Noticias en ‘Collserola’
December 26th, 2008
I found a palette of colours as autumn turned to winter in Collserola. It’s at this time of year that the variety of trees is most visible: the darker green of holm oak (Quercus ilex), the silvery olives (Olea europaea), the broccoli-green of stone pines (Pinus pinea), and the yellow-brown of deciduous oaks (Quercus cerroides), who are in no hurry to shed their leaves.
The constant rainfall this autumn – not the usual torrential storms, but steady day-long rain – has made moss and lichen flourish. A startling rock by the path is encrusted with orange-yellow lichen on top, and emerald-green moss on the side. The ground is a constellation of moss and earth stars, most of which have already popped. A vivid dark red fungus (a species of Russula) has pushed up through the pine needles, like a mole tunnelling its way out the ground.
A plastic strip tied to a tree guides you up the overgrown terraces, long abandoned. Butcher’s broom grows in the gloom, hung with smooth red balls. A gang of Pekin robins (Leiothrix lutea) express their displeasure at my presence with angry rasping calls. I climb up to the ridge, where spiny Mediterranean gorse (Ulex parviflorus) flowers among the rocks. You can see that Montseny is still powdered with snow, while the Pyrenees are solid icing-sugar white.
Instead of following the ridge back to Vallvidrera, I decide to take the path that skirts the coolest, shadiest corners of the valley. With so few shopping days left before Christmas, it’s very quiet. Probably only a handful of mountain bikers have passed all day. The wings of chaffinches vibrate inside a wild olive. The smallest member of a roving mixed flock, a goldcrest (Regulus regulus), investigates the tip of an oak branch.
The path steepens and it’s almost impossible not to run down . . . straight into a tribe of boars, who scatter through the leaf litter. A male with visible tusks gallops up the slope, where he stands huffing and puffing among the trees, staring belligerently. Poor light and the excitement of the moment has resulted in a less than clear image.
After they finally disperse, I reassure myself that no one in Collserola has ever been attacked by a boar. Their population in the park is estimated at 650 and rising. This season, the hunting clubs of the Collserola region are on strike in retaliation to new restrictions on their activities. Their demands have been partly met: they can continue killing thrushes, for instance. But rabbit shooting is still not permitted in the woods, and the number of days when hunting is allowed in the park has not been increased. So the hunters are envisaging a Collserola so overrun with rampaging boars that the administrative powers will come on bended knee next year and grant them all they desire.
Meanwhile, the boar population is controlled to some extent by forest rangers, who shoot the ones that leave the park limits to explore urban areas. This upsets the residents, some of whom can’t resist feeding the inquisitive beasts and become fond of them. After taming the boars, they have the unpleasant surprise of coming home to a bloodstained street and bodies piled up by their front doors.
Barcelona, Collserola, Mammals, Trees, fungi | Tags: boars in Barcelona, earth stars, goldcrest, hunting in Collserola, increase of boar population, Leiothrix lutea, Quercus cerroides, Quercus ilex, Regulus regulus, sus scrofa, trees in Collserola|
I found these Magpie Inkcaps (Coprinus picaceus) in a dark damp corner of Collserola, growing among brambles. When fresh, their glistening caps are cylindrical and covered in tattered veil remnants.
As the gills liquify, the cap shrinks and flattens. Its brim rolls up and drips an inky substance. This allows all the spores to get their turn at maximum exposure, so they can be carried away by air currents.
Spores dispersed, the inkcap collapses, dissolved like the Wicked Witch of the West.
Collserola, fungi | Tags: autumn in collserola, coprinus picaceus, magpie inkcap|
At the road side near Vallvidrera, a cellulose gymnast was swinging through the stems. If you’ve grown up thinking of Stick insects as exotic pets kept in glass containers, it’s a thrill to find them ranging free. They look fragile, but can re-grow a damaged limb after a moult.
Another plant imitator, the Praying mantis (Mantis religiosa), is quite visible in Collserola in October. Like Norma Desmond in Sunset Boulevard, this elegant specimen couldn’t take its eyes away from the camera.
The black spots, which look eerily like pupils, are an effect of light reflecting from the compound eyes. The mantis also has three “simple” eyes between the antennae that act as an auxilliary light metre. With its swivelling neck and stereoscopic vision, there’s not much that goes on unnoticed around a Praying mantis.
From camouflage to aposematism - currently every Wild carrot nest has a Striped shieldbug (Graphosoma lineatum) inside. Experiments have confirmed that the colouring of these bugs helps predators remember their bad taste. As if testing out the theory themselves, they are often in prominent positions on the top of plants.
Its vivid red and black colouring probably saved this Firebug (Pyrrhocoris apterus) in Palau de Pedralbes park. Climbing up the rocks, it stumbled onto a sunbathing Wall lizard. After assessing the situation, it hurriedly changed direction. The lizard watched, but made no move.
Barcelona, Collserola, Insects, Mammals, Palau de Pedralbes park, Reptiles | Tags: aposematism, Barcelona, camouflage, catalan insects, firebug, graphosoma lineatum, Mantis religiosa, Praying mantis, Pyrrhocoris apterus, stick insect, Striped shieldbug|
While out walking on a warm evening at the beginning of September, it was Nick who first spotted this tiny snake on the track, rippling as fast as it could, anxious to reach cover on the other side. Once caught, it remained still, except for the flickering of its tongue. We weren’t sure of its identity, so it paid to have the camera at hand. The photograph clearly shows a black coronet and an elusive blue shimmer: the marks of the non-venomous Southern smooth snake (Coronella girondica).
We were lucky to stumble on it, as they’re not common in Collserola. Shy and secretive night hunters, they search out geckos, skinks and grasshoppers and kill by constriction. A passing resemblance to the viper is thought to work as a defence. We found the snake in the more open southern part of Collserola, an area of grass, shrubs and scattered trees, a summer hunting ground for Short toed eagles.
At the opposite end of the park, not far from a spring, this dragonfly was captured clinging to a bush. I’d have described it as red, till I got home and saw its range of fairground colours: a horse from a devil’s carousel. The rows of spikes on the legs are impressive, ensuring a firm grip on prey. The dimensions of its eyes immediately suggest extraordinary powers of vision.
When identifying the dragonfly, the yellow stripe along the length of the legs pointed me to the Common darter (Sympetrum striolatum), which was confirmed when Sue put her shots up on the forum.
Finally, in the centre of Collserola, the most disturbed and built-up part, this creature was rescued from a busy track. A convoy of cars was driving away from a restaurant, coating us and everything around in dust. The Eyed hawk moth caterpillar (Smerinthus ocellata) was carried to a safer place on a notebook, hence the garish studio background for its portrait.
The caterpillar has a distinguishing blue horn, slanting white stripes (7 in all) and red spiracles (breathing holes).
Collserola, Insects, Reptiles | Tags: Common darter, Coronella girondica, dragonflies, Eyed hawk moth caterpillar, Smerinthus ocellata, Southern smooth snake, Sympetrum striolatum, walking near Barcelona|
In the narrow valley of Sant Just, sounds carry far. The whack of tennis balls on the courts under the radio transmitter of Sant Pere Màrtir is distinctly heard on the other side. This late August evening a flock of around 50 bee-eaters (Merops apiaster) fill it with their distinctive calls. They’ve congregated to feed on the insects that have risen in frenzied columns after the rain. Insubstantial fare compared to their habitual prey, bees or dragonflies, which are picked off one by one from a vantage point, but available in industrial quantities.
Unlike the swifts, who maintain an intense silence when hunting, bee-eaters communicate constantly. They glide and flutter, with acrobatic flourishes, adding tropical colour to the dried-out end-of-summer valley. I’d love to have included a photograph of their turquoise breasts, their sharply pointed wings and tails, but none came out. However, their whirling supper was impossible to miss.
The first rain in a month has also drawn out scents, dampened the dust, washed off the leaves. In the last phase of summer, one of the few plants in flower is fennel (Foeniculum vulgare), grown tall and wiry, covering the hillsides in delicate yellow filigree. The animal scats along the way are packed with seeds and remains of berries. The path is littered with gnawed pine cones – the culprit, a red squirrel (Sciurus vulgaris), gives itself away by shaking a branch overhead.
There’s not much daylight left when the bee-eaters withdraw, their calls gradually getting fainter. Alpine swifts plunge down the valley after them in a whoosh of strength. Soon it’ll be the bats’ turn to feast.
As I’m climbing up to Sant Pere Màrtir, the final outpost of the Collersola massif, the sun slips behind a cloud and then the horizon. I’m shocked to see it’s only 8.30pm - an hour of daylight has been docked since I was last up here. The low grey clouds are tinged violet, and eventually orange, as the city lights come on. Far below, the motorways are strung with golden beads, as cars pour into the city. Many people will be returning from their summer holidays.
I follow the ridge back to Vallvidrera in the dusk, bats flickering close to my head, and the pulsing crickets gaining volume. A family of boars is investigating the car park mirador. A deep grunt and they trot on, followed after a while by a tiny figure, scampering as fast as it can for fear of being left behind. This year’s boarlets have yet to experience the marvels of autumn - acorns without limit, softened earth that’s easy to dig, and muddy puddles to wallow in.
Barcelona, Birds, Collserola, Mammals, Plants | Tags: Barcelona bird watching, Bee-eaters, boars, Merops apiaster, Red squirrel, Sant Just, Sant Pere Màrtir, Sciurus vulgaris, vallvidrera|
Early Saturday evening, a good time to head to Collserola. If you get ensnared in its web of delights, it doesn’t matter, because the metro runs all night. The rendezvous for Nick, Monica and myself was 5.30pm outside Mundet station, one of the last stops of the green line. As you ride the escalators up to the street, you’re gliding out of the city itself.
An aim of the walk was to increase our knowledge of Collserola’s plants and trees. We went along, pooling our fragments of information and consulting a guide book. Monica tapped into a great store of knowledge acquired when studying biology at university. The further she walked, the more she remembered.
The northern part of Collserola, lying between Horta and Cerdanyola, is the most thickly wooded and least disturbed, with the greatest variety of trees. If you grow up in Britain, an oak is an oak, but here there are three: Holm, Cerrioides and Kermes.
At the side of the wide track, tall shrubs were thriving – Matabou and Matapolls – ox-killer and chicken-killer in Catalan, or Shrubby hare’s-ear, with its yellow umbels, and Flax-leaved daphne, not yet in flower.
As we walked deeper into the valley, a sparrowhawk skimmed the tree tops. Looking up among the branches, you could see alpine swifts soaring high above, reflecting the setting sun. As the woods swallowed us up, the atmosphere became more mysterious. The fading light didn’t stop the identification process.
Monica picked out a plant and held up a leaf: “This is not a leaf”, she informed. It was a stem masquerading as a leaf, with a small point in the centre – a cladode - where the flower would grow: Ruscus aculeatus or Butcher’s broom.
We passed an earthen bank riddled with holes, each entrance lined with webbing, suggesting a colony of tunnel-dwelling spiders. It emerged that two thirds of our group were arachnophobes (Nick and me). The real test would come later.
On the floor of the valley now, we were surrounded by impressively tall pines. Large bats flickered among them. The light was very poor, but it was still possible to debate the differences between hazlenut and elm leaves. Green woodpeckers flew away calling, startled by the intrusion. There was an increasing urge to speak quietly, like in church.
The route out of the valley was along a narrow path, following the rocky bed of a steep torrent, brought to life only after a storm. It was hot and tunnel-like, making us sweat (some more than others). At the top we emerged into a more sparsely wooded area: nightjar territory.
Churring filled the twilight. Then close at hand came a soft quick call, and we saw the silhouettes of a pair of nightjars. Their long wings rose and fell as they encircled us. The reason was a fledgling on the path a few metres ahead, its eye gleaming in the torch light. The parents circled us even faster, like in a playground game, clapping their wings. As we approached, the bird on the path silently flew off.
In the last hour we’d heard some rustling and grunting among the vegetation, suggesting boars. Now came a loud huffing sound, quite close, and coming straight towards us. A big man was slowly and heavily jogging through the woods, oblivious to our presence.
There was just enough light to distinguish the fox when it crossed the track, a grey shape materialising out of the darkness of the trees, and a hint of an outline against the paler background of the track. When it paused and turned, the torch picked up its eyes.
Back on the ridge, the electricity pylons - a feature of Collserola almost as much as the oaks and pines - were silhouetted against the sprawling city glitter. The lights spilled out onto the sea, from summer yachts and cargo ships moored off the coast.
A solitary bar hidden off the road, reached by a dusty track, was irresistible. We joined a small group of people eating and drinking in the cool night air. It was time to check the photos and recap what we’d seen before descending to the metro again. Three boars came trotting down the path we’d just taken. The bar owner said all his plants had been ruined. Only those in big sturdy pots were boar-proof.
Alert for boar sounds, we slowly and carefully picked our way down the steep crumbling path, fragrant with rosemary. The botanical identification didn’t lose pace: euphorbias, fragrant clematis, stonecrop, strawberry trees, lentisk. At a junction of paths, there was some lucky fox scat. Lucky for me, at least.
While we paused to prod and sniff the droppings, the torch light detected a glinting circular structure: a vast web blocking the path like a toll gate, and the owner, a fat spider waiting to seize its dues (possibly Araneus diadimatus.) As I’d been leading the way, concentrating mainly on the ground for my next foothold, or the plants at the side, my nose might have been the first contact point.
Unfortunately, there was no way round, and the web had to be partially unhooked. Adrenaline levels shot upwards at that point at the thought of what else might lie ahead.
At the halfway mark back to Horta, where the path levels out by a spring, loud grunting and snorting were heard. We turned off our lights, climbed onto a wooden picnic table, and waited. A female boar came along, and began tossing some fallen branches, rummaging under the leaves. Like the jogger, she ignored us. We could see her in detail, from moist black nose to short hairy tail. The world was vibrating with night insects, hypnotic and calming. Midwife toads bleeped – there are water containers nearby full of their tadpoles. We stayed long after the boar went her way.
Once the descent had been resumed, the peace of the night was shattered by my ear-splitting shrieks. Nick and Monica thought I’d come face to face with an enormous boar. That would’ve been infinitely preferable to being wrapped in one of the mega-webs I’d blundered into. There was a change in walking order, with Nick bravely leading the way now. Only one more spider blocked the path, spreadeagled in the centre of its impressive domain. On this occasion there was room to carefully duck underneath. Identification continued of the different berry-bearing shrubs: elder, hawthorn, Mediterranean buckthorn and the prolific laurustinus.
Back on asphalt, we were five minutes away from the metro when a small gang of boars galloped up the steps to the university buildings. They’d been ploughing up the roundabout, tossing aside plants as they dug in the freshly irrigated earth. We decided to sit on the grass nearby in case they returned, while bats hunted by the street lights. After a while, there were rustlings from behind, and the ivy rippled. Although the hedgehog increased its pace, it couldn’t avoid being snatched up, gently jiggled so it would unroll, and be identified as a Common European hedgehog.
The last few metres to the metro escalators were uneventful, and we were home by 3.00am.
Thanks to Monica for her picture of the boar.
Barcelona, Birds, Collserola, Mammals, Plants, Trees | Tags: boar, boars in Barcelona, Caprimulgus europaeus, erinaceus europaeus, hedgehog, nightjar, oak, Spain, sus scrofa, walking in Barcelona|
The city doesn’t get more pristine than this. It’s the middle of July, typically a month of stagnant heat, when the sky is discoloured by smog. But in today’s diaphanous atmosphere, Barcelona is visible in intricate detail and the sea is like deep blue silk. After yesterday’s torrential storm, there’s a mountain freshness in the air that promises a good night’s sleep. The soaring swifts take your heart that little bit higher.
I’m in the southern part of Collserola, after catching the funicular to Vallvidrera, where rich Barcelona citizens used to retire for the summer, in the days when people didn’t travel far for their holidays. Once you leave the houses behind, you can follow the ridge to Sant Pere Màrtir, the last hill before the Sierra de Collserola drops down to the Llobregat river plain. There used to be an ermita here, before they tore it down in the 1930s and put up a red and white radio transmitter. Only the name remains, and the stunning views, as the hill falls abruptly away to the city.
I turn inland, where the slopes are more gradual and there’s a labyrinth of paths among pines, small holm oaks and broom. There’s a restlessness about the landscape. A considerable part of Barcelona’s swift population are also spending their Sunday evening on Collserola and the hillsides are swarming with them.
Mainly Common swifts (Apus apus), but the majestic Alpine swifts (Apus melba) stand out with their gleaming white breasts. Their wingspan approaches that of the approaching kestrel, who suddenly accelerates and takes a swoop at one of the house martins mingling in the crowd, making it yelp in alarm.
The path takes me to one of the deepest recesses, where Fragrant clematis (Clematis flammella) has run amok, smothering other plants and bushes with white flowers. The swifts are here too, swishing past, cutting the air to ribbons.
I start climbing up among oak trees, and the swifts cast their shadows on the path. There must be hordes of insects after yesterday’s rain, and they’re intent on hoovering the lot up. The only sound is the slash of their narrow, flexible wings, interrupted by the cheerful gossip of some passing swallows.
Up the grassy slopes, nearly back to the top of the ridge, the density of swifts is even greater. They pass very close, turning incredibly tight circles at relentless speed, weaving intricate flight paths. My camera can only capture them as flickering symbols.
Most of the city is now in shadow, as the sun sets. Only the part nearest the coast still glows. To the north, powerful storm clouds have risen, reflected in the sea.
When the sun has gone down, the swifts ease up, and begin to drift back towards the city. Perhaps some will be going back to their nest holes, even though the breeding season is virtually over. The Alpines are here till October but the Common swifts only stay for three months a year. Each one is linked to a particular barrio, street, unobtrusive hole.
The orange horizon behind them, the swifts float out into the dusk. It’s a vertiginous thought that they’ll be on the wing non-stop till next spring. And those who survive their first migration have 2 or 3 years of flight ahead.
Excellent website about swifts:
http://www.commonswift.org/common_swift.html
Barcelona, Birds, Collserola | Tags: alpine swift, apus apus, apus melba, swift, swift migration, vallvidrera|
