Itinerary: The proposed route is circular and runs both along the banks of the Arroyo de Vallelargo, and in the oak grove of the Monte Norte.
Highlights: Bird watching, Mediterranean woodland.
Longitud: 2,4 km
- On foot: 1.5 - 2 h; recommended for bird watching
- Bicycle: not recommended for bird watching
Elevation: 677-705 MASL
Average: Grade: 4% - 4.8%. Maximum: 18%
Accessibility: Dirt roads in good condition, with possible sand patches; short sections with slopes.
The trail begins in the parking lot of the Boadilla del Monte Municipal Sports Centre, next to the M-513 highway on the section that connects Boadilla with Pozuelo de Alarcón. One may begin bird watching right here, where it is possible to observe house sparrows (Passer domesticus), the spotless starling (Sturnus unicolor) and, in spring and summer, swallows and swifts flying over the area. The woodland is accessed through the gate in the fence at the end of the parking lot, from where you proceed into the Monte Norte, crossing the bed of the Arroyo de Vallelargo under the M513 highway.
At this point you can see the Puente de Piedra (Stone Bridge), built by Ventura Rodríguez and restored in 2013; and one of the accesses to the shafts that conveyed water to the municipality from the springs in the woodland area. Continuing along this path, running parallel to the Arroyo de Vallelargo, you may hear the songs of birds hiding in the thick riverbank vegetation, such as Cetti's warbler (Cettia cetti), the nightingale (Luscinia megarhynchos), and the melodious warbler (Hippolais polyglotta).
This section of the stream is also inhabited, in the spring and summer, by one of the most colourful birds in Europe: the European bee-eater (Merops apiaster). If you hear their songs, try to spot them, waiting for them to emerge from their shelters.
Continue along this path, located in a setting rich in holm oaks, and a few large stone pines, making it a good place to view the chaffinch (Fringillacoelebs) and the unmistakable Eurasian hoopoe (Upupaepops) looking for earthworms and other food in the soil.
About 700 meters from the Stone Bridge, the route veers left into a planted pine area, recognisable due to the uniform size of the trees that compose it. Oaks and pines mix until you reach an intersection at which you may observe two large cork oaks, one of them listed as a Legacy Tree by the Community of Madrid. Here one often finds the passerine bird known as the great tit (Parus major) and the Eurasian blue tit (Cyanistes caeruleus) flitting about in the thin branches in search of insects, as well as a tiny bird, just 9 cm long, known as the common firecrest (Regulus ignicapilla).
As you walk along, listen closely for the songs and calls of the birds. For example, if you hear a delicate call characterised by a triple trill of "eez-eez-eez", it is bound to be a flock of long-tailed tits (Aegithalos caudatus) moving from tree to tree in search of food. It is also a good idea to gaze skyward from time to time, looking for birds that may be flying above, like the common buzzard (Buteo buteo), black kite (Milvus migrans), cinereous vulture (Aegypius monachus) and griffon vulture (Gyps fulvus). If you are particularly lucky, you just might spot an imperial eagle (Aquila adalberti), known to fly over the Monte de Boadilla between their nesting and hunting areas.
The route continues between holm oaks, along with species of rock rose, known as gum rock rose (Cistus ladanifer), the grey-leaved cistus, with its tell-tale pink flowers (Cistus albidus), sun rose (Hallimium hallimifolium), and cotton lavender (Santolina rosmarinifolia), etc., until reaching the Club de las Encinas, where you wil turn left before slowly descending towards the Puente de Piedra (Stone Bridge), thereby completing the loop route.
In this last section you will probably be able to spot a woodlark (Lullula arborea) or a serin (Serinus serinus), revealing their presence with their characteristic song: an accelerated, prolonged and strident twitter, emitted from the treetops, or even when in flight.
European Bee-eater (Merops apiaster):
One of the most colourful birds on the Peninsula, displaying a range covering almost the entire palette: blue, turquoise, yellow, brown, white, black, green, brown and even red (in the eyes).
In many places people consider the sound of this species an indication that it will rain.
Its chirping song is very distinctive. As its name suggests, bees and wasps are among its favourite prey. It is a Trans-Saharan migrant that winters in tropical Africa.
It excavates tunnels in slopes and ravines, where it builds its nests, forming colonies.
Common Finch (Fringilla coelebs):
A bird the size of a sparrow that is easily recognised by the striking white band on its wings, and the white outer feathers on its tail, easily spotted when it takes flight.
Finches are forest dwellers in spring, but in the winter they form large groups occupying fallows and meadows. They issue different calls, including a strong “chíiip” or “picinc” sound, or a soft and flutey “suiiit” or “juíiit”. The male's song is very characteristic, an ascending series of long, jumbled warbling composed of short notes, followed by a shorter and faster one, and, finally, a squeak that might be described as "Demetrrrio".
It is one of the most abundant birds on the Iberian Peninsula, being outnumbered only by species like the house sparrow (Passer domesticus).
The finch's diet is omnivorous, based primarily on insects, buds, shoots, fleshy fruits, seeds, etc.
Hoopoe (Upupa epops):
A bird with very peculiar physical features, a large crest that unfolds when it is alert, and wings with a great contrast between their black and white colouring.
It feeds on insects, which it captures with its long and curved beak specialised for this task.
It nests in hollows in trunks and branches and, unlike most birds, the hoopoe does not remove the excrements of its offspring from the nest, which gives it a strong smell. This unpleasant odour probably serves a purpose, rendering its young less appetizing. It is often said that its offspring have the capacity to throw feces to fend off predators that approach the nest.
The hoopoe uses its characteristic crest to warn other birds of its species of danger.
Its scientific name is onomatopoeic, transcribing its song, with its three low notes: "u-pu-pa".
It is a migratory species that winters throughout the Southern Sahara.
Long-tailed Tit (Aegithalos caudatus):
Occasionally referred to as the silver-throated tit or silver-throated dasher, it is found throughout Europe and Asia. Its tail is longer than the rest of its body (8-cm tail, 6- cm body).
Its oval, closed nests are very elaborate, built on the forks of trees or shrubs.
They are very social, and usually travel in groups (especially in the autumn and winter), so when you see one reach a tree or bush, others are likely to follow. There is a saying that "You don't see a long-tailed tit without a little friend." One of its most common sounds are three soft “eez-eez-eez” notes.
Black kite (Milvus migrans):
It is a migratory species, so we must wait for the spring and summer to spot them on a regular basis, this being the most common raptor in the Monte de Boadilla.
The black kite is not very selective in terms of food, and often settles for dead or injured animals, or food found in landfills.
During the breeding season it puts on an impressive display of aerobatics. Its tail is slightly bracketed ("V" shaped) and rotates noticeably as it glides.
Woodlark (Lullula arborea):
It is usually easier to hear it than to see it. Its song is a fluted trill that accelerates and is usually emitted during flight.
It inhabits open spaces with scattered trees or shrubs. In the Monte de Boadilla it is found in scrubland areas.
Like the rest of the larks, its colouring consists of various brown tones, but it can be differentiated by the distinctive white superciliar meeting on its nape.
It is essentially granivorous, but during the breeding season it also feeds on insects.
Other species that may be seen or heard on this trail include:
Wood Pigeon (Columba palumbus):
The largest pigeon in Spain, it inhabits a wide variety of ecosystems, but prefers forests and, to a lesser extent, wooded pastures and areas rich in shrubs. It is unmistakable for the white spots on its neck and wings, which in flight resemble backpack straps.
It feeds its chicks through a secretion on the adult's neck during the first two or three days, when the chicks put their heads inside the adult's beak to feed, instead of the other way around.
Common Magpie (Pica pica):
This bird features lack and white plumage, with a striking blue and green iridescence on its wings and tail. Extraordinarily adaptable and successful, it can be found in almost any environment. It is a very sedentary species, tending to stay within a 50-km radius.
Omnivorous and opportunistic, the magpie feeds on almost anything: grains, insects, small reptiles and mammals, carrion, chickens and eggs, human waste, etc. It emits a great variety of sounds, including alarms when fighting over food, or in the presence of predators, such as birds of prey, which they attack to scare away from the area, especially if they are close to a nest.
An interesting characteristic of their nests is that they are reinforced with mud, and sometimes even have a network of branches functioning as a parasol.
It is usually among the first birds in the woodland to reach carrion, where, after eating the soft parts, it constantly moves around and waves to attract the attention of crows, vultures and kites, which, with their stronger beaks, can better cut and chop it. The magpie then waits, and feeds on the remains.
Like all corvidae, they have an instinct to store, so they hide leftover food, as well as bright and colourful objects that catch their attention.
Short-toed Treecreeper (Certhia brachydactyla):
So called because it "creeps" in trees, this is a small forest bird with a fine, long and curved beak and varied plumage in its upper parts (head, wings, back and tail). It explores trunks and branches in search of invertebrates (spiders, weevils, earwigs, caterpillars, etc).
Unlike the Eurasian nuthatch, the treecreeper moves along trunks from the bottom upwards. It has particularly rigid tail feathers (a feature shared by woodpeckers), which it uses as a support to climb trees.
When it reaches a certain height while creeping along a tree, it jumps over to a neighboring one, perching on the lower part of the trunk, from where its begins to travel upwards again.
Its sounds are loud and sharp, including a typical "tweet".
The short-toed treecreeper nests in tree crevices or behind bark flakes. Old woodpecker nests, fissures in buildings or walls, and artificial nest boxes are also used.
The species is particularly affected by the use of pesticides in forest areas, and by the fragmentation of these spaces.
Little Owl (Athene noctua):
It is the easiest night raptor to spot, both because it is quite active during the day, and because it inhabits agricultural areas, where it often perches on walls and/or posts.
A compact raptor of limited size, it nevertheless has a large head and eyes.
Since ancient times this species has been associated with wisdom, and considered a symbol of the goddess Athena (or Minerva, in Roman culture).
It often reacts to a possible danger (such as when someone approaches) by nodding its head sharply, almost giving the impression of taking small leaps, when, in fact, it does not move the rest of its body.
It emits many sounds, almost all of them sharp and resembling “meows”.
In some places in Spain there has been a popular belief that it says: "mío, mío, mío" (mine, mine...).
It feeds mainly on invertebrates and, occasionally, small rodents.
One of the main threats to this species are the drastic changes on Spanish farmlands, environments to which it had already adapted.