the wonders of the region than on the rate of loss. In another 150 years it may only be the images that we are left with. And that will be our legacy...

Celebrating our First Birthday

2011-02-02T16:57:00.000+01:00

We celebrate our first birthday today!

In this first year we have been viewed by close to 4700 individual visitors from 95 countries.

There have been close to 11,500 views of our pages.

In Networkblogs we have achieved a following of 759. In our theme categories we have achieved the second highest following in Nature, third in Environment and fourth in History.

Thanks to all our facebook friends and followers for your support. We will try and build on this in our second year!

Diary - The Lammergeier

2011-01-29T00:05:00.000+01:00

The Lammergeier has become among the rarest of European breeding birds. The decline seems to have started as far back as the 19th Century and its causes seem to have been a combination of the rise of guns, poisoning and nest robbing. Colonel Irby in 1895 wrote how his friend Colonel Verner had already noticed a decline twenty years earlier when "...these birds nested regularly not far from Gibraltar, but owing to persecution have of late years disappeared or retired to less-frequented sierras."

Dr Stark, in the decade of the 1880s recorded how "In Andalucia is decidedly common in the Sierra Nevada, and all the region between Granada and Jaen. In a day’s ride five or six may be seen flying over the hill-sides or gliding along the face of a cliff or down some ravine. In the Ronda mountains they are fairly numerous, becoming scarcer towards Gibraltar and Tarifa."

It seems that the presence of the Griffon Vulture was somehow detrimental to the natural distribution of the Lammergeier. Dr Stark thus commented how "In certain districts of the Sierra Nevada, where the Griffon does not intrude, the Quebrantahuesos is especially numerous."

Stark's comments also suggest that the population near the Strait of Gibraltar was dominated by non-breeding immatures (above and below). "In the lower ranges of the Sierra de Ronda, towards Gibraltar and Tarifa, the Bearded Vulture is not very common; the Griffon being, on the contrary, abundant in that district. The majority of Bearded Vultures seen here have been birds in dark plumage, not fully adult."

Today, to have any chance of seeing (and photographing) Lammergeiers we have to travel to the Pyrenees, the main European nucleus of this species. Re-introduction programmes, such as those in the Sierra de Cazorla, offer hope of recovery which will be slow. These birds take eight years to reach breeding condition.

Subadult

First winter (left) and adult (right)

Today, in special places like Boumort in the Catalan Pyrenees, it is still possible to observe the complete array of European vultures together. Three of them - Griffon, Black and Lammergeier - are in this single photograph.

My gratitude to the management and staff of Boumort Reserve for permission to photograph within the reserve

Diary: The Bonelli's Eagle

2011-01-18T18:27:00.000+01:00

With the new year I am introducing a new section to the blog called diary. Whenever this word appears in front of the post title it means I will be drawing on written texts from 19th and early 20th Century naturalists and comparing to the present. Photographs may not all be from now but will include some from my archive. Today, I start with the Bonelli's Eagle Aquila fasciata.

This impressive cliff-nesting eagle has attracted the attention of naturtalists for a long time. Sadly, this bird is very much in decline and is rarer each year. The European population is of the order of 1000 breeding pairs, 80% of which are in Spain with smaller numbers in Portugal, Greece, France, Italy, Croatia and Albania.

Its geographical range once included many coastal cliffs where it is now gone. A traditional site was the Rock of Gibraltar where it nested annually until last recorded in 1936 - the disturbance of the war years probably caused their disappearance. They nested below the old Signal Station (below).

Colonel Howard Irby in the second edition of his Ornithology of the Straits of Gibraltar (1895) tells us how " a pair nest annually at Gibraltar, at the 'back of the Rock', to the south of the Signal Station; there are never more than a pair, though there are four situations where there are nests, one of which has not been used for several years.

typical eyrie with two chicks

My friend and colleague Dr Juan Pleguezuelos of the University of Granada studied this habit of use of alternative nests and found that it was a way of avoiding parasite infestation. What is more he was able to show that birds which lined the nests with fresh branches of Maritime Pine Pinus pinaster had a greater breeding success rate. The chemicals produced by this pine acted as an effective insect repellent that kept the nests clean and the chicks healthy!

Bonelli's Eagles were once widely distributed across southern Iberia and our Pleistocene cave sites on the Rock have revealed evidence of their presence since at least 50 thousand years ago (above).

Irby tells us how "when not breeding they hunt together (male and female), one high above the other, suddenly stooping down on some luckless rabbit or else gliding off to take up a fresh aerial station whence to watch for their prey, which seems to be taken on the ground." The other favourite prey of this bird is the partridge.

Irby relates some fascinating accounts of situations and contexts unlikely to be found today. Ospreys also nested on Gibraltars cliffs and he tells us what happened when they came across each other: "on another occasion, in the same month, I saw a Bonelli's Eagle flying about not far from the Osprey's nest, when down swooped an Osprey, like a stone, striking the Eagle on the back and knocking out a lot of feathers. Shrieking out, they were bound together for a few seconds, and then separated, neither apparently the worse for the encounter, and each flying off towards their respective eyries.

Lt Colonel Willougby Verner, writing in 1909, was equally impressed by this powerful eagle. As a falconer and son of a falconer he "was intensely attracted by Bonelli's Eagle when I learnt that it was the same species which the Afghans employ for hawking small deer."

He further observed "as regards their structure, few Eagles, if indeed any, are so powerful for their size as is Bonelli's. Their massive legs and feet and abnormally large claws are seemingly out of all proportion to the rest of their body."

It is a real pity that such a majestic animal should be suffering such a fate as we progressively eat into their territories and sever traditional connections that have maintained viable populations for tens of millennia...

The Chiffchaff and the Aloe

2011-01-03T01:43:00.000+01:00

South African aloes were introduced in Gibraltar in the 19th Century. They did well in the Mediterranean climate, similar to that in their home, and spread. They fared best on warm limestone slopes.

The mild, frost-free, winter climate of Gibraltar has allowed the aloes to flower in December and January, the corresponding South African summer.

the slopes take on a spectacular colour as the stands of aloe come into full bloom

These aloes are pollinated in their native South Africa by sunbirds, which have coevolved with the plants and have developed specialised bills for extracting the nectar. The red of the aloes attracts the birds and pollen is transferred by the birds who get their nectar reward. There are no sunbirds in Gibraltar but some species have learnt, in the short time since the 19th Century, that the red aloes mean food.

The main species visiting the aloes is the Chiffchaff, a winter visitor. It seems that the nectar is used as supplement to their usual diet of insects.

Chiffchaffs (above and below) drinking nectar

The Sardinian Warbler, a local resident, is another regular visitor to the aloe stands (above and below)

Sardinian Warblers (male above and female below) are larger than Chiffchaffs and will supplant them from the flowers

but the Chiffchaffs have a trick - they hover and collect nectar from the flower heads that are inaccessible to the heavier Sardinians

So the sunny slopes of Gibraltar in late December and January are a little laboratory with a natural experiment in action. Here we observe a behavioural change in the behaviour of bird populations, both migratory and resident. And, while for a long time the aloes seemed unable to cross pollinate and only spread vegetatively, there is clear evidence now that plants are getting fertilised. The Chiffchaffs are doing the trick, it seems!

Butterfly on aloe - with the warm weather (temperatures around 20C in the middle of the day) many insects are active around the flowers too, providing additional temptation to the insectivorous warblers

European Bee-eater - Bird of 2010

2010-12-27T16:38:00.001+01:00

The bird of 2010, selected by blog and facebook followers, is the European Bee-eater Merops apiaster. My thanks to all my friends for joining in the fun of selecting this species. It has been your choice! Here is a small selection for all to enjoy...

A wagtail for all seasons

2010-12-23T00:25:00.000+01:00

The marshes and other wetlands of south-western Iberia are home for many birds, some migratory and others less so. It so happens that there is always one species of wagtail exploiting the diverse and abundant insect life that thrives in small pools, ditches and flooded fields. Now it is the White Wagtail that abounds in these habitats.

they arrived in September and October and will depart in February and March

they head back north into north-western Europe and do not breed in these lowland wetlands. Come February and March it is the Yellow Wagtails that arrive from the south, Morocco and sub-Saharan Africa, to breed in these same places.

By the time they have finished raising their young and are migrating south once again, its cousins from the north return and fill the empty space.

Bird of the Autumn - The Results

2010-12-20T16:32:00.000+01:00

Adding your comments in this blog, facebook and by email gave a clear winner - the Bluethroat. Thank you all for giving your views!

Second place went to Cory's Shearwater

Barbary Partridge (above) and Wheatear (below) took joint third.

The Charming Goldfinch

2010-12-18T19:35:00.000+01:00

The Goldfinch is an abundant resident bird whose numbers are largely augmented in the region of the Strait of Gibraltar during migration and in the winter. Its beauty and colour matches, in my opinion, that of many tropical passerines.

Goldfinches are the second most numerous passerine migrant crossing the Strait of Gibraltar. Only the Swallow is more abundant. The migration is most pronounced in the autumn when tens of thousands arrive in late October and early November, many crossing south to spend the winter months in Morocco.

But many remain on the northern shore of the Strait where they are a dominant component of the bird community of pastures where they feed largely on the seeds of thistles. Here their density averages around 7 birds per hectare, giving a clear indication that the region is a main wintering area.

Most of the wintering Goldfinches come from western Europe, principally France, the British Isles, Germany, Belgium and Switzerland but a small contingent comes from further east. These are birds from Russia, the Czech Republic, Austria, Italy and Yugoslavia.

Their long bills are specialised for probing into thistle heads from which they can extract the most difficult of seeds, inaccessible to most other finches (above and below).

Come March, these birds will join others coming from Morocco to return back to their breeding grounds, leaving the local breeding birds behind. The phenomenon of the Goldfinch migration and wintering in the Strait of Gibraltar is another of those hidden secrets that this rich land reveals to those who venture into the fields of places like La Janda...

Bird of the Autumn

2010-12-11T17:23:00.000+01:00

With the end of the autumn I thought it might be fun to pick the top three birds of the past season, just like we did for the spring. So here I am posting 25 birds in alphabetical order. Why not have some fun with me and select your top three? Just put your favourites numbered 1, 2 and 3 in the comments section (or on facebook) and we can see which species win. Here they go:

Azure-winged Magpie

Barbary Partridge

Barn Owl

Bluethroat

Booted Eagle

Black-winged Kite

Cattle Egret

Cetti's Warbler

Common Sandpiper

Cory's Shearwater

Egyptian Vulture

Fan-tailed Warbler

Gannet

Greater Flamingo

Griffon Vulture

Little Egret

Meadow Pipit

Pallid Swift

Peregrine Falcon

Red-rumped Swallow

Sparrowhawk

Spotless Starling

Squacco Heron

Wheatear

White Wagtail

With the Ring Ouzels

2010-12-05T18:55:00.000+01:00

Ring Ouzels pass through our area but many stay for the winter, usually in localised spots on the sierras. They choose open habitats, with scattered shrubs, pasture and rocks, with cliffs close by. The karstic (limestone) mountains of the Serrania de Ronda are a favourite for these birds.

Ring Ouzel winter habitat

This habitat is shared with a diversity of other birds, including Rock Bunting, Black Wheatear, Rock Sparrow and the Griffon Vultures which watch proceedings from their cliff ledges or the sky.

The ouzels seem to be fixed on the fruiting hawthorns which must provide a large proportion of the winter diet.

Hawthorn fruit with Mistletoe, typical view for a wintering Ring Ouzel

Numbers vary from site to site. In this one around 20 birds have settled for now. We will keep an eye out for them as the winter progresses...

Deep Purple

2010-11-30T18:36:00.000+01:00

A decade or more ago finding a Purple Gallinule, sorry Purple Swamphen, was quite an achievement. You could find them but they were localised in some well protected lakes and other wetlands.

In the early to mid 1990s you would certainly be very lucky to find one in La Janda. Then, possibly thanks to improved conservation, they started to turn up in the oddest of places. I even found them in small ponds within industrial estates. They certainly took off!

La Janda is now a great site to see them, often in flocks. They are quite bold and will come out of the reed beds into the open in broad daylight.

In fact they are so bold that they will venture onto tracks frequented by vehicles that simply drive too fast, to the detriment of these amazing birds...

But the balance is a positive one and we are now able to enjoy these iridescent birds where until recently there were none...

Winter paradoxes

2010-11-29T18:56:00.000+01:00

Yesterday I saw this young Short-toed Eagle over La Janda. This is a predominantly reptile hunter, though it does take other prey, and most books tell you they all go to spend the winter in tropical Africa. Before anyone jumps to the conclusion that global warming is changing the habits of this bird, I hasten to add that I have seen these majestic raptors in the area of the Strait most winters over the past 45 years.

So how do they survive? For starters we have to realise that only a few do it as the carrying capacity of the area for these birds cannot now be that high. But the ones that stay seem to survive, probably on a combination of snakes, lizards and small mammals. The reason is that these lowland areas of south-western Iberia are mild. But even here the nights can be cold, temperatures dropping below zero away from the coast. But the secret is that the sun retains a position high in the sky at noon which means that it rapidly warms up, even up to 20 or more degrees Celsius in mid-winter. This generates reptile activity and food for the eagles...

This is also the reason why many insectivorous birds also stay down here, or arrive from the north and go no further. Even obligate insect eaters, like the Crag Martin (below), winter here. This is the only European hirundine to winter north of the Sahara. I studied them many years ago and found that they survived by laying down fat reserves when conditions were favourable and surviving on these when it rained and they could not hunt. They were behaving like birds on migration throughout the winter. Adults, I found were better at it than first winter birds. In particularly bad years many young birds died and I would pick up their emaciated corpses at the base of their cave roosts.

Two other largely insectivorous birds winter down here in very large numbers. White Wagtail (above) and Meadow Pipit (below) also rely on small insects, especially those that live close to water. In winter swarms of these rise in the middle of the day as temperatures rise. The ones that the wagtails and pipits miss are probably taken by the martins!

All this should not surpise us. The latitude of Gibraltar is, for example, lower than parts of North Africa. And as Abel Chapman wrote more than a century ago this is, after all, a little piece of Africa in Europe!

In Search of the Ibex

2010-11-21T23:23:00.001+01:00

The Spanish Ibex is one of those gems of Nature that have somehow managed to survive, by a combination of luck and dedicated individuals prepared to come to their rescue, amidst the increasing human pressure on the fauna of Europe. Now confined to inaccessible high mountains, these animals once roamed rocky terrain down to sea level where they were hunted 40 thousand years ago by Neanderthals on the rocks by the sea at Gibraltar. But intense human pressure has driven these animals from any ancient favoured haunts.

To find and photograph these animals, my son Stewart and I climbed up the rocky terrain of the Sierra de Gredos in Western Spain. Winter is a good time as the snows push these animals down to where they can graze but this does not mean they are easy to find. To get to them requires hard work, not made any easier by altitude (we were between 1800 and 2000 metres) and snow showers...

Finally, a chance as a group of young and females allow approach during a heavy snow shower...

Stealth, while keeping downwind, allows a window of opportunity to get the shots we were after!

...not winking - left eye closed as the driving snow hit this ibex's face on its left side!

baby ibex

then a spectacular male, casually shows itself as it forages among the rocks, allowing an opportunity for good close-ups!

Exhausted but exhilarated we start the long trek back. A clearing in the the weather allows Stewart a chance to take some stunning photographs of Ibex Country...

father and son after a hard day's work!

Among the Reeds and Rushes in La Janda

2010-11-13T18:23:00.000+01:00

The warm spring days when Great Reed Warblers (above) and Yellow Wagtails (below) dominated the aquatic vegetation of south-western Iberia are a distant memory. These birds are now somewhere in tropical Africa, south of the Sahara...

but the bullrushes (above) and reeds (below) continue to provide cover and food for other birds...

Cetti's Warblers (above and below) lead the line of skulkers that can go by undetected if we are not patient and careful. These warblers were there alongside the Great Reed Warblers in the spring but manage to hang on and find sufficient food throughout the winter...

The Bluethroats are winter visitors (see also post of 19th October) and occupy most patches of swampy vegetation. The females (above and below) are easily passed by...

the males (below) are equally hard to pick up but when they show themselves they are stunning...

from above, even the males look cryptic...

which is not a bad thing seeing the predators that patrol the swamp...

Marsh Harrier

Buzzard

Barn Owl

other migrants and local birds also focus on the reeds and its insects. These include Chiffchaffs (above) now in bid numbers and Stonechats (below) which use the reeds as hunting perches.

...but the star of the show has to be the Bluethroat

A day in the life of a young Griffon

2010-11-11T18:17:00.000+01:00

The day promised to be interesting as gulls attracted my attention mid-morning. I climbed onto the museum's roof to see a juvenile Griffon Vulture rapidly dropping from the sky, undercarriage down...

I took these photos from the roof and then lost the bird as it dropped somewhere between the buildings of the City of Gibraltar. I knew that, sooner or later, he'd have to fly and the gulls would give his presence away. So I waited. A couple of hours later a friend called to say a large vulture was sitting on the roof of a house, attracting the attention of gulls and passers by so off I went...

and there he was, resting in stoic fashion, almost accepting its lot...

at this time of year tired young birds get separated from the flock and become disorientated. They tire and seek a place in which they can rest and recover. But, try as it might, moving from rooftop to rooftop he just couldn't get away from the gulls...

as he moved I got good chances of getting close to him as the following shots show...

A few minutes ago he was roosting on a high building and the gulls seemed to have left him. The saga will continue in the morning...

Gannet influxes

2010-11-10T23:55:00.000+01:00

The dominance of juvenile Gannets in the early autumn (see post of 20 October) gives way to a balanced distribution of birds of different ages. This change is partly due to many juveniles continuing south down the coast of West Africa and partly due to the arrival of adults and sub-adults from the north.

There is usually a small number of birds fishing offshore around the coasts of the Strait of Gibraltar but many more come in from the Atlantic when low pressures force them in to shelter and find good fishing. This is the case at the moment as many Gannets came in with yesterday's bad weather. These birds have been fishing offshore and some of Gibraltar's sea cliffs provide excellent opportunities for getting close to them. The photos in this post were all taken today and show the diversity of ages around (from all brown juveniles to white adults).

Peregrines on the prowl

2010-11-03T23:14:00.000+01:00

The Mediterranean Peregrine Falcons that breed on the Rock of Gibraltar depend heavily on migrant birds at particular times of the year. This is one of those times. Many finches - Chaffinches, Greenfinches, Goldfinches, Linnets and Serins - are now flying south. The Peregrines wait for them in mid-air and dive at the vulnerable migrants.

The high density of Peregrines means they often invade each other's air space, leading to spectacular mid-air quarrels (above and below).

They are so concentrated in finding the migrant flocks that they get close to the observer sitting on the cliff edge (below).

See also posts of 9th and 14th February...

The Monkey and the Vulture

2010-11-01T19:44:00.001+01:00

It was a chilly morning. Around 10am the temperature was still at 14 Celsius. A stiff breeze blew from the north-west. The sky was clear. A monkey gorged on ripening wild olives while others took the morning sun. Little did they know what was to unfold...

I sat on a cliff edge on the Rock of Gibraltar and scoured the hill opposite me with binoculars. This is Sierra Carbonera, a barren, stony hill that does not seem to offer much. But I knew better. This has been a traditional stopover roost for migrating Griffon Vultures as far as I can remember. That was the first days of November 1972 when a flock of 200 migrating Griffon Vultures came straight at me and flew past as if I wasn't there. The memory has remained imprinted in my mind since those teenage days.

A Peregrine eyed me curiously as it flew past. It had been hunting migrating Chaffinches, Goldfinches and Greenfinches all morning. The time was now 1040 and the temperature had risen to 18 Celsius. Soon it would pass the 20C mark. Time for the vultures to make their move! Right enough, first a few, then a score and soon the sky above Sierra Carbonera was crowded with specks. For an hour they struggled into the north-westerly but every time they soared they were pushed back to the starting point. I was beginning to wonder whether they would come close when one bird started heading in my direction. The adrenalin surged and I prepared. I'll let the photographs tell the rest of the story...

These vultures - nearly all juveniles with some immatures among them - catch the morning thermals over a beautiful countryside of cork oak forests and pastures (below). They are on their way to Africa and many will cross the Sahara Desert. The adults remain behind. These birds return between April and June (see post of 15th May) well after the adults have started their long breeding season (which starts in January).

They might be forgiven for thinking that there is no barrier between these hills and the mountain in the background - Jebel Musa in North Africa (below)

...and the Rock of Gibraltar beckons (below)

but once there, the reality of the sea crossing becomes clear and the vultures run the gauntlet...

Several hundred vultures flew past me today, some so close that I could smell their unmistakeable odour!

Changing behaviour of the White Stork

2010-10-27T17:56:00.000+02:00

The site of a mass of White Storks migrating across the Strait of Gibraltar is still a typical sight in July, August and again between November and April.

These are largely Iberian breeding birds which arrive and go with the rains. Their spring usually starts, variably in October, November or December, depending on when the rains come.

Choice of breeding habitat varies. In south-western Iberia many nest in trees (below) and feed in the rich marshes (above), on frogs, crustaceans and fish.

Adult peers from nest in eucalypt (above) and two chicks sleep in their tree-top nest (below).

Here they often nest in large colonies alongside Grey Herons and Spoonbills (above) but they may also nest alone (below).

In western Iberia they often feed on the open plains (above). In the absence of trees they often make their nests high in the rooftops of medieval towns (below).

In spring they make the most of the wet and grassy fields in the oak dehesas where they take a variety of prey. Come the summer, when the fields dry up, they exploit the abundance of large insects ahead of the migration south (below).

Bush Crickets (above) and grasshoppers (below) are favourite prey in the early summer.

Traditionally, these storks left with the summer drought to spend the months of July to September in West Africa, south of the Sahara. Here, in places like the wetlands of the Niger in Mali, they would arrive precisely with the monsoon rains. With the end of the rains in October they would start returning north to catch the start of the rains north of the Sahara Desert.

...but for a few years now this pattern has started to change with many storks never leaving at all.

They have the advantage that, being on or close to the breeding grounds, they can time the start of nesting much better than their counterparts in Africa.

so what has changed?

we changed! We developed the habit of creating large, open air, rubbish tips and the adaptable storks learnt to scavenge here during the breeding season. Food was easy to get and, as the supply did not vary with the season, they never left.

so storks now patiently line up and wait for the next refuse lorry which brings many potential meals!

so we can imagine a time when we produce so much refuse and have so many such tips, that the entire pattern of the storks' behaviour will have changed from migratory to resident.

Magic of La Janda - the Black-winged Kite

2010-10-25T18:52:00.000+02:00

The Black-winged Kite inhabits open areas with scattered trees in western and southern Iberia. It is a species that also breeds in Morocco and which finds in Iberia the northern edge of its range.

This beautiful bird seems to have experienced a range expansion during the twentieth century and its success has been linked to the spread of managed dehesas - open parkland with grazing mammals - which is structurally similar to its native African savannahs. It is here that it finds the small mammals which make up a large part of its diet.

La Janda, former site of Spain's largest lake, in south-western Spain is a favourite site of these birds in the autumn and winter. Here the habitat is ideal for this species that arrives in substantial numbers making La Janda a great place to see these birds.

La Janda showing typical Black-winged Kite habitat. Riverside poplars surrounded by fields with the town of Vejer in the background (above) and olive dehesas in spring (below).

During migration time this habitat is also used by passage Black Kites (above), here waiting for the sun to clear the morning mist. Marsh Harriers (below) also frequent the canal embankments where the kites also hunt.

The greatest competitors seem to be Kestrels with which they often fight (below).

This competition seems to be for prized perches from which they patiently watch for prey on the ground (below).

This leads to spectacular interactions between different kites (below).

But they also hunt from the air with their unique yawing glide, with wings held up. Their black upper-wing is then most obvious.

The juvenile birds of the year (above and below), with traces of brown plumage and a scaly upper wing pattern, seem to stay close to the adults in the autumn but they hunt independently.

Watching these birds is one of those priveleges of Nature that are hard to describe. I hope these photos have gone some way.

Wintering passerines arriving each day

2010-10-21T17:33:00.000+02:00

Most of the trans-Saharan migrants have gone through by now and it is the turn of those that will spend the winter in our area. Among these are the Chiffchaffs from north-western Europe.

These small insectivorous birds are great opportunists, a good quality if you are a migrant. At this stage they spend their time in marginal habitats where flowering plants, like the Aromatic Inula (above) or the Culinary Fennel (below), attract many insects.

Blackcaps (above), distinguishable by their pale plumage and long wings compared to the local birds (see post of 12th March), and White Wagtails (below) are among the most numerous of these arrivals.

Now commencing is the spectacular diurnal migration of finches which will dominate the scene in late October and early November when the skies get covered in flocks of Chaffinch, Greenfinch, Serin, Linnet and Goldfinch (below) in particular.

Return of the Gannet

2010-10-20T19:05:00.000+02:00

Gannets return to the Strait of Gibraltar during September and October. Juvenile birds are most obvious at first and are the ones which migrate furthest, reaching down to tropical West Africa.

These birds were born this summer in colonies on the north-west coasts of Europe, in France, the British Isles and Scandinavia and quickly make their way south to avoid the harsh northern winters and make the most of the concentrations of fish in the Strait of Gibraltar and coastal upwellings along the proximal Atlantic coasts of Portugal, Spain and Morocco.

Large shoal of Grey Mullet off Gibraltar today (above).

These birds will now remain with us until the spring and many will linger on through their first summer. It is only as they get older, and their plumage progressively whiter (below) that the urge to migrate north in the spring gets stronger.

So here are a few more images of these amazingly "painted" birds, which appear drab and brown at distance but which reveal beauty at close quarters - don't you think so too?

Bluethroats

2010-10-19T18:56:00.001+02:00

With the Bluethroat I will start a series of posts that will introduce the birds which are now arriving to winter in the area of the Strait of Gibraltar.

In my post of 30th April, I introduced this species, breeding in the high mountains of the Iberian Peninsula. These birds lacked a spot on the blue throat, a characteristic of the Iberian breeding subspecies azuricollis.

This is one of ten sub-species which are distributed across the Palaearctic and reaching across Bering into Alaska, a feature of only a few Palaearctic species.

But it is another sub-species, the white-spotted cyanecula that reaches these shores for the winter. These birds are coming down from north-western Europe and winter in reed beds in sites like La Janda where they are numerous. The Scandinavian red-spotted svecica sub-species occurs on passage.

the best time to see them is early in the morning when birds sing to establish winter territories. Otherwise, the best views tend to be of birds flying between the reeds when the chestnut panels at the base of the tail give them away.

These birds will stay in the reed beds until next March when they will return north.

Desperate for water

2010-10-09T11:50:00.001+02:00

The long, dry, summer takes its toll. This year it hasn't been as bad as usual. In spite of no rain for three months, the heavy rains of last winter have kept a few pools alive. Clouds threaten but little water has fallen so far. It seems hard to think how much we wanted the rains to stop, and now everything alive needs the rejuvenating water. The surviving pools attract all manner of animals (below):

In Doñana the wild horses gather in the remaining lakes where they share the water with flamingoes and ducks.

...but not all of the lakes have retained water, so these animals have to wander across large areas in search of water.

Red Deer (above), just finishing the rut, warily approach the lakes while Fallow Deer (below), just starting the rut, set up territories on the edge of the marshes where there is some fresh grazing.

Patrolling drainage channels, close to large rivers and salt pans, is a favourite pastime of the heron family, particularly Little Egrets

Little Egrets (above) and Grey Herons (below) patiently stalk the water margin

But they are not always left to themselves. Sometimes a surprise (below) lurks out from the reeds

Hermit Crabs, which live on the muddy banks, seem to be a main target

but the herons don't have it all to themselves (below)...

though they try and get their own back, looking for an opportunity in the fish farms (below)!

when all else fails, waterbirds will gather between the locks on drainage canals (below)

where they have to keep a watchful eye on the predatory Marsh Harriers that incessantly patrol its edges (below)

the remaining lakes gather thousands of waterbirds

the pink Greater Flamingoes are among the most spectacular

their numbers are overtaken, though, by the tight flocks of Glossy Ibises (below)

...and there are the migrants. Thousands of waders arrive from the north-western Europe and the High Arctic, on their way south to West Africa or to remain here for the winter. They mix with the local waders (below)

Local and migrant Avocets mix with migrant Black-tailed Godwits (above) in salt pans

Flight of Black-tailed Godwits (above) and Avocets with Black-tailed Godwits (below)

Single Avocet feeding in salt pan

Bar-tailed Godwits (above and below) prefer to feed on the river's edge

Redshank

Common Sandpiper

Greenshank (left) with Bar-tailed Godwit

Ringed Plover

Temminck's Stint

Black-winged Stilts

Squacco Heron

...as I began to write these lines, itstarted to rain outside!

Travellers under the cover of darkness

2010-10-05T00:00:00.000+02:00

Sunset over the Atlantic in south-western Iberia at this time of the year signals the start of a wave of small migratory birds that rise from the vegetation into the darkness above. They take a south-westerly heading which takes them out over the open ocean towards Africa. They reach land once again over Morocco. Some may land but others press on south towards the western Sahara Desert. Flying along its western margin minimizes an otherwise dangerous and tedious journey over a sea of sand dunes. This means that, even though many migrants overfly the Sahara, there is a real concentration of birds along the west, coming down the coast of Portugal and making the most of the wetter Atlantic coast of Iberia. Predators have learnt that the coasts of south-western Iberia and Atlantic Morocco are a source of migrants at this time of year and they make the most of the bonanza. Eleonora's Falcons breed late in the year, on rocky islands, and feed almost exclusively on migrants. Less known but far more dramatic is the predation on migrants by noctule bats. These mammals fly high into the night sky and track down the migrants that are flying at night precisely to avoid falcons and other diurnal predators!

Willow Warblers are among the commonest of these migrants, many yellowish juveniles among them. These tiny birds were only born a few weeks ago and instinctively find their way to their winter quarters. When they come down during the daylight hours, they make the most of the time to feed and regain lost energy.

Some of these migrants, among them Pied Flycatchers, may remain in an area for a few days before moving on. They are fiercely territorial and may stick to a small clump of trees where they will spend the day pouncing on insects on the ground or flycatching others in mid-air.

Pied Flycatchers track a south-westerly route across Europe to reach northern and central Portugal where they spend time refattening. From here, many make a direct flight south to cross the Sahara Desert. They rely on fat reserves deposited in their bodies. These get broken down during the journey to produce energy and water.

Greenland Wheatears are among the greatest of these travellers. These birds make a long sea crossing from Greenland to the British isles, via Iceland. From there they travel south towards the Atlantic coast of Iberia and then move south into Africa from here. They move south later than their smaller European cousins and October is their month in Iberia.

Diurnal trans-Saharan migrants are also on the move down the western coast of Iberia and many of these make the most of the swarms of grasshoppers, locusts and other large insects on the way. The last of the White Storks continue to make their way towards the Strait of Gibraltar. It is the Lesser Kestrels that are now flocking in the open fields, as at la Janda, where they are actively hunting ahead of their journey to winter quarters in West Africa.

September feeding frenzies in the Strait of Gibraltar

2010-09-20T17:46:00.000+02:00

September is the month of the flying fish in the Strait of Gibraltar. If they turn up in good numbers they unleash a chain of spectacular events as all kinds of predators converge on this rich food resource. It is the dolphins that get things moving by chasing the fish near the surface where seabirds also get a chance to have a go at them. Yesterday morning was a calm easterly, ideal for a feeding frenzy. It was also the end of the Calpe Conference on the evolution of bird migration, so what better time than to go out on a boat and see what was happening.

Rafts of Cory's Shearwaters Calonectris diomedea at the entrance to the Bay of Gibraltar soon have a hint that the morning would be a good one...

Once round Europa Point and into the entrance to the Mediterranean, a wonderful spectacle unfolded which combined dolphins, breeding shearwaters and migratory seabirds. A migrating Loggerhead Turtle Caretta caretta was a promising sign...

Soon we found the pods of Common Dolphins Delphinus delphis that were frantically chasing the flying fish...

Cory's Shearwaters flew over the pods keeping an eye for shoals of fish

Several thousand Cory's Shearwaters were about, having flown down the Mediterranean coast some 400 kilometres to feed in these rich waters where the Atlantic meets the Mediterranean. These are daily feeding movements as they have hungry chicks in their nests.

As soon as the dolphins have got going, the shearwaters get busy catching the fish that try to escape by gliding...

...and competition is severe among the shearwaters

but the shearwaters do not have it all to themselves as gulls try and steal the tasty meals...

but gulls are insignificant compared to the big bullies that, passing by on migration, get attracted by the concentrations - Arctic Stercorarius parasiticus and Great Catharacta skua (below) skuas are more formidable opponents...

other migrants also joined in the fun. Among these were juvenile Gannets Morus bassanus, just arrived ftom the North Atlantic.

Black Chlidonias nigra, Common Sterna hirundo and Sandwich Thalasseus sandvicensis terns moving towards the Atlantic wintering grounds also got drawn in...

as were other locally breeding shearwaters - the smaller and browner Balearic Shearwaters Puffinus mauretanicus

but the day belonged to the larger shearwaters, adding plunge-diving to their hunting techniques until the food was gone...

My thanks to Tony and Angie Watkins of Dive Charters for taking us out on their boat

Honey Buzzards - the great travellers

2010-09-06T21:10:00.000+02:00

European Honey Buzzards Pernis apivorus are amongst the most beautiful of raptors and they are great travellers

This species breeds in the western and central Palaearctic and is replaced further east by the Oriental Honey Buzzard P. ptilyorhynchus.

There is a third species, the ancestral form, which lives across many islands of south-east Asia - in Sulawesi and the Philippines - where the Oriental Honey Buzzard's range, which has populations across South and South East Asia, ends. It is the Barred Honey Buzzard P. celebensis. These tropical Honey Buzzards are sedentary but the Palaearctic populations of Oriental and all European Honey Buzzards migrate. Their specialised diet of bees and their larvae prevents them being resident away from the tropics.

Hundreds of thousands of European Honey Buzzards arrive in Europe and western Asia to breed in late April and May. They have a short breeding season, capitalising on the abundance of their favourite prey, and leave as soon as breeding is over. They cross the major flyways, avoiding long sea crossings, but are better able to cope with flying over the sea than most raptors and they even get across into Africa via Malta.

Even so flying over the sea can be hazardous.

The Honey Buzzards that are now peaking over the Strait of Gibraltar, with numbers exceeding 11 thousand on good days, are coming from western Europe, Scandinavia and western Russia. Many have crossed from Scandinavia into continental Europe at Falsterbo and the journey to Gibraltar takes them about a week.

These birds are heading for the forests of tropical West Africa, so they still have the big hurdle of the Sahara Desert - 1500 kilometres of sand without chance of eating or drinking - before arriving home.

The Honey Buzzard is typified by a variable plumage. Most birds are of the typically barred phase (above) but others are chocolate brown (below).

and others white (below).

I will keep an eye out for these migrants in the next few days and report back on their progress, along with that of other raptors...

thermal of Honey Buzzards on the move (above). These flocks may number in the thousands.

Swifts in an Attic

2010-08-18T00:24:00.000+02:00

2000 pairs of Pallid Swifts breed each year in Gibraltar. They are the great masters of the air, only coming down to breed. These birds spend their lives in the air where they catch airborne insects - they live off aerial plankton.

They arrive at the end of February and leave in October, some staying into November. So they're not away for long and they don't go too far either. Most winter in the Sahel region, south of the Sahara. Breeding usually starts as soon as it gets warm and varies from year to year. First clutches average three eggs and second clutches two eggs. Once the first brood fledges many pairs return to the nest for the second brood of the year. This is unusual among swifts. Common Swifts, even in these latitudes, raise only a single brood.

All swifts have a problem when the time to moult arrives. Spending most of their time on the wing, they need to moult the flight feathers slowly. It takes a long time. Pallid Swifts starting a second clutch, in late July and August, cannot wait until they raise their young to moult. Once the young are fledged they have to migrate. They live on the limit. So they have to start wing moult while breeding. Notice the adult on the right (above) has started moulting the inner primaries (which look darker).

But before they can start a second time they have to encourage the first generation out of the nest holes. A juvenile Pallid Swift (above) peeps out wondering what the fuss (below) is all about!

Juveniles (above and below) are easily recognised by their scaly plumage, primaries and wing coverts having pale edges. Notice the large eyes, ideal for spotting insects in mid-air.

The task of feeding chicks requires special consideration when you spend your life in the air. Swifts collect insects in their wide mouths and bring back large food balls, glued by saliva, which may contain several hundred insects at a time. This technique reduces on travel time to and from the nest and also allows the adults to range widely away from the nest in search of food.

They are the masters of the air, experts at catching small insects and hunting in packs, like wolves or orcas.

And their streamlined bodies, millions of years of evolution, are perfect for the job

The magpie's tale

2010-07-25T17:42:00.000+02:00

The wonderful Iberian Azure-winged Magpies Cyanopica cooki are now busy getting around in gangs of youths and adults, making their presence felt with their raucous cries. They are a species of open, savannah-type woodland and their native habitat in Iberia is the Stone Pine Pinus pinea woodland.

For some time we hadn't realised the importance of these pine woods and many thought that they were largely introduced. True, many coastal pine woods have been planted but we know that they have been there for millennia. In our excavations at Gorham's Cave in Gibraltar we have found charcoal remains of Neanderthal camp fires. The charcoal belonged to the Stone Pine and we have found such remains in all the archaeological levels, the oldest being around 50 thousand years old. So coastal Stone Pine woods, in warm climate and sandy soils, have been around for a long time creating spectacular Mediterranean savannah landscapes.

For a long time too we had been under the mistaken impression that pine woods were not the natural formations in Iberia that had instead been dominated by oak woods. But the reality is that wherever we look in archaeological and lake pollen sites, the natural vegetation of large areas of Iberia was pine dominated. When we find Azure-winged Magpies today in oak dehesas (managed parkland) we are seeing them in secondary habitats; they are habitats that suited them because they had a similar structure to their native pine woods (not too dense to make closed forest which they don't like).

The other great misconception that was prevalent when I started birdwatching was that the Iberian Azure winged Magpies were not native here. Instead the colourful birds had been brought back by Portuguese mariners from China and escaped. We were looking at feral birds. How else could we explain a small range in south-west Iberia and a larger one in China, Korea and Japan, and nothing in-between?

Then we found the fossil remains of the Azure-winged Magpies in our caves too, along with the Stone Pine charcoal, going back 40 thousand years. Everyhting changed overnight. These magpies had been here all along!

Since then genetic studies of the Iberian and East Asian birds have revealed a separation that is probably over two million years old and the differences between them warrant giving them species status. So we have the Eastern Azure-winged Magpie C. cyanus and the Iberian one.

...and it helped us understand something else that we had been suspecting for a while - that the mid-latitude belt between Portugal and China had once been a vast belt of savannah that was broken down when the deserts of Central Asia, Arabia and the Sahara expanded.

Today, these beautiful, intelligent and social birds occupy the medium-sized crow job in the open woodland. Where the trees become too dense, they are gone and it is the Jay Garrulus glandarius (below) that takes over.

...and where trees are to few the Black-billed Magpies Pica pica and Jackdaws Corvus monedula rule (below).

But the Iberian Azure-winged Magpie will always have a place in my heart - because of its social character, antics, intelligence, and because they taught me a huge lesson in biogeography!

Bird of the Spring - The Results

2010-07-08T18:08:00.000+02:00

Thank you all for taking the trouble to give your ranking and "likes" here and in facebook. In the end the outcome was clear - you preferred the Bee-eater by far so it is 2010 spring bird!

Second place went to the Lesser Kestrel

and third to the Puffin! These three were well ahead of the rest.