Admin questo pomeriggio ti parlo di un totem molto puccioso, pensa che i cani della prateria sono animali molto socievoli che amano salutarsi baciandosi e abbracciandosi.
Come vedremo nella seconda parte di questa scheda questo totem insegnerà a partecipare più attivamente alla vita di comunità, che si tratti della famgilia, delle amicizie, della società o dell'ambiente di lavoro.FONTE:
FONTE IMMAGINE: http://it.wikipedia.org/wiki/File:Pr%C3%A4riehund.jpg
Da Wikipedia, l'enciclopedia libera.
I cani della prateria (Cynomys, Rafinesque 1817) sono un genere di mammiferi appartenenti all'ordine dei Roditori e alla famiglia Sciuridae, indigeno delle praterie americane.
Nonostante il nome, non sono dunque canidi, bensì roditori, della stessa famiglia delle marmotte. Devono il loro nome ad un suono, simile ad un latrato, che emettono in caso di pericolo. Diversamente dalle marmotte, non vanno in letargo.
Pesano da 800 a 1500 gr per ca 30-35 cm di lunghezza.
Sono animali estremamente socievoli e vivono in larghe colonie, formate da gruppi familiari di un maschio, 3-4 femmine e i piccoli dell'anno. La femmina, dopo una gestazione di 33-37 giorni, mette al mondo da 1 a 8 piccoli, che nascono molto immaturi e necessitano delle cure materne prima di poter uscire dal nido per almeno altri 40 giorni. Allo stato selvatico vivono per circa 5 anni, in cattività fino a 8 o 10.
I cani della prateria sono animali dotati di elevata intelligenza e capaci di emettere più di 25 suoni diversi in base al tipo di pericolo che si avvicina (un uccello, un bovino, un uomo ecc.).
Il genere include le seguenti specie:
Cane della prateria dalla coda nera (Cynomys ludovicianus), il più diffuso
Cane della prateria dalla coda bianca (Cynomys leucurus)
Cane della prateria di Gunnison (Cynomys gunissoni)
Cane della prateria messicano (Cynomys mexicanus)
Cane della prateria dello Utah (Cynomys parvidens)
Presenti originalmente in colonie di milioni di individui, le popolazioni si riducono oggi a poche centinaia di migliaia per i cani della prateria dalla coda nera e a numeri molto più ridotti per le altre specie, considerate ormai a rischio di estinzione.
Gli allevatori di bovini americani hanno fatto loro e fanno tutt'oggi una guerra indiscriminata, sostenendo che competono per l'erba con le mandrie. La convivenza tra le specie in un ambiente così povero di risorse e dall'equilibrio ecologico fragilissimo è invece fondamentale: dal cane della prateria dipendono per nidificare la civetta delle tane e il serpente delle praterie. Esso costituisce inoltre un cibo necessario alle aquile.
L'habitat del cane della prateria è infine fortemente minacciato dalla progressiva urbanizzazione.
Diversi tentativi sono stati fatti per ricollocare le colonie e per mettere gli animali sotto tutela, ma per ora persiste l'indiscriminata uccisione, che mette in serio pericolo la sopravvivenza della specie.
FONTE IMMAGINE: http://en.wikipedia.org/wiki/File:Cynomys_ludovicianus_-Paignton_Zoo,_Devon,_England-8a.jpg
From Wikipedia, the free encyclopedia
Prairie dogs (genus Cynomys) are burrowing rodents native to the grasslands of North America. There are five different species of prairie dogs: black-tailed, white-tailed, Gunnison's, Utah and Mexican prairie dogs. They are a type of ground squirrel, found in the United States, Canada and Mexico. In Mexico, prairie dogs are primarily found in the northern states which are the southern end of the great plains: northeastern Sonora, north and northeastern Chihuahua, northern Coahuila, northern Nuevo León, and northern Tamaulipas. In the U.S., they range primarily to the west of the Mississippi River, though they have also been introduced in a few eastern locales. They are herbivorous, and will eat all sorts of vegetables and fruits.
Prairie dogs are named for their habitat and warning call, which sounds similar to a dog's bark. The name was in use at least as early as 1774. The 1804 journals of the Lewis and Clark Expedition note that in September 1804, they "discovered a Village of an animal the French Call the Prairie Dog." Its genus, Cynomys, derives from the Greek for dog mouse.
In companies that use large numbers of cubicles in a common space, employees sometimes use the term prairie dogging to refer to the action of several people simultaneously looking over the walls of their cubicles in response to a noise or other distraction. This action is thought to resemble the startled response of a group of prairie dogs.
Classification and first identification
The Black-tailed Prairie Dog (Cynomys ludovicianus) was first described by Lewis and Clark in 1804 during the Lewis and Clark Expedition. Lewis described it in more detail in 1806, calling it the "barking squirrel."
FAMILY SCIURIDAE (Squirrels, chipmunks, marmots, and prairie dogs)
Gunnison's Prairie Dog, Cynomys gunnisonium nocterna
White-tailed Prairie Dog, Cynomys leudacurus
Black-tailed Prairie Dog, Cynomys ludovicianus
Mexican Prairie Dog, Cynomys mexican
Utah Prairie Dog, Cynomys pardos
About 14 other genera in subfamily
On average, these stout-bodied rodents will grow to be between 30–40 centimetres (12–16 in) long, including the short tail and weigh between 0.5–1.5 kilograms (1–3 lb). There is sexual dimorphism in body mass in the prairie dog which varies between a 105-136% difference between the sexes. Among the species, black-tailed prairie dogs tend to be the least sexually dimorphic and white-tailed prairie dogs tend to be the most sexually dimorphic. Sexual dimorphism peaks during weaning when the females lose weight and the males start eating more and is at its lowest when the females are pregnant which is also when the males are tired from breeding.
FONTE IMMAGINE: http://en.wikipedia.org/wiki/File:Cynomys_ludovicianus_2.jpg
Biology and behavior
Prairie dogs are chiefly herbivorous, though they eat some insects. They feed primarily on grasses and, in the fall, broadleaf forbs. In the winter, lactating and pregnant females supplement their diet with snow for extra water. They also will eat roots, seeds, fruit and buds. Grasses of various species are eaten. Black-tailed prairie dogs in South Dakota eat western bluegrass, blue grama, buffalo grass, six weeks fescue, and tumblegrass, while Gunnison’s prairie dogs eat rabbit basin, tumbleweeds, dandelions, saltbush and cacti in addition to buffalo grass and blue grama.
Habitat and burrowing
Prairie dogs mainly live in altitudes ranging from 2,000-10,000ft above sea level. In the areas in which they live can get as high as 100 degrees in the summer and as low as -35 degrees in the winter. As prairie dogs live in areas that are prone to environmental threats including hailstorms, blizzards, and floods as well as drought and prairie fires, burrows provide important protection for them. Prairie dog burrows can serve to control temperature as they are 5-10 degrees Celsius during the winter and 15-25 degrees Celsius in the summer. Prairie dog tunnel systems help channel rainwater into the water table to prevent runoff and erosion, and can also serve to change the composition of the soil in a region by reversing soil compaction that can be a result of cattle grazing.
Prairie dog burrows are 5-10m long and 2-3m below the ground. The entrance holes are generally 10-30cm in diameter. Prairie dogs burrow can have 1-6 entrances. Sometimes the entrances are simply flat holes in the ground while other times they are surrounded by mounds of dirt that are either left as piles or packed down hard. Some mounds, known as dome craters, can be as high as 0.2-0.3 meters high. Other mounds, known as rim craters, can be as high as 1m. Dome craters and rim craters serve as observation posts which the animals use to watch out for predators. They also function to protect the burrows from flooding. It is also possible that the holes also provide ventilation as the air enters through the dome crater and leaves through the rim crater causing a breeze though the burrow. Prairie dog burrows contain chambers that provide certain functions. They have chamber for their young called nursery chambers; chamber for night-time and chambers for the winter. They also contain air chambers that may function to protect the burrow from flooding and a listen post for predators. When hiding from predators, prairie dogs use less deep chambers that are usually a meter below the surface. Nursery chambers tend to be deeper, being 2-2 ½ feet below the surface.
Social organization and spacing
Attribution: I, Mbz1
FONTE IMMAGINE: http://en.wikipedia.org/wiki/File:Kissing_Prairie_dog_edit_3.jpg
Highly social, prairie dogs live in large colonies or "towns" – collections of prairie dog families that can span hundreds of acres. The prairie dog family groups are the most basic units of its society. Members of a family group inhabit the same territory. Family groups of black-tailed and Mexican prairie dogs are called "coteries" while "clans" are used to describe family groups of white-tailed, Gunnison’s and Utah prairie dogs. Although these two family groups are similar, coteries tend to be more closely knit than clans. Members of a family group interact through oral contact or "kissing" and groom one another. They do not perform these behaviors with prairie dogs from other family groups.
A prairie dog town may contain 15-26 family groups. There may also be sub-groups within a town called "wards" which are separated by a physical barrier. Family groups exist within these wards. Most prairie dog family groups are made up of one adult breeding male, two to three adult females and one to two male offspring and one to two female offspring. Females remain in their natal groups for life and are thus the source of stability in the groups. Males leave their natal groups when they mature to find another family group to defend and breed in. Some family groups contain more breeding females than one male can control as thus have more than one breeding adult male in them. Among these multiple male groups, some may contain males they have friendly relationships but the majority have males that have largely antagonistic relationships. In the former, the males tend to be related while in the latter they tend to not to be related. There may be two to three groups of females controlled by one male. However among these female groups there are no friendly relations.
The average prairie dog territory takes up 0.05-1.01 hectares. Territories have well established borders that coincide with physical barriers like rocks and trees. The resident male of a territory defends it and agonistic behavior will occur between two males of different families defend their territories. These interactions may happen 20 times per day and last 5 minutes. When two prairie dogs encounter each other at the edges of their territories that will start staring, make bluff charges, flare their tails, chatter their teeth, and sniff each others perianal scent glands. When fighting, prairie dogs will bite, kick and ram each other. If their competitor is around their size or less, the females will participate in fighting. Otherwise, if a competitor is sighted, the females signal for the resident male.
FONTE IMMAGINE: http://en.wikipedia.org/wiki/File:Juvenile_black-tailed_prairie_dogs.jpg
The prairie dog is well adapted to predators. Using its dichromatic color vision, it can detect predators from a far distance and then alert other prairie dogs to the danger with a special, high-pitched call. Constantine Slobodchikoff and others assert that prairie dogs use a sophisticated system of vocal communication to describe specific predators. According to them, prairie dog calls contain specific information as to what the predator is, how big it is and how fast it is approaching.. These have been described as a form of grammar. According to Slobodchikoff, these calls, with their individuality in response to a specific predator imply that prairie dogs have highly developed cognitive abilities. He also writes that prairie dogs have calls for things that are not predators to them. This is cited as evidence that the animals have a very descriptive language and have calls for any potential threat.
There is debate over whether the alarm calling of prairie dogs is selfish or altruistic. It is possible that prairie dogs alarm others to the presence of a predator so they can protect themselves. However it is also possible that the calls are meant to cause confusion and panic in the groups and cause the others to be more conspicuous to the predator than the caller. Studies of black-tailed prairie dogs suggest that alarm calling is a form of kin selection as a prairie dog’s call alerts both offspring as well as non-descended kin like cousins, nephews and nieces. Prairie dogs with kin close by called more often than those that didn’t have kin nearby. In addition, it may be the caller, may making itself more noticeable to the predator. However, it seems that a predator has difficulty determining which prairie dog is making the call due to its "ventriloquial" nature. Also, it seems when a prairie dog makes a call, the others do not run into the burrows but stand on the mounds to see where the predator is, making themselves visible to the predator.
Attribution: Aaron Siirila
FONTE IMMAGINE: http://en.wikipedia.org/wiki/File:Prairie_Dog_Washington_Zoo.JPG
FONTE IMMAGINE: http://commons.wikimedia.org/wiki/File:Pr%C3%A4riehund_mit_Walnussh%C3%A4lfte_Tiergarten_Heidelberg.jpg