Zooming in on Montjuic (vi): autumn

Written by Lucy Brzoska

An old olive tree is creaking.  It’s not the wind, but the sound of a tree frog singing from somewhere inside the hollow trunk.  The warm humid October weather suits Mediterranean tree frogs, and they appear on the dew-saturated leaves, in bushes and flower beds.  Some had shimmied up the newly blooming Red hot pokers.

Migrating song thrushes have settled unobtrusively on the hill. You’re aware of them but they hide out of sight, communicating with low calls.  Other arrivals are chiffchaffs.  They’re far less shy, too small to fear the shotgun.

I’m going along the cobbled path to the Sot del Migdia, and feel watched.  Just above me, I see tall ears, and a prominent brown eye.  It’s a boom year for rabbits on Montjuic – newly excavated warrens are gaping. They’ll be glad summer’s over, and the arid slopes have turned green, not so much from rain, which has been scarce, but from the heavy dew.

Wild couples in Barcelona

Written by Lucy Brzoska

In Barcelona, a sign that spring isn’t far away is an intensification of twig gathering by Monk parakeets (an activity they tend to do all year round). Away from their raucous nest colonies, built high up in the towering pines of Palau de Pedralbes park, a parakeet couple were snatching some quality time together.  Snuggled up close, they were taking it in turns to preen.

Another sign of incipient spring in the city is the sound of serins singing. The jangling, irrepressible song, delivered from a suitably high spot, can be traced to a small yellow-breasted bird – Europe’s smallest finch and close relation to the canary.

In a prelude to copulation, the more discretely coloured female serin leaned over to receive her mate’s gift of food.

On Montjuic, two large fuzzy black carpenter bees flew past in an embrace – the female had been seized by the male, recognisable by its smaller size and orange-tipped antennae. When they settled on a leaf, you could see another distinguishing feature: the male’s silvery grey mesosomal hairs.

It seems that carpenter bees are prone to overheating, as they fly slowly and are black, so the pale colour is thought to be useful in reflecting away sunlight. Males spend more time out in the open – territory patrolling, looking for females, and then feeding in the afternoons, when the females are back in their shelters. (See this study for more interesting info.)

Much of the private life of the Red squirrels in Palau de Pedralbes park goes on out of sight, very high up in the trees. They come down to earth to dig up their stashed autumnal loot or explore the rubbish bins. This one was pulling up dried grass.  With a very large mouthful, it ran up an Aleppo pine to furnish its drey, where it would soon be giving birth.

 

Iberian Blue-tailed Damselflies on Montjuic

Written by Lucy Brzoska

Large flocks of Blue-tailed damselflies (Ischnura graellsii) emerge from the ponds in Montjuic’s Jardins de Verdaguer.  They’re so tiny that in flight often all you can make out is a quivering blue blob.  When they settle, the spot of blue turns out to be the tail end of an endless abdomen (segment 8, to be precise).

the-tiny-iberian-blue-tailed-damselfly-ischnura-graellsii

Throughout the month of June the Blue-tails are harvested by House sparrows.  Bills bristling with wings,  the sparrows somehow manage to keep on collecting without dropping any of the existing catch.  You can imagine their nestlings getting fat on plentiful damselfly protein.

house-sparrow-hunts-for-damselflies-in-the-pond

By the end of July, the pond vegetation is full of Tree frogs (Hyla meridionalis),  perching motionless alongside the Blue-tails.  I found one very slowly ingesting its meal, till it seemed to be champing on a blue-tipped cigar.  One tremendous gulp and the rest was engulfed.

tree-frog-hyla-meridionalis-eats-bluetailed-damselfly-ischnura-graellsii

Food chains are long and complex.  Damselflies hunt small flies . . .

cannibalism-in-blue-tailed-damselfies-female-eats-teneral

. . . and each other.  As the sunlight broke free of the early morning clouds, it stirred the damsels from their resting places. A newly emerged Blue-tail on its maiden flight was immediately snatched, hoisted up and devoured by a mature female.

Black-tailed Skimmers at lunchtime

Written by Lucy Brzoska

With parallel worlds evolving in the park, it’s amazing what can be happening by your elbow, unnoticed.

I’ve seen squirrels hanging upside down on the tree trunks, looking down at oblivious heads only inches away.  Or Black rats bursting out of the hedge, flying straight into a litter bin, while people chat or have lunch nearby, none the wiser. And the other day it was the Black-tailed Skimmers.

A pair were trying to mate in the wide expanse of the palace forecourt, getting pestered by a lone marauding male.   The couple finally found some peace and quiet on the stone balustrade that runs behind the semi circle of benches.

black-tailed-skimmers-orthetrum-cancellatum

You could clearly see the way the male folds the darkened tip of his flexible abdomen over the head of the female, to secure her in position.  Or the way the female uses four legs to hold onto her partner, while the third pair gets tucked right back, neatly out of the way.

Perhaps I disturbed them, because the Skimmers flew over to a flowering bush, next to a woman absorbed in her newspaper. The dragonflies, their green eyes like aviator goggles, held on tight, as the twig swung in the breeze.

black-tailed-skimmers-in-wheel-position

After separating, the female rested on the ground for a while.  Female Black-tailed Skimmers emerge into the world bright yellow, but with age can change colour.  This one had an indeterminate grey green shimmer.

female-black-tailed-skimmer1

I saw her zipping over the ornamental fountain, dropping off eggs at a terrific speed.  The only pity is it wasn’t the pond, where chances of hatching are significantly higher.

A new generation of damselflies

Written by Lucy Brzoska

All round the pond, firmly stuck to the low concrete wall, were quantities of papery husks.  I immediately suspected what they might be, remembering the concentration of mating Western Willow Spreadwings (Lestes viridis) in the park last autumn.  It must have been a spectacular sight to see the nymphs emerge from the pond in such numbers and burst out of their unravelling skins.

One damselfly was still clinging to an exuvia, much smaller than itself. How could it fit inside?  Reading up, I found that once half out, they pause and inflate their wings and abdomen into shape with hemolymph, the insect equivalent of blood.

lestes-viridis-damselfly-with-exuvia

Looking closely at one of the exuvia, it appears like a Mutoid Waste sculpture. The long “snout” is the labial mask, or lower lip, which the nymph flips open to grab passing prey.

lestes-viridis-exuvia-showing-labial-mask

The nymphs do their work well. The two biology students who volunteer to keep algae levels at a  level acceptable for park authorities found no mosquito larvae in the pond at all.

After the mass metamorphosis, the damselflies had dispersed, but I did find one pristine young female clinging to a leaf.  Her wings had a pink shimmer and were still held close together, not at the 45 degree angle that gives the species its name.  With any luck, in a few weeks she would be laying eggs in the bamboo grove by the water’s edge.

lestes-viridis-damselfy-recently-emerged

October heat

Written by Lucy Brzoska

red-squirrel-in-pedralbes-park

The roast chestnut stands were raising the temperature of the city streets while people roasted in the October sun. In the park, where benches in the shade were at a premium, there were other reminders it was officially no longer summer: the rustling of squirrels picking acorns in the oaks, or the engrossed silence of parakeets gorging on berries and seeds. One day the grass was cut, and a flock of swallows paused to dip and dive and feast on the disturbed insects. Pedralbes Park is on the busy Diagonal road, a causeway for migrating hirundines, just like the coast.

monk-parakeet-eating-berries

A  new sign has appeared at the pond: “Urban diversity protection programme. Amphibian reproduction point.” Hopefully, pond life will be allowed to develop undisturbed and the bright spark who thought to drain and scrub it out mid-May will now be restrained. Sheltering from the heat, I sat down under the Buckthorn tree to watch the legion of Darters who’d gathered to mate.

One had set up his territory in front and hovered in a haze of just-discernable wing-movement. I was awestruck by this display of energy. It only allowed itself the briefest of rests on the ledge. These breaks would last all of 2 seconds before it zipped off in pursuit of a rival Darter, driving it into another part of the pond. As well as aerial pursuits, there was also a lot of ovipositing going on, the darters still in tandem as the female dipped into the water.

hovering-darter-sympetrum-sp

Even more copious, though much less conspicuous, were the Western Willow Spreadwings. They’ve been in the park throughout summer and autumn, barely noticeable except as a spindly insect presence, dangling off leaf tips.

western-willow-spreadwing-on-leaf

But if one lands nearby you notice their beautiful green and coppery colouring, and their astonishing eyes. Our eyes, set deep in sockets, are half hidden. These orbs are on full display.

western-willow-spreadwing-lestes-viridis

On this day there were couples of Spreadwings dangling all over the place, looking for a quiet spot. One pair alighted in the Buckthorn tree. The male clasped the branch and then his long straight abdomen began to fold. He slowly lifted the female, like a dancer raising his partner.

lestes-viridis-mating-female

She reciprocated by thrusting her abdomen up in the air, until they were linked together in a jagged heart. While he clung to the branch, she clasped her abdomen. They remained like this, rocking gently from side to side.

lestes-viridis-mating-damselflies

This year I’ve seen 5 Dragonfly species in the park: the Broad Scarlet Darter (Crocothemis erythraea), Blacktailed Skimmer (Orthetrum cancellatum), Red-veined Darter (Sympetrum fonscolombii), Desert Darter (Sympetrum sinaiticum) and the Emperor Dragonfly (Anax imperator).  On this occasion, despite clicking away, I somehow managed to avoid all the best ID angles!  They might have been Common Darters, but a positive ID is impossible.

 

Birds in the bush

Written by Lucy Brzoska

There are two main parts to Pedralbes Park – an ornamental open space, divided by an avenue of lime trees, which leads to a wooded area further back. Bushes of Japanese spindle (Euonymus japonicus) – an oriental evergreen shrub – add symmetry to the triangular lawns. Gardeners find this unfussy and drought-resistant plant very useful, as do robins (Erithacus rubecula), who appreciate its dense cover. In January the berries attract Sardinian warblers (Sylvia melanocephala) at a time when insects are scarce.

It’s not only birds that enjoy the fruit. The Japanese spindle has been trimmed into an extensive hedge, enclosing the lawns. Protracted rustling from within attracted my attention.

Two Black rats (Rattus rattus) were feasting on the orange pulp. They looked clean and wholesome, with their pink paws and pale grey underparts.  Their ears are proportionally larger than those of their more urban cousins, the Brown rats, millions of whom are reported to live in Barcelona’s sewers.

Over in the bush near my bench, a robin had appeared in a gap, like a proprietor at the gate, on the lookout for a bit of lunch.

While retrieving a piece of apple, the robin tilted its head skywards, alerting me to the kestrel surveying the park. The parakeets soon drove the predator away.

Firecrest season

Written by Lucy Brzoska

Bitterly cold winds keep people out of the park. In a low season atmosphere, the gardeners are cleaning the pond and cutting the hedges. The rows of lime trees are nearly bare, their last leaves flying across the grass. Only the Ginkgos are still in full flare, with a pool of fan-shaped leaves accumulating beneath.

Another source of intense colour, though much more condensed, are the firecrests, plentiful this season, and mixed up with assorted tits and the occasional goldcrest. Firecrests (Regulus ignicapillus) are very tolerant of people: they seem far too busy making inventories of every bush and tree to spare you any attention. You hear their high thin calls and realise you’re surrounded by tiny birds, whirring and hovering. You get quick glimpses of masked eyes, orange crests, and yellowy-green mantles.

Another energetic feeder, a Grey wagtail (Motacilla cinerea), speedwalks on the grass, constantly changing direction. It sallies forth, tail bobbing, then veers to the left before suddenly taking off, only to land again and take a completely new route. Like the firecrest, it’s moved into town for the winter. Its more usual habitat of fast-flowing water is reflected in its Spanish and Catalan names: Lavandera cascadeña and Cuereta torrentera.

The round ornamental hedges have been claimed by robins, who stay vigilant inside their thick cover, planning their next move. Their numbers increase considerably in October, a month when more transient migrants also swell the park’s bird population. This year I saw Pied flycatchers and a kingfisher, as well as a Song thrush digging for worms – a common enough species in other parts but a rare visitor to Pedralbes park.

Going back to the regulars, in this cold season the Monk parakeets (Myiopsitta monachus) look round and well-fed. Watching these versatile feeders happily grazing on grass, you feel they could never go hungry. A group opposite my bench chew their way through endless stalks of the stuff, blinking placidly, as if they find the act of munching on grass calming.

Cattle Egret in the Park

Written by Lucy Brzoska

An unusual visitor came to the park this week. While people lolled on the grass, kissing, reading and eating lunch, it quietly decimated the park’s lizard population.

Cattle egrets (Bubulcus ibis) breed in Barcelona zoo within the Grey heron colony. Unlike their bigger relatives, they are mainly land foragers and can usually be seen in the fields around the Llobregat Delta. Their adaptability to man-altered habitats is one of the reasons for the Cattle egret’s spectacular worldwide expansion over the last century (first pair bred in UK this year).

The opportunism of the egret in the park was richly rewarded. It stalked the ivy-covered ground, alert for rustling movements. Whenever potential prey was spotted, its neck would start wobbling. The undulation would travel back in waves, till even its tail was shaking. Its head, however, remained quite still. The sinuous movements seemed to be a way of warming up for the final pounce, which was nearly always successful.

The egret’s bill was an efficient pincer, applied with masterful technique. Each lizard was grabbed firmly by the body, away from the detachable tail. Sometimes the helpless lizards would wrap their tails around the egret’s bill, as if desperately trying to bind it. But struggling was useless. Inevitably they would be swallowed head-first, to join the ever-growing pile in the egret’s powerful digestive system.

On a short break, it stopped to preen, and caught a couple of flies, particularly annoying at this time of year. It was a reminder why Cattle egrets are valued by ranchers as an alternative to pesticides. They are often to be seen delicately picking bugs off animals’ backs. But the egret in the park soon went back to its more solid menu, swallowing reptile after reptile.

I began to worry about the park’s lizards, (mainly Podarcis hispanica), who normally enjoy a placid predator-free existence. But later I read about a study of an island population of lizards – the park is like an island in the city, after all – which involved unleashing an alien predator and observing the effect on the resident reptiles. The population was badly hit initially, but the species triumphed, exhibiting longer legs at first (better to run with) and then shorter legs (more useful when they took to the trees). An example of rapid evolutionary resilience.

The Cattle egret returned to hunting, but I’d had enough of observing. My lunch-break was nearly over, and I was starving.

The Red Squirrels of Pedralbes

Written by Lucy Brzoska

The red squirrels (Sciurus vulgaris) of Palau de Pedralbes park stream along the branches unobserved, and build their dreys out of sight in the towering Aleppo pines, somewhere among the parakeet nests.

But sometimes they come to ground, especially in the afternoon when the army of gardeners have gone home and stopped their pruning, spraying and sweeping. Tails undulate in the grass like plumes as squirrels forage. Litter bins are investigated too, though at the moment there are plenty of seeds and nuts to gather.

Red squirrels vary in colour: those in the park tend to be a russet-brown, set off by white breasts, and black tails. At the moment their pelts are particularly lustrous, topped off by lavish ear tufts, their winter adornment.

When two squirrels meet, a helter-skelter pursuit often ensues. They scrabble noisily round and around the tree trunks, loosening a shower of bark debris. Spread eagled on opposite sides of the tree, they await each other’s next move. When one’s nerve breaks, the manic chasing resumes.

This ensures they’ll be fit for next spring, when the females go on heat and lengthy chasing begins in earnest, a prelude to mating. If climate and food supplies permit, which is surely the case in this Barcelona park, the females go on heat twice a year: between January and April, and then again between the end of May and August.

Red squirrels seem weightless as they skim through fragile canopies: the larger males reach a mere 350 grams. Other interesting anatomical features of squirrels include double-jointed ankles and long claws, permitting secure vertical descents. Like all rodents, their chiselled incisors never stop growing – about 15cm in a year. This red squirrel looks set to wear them down a little on a hard green pine cone.