The biggest of them all

Black Vulture (photo by Nigel Sprowell)

The first hour of daylight and I am walking slowly along a quiet track on the plains near Trujillo. The air is damp and there is the faintest of mists, softening the undulations of the land, the exposed dogs' teeth of bedrock and the outlines of the retama shrubs. Distance becomes difficult to ascertain. The moist air muffles the sound of sheep bells. At the crest of a nearby slope, a hunched figure sits, in dark apparel, broad-shouldered but stooped. This silhouette begs my attention, and for a brief moment, the nearby livestock lull me to a conclusion that I am looking at a lone shepherd, starting his day in the reverie that must be his mainstay, to challenge his solitude as he keeps vigil over the flock. But as I shake myself out of my own drifting thoughts, the true identify of this lonely figure is obvious as soon as I stop to look at this creature with my binoculars. It is the massive Black Vulture. Also known as Monk Vulture (because of its friar-like cowl -see John Hawkins' photo below) or Cinereous Vulture (because of its sooty black plumage), this is the biggest of all of our birds of prey. With a length of up to 115 cms and weighing up to 12 kgs, its sheer bulk when standing in typical hunched posture on the ground makes my initial case of mistaken identification forgivable. Indeed, on more than one occasion in similar circumstances I have had to "double-take", because its size and shape can make it appear at a distance almost like a seated human being, especially of someone of small stocky frame.

The time of day was a clue to the bird's apparent inactivity. Being such huge and heavy birds, vultures are highly dependent on thermals during the day for gaining height in order to glide long distances, thus minimising the energy that they would need to expend flapping. My Black Vulture had probably been feeding on a sheep carcass nearby the previous afternoon, but as the winter's day drew to an end, the air temperature would have fallen quickly. Under such conditions, especially if it had been cloudy, it would have been hard for this bird to have gained enough height to set off back to its roosting area. Perhaps it had also gorged itself, adding additional payload. So it stayed put, standing on a rise on the ground, near some rocks and bivouacked there.

Black Vulture (John Hawkins)

But it is in flight that this species drives home this sense of enormity. Its wingspan can reach almost three metres and as Nigel Sprowell's photo at the start of this posting shows superbly, the wings are also impressively broad, plank-like with parallel-sides and widely-splayed outer primaries at each extreme. The photo captures the bird in mid-flap, as this individual was crossing a gorge. When gliding the bird takes on quite a different demeanour. One can identify a Black Vulture as it approaches head-on from a vast distance. It is as if the wings are so heavy, even the powerful breast muscles cannot support their weight, so that they droop, only rarely reaching the horizontal. This is quite different from the slightly smaller Griffon Vulture, with wings that tend to taper towards the tip, which will hold its wings when gliding in a shallow "V". This gives the Black Vulture a rather sinister appearance as it approaches, as it does on a level bearing on motionless wings, materialising out of nowhere.

Black Vultures have a small global population (estimated by BirdLife International to be probably less than 10,000 pairs) which is decreasing, which makes the species officially considered to be Near-Threatened. In Spain however, and especially in Extremadura, the species is increasing in numbers. Government figures show that from just 86 known pairs in 1974, the breeding population in 2013 was 897 pairs in Extremadura alone, see this link to the Birds of Extremadura blog for more information. This makes our region home to the highest density of Black Vultures in the world and certainly the most important area for them in Europe. The Griffon Vulture population here has also grown during this period. I think that the main driving force for this is linked to what I describe in my early morning encounter above. There are several million sheep living on the plains of Extremadura. As my imagined shepherd turned out to be a vulture, the fact is that there are now far fewer shepherds accompanying the flocks than there used to be. This is in part because of the investment, thanks to available finance, that farmers have made in recent decades to fencing the land, enabling flocks of increasing size to forage unattended. Injured or sick animals die and their carcasses are found by vultures before the farmers do in these extensive range lands in Extremadura. Some farmers as well still cling onto the traditional approach of leaving the carcass when it fell, especially it lies in a remote and seldom-visited corner of their land. The vultures thrive here. Exciting as Monfragüe National Park is as one of the top concentrations of breeding vultures, where their nesting activity is now (in mid-February) well underway, my preferred landscape for watching vultures is without doubt the steppe-like plains. Here under the vast open skies I can watch a vulture cross from one horizon to the other, on perhaps a single glide, tracking a straight line. It passes low overhead as it does so, tilting its head to register me in its vision, perhaps for a mere second, whilst I in deference keep it in view until as a dot in the sky already kilometres away it disappears from mine.