Forskel mellem versioner af "Bruger:Jens-Egon/Sandkasse"

ingen ændringskommentar
 
 
'''Kaniner'' er små pattedyr i familen [[Leporidae]] ([[hare]]r og Kaniner) fra ordnen [[støttetandede]]. Kaniner adskiller sig fra harer ved at være skovlevende eller gravende dyr, der ikke løber særlig godt over lange stræk.
 
==Biologi==
 
Kaniner adskiller sig fra harer ved at føde små hjælpeløse [[redeunge]]r i modsætning til [[harekilling]]er der kan se og løbe omkring lige fra [[fødsel|fødslen]].
 
==Behavior==
 
==Diet and eating habits==
Rabbits are [[herbivore]]s who feed by grazing on [[grass]], forbs, and leafy weeds. In addition, their diet contains large amounts of cellulose, which is hard to digest. Rabbits solve this problem by passing two distinctive types of feces: hard droppings and soft black viscous pellets, the latter of which are immediately eaten. Rabbits [[coprophagia|reingest their own droppings]] (rather than [[Ruminant|chewing the cud]] as do cows and many other herbivores) in order to fully digest their food and extract sufficient nutrients. <ref>[http://www.scottveterinaryclinic.co.uk/rabbits.html rabbits<!-- Bot generated title -->]</ref> <ref>[http://www.oaktreevet.co.uk/Pages/leaflets/rabbit%20general.htm rabbits general<!-- Bot generated title -->]</ref>
 
Rabbits graze heavily and rapidly for roughly the first half hour of a grazing period (usually in the late afternoon), followed by about half an hour of more selective feeding. In this time, the rabbit will also excrete many hard faecal pellets, being waste pellets that will not be reingested. If the environment is relatively non-threatening, the rabbit will remain outdoors for many hours, grazing at intervals. While out of the burrow, the rabbit will occasionally reingest its soft, partially digested pellets; this is rarely observed, since the pellets are reingested as they are produced. Reingestion is most common within the burrow between 8 o'clock in the morning and 5 o'clock in the evening, being carried out intermittently within that period.
 
Hard pellets are made up of hay-like fragments of plant cuticle and stalk, being the final waste product after redigestion of soft pellets. These are only released outside the burrow and are not reingested. Soft pellets are usually produced several hours after grazing, after the hard pellets have all been excreted. They are made up of micro-organisms and undigested plant cell walls.
 
The chewed plant material collects in the large cecum, a secondary chamber between the large and small intestine containing large quantities of symbiotic bacteria that aid in the digestion of cellulose and also produce certain B vitamins. The pellets are about 56% bacteria by dry weight, largely accounting for the pellets being 24.4% protein on average. These pellets remain intact for up to six hours in the stomach, the bacteria within continuing to digest the plant carbohydrates. The soft feces form here and contain up to five times the vitamins of hard feces. After being excreted, they are eaten whole by the rabbit and redigested in a special part of the stomach. This double-digestion process enables rabbits to utilize nutrients that they may have missed during the first passage through the gut and thus ensures that maximum nutrition is derived from the food they eat. <ref name="Encyclopædia Britannica"/> This process serves the same purpose within the rabbit as [[rumination]] does in cattle and sheep. <ref>''The Private Life of the Rabbit'', R. M. Lockley, 1964. Chapter 10.</ref> <!-- This reference is for the whole section, as written 30th July 2007 -->
 
Rabbits are incapable of [[vomiting]] due to the [[physiology]] of their digestive system.<ref name="rabbit.org2">
{{Cite web
|url = http://www.rabbit.org/fun/answer11.html
|title = True or False? Rabbits are physically incapable of vomiting. (Answer to Pop Quiz)}}</ref>
 
==Behavior==
While the European rabbit is the best-known species, it is probably also the least typical, as there is considerable variability in the natural history of rabbits. Many rabbits dig burrows, but cottontails and hispid hares do not. The European rabbit constructs the most extensive burrow systems, called warrens. Nonburrowing rabbits make surface nests called forms, generally under dense protective cover. The European rabbit occupies open landscapes such as fields, parks, and gardens, although it has colonized habitats from stony deserts to subalpine valleys. It is the most social rabbit, sometimes forming groups in warrens of up to 20 individuals. However, even in European rabbits social behaviour can be quite flexible, depending on habitat and other local conditions, so that at times the primary social unit is a territorial breeding pair. Most rabbits are relatively solitary and sometimes territorial, coming together only to breed or occasionally to forage in small groups. During territorial disputes rabbits will sometimes “box,” using their front limbs. Rabbits are active throughout the year; no species is known to hibernate. Rabbits are generally nocturnal, and they also are relatively silent. Other than loud screams when frightened or caught by a predator, the only auditory signal known for most species is a loud foot thump made to indicate alarm or aggression. Notable exceptions are the [[Amami rabbit]] and the volcano rabbit of Mexico, which both utter a variety of calls. <ref name="Encyclopædia Britannica"/>
 
Instead of sound, scent seems to play a predominant role in the communication systems of most rabbits; they possess well-developed glands throughout their body and rub them on fixed objects to convey group identity, sex, age, social and reproductive status, and territory ownership. Urine is also used in chemical communication. When danger is perceived, the general tendency of rabbits is to freeze and hide under cover. If chased by a predator, they engage in quick, irregular movement, designed more to evade and confuse than to outdistance a pursuer. Skeletal adaptations such as long hind limbs and a strengthened pelvic girdle enable their agility and speed (up to 80 km [50 miles] per hour). <ref name="Encyclopædia Britannica"/>
 
==Reproduction==
90

redigeringer