Una serie di cache dedicata alle specie di uccelli che più frequentemente si possono osservare nella Riserva Naturale Pian di Spagna-Lago di Mezzola.
La Riserva, istituita nel 1985, è sito di interesse comunitario (SIC) ed è una delle zone di sosta degli uccelli migratori più importanti d'Europa; a sud dell’arco alpino ne sono rimaste soltanto quattro (le altre tre sono le Bolle di Magadino in Canton Ticino, le torbiere del Lago d’Iseo e i Laghi della Brianza).
Essa si trova lungo uno dei corridoi più brevi per l’attraversamento delle Alpi, quello che passa dallo Spluga.
Il lago di Como circa 2000 anni fa si estendeva verso la Valchiavenna fino a Samolaco; a seguito dei depositi dell’Adda e delle alluvioni del 1600 si formò un’area paludosa che divise il lago in due parti formando a nord il lago di Mezzola; l’aspetto attuale è quello che deriva dall’opera di canalizzazione dell’Adda da parte degli austriaci nel 1858.
Per qualsiasi informazione sulla Riserva Naturale consultate il sito www.piandispagna.it
Forse non tutti sanno che nella Riserva, oltre all’osservazione degli uccelli si possono effettuare bellissime pedalate e passeggiate lungo i percorsi segnalati. Questa serie di cache è stata approntata proprio per suggerire una visita a questi luoghi magnifici.
Le cache sono posizionate in zone liberamente accessibili senza il bisogno di uscire dai percorsi segnalati. Alcune di esse sono al di fuori del perimetro vero e proprio della Riserva.
La cinciarella (Cyanistes caeruleus Linnaeus, 1758) è un uccello passeriforme appartenente alla famiglia dei Paridi.
Descrizione
È lungo circa 10,5–12 cm e pesa intorno ai 12 g Il piumaggio è molto vivace, presentando per entrambi i sessi una colorazione blu cobalto sulla nuca, sulle ali e sulla coda, verdastra sul dorso, una mascherina bianca, attraversata da una linea nera all'altezza degli occhi, e petto giallo zolfo. Ha il becco nero a punta e zampe corte e robuste grigio-blu. I giovani sono molto più gialli degli esemplari adulti, ed hanno un carattere particolarmente giocoso (spesso si possono osservare individui assieme ad esemplari di codibugnolo).
Biologia
Alimentazione
La cinciarella è un insettivoro.
Il suo cibo preferito consiste in coccidi, afidi, larve, ragni e piccoli invertebrati che trova sugli alberi.
Nel periodo invernale non disdegna comunque semi, bacche e frutta.
Un interessante esempio di strategia alimentare e trasmissione di insegnamenti tra gli uccelli fu notato negli anni sessanta in Inghilterra, quando si osservò come le cinciarelle avessero imparato ad aprire a colpi di becco i tappi di alluminio delle tradizionali bottiglie del latte per berne il contenuto.
In inverno accettano molto volentieri: palline di grasso, arachidi e semi di girasole nelle mangiatoie.
Riproduzione
Il periodo dell'accoppiamento inizia a febbraio.
La cinciarella nidifica in qualsiasi cavità degli alberi, ceppi, muri o nei nidi artificiali. Lo stesso nido è utilizzato anno dopo anno e costantemente protetto durante la cova. Viene realizzato utilizzando muschio, lana, peli e piume e le uova (normalmente 7-10 con guscio bianco screziato da punti scuri) vengono deposte tra aprile e maggio e covate per circa 15 giorni.
I piccoli vengono accuditi da tutti e due i genitori per 15-20 giorni.
Canto
Il canto è molto articolato e può essere udito tutto l'anno ma maggiormente nel periodo da febbraio a giugno. Varia tra un vivace teerrrr, tee, tee, tee ad un rimbrottante churr.
Se disturbate mentre sono nel nido, le cinciarelle emettono un sibilo simile a quello dei serpenti, e possono cercare di saltare nel tentativo di intimorire l'aggressore.
Distribuzione e habitat
È diffuso dall'Europa occidentale fino all'Asia occidentale e settentrionale.
Vive prevalentemente nei boschi collinari e pianeggianti, ma è anche un assiduo frequentatore di frutteti e giardini dove è possibile ammirarlo nelle sue acrobazie tra i rami, alla ricerca di cibo.
Tassonomia
Sono note le seguenti sottospecie:
-Cyanistes caeruleus obscurus (Pražák, 1894)
-Cyanistes caeruleus caeruleus (Linnaeus, 1758)
-Cyanistes caeruleus balearicus (von Jordans, 1913)
-Cyanistes caeruleus ogliastrae (Hartert, 1905)
-Cyanistes caeruleus calamensis (Parrot, 1908)
-Cyanistes caeruleus orientalis Zarudny & Loudon, 1905
-Cyanistes caeruleus satunini Zarudny, 1908
-Cyanistes caeruleus raddei Zarudny, 1908
-Cyanistes caeruleus persicus (Blanford, 1873)
La sottospecie Cyanistes caeruleus teneriffae è oggi inquadrata come specie a sé stante (Cyanistes teneriffae)
Fonte: "Cyanistes caeruleus." Wikipedia, L'enciclopedia libera. 11 giu 2017, 16:20 UTC. 29 giu 2017, 09:56 <//it.wikipedia.org/w/index.php?title=Cyanistes_caeruleus&oldid=88360532>.
A series of caches dedicated to the species of birds that can be observed more frequently in the Natural Reserve of Pian di Spagna-Lake Mezzola.
The Reserve was established in 1985. It's a Site of Community Interest and is one of the most important stopover areas for migratory birds of Europe; in the south of the Alps there are only four left (the other three are: the Bolle di Magadino in Canton Ticino; the peat bogs of Lake Iseo; the Brianza lakes).
It is located along one of the shorter corridors for crossing of the Alps, the one that passes through Splugen Pass.
Lake Como, about 2,000 years ago stretched towards Chiavenna to Samolaco; as a result of deposits of the Adda and the floods of XVII century it was formed a marshy area that divided the lake into two parts, forming the northern Lake Mezzola; the current appearance is what comes from the work of channeling Adda by the Austrians in 1858.
For any further information please visit the Natural Reserve website www.piandispagna.it
Perhaps not everybody knows that in the Reserve, in addition to the observation of birds it is possible to make beautiful bike and walk trails. This series of caches was prepared precisely to suggest a visit to these magnificent places.
The caches are placed in areas freely accessible. It is recommended not to leave the marked trails. Some caches are hidden outside of the Reserve area.
The Eurasian blue tit (Cyanistes caeruleus) is a small passerine bird in the tit family Paridae. The bird is easily recognisable by its blue and yellow plumage and its size.
Eurasian blue tits, usually resident and non-migratory birds, are widespread and a common resident breeder throughout temperate and subarctic Europe and western Asia in deciduous or mixed woodlands with a high proportion of oak. They usually nest in tree holes, although they easily adapt to nest boxes where necessary. Their main rival for nests and in the search for food is the larger great tit.
The Eurasian blue tit prefers insects and spiders for its diet. Outside the breeding season, they also eat seeds and other vegetable-based foods. The birds are famed for their skill, as they can cling to the outermost branches and hang upside down when looking for food.
Taxonomy
The Eurasian blue tit was described by Carl Linnaeus in 1758 in the 10th edition of his Systema Naturae under the binomial name Parus caeruleus. Parus is the classical Latin for a tit and caeruleus is the Latin for dark blue or cerulean. Two centuries earlier, before the introduction of the binomial nomenclature, the same Latin name had been used by the Swiss naturalist Conrad Gesner when he described and illustrated the blue tit in his Historiae animalium of 1555.
In 2005, analysis of the mtDNA cytochrome b sequences of the Paridae indicated that Cyanistes was an early offshoot from the lineage of other tits, and more accurately regarded as a genus rather than a subgenus of Parus. The current genus name, Cyanistes, is from the Ancient Greek kuanos, "dark blue". The African blue tit (Cyanistes teneriffae) was formerly considered conspecific.
Subspecies
There are currently at least nine recognised subspecies:
-C. c. caeruleus – (Linnaeus, 1758): the nominate subspecies, occurring in Continental Europe to northern Spain, Sicily, northern Turkey and northern Urals
-C. c. obscurus – (Pražák, 1894): found in Ireland, Britain and Channel Islands
-C. c. ogliastrae – (Hartert, 1905): found in Portugal, southern Spain, Corsica and Sardinia
-C. c. balearicus – (von Jordans, 1913): found on Majorca Island (Balearic Islands)
-C. c. calamensis – (Parrot, 1908): found in southern Greece, Pelopónnisos, Cyclades, Crete and Rhodes
-C. c. orientalis – Zarudny & Loudon, 1905: found in southern European Russia (Volga River to central and southern Urals)
-C. c. satunini – Zarudny, 1908: found in the Crimean Peninsula, Caucasus, Transcaucasia and northwestern Iran to eastern Turkey
-C. c. raddei – Zarudny, 1908: found in northern Iran
-C. c. persicus – (Blanford, 1873): found in the Zagros Mountains
Hybrids
Pleske's tit (Cyanistes pleskei) is a common hybrid between this species and the azure tit in western Russia. The cap is usually darker than the azure tit, and the tail is paler than the Eurasian blue tit.
Description
The Eurasian blue tit is usually 12 cm (4.7 in) long with a wingspan of 18 cm (7.1 in) for all genders, and weighs about 11 g (0.39 oz). A typical Eurasian blue tit has an azure blue crown and dark blue line passing through the eye, and encircling the white cheeks to the chin, giving the bird a very distinctive appearance. The forehead and a bar on the wing are white. The nape, wings and tail are blue and the back is yellowish green. The underparts is mostly sulphur-yellow with a dark line down the abdomen—the yellowness is indicative of the number of yellowy-green caterpillars eaten, due to high levels of carotene pigments in the diet. The bill is black, the legs bluish grey, and the irides dark brown. The sexes are similar, but under ultraviolet light, males have a brighter blue crown. Young blue tits are noticeably more yellow.
Distribution and habitat
There are currently around 20–44 million pairs in Europe.
The Eurasian blue tit and the related hybrids are considered native species in areas of the European continent with a mainly temperate or Mediterranean climate, and in parts of the Middle East. These areas include Ireland, the United Kingdom and most of the European Union and EFTA (except Malta, where they are considered vagrant, and Iceland, where they are absent), plus: Albania, Algeria, Andorra, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Georgia, Iran, Iraq, Jordan, Kazakhstan, Lebanon, Libya, the Republic of Macedonia, Moldova, Montenegro, Morocco, Russia, San Marino, Serbia, Syria, Tunisia, Turkey, Vatican City and Ukraine.
In Great Britain the Eurasian blue tit is typically found in deciduous woodland, parks, gardens and even in the centre of towns.
Behaviour and ecology
Eurasian blue and great tits form mixed winter flocks, and the former are perhaps the better gymnasts in the slender twigs. A Eurasian blue tit will often ascend a trunk in short jerky hops, imitating a treecreeper. As a rule the bird roosts in ivy or evergreens, but in harsh winters will nest wherever there is a suitable small hole, be it in a tree or nesting box. They are very agile and can hang from almost anywhere.
This is a common and popular European garden bird, due to its perky acrobatic performances when feeding on nuts or suet. It swings beneath the holder, calling "tee, tee, tee" or a scolding "churr".
Breeding
The Eurasian blue tit will nest in any suitable hole in a tree, wall, or stump, or an artificial nest box, often competing with house sparrows or great tits for the site. Few birds more readily accept the shelter of a nesting box; the same hole is returned to year after year, and when one pair dies another takes possession. It is estimated by the RSPB that there are 3,535,000 breeding pairs in the UK.
Eggs are 14–18 mm (0.55–0.71 in) long and 10.7–13.5 mm (0.42–0.53 in) wide. Egg size appears to depend mostly on the size of individual females and secondarily on habitat, with smaller eggs found at higher altitudes. The clutch's total weight can be 1.5 times as heavy as the female bird.
The bird is a close sitter, hissing and biting at an intruding finger. In the South West of England such behaviour has earned the Eurasian blue tit the colloquial nickname "Little Billy Biter". When protecting its eggs it raises its crest, but this is a sign of excitement rather than anger, for it is also elevated during nuptial display. The nesting material is usually moss, wool, hair and feathers, and the eggs are laid in April or May. The number in the clutch is often very large, but seven or eight are normal, and bigger clutches are usually laid by two or even more hens. It is not unusual for a single bird to feed the chicks in the nest at a rate of one feed every 90 seconds during the height of the breeding season. In winter they form flocks with other tit species.
In an analysis carried out using ring-recovery data in Britain, the survival rate for juveniles in their first year was 38%, while the adult annual survival rate was 53%. From these figures the typical lifespan is only three years. Within Britain, the maximum recorded age is 10 years and 3 months for a bird that was ringed in Bedfordshire. The maximum age is 11 years and 7 months for a bird in the Czech Republic.
Diet
The Eurasian blue tit is a valuable destroyer of pests, though it is fond of young buds of various trees, especially when insect prey is scarce, and may pull them to bits in the hope of finding insects. No species, however, destroys more coccids and aphids, the worst foes of many plants. It takes leaf miner grubs and green tortrix moths (Tortricidae). Seeds are eaten, as with all this family, and blue tits in British urban areas have evolved the ability to digest milk and cream.
Voice
Eurasian blue tits use songs and calls throughout the year. Songs are mostly used in late winter and spring to defend the territory or to attract mates. Calls are used for multiple reasons. Communication with other Eurasian blue tits is the most important motivation for the use of calls. They inform one another on their location in trees by means of contact-calls. They use alarm-calls to warn others (including birds of other species such as the great tit, the European robin or the treecreeper) about the presence of predators in the neighbourhood. Scolding, for example, is used when a ground predator (e.g. fox, cat or dog), a low flying predator or a perched owl are noticed. Sometimes this is followed by mobbing behaviour in which birds gather together in flocks to counter a predator. The alarm-whistle warns other birds about the proximity of a Eurasian sparrowhawk, a northern goshawk, a common buzzard or other flying predators that form a potential danger in the air. A series of high-pitched 'zeedling' notes are given by both partners before and during copulation. The begging-call is used by juveniles to beg for food from parents.
Learning
Eurasian blue tits are able to culturally transmit learning to other tit species. An example of this, dating from the 1920s, is the ability to open milk bottles with foil tops, to get at the cream underneath. Such behaviour has been suppressed recently by the gradual change of human dietary habits (low-fat or skimmed milk instead of full-fat), and the way of getting them (from a supermarket in plastic containers with hard plastic lids), instead of the milkman.
Predators and natural threats
The small size of the Eurasian blue tit makes it vulnerable to prey by larger birds such as jays who catch the vulnerable fledglings when leaving the nest. The most important predator is probably the sparrowhawk, closely followed by the domestic cat. Nests may be robbed by mammals such as weasels and red squirrels, as well as introduced grey squirrels in the UK.
The successful breeding of chicks is dependent on sufficient supply of green caterpillars as well as satisfactory weather. Breeding seasons may be affected badly if the weather is cold and wet between May and July, particularly if this coincides with the emergence of the caterpillars on which the nestlings are fed.
Parasites
Eurasian blue tits are known to be host to feather mites, and rarely lice and flat flies. In Europe, the only feather mite species known to live on the blue tit host is Proctophyllodes stylifer. P. stylifer however seems to be of no concern to the bird as, until now, it is only known to feed on dead feather tissue. P. stylifer lives all its developmental stages, i.e. egg, larva, protonymph, tritonymph and adult, within the plumage of the same host. The usual sites where P. stylifer is encountered are the remiges and the rectrices of the bird where they can be found tandemly positioned between the barbs of the rachis.
Status and conservation
The Eurasian blue tit is classified as a least concern species on the IUCN Red List (version 3.1), and as a Green Status species, since 1996, by the Royal Society for the Protection of Birds in the United Kingdom.
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Source: Wikipedia contributors. "Eurasian blue tit." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 26 Jun. 2017. Web. 29 Jun. 2017
Questa cache fa parte della serie Geo Summer Games 2017.
This cache take part to the Geo Summer Games 2017.
FTF = 5 points
STF = 3 points
TTF = 2 points
Following finds = 1 point
Difficulty = 1,5 points
Terrain = 1,5 points
C'è tempo fino alle ore 23.59 del 22 luglio 2017 per ottenere punti trovando e loggando questa cache.
It is possible to gain points until July 22, 2017 @ 11.59p.m. by finding and logging this cache.
La cache ovviamente continuerà ad essere disponibile anche dopo i Geo Summer Games 2017!
The cache of course will keep on to be available after the end of the Geo Summer Games 2017!
