Archive for December, 2009

Zooming in on Montjuic castle(ii): a Montpellier snake

Written by Lucy Brzoska

A fierce northerly wind had blown November’s mild mist into space.  But on the south side of Montjuic castle, in early December, it was warm enough for the geckos to materialise from their nooks and for a very small Montpellier snake to go in search of them.

I found it coiled at the foot of the wall, pale brown and very slender, gazing upwards. When it began to negotiate the irregular stones, it revealed a length of only about 30-40 cm.  Montpelliers are Europe’s largest snakes, with adult males reaching 2 metres or more, so this was still a baby.

young-montpellier-snake

For the moment it was perfectly suited for life in the castle wall, threading neatly in and out of the crevices, among the snail shells and woodlice.

montpellier-snake-moving-on-wall

Despite the scrutiny, the young snake didn’t go into hiding.  Instead it began gathering information by flickering its forked tongue at me, the equivalent of twitching a nose in the air, picking up scent particles.

malpolon-monspessulanus-montpellier-snake-tongue-flickering

From a distance the snake was well camouflaged and plain.  Close up, it showed intricate and rhythmic patterns.   The particularly striking markings on the head will soon disappear as the snake grows.  The juvenile Montpellier spotted here a year ago had already lost them.

Varied in size and shape, each scale on a snake’s head is carefully labelled and mapped out for identification.  The Montpellier is distinguished by having two loreal scales, located between the eye and nostril but without touching either.  The narrow shape of its small head means the frontal scale, centre-top, is also long and thin, squashed in by the supraoculars.

young-montpellier-snake-malpolon-monspessulanus

Grateful for letting me have such a good look, I left and let the little Montpellier get on with the business of hunting.

Zooming in on Montjuic Castle (i)

Written by Lucy Brzoska

You barely notice the ants unless they’re lugging some eye-catching, outsize object, such as the remains of a woodlouse.  It was an awkward task, requiring tenacity and strong pincers.

ants-carry-woodlouse

Team effort successfully manoeuvred the crustacean through the crack.  There was barely any flesh on it but woodlice themselves will eat their own or each other’s cast-off cuticles.  The hard, over-lapping armour plating is made of calcium carbonate, a form of calcium we get in dietary supplements.  In any case, ants bring back all kinds of booty to  their galleries, edible or not.

ants-squeeze-woodlouse-through-hole

A jumping spider was darting among the busy ants:  Menemerus semilimbatus, a Mediterranean species often found on sunny walls and rocks.  Upside-down, it surveyed me with a fine set of four bright eyes.

jumping-spider-menemerus-semilimbatus

The other four are located on the carapace, slightly disconcerting until you get used to it.  Two of them are clearly visible here.

menemerus-semilimbatus-jumping-spider-from-above

Salticids are renowned for their visual acuity.  They hunt by stealth and pounce with deadly accuracy.  In their courtship dancing, the males often flaunt brightly coloured parts of their body.  Some species have impressive John Travolta disco moves (click on second image down).

Another movement caught my eye and I was just in time to see a soft downy feather disappear through a hole, as an ant whisked it into the depths of the castle wall.  You can only wonder what use the ants would find for it.

ant-carries-feather