Archive for July, 2011

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.

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

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. . . 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.

On the rocks: high altitude flora in the eastern Pyrenees

Written by Lucy Brzoska

We turned our backs on the complex of buildings, ski lifts and artificial lake, and started climbing. It was a cold clear morning in Núria on Sant Joan’s day, and the group of walkers off the cremallera* rapidly dispersed in a variety of directions.   * rack railway

The valley of Núria is an olla, or pot.  In a tough annual race, runners follow its rim, tracing the circle of mountains, which range between 2,700 and 3,000 metres.  But individually the peaks are very accessible for a day’s walk, considering your starting point is at 2,000 m.  Our destination was Noucreus, at 2,790 m.

Past the pines and extensions of alpenrose (Rhododendron ferrugineum), marmots were bounding across the grassy slopes. One got chased into its burrow by a wheatear. The nesting bird fluttered incessantly around the rodent’s head like an angry butterfly.  Alpine gentians (Gentiana nivalis) cover the grass here, low to the ground, barely flinching in the sudden strong gusts of wind.

alpine-gentian-gentiana nivalis-in-nuria-pyrenees

The way is steep, so before long you’re commanding a good view of the valley, the Núria complex still in view but increasingly remote. Then the path zigzags onto the scree and the majesty of the surroundings takes over completely.

climbing-to-noucreus-from-nuria-in-catalan-pyrenees

The sight of plants cheerfully flowering in this desolate expanse of rock took me by surprise. The Parnassus-leaved buttercup (Ranunculus parnassifolius) has large white petals densely veined in pink, and dark green leaves. Its secret to surviving in this shifting world of rubble is a thick clump of roots, ensuring a secure anchorage.

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parnassus-leaved-buttercup-ranunculus-parnassifolius-in-the-scree

Nearby Spoon-leaved Candytuft (Iberis spathulata), a member of the Crucifer family, was peeking coquettishly out of the rocks.  This plant adopts a different strategy, spending the winter in seed-form until the next growing season.

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spoon-leaved-candytuft-flowers-iberis-spathulata

Another plant, Senecio leucophyllus, still hadn’t produced its dense yellow flowerheads, but its velvety frilly leaves had spread widely.  Once decomposed, all this biomass would be a great contribution to the richness of the soil below the scree.

senecio-leucophyllus-in-scree-above-nuria-in-catalan-pyrenees

I felt exposed on this narrow path, teetering slightly after bending to take photographs. There was nothing to hold onto, just an expanse of grey stone, falling away steeply. But what at first glance might seem a harsh, inhospitable desert is clearly a good home for a well-adapted plant. Low clouds frequently shroud these mountains, and the moisture condenses on the stones, to trickle down below. The scree then protects the soil from drying out in the strong sun.

The stark scattering of iron crosses on the Noucreus pass mark the deaths of travellers who tried to cross the mountain in snow but conditions that June morning were very benign. We lingered for hours, enthralled by the view and the vultures that regularly coasted past, including two Lammergeiers, who cruised slowly above the peaks.  Far below in another valley was a herd of about 100 chamois – the young taking it easy while the mothers foraged.

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On the peak itself there’s a sloping slab of rock, and sheltering underneath I found a Pyrenean endemic, Saxifraga pubescens.

saxifrage-pubescens-at-2870-metres-noucreus-nuria-pyrenees

Nearby, a tight cluster of soil-hugging rock plants had enabled the Alpine Forgetmenot to survive on the peaks, well above its usual alpine pasture habitat.

alpine-forgetmenot-myosotis-alpestris-at-over-2700-metres-in-catalan-pyrenees