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93-457: All Podengo types are hardy, intelligent and lively dogs, excelling at agility and making fine companions. Loyal and fearless, Podengos are also good house guards and are amenable to training by dog experienced people and those that enjoy primitive (unrefined, "less domesticated") dog behavior. Keen hunting dogs, the Podengo has an affinity for game regardless of size. Typically, the dogs hunt in

186-511: A pack with their handler following. When game is found, they kill and retrieve it, or flush it towards the hunter to be shot. Each size category traditionally hunts game appropriate to their size and temperament. (Pequeno: rabbits ; Medio: rabbits and wild boar ; Grande: deer and wild boar). The Portuguese Podengo is bred in three size varieties, the Large, Medium and Small (in Portuguese

279-414: A burrow and one male defending a territory around the burrow. At high population densities, this system breaks down and males show a hierarchical system of dominance with overlapping ranges. Female offspring remain in the colony while male young disperse. The prairie vole is monogamous and forms a lifelong pair bond. Outside the breeding season, prairie voles live with others in small colonies. A male

372-491: A colony of their own. Rodents use scent marking in many social contexts including inter- and intra-species communication, the marking of trails and the establishment of territories. Their urine provides genetic information about individuals including the species, the sex and individual identity, and metabolic information on dominance, reproductive status and health. Compounds derived from the major histocompatibility complex (MHC) are bound to several urinary proteins. The odor of

465-400: A culture within wolf packs, and this is passed on to the offspring by the elders of the group.  Pups learn something from each member of the pack and attain the vital social skills required to create powerful bonds upon which the wolf's societal structure relies. Animals that typically predominate over others are associated with the term alpha . Among pack-living wolves, alpha wolves are

558-406: A distinct "chirping", has been likened to laughter , and is interpreted as an expectation of something rewarding. In clinical studies, the chirping is associated with positive emotional feelings, and social bonding occurs with the tickler, resulting in the rats becoming conditioned to seek the tickling. However, as the rats age, the tendency to chirp declines. Like most rat vocalizations, the chirping

651-485: A few are predators. The field vole is a typical herbivorous rodent and feeds on grasses, herbs, root tubers, moss, and other vegetation, and gnaws on bark during the winter. It occasionally eats invertebrates such as insect larvae. The plains pocket gopher eats plant material found underground during tunneling, and also collects grasses, roots, and tubers in its cheek pouches and caches them in underground larder chambers. The Texas pocket gopher avoids emerging onto

744-588: A few have become specialized to rely on a diet of animal matter. A functional-morphological study of the rodent tooth system supports the idea that primitive rodents were omnivores rather than herbivores. Studies of the literature show that numerous members of the Sciuromorpha and Myomorpha, and a few members of the Hystricomorpha, have either included animal matter in their diets or been prepared to eat such food when offered it in captivity. Examination of

837-444: A high-fiber diet; their molars have no roots and grow continuously like their incisors. In many species, the molars are relatively large, intricately structured, and highly cusped or ridged. Rodent molars are well equipped to grind food into small particles. The jaw musculature is strong. The lower jaw is thrust forward while gnawing and is pulled backwards during chewing. Gnawing uses incisors and chewing uses molars, however, due to

930-539: A means of intra-specific communication during courtship among the Cape mole rat . Footdrumming has been reported to be involved in male-male competition; the dominant male indicates its resource holding potential by drumming, thus minimizing physical contact with potential rivals. Some species of rodent are monogamous, with an adult male and female forming a lasting pair bond . Monogamy can come in two forms; obligate and facultative. In obligate monogamy, both parents care for

1023-440: A member of the wolf pack; the weak are supported by the efforts of stronger wolves, and higher-ranking individuals enjoy better and larger kills than could be taken on their own. Protection is granted by sheer number, and larger, more plentiful territory can be won and sustained. Care and protection of the young are shared, and knowledge can be passed down through generations, creating a unique culture within each group The pack

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1116-426: A pack is, the less status of alpha is likely to be obtained through fighting, and young wolves instead leave the pack to find a mate and produce offspring of their own. Larger or less-nuclear packs may operate differently and possess more complex and flexible social structures. In the case of other wild canids, the alpha male may not have exclusive access to the alpha female; moreover, other pack members may guard

1209-686: A part in social communication between dormice and are used when the individuals are out of sight of each other. House mice use both audible and ultrasonic calls in a variety of contexts. Audible vocalizations can often be heard during agonistic or aggressive encounters, whereas ultrasound is used in sexual communication and also by pups when they have fallen out of the nest. Laboratory rats (which are brown rats, Rattus norvegicus ) emit short, high frequency, ultrasonic vocalizations during purportedly pleasurable experiences such as rough-and-tumble play, when anticipating routine doses of morphine , during mating, and when tickled. The vocalization, described as

1302-458: A predator depresses scent-marking behavior. Rodents are able to recognize close relatives by smell and this allows them to show nepotism (preferential behavior toward their kin) and also avoid inbreeding. This kin recognition is by olfactory cues from urine, feces and glandular secretions. The main assessment may involve the MHC, where the degree of relatedness of two individuals is correlated to

1395-499: A predator warning or defensive action. It is used primarily by fossorial or semi-fossorial rodents. The banner-tailed kangaroo rat produces several complex footdrumming patterns in a number of different contexts, one of which is when it encounters a snake. The footdrumming may alert nearby offspring but most likely conveys that the rat is too alert for a successful attack, thus preventing the snake's predatory pursuit. Several studies have indicated intentional use of ground vibrations as

1488-417: A reflection of the relationships they present in the pack, reflecting any tension, cooperation, and competition present. Tensions are noted to become higher around breeding season. This is due to increased opportunities for reproduction. Individuals challenge the group hierarchy to gain better-quality mates. This leads to greater intraspecific competition and rising tensions. Female wolves are known for being

1581-403: A single female monopolizes mating from at least three males. In most rodent species, such as brown rats and house mice, ovulation occurs on a regular cycle while in others, such as voles, it is induced by mating . During copulation, males of some rodent species deposit a mating plug in the female's genital opening, both to prevent sperm leakage and to protect against other males inseminating

1674-412: A single upper and lower pair of ever-growing incisors. Well-known rodents include mice , rats , squirrels , prairie dogs , porcupines , beavers , guinea pigs , and hamsters . However, rabbits , hares , and pikas , which also have incisors that grow continuously (but have two pairs of upper incisors instead of one), were once included with rodents, but are now considered to be in a separate order,

1767-549: A small part of its diet is plant material. It has a chunky body with short legs and tail, but is agile and can easily overpower prey as large as itself. Rodents exhibit a wide range of types of social behavior ranging from the mammalian caste system of the naked mole-rat , the extensive "town" of the colonial prairie dog , through family groups to the independent, solitary life of the edible dormouse . Adult dormice may have overlapping feeding ranges, but they live in individual nests and feed separately, coming together briefly in

1860-443: A wolf an alpha is usually no more appropriate than referring to a human parent or a doe deer as an alpha . Any parent is dominant to its young offspring, so alpha adds no information. Why not refer to an alpha female as the female parent , the breeding female , the matriarch , or simply the mother ? Such a designation emphasizes not the animal's dominant status, which is trivial information, but its role as pack progenitor, which

1953-480: Is a collaborative venture – all members contribute to their development. In times of scarcity, the breeding pair will often prioritise the care of the pups and preferentially feed the youngest wolves first. Despite this committed involvement, pup mortality is high, with researchers citing that only roughly 30% survive their first year of life. Those who survive, however, grow up with the added advantage of being surrounded by numerous caretakers and teachers. There exists

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2046-404: Is at frequencies too high for humans to hear without special equipment, so bat detectors have been used for this purpose. Rodents, like all placental mammals except primates, have just two types of light receptive cones in their retina, a short wavelength "blue-UV" type and a middle wavelength "green" type. They are therefore classified as dichromats ; however, they are visually sensitive into

2139-435: Is critical information. The one use we may still want to reserve for alpha is in the relatively few large wolf packs comprised of multiple litters. ... In such cases, the older breeders are probably dominant to the younger breeders and perhaps can more appropriately be called the alphas . ... The point here is not so much the terminology but what the terminology falsely implies: a rigid, force-based dominance hierarchy. One of

2232-641: Is evident in particular subgroups of rodents like kangaroo rats , hamsters, chipmunks and gophers which have two bags that may range from the mouth to the front of the shoulders. True mice and rats do not contain this structure but their cheeks are elastic due to a high degree of musculature and innervation in the region. While the largest species, the capybara , can weigh as much as 66 kg (146 lb), most rodents weigh less than 100 g (3.5 oz). Rodents have wide-ranging morphologies, but typically have squat bodies and short limbs. The fore limbs usually have five digits, including an opposable thumb, while

2325-402: Is mostly driven by the brain stem, which is itself provoked by the cortex. However Legg et al. 1989 find an alternate circuit between the cortex and whiskers through the cerebellar circuits, and Hemelt & Keller 2008 the superior colliculus. Some rodents have cheek pouches , which may be lined with fur. These can be turned inside out for cleaning. In many species, the tongue cannot reach past

2418-915: Is not aggressive towards other males until he has mated, after which time he defends a territory, a female, and a nest against other males. The pair huddles together, grooms one another, and shares nesting and pup-raising responsibilities. Among the most social of rodents are the ground squirrels, which typically form colonies based on female kinship, with males dispersing after weaning and becoming nomadic as adults. Cooperation in ground squirrels varies between species and typically includes making alarm calls, defending territories, sharing food, protecting nesting areas, and preventing infanticide. The black-tailed prairie dog forms large towns that may cover many hectares. The burrows do not interconnect, but are excavated and occupied by territorial family groups known as coteries. A coterie often consists of an adult male, three or four adult females, several nonbreeding yearlings, and

2511-405: Is not necessarily equal. The majority of wolves are known for dispersing from their birth pack; this makes measuring attachment behavior within the packs difficult. There are cases in which wolves leave their pack, typically when accompanying siblings of the same sex. This behaviour is suggested to be adaptive, which will benefit pack mates in future conflicts. All individuals benefit from being

2604-400: Is not understood why this pattern occurs, but in the case of yellow-pine chipmunks , males may have selected larger females due to their greater reproductive success. In some species, such as voles , sexual dimorphism can vary from population to population. In bank voles , females are typically larger than males, but male-bias sexual dimorphism occurs in alpine populations, possibly because of

2697-490: Is present to breed with all males. African wild dogs are not territorial , and hunt cooperatively in their packs. For example, they will run down large game and tear it apart with their pack. They also cooperate in caring for wounded, sick, and young pack members. Gray wolves ( Canis lupus ) tend to live in packs that consist of adult parents and their offspring of the last two or three years. The adult parents are usually unrelated, and other unrelated wolves may sometimes join

2790-538: Is some question as to whether these mothers can distinguish which young are theirs. In the Patagonian mara , young are also placed in communal warrens, but mothers do not permit youngsters other than their own to nurse. Infanticide exists in numerous rodent species and may be practiced by adult conspecifics of either sex. Several reasons have been proposed for this behavior, including nutritional stress, resource competition, avoiding misdirecting parental care and, in

2883-451: Is typically a nuclear family unit. It often consists of 5–10 (though in areas of high prey abundance can be up to 30) mostly related individuals, specifically consisting of a typically unrelated breeding pair also known as the alphas, their offspring, and occasionally a handful of other wolves which can be related or not. Membership may be fluid and is subject to change. Outside wolves may be shunned or, more rarely, accepted, depending on

Portuguese Podengo - Misplaced Pages Continue

2976-426: Is very important in a pack. Canine packs are led by a breeding pair , consisting of the alpha male and alpha female . African wild dogs ( Lycaon pictus ) live and hunt in packs . Males assist in raising the pups, and stay with their pack for life. The females leave their birth pack at approximately 2.5 years old to join another pack without females. Males outnumber the females in a pack. Typically, only one female

3069-406: The Cape ground squirrel , the male's testes can be 20 percent of its head-body length. Several rodent species have flexible mating systems that can vary between monogamy, polygyny and promiscuity. Female rodents play an active role in choosing their mates. Factors that contribute to female preference may include the size, dominance and spatial ability of the male. In the eusocial naked mole rats,

3162-605: The Great Plains of North America, the burrowing activities of prairie dogs play important roles in soil aeration and nutrient redistribution, raising the organic content of the soil and increasing the absorption of water. They maintain these grassland habitats, and some large herbivores such as bison and pronghorn prefer to graze near prairie dog colonies due to the increased nutritional quality of forage. Extirpation of prairie dogs can also contribute to regional and local biodiversity loss , increased seed depredation, and

3255-524: The Ibizan Hound , it often jumps above the prey before landing on or near it to flush it out of dense brush, rock crevices or burrows. It will dig if necessary to flush prey. The Pequeno (small) was also developed for flushing rabbits from cover. It is also a good mouser. Pack (canine) A pack is a social group of conspecific canines . The number of members in a pack and their social behavior varies from species to species. Social structure

3348-811: The Lagomorpha . Nonetheless, Rodentia and Lagomorpha are sister groups , sharing a single common ancestor and forming the clade of Glires . Most rodents are small animals with robust bodies, short limbs, and long tails. They use their sharp incisors to gnaw food, excavate burrows, and defend themselves. Most eat seeds or other plant material, but some have more varied diets. They tend to be social animals and many species live in societies with complex ways of communicating with each other. Mating among rodents can vary from monogamy , to polygyny , to promiscuity . Many have litters of underdeveloped, altricial young, while others are precocial (relatively well developed) at birth. The rodent fossil record dates back to

3441-585: The Paleocene on the supercontinent of Laurasia . Rodents greatly diversified in the Eocene , as they spread across continents, sometimes even crossing oceans . Rodents reached both South America and Madagascar from Africa and, until the arrival of Homo sapiens , were the only terrestrial placental mammals to reach and colonize Australia. Rodents have been used as food, for clothing, as pets , and as laboratory animals in research. Some species, in particular,

3534-408: The brown rat , the black rat , and the house mouse , are serious pests , eating and spoiling food stored by humans and spreading diseases. Accidentally introduced species of rodents are often considered to be invasive and have caused the extinction of numerous species, such as island birds, the dodo being an example, previously isolated from land-based predators. The distinguishing feature of

3627-410: The eastern grey squirrel , have a large deep masseter , making them efficient at biting with the incisors. The Myomorpha , such as the brown rat, have enlarged temporalis and masseter muscles, making them able to chew powerfully with their molars. In rodents, masseter muscles insert behind the eyes and contribute to eye boggling that occurs during gnawing where the quick contraction and relaxation of

3720-500: The maternity den used by the alpha female; as with the African wild dog , Lycaon pictus . As dominant roles may be deemed normal among social species with extended parenting, it has been suggested that the additional term alpha is not required merely to describe dominance due to its ubiquity but should be reserved for where they are the predominant pack progenitor. For instance, wolf biologist L. David Mech stated: ...calling

3813-445: The 2001 book How to Speak Dog , "You are the alpha dog... You must communicate that you are the pack leader and dominant". It has been suggested that the use of such techniques may have more to do with human psychology than with dog behavior; "dominance hierarchies and dominance disputes and testing are a fundamental characteristic of all social groups... But perhaps only we humans learn to use punishment primarily to gain for ourselves

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3906-669: The Grande, Medio and Pequeno). According to the Clube Português de Canicultura 's breed standard states the Large stands 55 to 70 centimetres (22 to 28 in) at the withers and healthy adults weigh 20 to 30 kilograms (44 to 66 lb), the Medium stands 40 to 54 centimetres (16 to 21 in) at the withers and healthy adults weigh 16 to 20 kilograms (35 to 44 lb), and the Small stands 20 to 30 centimetres (7.9 to 11.8 in) at

3999-621: The MHC genes they have in common. In non-kin communication, where more permanent odor markers are required, as at territorial borders, then non-volatile major urinary proteins (MUPs), which function as pheromone transporters, may also be used. MUPs may also signal individual identity, with each male house mouse ( Mus musculus ) excreting urine containing about a dozen genetically encoded MUPs. House mice deposit urine, which contains pheromones, for territorial marking, individual and group recognition, and social organization. Territorial beavers and red squirrels investigate and become familiar with

4092-441: The amount of UV that is reflected decreases with time, which in some circumstances can be disadvantageous; the common kestrel can distinguish between old and fresh rodent trails and has greater success hunting over more recently marked routes. Vibrations can provide cues to conspecifics about specific behaviors being performed, predator warning and avoidance, herd or group maintenance, and courtship. The Middle East blind mole rat

4185-422: The behaviour of captive packs consisting of unrelated individuals, while in nature a pack is usually made up of members of a family. The term alpha was popularised as early as 1976 in the dog training book How to Be Your Dog's Best Friend (Monks of New Skete), which introduced the idea of the alpha roll , a technique for punishing unwanted dog behaviours. Psychologist and dog trainer Stanley Coren wrote in

4278-795: The breeding pair and their current young. They occasionally cooperate in larger packs to hunt big game, but rarely hunt animals larger than a small, young antelope . Black-backed jackals are not typically considered 'aggressive' towards larger animals but tend to be wary of humans. However, they will become aggressive if they feel threatened, in order to defend the boundaries of their territories. The Ethiopian wolf ( Canis simensis ) pack members hunt for rodents alone, and come together mainly to defend their territory from rival packs. Corsac foxes sometimes form packs, unlike some other fox species. Wolves are recognized for creating cooperative relationships within their pack structure, which significantly influence their interactions with one another, perhaps as

4371-524: The breeding season to mate. The pocket gopher is also a solitary animal outside the breeding season, each individual digging a complex tunnel system and maintaining a territory. Larger rodents tend to live in family units where parents and their offspring live together until the young disperse. Beavers live in extended family units typically with a pair of adults, this year's kits, the previous year's offspring, and sometimes older young. Brown rats usually live in small colonies with up to six females sharing

4464-713: The case of males, attempting to make the mother sexually receptive. The latter reason is well supported in primates and lions but less so in rodents. Infanticide appears to be widespread in black-tailed prairie dogs, including infanticide from invading males and immigrant females, as well as occasional cannibalism of an individual's own offspring. To protect against infanticide from other adults, female rodents may employ avoidance or direct aggression against potential perpetrators, multiple mating, territoriality or early termination of pregnancy. Feticide can also occur among rodents; in Alpine marmots , dominant females tend to suppress

4557-479: The cranial anatomy of rodents these feeding methods cannot be used at the same time and are considered to be mutually exclusive. Among rodents, the masseter muscle plays a key role in chewing, making up 60% – 80% of the total muscle mass among masticatory muscles and reflects rodents' herbivorous diet. Rodent groups differ in the arrangement of the jaw muscles and associated skull structures, both from other mammals and amongst themselves. The Sciuromorpha , such as

4650-412: The current year's offspring. Individuals within coteries are friendly with each other, but hostile towards outsiders. Perhaps the most extreme examples of colonial behavior in rodents are the eusocial naked mole rat and Damaraland mole rat . The naked mole rat lives completely underground and can form colonies of up to 80 individuals. Only one female and up to three males in the colony reproduce, while

4743-594: The degu less visible to predators. Ultraviolet light is abundant during the day but not at night. There is a large increase in the ratio of ultraviolet to visible light in the morning and evening twilight hours. Many rodents are active during twilight hours (crepuscular activity), and UV-sensitivity would be advantageous at these times. Ultraviolet reflectivity is of dubious value for nocturnal rodents. The urine of many rodents (e.g. voles, degus, mice, rats) strongly reflects UV light and this may be used in communication by leaving visible as well as olfactory markings. However,

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4836-489: The establishment and spread of invasive shrubs. Burrowing rodents may eat the fruiting bodies of fungi and spread spores through their feces, thereby allowing the fungi to disperse and form symbiotic relationships with the roots of plants (which usually cannot thrive without them). As such, these rodents may play a role in maintaining healthy forests. In many temperate regions, beavers play an essential hydrological role. When building their dams and lodges, beavers alter

4929-821: The female. Females can remove the plug and may do so either immediately or after several hours. Metabolism of thyroid hormones and iodine in the mediobasal hypothalamus changes in response to photoperiod . Thyroid hormones in turn induce reproductive changes. This is found by Watanabe et al. 2004 and 2007, Barrett et al. 2007, Freeman et al. 2007, and Herwig et al. 2009 in Siberian hamsters , Revel et al. 2006 and Yasuo et al. 2007 in Syrian hamsters , Yasuo et al. 2007 and Ross et al. 2011 in rats, and Ono et al. 2008 in mice. Rodents may be born either altricial (blind, hairless and relatively underdeveloped) or precocial (mostly furred, eyes open and fairly developed) depending on

5022-498: The females that live within the territories are known as "resident" females. In the case of marmots, resident males do not appear to ever lose their territories and always win encounters with invading males. Some species are also known to directly defend their resident females and the ensuing fights can lead to severe wounding. In species with non-defense polygyny, males are not territorial and wander widely in search of females to monopolize. These males establish dominance hierarchies, with

5115-517: The few animal groups that can break open the large capsules of the Brazil nut fruit. Too many seeds are inside to be consumed in one meal, so the agouti carries some off and caches them. This helps dispersal of the seeds as any that the agouti fails to retrieve are distant from the parent tree when they germinate. Other nut-bearing trees tend to bear a glut of fruits in the autumn. These are too numerous to be eaten in one meal and squirrels gather and store

5208-600: The finding that rodents entirely lack the ability to vomit. In many species, the penis contains a bone, the baculum ; the testes can be located either abdominally or at the groin. Sexual dimorphism occurs in many rodent species. In some rodents, males are larger than females, while in others the reverse is true. Male-bias sexual dimorphism is typical for ground squirrels , kangaroo rats, solitary mole rats and pocket gophers ; it likely developed due to sexual selection and greater male–male combat. Female-bias sexual dimorphism exists among chipmunks and jumping mice . It

5301-468: The fore to the hind limbs. The agouti is fleet-footed and antelope -like, being digitigrade and having hoof-like nails. The majority of rodents have tails, which can be of many shapes and sizes. Some tails are prehensile , as in the Eurasian harvest mouse , and the fur on the tails can vary from bushy to completely bald. The tail is sometimes used for communication, as when beavers slap their tails on

5394-514: The genetic parents of most cubs in the pack. Such access to mating females creates strong selective pressure for intra-sex competition. Wolves show deference to the alpha pair in their pack by allowing them to allocate the distribution of food, typically preferentially feeding the youngest wolves. Wolves use eye contact and posture as an indicator of dominance or submission, which are largely age-based; these postures are rare except concerning food, as described previously. The smaller and more nuclear

5487-444: The high-ranking males having access to the most females. This occurs in species like Belding's ground squirrels and some tree squirrel species. Promiscuity , in which both males and females mate with multiple partners, also occurs in rodents. In species such as the white-footed mouse, females give birth to litters with multiple paternities. Promiscuity leads to increased sperm competition and males tend to have larger testicles. In

5580-690: The hind limbs have three to five digits. The elbow gives the forearms great flexibility. The majority of species are plantigrade , walking on both the palms and soles of their feet, and have claw-like nails. The nails of burrowing species tend to be long and strong, while arboreal rodents have shorter, sharper nails. Rodent species use a wide variety of methods of locomotion including quadrupedal walking, running, burrowing, climbing, bipedal hopping ( kangaroo rats and hopping mice ), swimming and even gliding. Scaly-tailed squirrels and flying squirrels , although not closely related, can both glide from tree to tree using parachute-like membranes that stretch from

5673-442: The incisors. Rodents have efficient digestive systems, absorbing nearly 80% of ingested energy. When eating cellulose , the food is softened in the stomach and passed to the cecum , where bacteria reduce it to its carbohydrate elements. The rodent then practices coprophagy , eating its own fecal pellets, so the nutrients can be absorbed by the gut. Rodents therefore often produce a hard and dry fecal pellet. Horn et al. 2013 makes

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5766-818: The lack of predators and greater competition between males. One of the most widespread groups of mammals, rodents can be found on every continent except Antarctica. They are the only terrestrial placental mammals to have colonized Australia and New Guinea without human intervention. Humans have also allowed the animals to spread to many remote oceanic islands (e.g., the Polynesian rat ). Rodents have adapted to almost every terrestrial habitat, from cold tundra (where they can live under snow) to hot deserts. Some species such as tree squirrels and New World porcupines are arboreal , while some, such as gophers , tuco-tucos , and mole rats, live almost completely underground, where they build complex burrow systems. Others dwell on

5859-502: The leaves, buds, and inner bark of growing trees, as well as aquatic plants. They store food for winter use by felling small trees and leafy branches in the autumn and immersing them in their pond, sticking the ends into the mud to anchor them. Here, they can access their food supply underwater even when their pond is frozen over. Although rodents have been regarded traditionally as herbivores, most small rodents opportunistically include insects, worms, fungi, fish, or meat in their diets and

5952-402: The main initiators of affiliative interactions, though a small percentage of males will initiate affiliative interactions. The omega male is not a target of any affiliative interaction. In other studies, researchers have separated the most dominant wolf from the most subordinate wolves. It was recorded that the dominant wolf spent less time sleeping and showed more behavioural stress compared to

6045-760: The males do not provide direct parental care and stay with one female because they cannot access others due to being spatially dispersed. Prairie voles appear to be an example of this form of monogamy, with males guarding and defending females within their vicinity. In polygynous species, males will try to monopolize and mate with multiple females. As with monogamy, polygyny in rodents can come in two forms; defense and non-defense. Defense polygyny involves males controlling territories that contain resources that attract females. This occurs in ground squirrels like yellow-bellied marmots , California ground squirrels , Columbian ground squirrels and Richardson's ground squirrels . Males with territories are known as "resident" males and

6138-407: The matriarch and patriarch of the family. It was previously believed to be common for an aging or sick alpha to be replaced by one of their offspring, but more recent studies have shown this incestuous behaviour to be very rare. The importance of the alpha is rivalled only by that of the pups. The fundamental purpose of the pack is the successful production of offspring, and so raising the litter

6231-403: The most persistent but disputed theories in dog training literature is the idea of the alpha wolf , an individual gray wolf who uses body language and, when needed, physical force to maintain dominance within the wolf pack. The idea was first reported in early wolf research. It was subsequently adopted by dog trainers. Later research has disputed the theory, pointing out that it was based on

6324-451: The muscle causes the eyeballs to move up and down. The Hystricomorpha , such as the guinea pig, have larger superficial masseter muscles and smaller deep masseter muscles than rats or squirrels, possibly making them less efficient at biting with the incisors, but their enlarged internal pterygoid muscles may allow them to move the jaw further sideways when chewing. The cheek pouch is a specific morphological feature used for storing food and

6417-521: The nature of the precise threat. The urgency of the threat is also conveyed by the acoustic properties of the call. Social rodents have a wider range of vocalizations than do solitary species. Fifteen different call-types have been recognized in adult Kataba mole rats and four in juveniles. Similarly, the common degu , another social, burrowing rodent, exhibits a wide array of communication methods and has an elaborate vocal repertoire comprising fifteen different categories of sound. Ultrasonic calls play

6510-675: The nest a few days after they have opened their eyes and initially keep returning regularly. As they get older and more developed, they visit the nest less often and leave permanently when weaned. In precocial species, the mothers invest little in nest building and some do not build nests at all. The female gives birth standing and the young emerge behind her. Mothers of these species maintain contact with their highly mobile young with maternal contact calls. Though relatively independent and weaned within days, precocial young may continue to nurse and be groomed by their mothers. Rodent litter sizes also vary and females with smaller litters spend more time in

6603-564: The nest than those with larger litters. Mother rodents provide both direct parental care, such as nursing, grooming, retrieving and huddling, and indirect parenting, such as food caching, nest building and protection to their offspring. In many social species, young may be cared for by individuals other than their parents, a practice known as alloparenting or cooperative breeding . This is known to occur in black-tailed prairie dogs and Belding's ground squirrels, where mothers have communal nests and nurse unrelated young along with their own. There

6696-437: The offspring and play an important part in their survival. This occurs in species such as California mice , oldfield mice , Malagasy giant rats and beavers. In these species, males usually mate only with their partners. In addition to increased care for young, obligate monogamy can also be beneficial to the adult male as it decreases the chances of never finding a mate or mating with an infertile female. In facultative monogamy,

6789-400: The omega wolf. The dominant wolf was reported to rest in the section of his enclosure closest to his pack. Furthermore, researchers noted that younger, more subordinate wolves appear to have less attachment to their pack compared to their higher-ranking compatriots. Cooperation is essential for tasks such as hunting and protecting the young, though the level of attachment present in the pack

6882-943: The owner's everyday life. Rodent This is an accepted version of this page Rodents (from Latin rodere , 'to gnaw') are mammals of the order Rodentia ( / r oʊ ˈ d ɛ n ʃ ə / roh- DEN -shə ), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws . About 40% of all mammal species are rodents. They are native to all major land masses except for Antarctica , and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal , fossorial (burrowing), saltatorial /ricochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only

6975-458: The pack cannot supply sufficient food. These lone wolves may then attempt to join an existing wolf pack or, more commonly, find a mate and begin a new pack family as the alphas. Within the wolf pack, the breeding pair or the dominant breeding pair (in packs with multiple breeders), often referred to in familiar language as the "alpha pair" or the "alpha wolves", are typically the members of the family unit which breed and produce offspring; they are

7068-525: The pack. Wolves usually hunt in packs, but they hunt alone in the spring and summer months when plenty of prey is available. They are found in both Eurasia and North America . Black-backed jackals ( Canis mesomelas ) in Southern and Eastern Africa and coyotes ( Canis latrans ) in North America have a single long-term mate. As such, they usually hunt alone or in pairs. A pack consists of

7161-518: The paths of streams and rivers and allow for the creation of extensive wetland habitats. One study found that engineering by beavers leads to a 33 percent increase in the number of herbaceous plant species in riparian areas . Another study found that beavers increase wild salmon populations. Meanwhile, some rodents are seen as pests , due to their wide range. Most rodents are herbivorous , feeding exclusively on plant material such as seeds, stems, leaves, flowers, and roots. Some are omnivorous and

7254-414: The rest of the members are smaller and sterile, and function as workers. Some individuals are of intermediate size. They help with the rearing of the young and can take the place of a reproductive if one dies. The Damaraland mole rat is characterized by having a single reproductively active male and female in a colony where the remaining animals are not truly sterile, but become fertile only if they establish

7347-449: The reward of being dominant. Most leading veterinary and animal behaviour associations and most contemporary trainers would agree to advocate the use of rewards to teach commands and encourage good communication between owners and their pets. Many modern practices dictate the abandonment of outdated "pack" methods. Some canine behaviourists suggest that kind, efficient training uses games to teach commands which can be utilised to benefit

7440-408: The rodents is their pairs of continuously growing, razor-sharp, open-rooted incisors . These incisors have thick layers of enamel on the front and little enamel on the back. Because they do not stop growing, the animal must continue to wear them down so that they do not reach and pierce the skull. As the incisors grind against each other, the softer dentine on the rear of the teeth wears away, leaving

7533-798: The scents of their neighbors and respond less aggressively to intrusions by them than to those made by non-territorial "floaters" or strangers. This is known as the " dear enemy effect ". Many rodent species, particularly those that are diurnal and social, have a wide range of alarm calls that are emitted when they perceive threats. There are both direct and indirect benefits of doing this. A potential predator may stop when it knows it has been detected, or an alarm call can allow conspecifics or related individuals to take evasive action. Several species, for example prairie dogs, have complex anti-predator alarm call systems. These species may have different calls for different predators (e.g. aerial predators or ground-based predators) and each call contains information about

7626-441: The sharp enamel edge shaped like the blade of a chisel . Most species have up to 22 teeth with no canines or anterior premolars . A gap, or diastema , occurs between the incisors and the cheek teeth in most species. This allows rodents to suck in their cheeks or lips to shield their mouth and throat from wood shavings and other inedible material, discarding this waste from the sides of their mouths. Chinchillas and guinea pigs have

7719-422: The species. The altricial state is typical for squirrels and mice, while the precocial state usually occurs in species like guinea pigs and porcupines. Females with altricial young typically build elaborate nests before they give birth and maintain them until their offspring are weaned . The female gives birth sitting or lying down and the young emerge in the direction she is facing. The newborns first venture out of

7812-482: The specific circumstances. Genetic variability can become limited within such an interrelated group, and so conditions for gene flow must exist. Outside wolves can provide these opportunities. A pack may accept another wolf into their group if it is a distant relative, if reproduction rates are low due to the loss or infertility of an alpha, or if their numbers are significantly reduced. Characterisation of wolves into dominance hierarchies of alpha, beta, and omega

7905-652: The stomach contents of the North American white-footed mouse , normally considered to be herbivorous, showed 34% animal matter. More specialized carnivores include the shrewlike rats of the Philippines, which feed on insects and soft-bodied invertebrates, and the rakali or Australian water-rat, which devours aquatic insects, fish, crustaceans, mussels, snails, frogs, birds' eggs, and water birds. The grasshopper mouse from dry regions of North America feeds on insects, scorpions, and other small mice, and only

7998-536: The surface of the ground, but may have a burrow into which they can retreat. Beavers and muskrats are known for being semiaquatic, but the rodent best adapted for aquatic life is probably the earless water rat from New Guinea. Rodents have also thrived in human-created environments such as agricultural and urban areas . Though some species are common pests for humans, rodents also play important ecological roles. Some rodents are considered keystone species and ecosystem engineers in their respective habitats. In

8091-435: The surface to feed by seizing the roots of plants with its jaws and pulling them downwards into its burrow. It also practices coprophagy. The African pouched rat forages on the surface, gathering anything that might be edible into its capacious cheek pouches until its face bulges out sideways. It then returns to its burrow to sort through the material it has gathered and eats the nutritious items. Agouti species are one of

8184-484: The surplus in crevices and hollow trees. In desert regions, seeds are often available only for short periods. The kangaroo rat collects all it can find and stores them in larder chambers in its burrow. A strategy for dealing with seasonal plenty is to eat as much as possible and store the surplus nutrients as fat. Marmots do this, and may be 50% heavier in the autumn than in the spring. They rely on their fat reserves during their long winter hibernation . Beavers feed on

8277-469: The ultraviolet (UV) spectrum and therefore can see light that humans can not. The functions of this UV sensitivity are not always clear. In degus , for example, the belly reflects more UV light than the back. Therefore, when a degu stands up on its hind legs, which it does when alarmed, it exposes its belly to other degus and ultraviolet vision may serve a purpose in communicating the alarm. When it stands on all fours, its low UV-reflectance back could help make

8370-474: The water surface or house mice rattle their tails to indicate alarm. Some species have vestigial tails or no tails at all. In some species, the tail is capable of regeneration if a part is broken off. Rodents generally have well-developed senses of smell , hearing, and vision. Nocturnal species often have enlarged eyes and some are sensitive to ultraviolet light. Many species have long, sensitive whiskers or vibrissae for touch or "whisking" . Whisker action

8463-415: The withers and healthy adults weigh 4 to 6 kilograms (8.8 to 13.2 lb). The Grande (large) was developed for deer and wild boar hunting . It will exhaust and hold down the prey and await the hunter's gun. The Grande is now very rare in its home country. The Medio (medium) was developed for rabbit chasing, flushing, hunting and retrieval. Its hunting style includes catlike stalking and, similar to

8556-585: Was based on behavioural studies of unrelated wolves in captivity, and this assemblage largely does not apply to natural wolf packs, which are familial units. These singular outside wolves, often referred to as lone wolves, are vulnerable to food scarcity and territorial attacks and generally comprise less than 15% of the total wolf population. Lone wolves usually result from sexually mature offspring leaving their parental pack, though may also occur if harassed subordinates chose to disperse. In times of prey scarcity, low-ranking wolves may choose to go off on their own if

8649-412: Was the first mammal for which seismic communication was documented. These fossorial rodents bang their head against the walls of their tunnels. This behavior was initially interpreted as part of their tunnel building behavior, but it was eventually realized that they generate temporally patterned seismic signals for long-distance communication with neighboring mole rats. Footdrumming is used widely as

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