Friday, 8 February 2019

Eagles in the Spanish savannas

Male Bonelli's Eagle (Martin Kelsey)

A western outreach of the Montes de Toledo, the Sierra de San Pedro is a chain of low-altitude mountains dividing the basins of the Tagus and Guadiana Rivers, and acting as a political boundary too, with Cáceres province to the north and Badajoz to the south. It extends for over 60 km, running east-west from the city of Cáceres to the Portuguese border. Part of the Sierra is a Special Protection Area for birds, covering over 115,000 hectares.  Despite its relatively low elevation, from our vantage point, and thanks to a morning of extraordinary clean winter light, we could look north across the plains of Brozas and see the arc of the Central System of mountains, with the snow-capped Serra da Estela in Portugal, spanning east to the Sierra de Gata and then the Sierra de Gredos, the granite wall marking the northern limits of Extremadura, views extending for perhaps 150 kilometres.

Sierra de San Pedro (Martin Kelsey)

Closer at hand, we could look down on broad, gentle valleys covered by dehesa woodland, where the cork oaks and holm oaks grow far enough apart for light to reach the ground and for grass to grow. A medieval wood pasture, managed as such still today. But our panoramic view evoked a more primeval response. Our host, Helios, described what we saw as "savanna" and this huge landscape of open woodland, ruptured by wild rocky ridges, bore an African feel. As if to reinforce this sensation, Helios told us that across this expanse there were numerous dolmens, megalithic tombs, remnants of a human presence over thousands of years. The dehesa landscape itself was shaped by people, much more recently than the cultures who built dolmens. But paradoxically within the undulating arenas surrounding us, save for occasional meagre collections of farm buildings, people were absent. Indeed, during our whole morning we saw just one other person.

People were far out-numbered by birds of prey. The Sierra de San Pedro has the largest population of Black Vultures in the world and Extremadura's largest Spanish Imperial Eagle population (about 25 pairs). We were visiting the area with Helios to get front-row seats for another eagle species, one that epitomises sheer power and mystique.

Bonelli's Eagles never give advance notice of their arrival. They hunt by subterfuge and ambush. They are not called in both German and Spanish "Goshawk Eagles" for nothing. They are birds of deep-wooded valleys, crowned by rocky outcrops. The topography of such landscapes is intrinsic to their hunting technique. Their craft is to hug the contour, rising only to make a final stoop on their prey, of which pigeons are a particular favourite. Claudia and I entered the hide and took a seat whilst Helios started hanging pieces of dead bait on exposed branches of cork oak in front of us. His very appearance seemed to be a cue for the eagle. Indeed as Helios was climbing a ladder to our left, the Bonelli's Eagle swung into view and briefly perched on a branch to our right, before taking off and disappearing behind the spur of the hill. Task completed, Helios departed to leave us to sit and wait.

I had forewarned Claudia that we may need to wait a couple of hours. A couple of minutes, more like! As soon as the stage was empty, the Bonelli's Eagle returned. It was the male and he stood for moment to check the scene before starting to feed. This was the start of an extraordinary session of four hours, during which the Bonelli's Eagles were present the entire time.
Male Bonelli's Eagle (Martin Kelsey)

About two-thirds of the way through, the male started to call quietly: a series of soft piping notes. He paused and looked earnestly across the domain of the valley in front of us and towards distant crags. He called again, this time fractionally louder. I looked in the same direction as his gaze and saw a movement. It was his mate approaching from the outcrops, over a kilometre away. Had she heard this barely audible call? She approached on a long glide, coming to settle beside him on the branch in front of us. He had left some food for her and as she fed, he shuffled along the branch to stand in the shade.

Pair of Bonelli's Eagle (Martin Kelsey)

Young female Bonelli's Eagle (Martin Kelsey)

She was a much younger bird. Whilst his trousers were white with blackish oak-leafed shaped centres to the loose soft feathers and his cheeks were white with fine greyish streaks, she had tawny-plumaged legs and her face bore a warm buff tan. We were close enough even to observe the difference of the colour of their eyes.

The creamy-coloured eye of the older bird (Martin Kelsey)

The older male with a rich butter-cream iris, with suffused grey radial marks, whilst the bigger female had a deeper orange-tawny iris, and it seemed to me, a sterner stronger brow. Those eyes had evolved a far greater acuity than my own.

As they departed, we watched as they crossed the valley, their shape just discernible against the stippled background of the crowns of the dehesa evergreen oaks and the grey eruptions of rock. Then, they disappeared, absorbed as it were by distance. And like wherever I have encountered this most alluring of eagles, this place became enchanted.

We visited the Bonelli's Eagle Hide set up by Photo Raptors in the Sierra de San Pedro. Photo Raptors can also offer hides for Spanish Imperial Eagle, vultures and passerines, as well as for Common Cranes in the winter.  

One of the hides for Bonelli's Eagle offered by Photo Raptors 

Thursday, 31 January 2019

Elegy for the Little Bustard

Little Bustards in winter (Martin Kelsey)

It was the second of March 2006 and the late afternoon light was just at the right angle to push through the ashen-grey stems of the dead thistles and reflect against the white feathers on their bellies. Their upperparts were a marginally sandier tone than the thistles that gave them cover, but the vermiculations of darker streaking on the feathers gave crypsis, blending their outline into the jarring, discontinuities of the withered spiky plants. Nevertheless, from where I stood, my back to the sun, I could scan across the slope where they stood. The flock was at rest, stationary, and I could count them one-by-one. There were 330 individuals all told (give or take a couple) and they were Little Bustards.

For a few winters after that, I could still come across sizeable flocks, but never much more than 150. But by the time I was helping with fieldwork in 2016 for the winter census of the species across the whole of Spain, the largest flock I found was 92 birds. Indeed at the national level there were only two flocks bigger than the group that I had counted ten years earlier (and only 14 flocks greater than 100 birds counted in the whole of the country!). This winter the biggest flock I have seen was 39 birds.

SEO/BirdLife has just published the results of the 2016 Little Bustard census. There are two populations of the species: an eastern one which extends through Central Asia to North-east China and which appears to be in good numbers, and the western one, in the Iberian Peninsula, France and Sardinia (with populations on mainland Italy and Morroco practically extinct). The western population is in very fast decline. In western France the species suffered an extraordinary drop of 94% of its population over the last two decades of the twentieth century, whilst the SEO/BirdLife census documents a fall in Spain of both the wintering population and the count of males in spring of 48% between 2005 and 2016. In Extremadura the decline is somewhat sharper, with a drop of 56% of males in spring and a decline of 33% in the winter population.

It is estimated that across Spain over the same period, 17% of suitable habitat was lost. But what is a telling indicator is the lower density of the birds compared with a decade earlier (1.13 males/square kilometre to 0.67). This is showing that, more important than habitat loss, is the reduction in the quality of the habitat. It is a creeping, insiduous threat, invisible, but happening under our very noses, under our watch. If I look at photos I have taken across the plains of Extrenadura over that period, it is hard to see any obvious  difference. But when I walk across the plains in late spring, every footstep I take tells the same story.

When I first visited Extremadura over 25 years ago, I wrote down in my notebook the number of Great Bustards I saw at each place I visited. To my subsequent regret, I did not count the Little Bustards: they were present everywhere I stopped. And on the ground, as I walked, there was an eruption of leaping grasshoppers. Even ten years ago, each step through the vegetation spoke of a vast biomass of invertebrates.  No more. Changes to the plains have not dramatically changed the landscape, but are breaking the trophic pyramid. Shifts towards more intensive grazing, less arable land - and those crops that are grown are now harvested earlier in the season, destined as they are for livestock feed.

As Nigel Collar in his prologue to the findings of the Little Bustard census says, there is the danger of shifting baselines. Twenty years ago people found winter flocks of a thousand Little Bustards, ten years ago we looked for flocks of a hundred, now I am relieved to come across two dozen. Is that now our norm?  Mark Cocker in his book Our Place speaks of environmental melancholia. It is a syndrome I recognise when I see these wonderful creatures hunched amongst the dead thistles on a winter's day, or springing with a shock of white in their whirring wings which sing their Spanish name "Sisón, sisón" as they take flight. I do not believe I shall ever see a flock of 330 Little Bustards again.

A flock of Little Bustard (Martin Kelsey)