Wild Barcelona: Mud, glorious mud

If the showers fall as they should, Collserola is sticky with mud in April.

None are happier than the boars, for whom summer, with its hard dusty ground, is the season of scarcity. In spring, the soft wet earth yields easily to their restless muscular snouts, as they dig in search of roots and invertebrates. Signs of their energetic ploughing are everywhere as you walk around Collserola. This mixing of soil layers can be beneficial for plants, but only up to a point. The decline of Collserola’s orchids has been blamed on the booming boar population (given as 900 and rising). The layer upon layer of hoof prints visible after the rain is a graphic reminder of how numerous they’ve become.

Mud is also for wallowing. Near Vallvidrera, there’s a stream that almost never dries up. Even at the end of summer, a trickle finds its way down to the catchment area of the reservoir. Judging by the signs, boars visit the spot in large numbers. Looking at the steep, well-worn path among the trees you can imagine wild night-time scenes, as bristly hulks come galloping down, landing straight in the mud pit.

After a soak and a roll, it’s time for a scrub. Many of the nearby trees are thickly slathered with scraped-off mud: if you look closely, you can see bristles caught on the bark. If there is no handy tree near a wallow, a rock or an iron pylon will do.

For animals without sweat glands, this is a pleasurable way to keep cool and clean, as well as dislodge any tenacious ticks, to which boars are particularly prone. If pine trees are rubbed vigorously enough, the secreted resin provides an additional anti-parasite treatment. And during the mating season (mainly in autumn, but also in late summer), the males scent the mud and make their presence known on strategic landmarks.