Pudu puda

Geographic Range

Southern pudus are native to southern Chile and southwestern Argentina. Their range occupies the space between the Maule River as the northern boundary and Chiloé province as the southern boundary. They can be found in humid temperate rainforests that occupy parts of both Chile and Argentina and along the Cordilleran coast. More southern pudus are found on Chiloé Island than on mainland Chile. Southern pudus originally ranged from 35 degrees south to 53 degrees south, but with decreasing population density.

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Southern pudus mostly dwell in second-growth or previously disturbed forests. They also inhabit temperate evergreen rainforests and deciduous forests. Southern pudus prefer areas of understory with small trees and low-lying vegetation. The dense vegetation that is found in lowland habitats consists of avellano ( Gevuina avellana ), chilco ( Fuchsia magellanica ), luma ( Amomyrtus luma ), maqui ( Aristotelia chilensis ), tiaca ( Caldcluvia paniculata ) and, at higher latitudes, quila bamboo ( Chusquea quila ) and colihue ( Chusquea culeou ). Some researchers suggest that living near water is an important aspect of their habitat. Southern pudus seek protection from the sun beneath a shady canopy or in valleys, as they appear to be heat-intolerant. They occupy lowlands and are typically not found at altitudes above 1,700 m. There is constant snow cover over about 2,000 meters, which is a likely deterrent to southern pudus. Southern pudus in southern Chile and southwestern Argentina experience high levels of year-long precipitation, mild, wet winters and short, dry summers. In the range of southern pudus, mean annual precipitation was measured at 2 to 4 meters. Southern pudus at higher elevations may migrate downwards in winter and inhabit warm valleys (Molina in Hershkovitz 1982).

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest
• rainforest rainforest

Physical Description

Southern pudus are the second smallest deer in the world. Generally, they are larger than northern pudus ( Pudu mephistophiles ), and smaller than dwarf brocket ( Mazama chunyi ). Average height measured at the shoulder is from 35 to 45 cm and body length is short, usually not exceeding 85 cm. They typically weigh between 6.5 and 13.5 kg, with females weighing approximately 1 kg less than males. Growth rate in southern pudus is 53 grams per day until adult weight is achieved. Southern pudus are short with short legs, the rump is not raised, which distinguishes them from other cervids . They have slender hooves with an interdigital gland enclosed in a deep pocket, a short snout, and their ears are not pointed. The tail is small and concealed; it ranges from 30 to 40 mm in length. Southern pudus have short rostra because of reduced premaxilla and nasal bones and a short diastema. Skull length ranges from approximately 134 to 155 mm, while braincase width ranges from approximately 47 to 51 mm. Zygomatic breadth ranges from approximately 64 to 70 mm. Nasal bone width has a reported range from 31 to 44 mm and the diastema measures approximately 35 to 43 mm in length. The incisors have rectangular crowns (Traub in Jiménez 2010). The dental formula of southern pudus is not reported but other members of the Family Cervidae have the following formula: I 0/3, C 0/1, P 3/3, M 3/3 = 32. Cervids typically lack one premolar in both their deciduous and adult set of teeth. The upper canine is sometimes present in fawns, but is not present in adults.

Besides a slightly larger mass and small antlers on males, there is limited sexual dimorphism between males and females as both sexes have similar height and appearance and reach their adult weight at approximately the same time early in life. The appearance of the glans penis on males is similar to that of Odocoileus species. Southern pudu fur color is a dark red-brown and the hue varies between individuals and between seasons. The fur is strong and stiff but sparse with approximately 800 to 2500 hairs per square cm on the trunk. Individual hairs are long and characteristically hollow. Juveniles show three rows of lighter spots on their dorsal surface that are lost by the age of 8 weeks. Southern pudus shed their fur in both the spring and in the fall and it was reported that fur color in captive species became darker after the September molt. Northern pudus ( Pudu mephistophiles ) are smaller, with shorter legs and have dark brown to black color on the ears, chin, face, forefeet, and hindfeet whereas southern pudus are larger, brown with red markings on the ears and chin. Southern pudus have visible preorbital glands, while northern pudus do not. The preorbital gland is large with a wide opening on the rostrum. These glands are not as visible on female southern pudus. The antlers of males are very small (between 60 and 90 mm). Antlers first form on young males between the ages of 9 to 12 months. New antler growth occurs mostly in July, which correlates with decreased levels of leutinizing hormone (LH) and testosterone. The antlers mature and are polished by November as LH and testosterone levels start to rise again, and are shed in the austral summer months. Females do not produce antlers. At some latitudes, pudus shed the velvet of the antlers. Southern pudus living at higher latitudes have a higher metabolic rate and higher levels of triiodothyronine. A specific metabolic rate for the southern pudu is not yet reported, but artiodactyls have relatively high metabolic rates compared to other mammalian orders.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry
• polymorphic polymorphic

• Sexual Dimorphism
• male larger
• ornamentation ornamentation

Reproduction

Because southern pudus are elusive and cryptic, most of what is know about the reproduction and mating system has been learned via captive animals. Southern pudus have a polygynous mating system. In wild populations, southern pudus form pair bonds in the fall and mate. The male is attracted to a female in estrus and will approach the female in a low, slow crouch. After the male judges the female’s responsiveness by sniffing and licking, they proceed to engage in butting the groin or sides, followed by grooming. For a three-day period, the male mounts the doe repeatedly and intercourse occurs for two to three seconds each time.

• Mating System
• polygynous polygynous

The mating season occurs from April to June and gestation lasts approximately 7 months. Female southern pudus may employ delayed implantation. The exact length of gestation is debatable. One researcher noted that it lasts between 203 and 223 days, while another claims it can be between 197 and 223 days. This is a very long gestation when compared with other, heavier deer. Most fawns are born in austral spring, between November and January. Females have one fawn per year, though it is not uncommon for her to have twins. Over the female’s entire lifespan, the mean number of offspring is 3.88 fawns. Southern pudus are seasonally polyestrous breeder with a cycle lasting approximately 11 days (Vidal et al. 2012). Cycle length is variable and responsive to seasonal and environmental cues, particularly photoperiod and food quality. Males exhibit peak levels of various reproductive hormones at different times of the year. One study indicated that follicle-stimulating hormone and testosterone peaked twice within a single year. The peaks are suggested to be associated with antler mineralization and rutting behavior. Another study suggests that it is luteinizing hormone and testosterone that have two annual peaks, while follicle stimulating hormone and prolactin have only one peak. An endocrine study performed in 1993 found that testosterone and leutenizing hormone had one peak level in March, during the rut. Furthermore, spermatogenesis increases substantially only during the mating ruts, though it lasts for several months afterwards. Males are fertile approximately 7 months of the year. There is also an increase in testes size during these peaks. There are two peaks of cortisol levels in male pudu that are likely associated with elevated stress levels; one peak during the rut and the other in August. Southern pudus can breed twice per year. If a female does not become pregnant between April and June, she can ovulate again between November and January when males reach their second peak of reproductive hormones. Further research is required to understand the regulation of such a breeding pattern.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous
• delayed implantation delayed implantation

Most of what is known about parental investment in southern pudus was studied in captive animals. Young are born precocial, with their eyes open, and are able to stand after birth. When they are born, fawns are approximately 20 cm in height and weigh less than 1 kg (Jiménez 2010). The female parent cares entirely for her offspring. The female ingests the afterbirth and licks the offspring clean. She attempts to stimulate urination and defecation in the infant. The mother allows her infant to suckle within an hour after birth. The female’s milk is composed of fat, albumin, lactose and high quantities of sodium and potassium. Under captive conditions, when an infant would bleat, the mother rushed to her offspring and allowed nursing. According to one study, a fawn was last seen suckling at 30 days old, but when the fawn attempted to suckle at 60 days old, it was rejected by the mother. Another study states that the weaning age is 1.8 months, at an approximate weight of 3 kg. Young fawns become independent from their parents at approximately 8 months old. Young southern pudus must establish a new home range away from their parents due to their solitary nature.

• Parental Investment
• precocial precocial
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

The longest lifespan in captivity was measured at 17.9 years in the Rotterdam Zoo, though the expected lifespan in captivity is between 4.35 and 17.4 years for females and between 4.44 and 15.8 for males. Mortality within the first month of life is 26%, for both males and females.

Behavior

Southern pudus show relatively high levels of daily activity. They are active both during the day and night. They tend to rest and groom during the middle of the day and are active during the late afternoon, evening, and morning. Southern pudus exhibit play behavior; they skip, run and playfully fight with each other. They groom themselves by licking their fur and combing their fur it with their incisors. They rub their antlers and scrape their teeth on trees and some plants. Weather appears to play a role in their activity levels. Southern pudus shows more activity on windy days rather than calm days, an indicator of their intolerance to heat. Though not solitary, southern pudus appear to move together when feeding, but do not form groups larger than 2 or 3. However, most of the time, southern pudus are solitary, cryptic, and sedentary. Southern pudus can easily adapt to many temperature zones in which other deer can live, as demonstrated by their behavior in captivity. When exposed to prolonged cold during the spring and summer months of the southern hemisphere, southern pudus have a seasonal peak in triiodothyronine, as it adjusts its metabolic rate.

Most of what is known about southern pudu hierarchy systems was gathered from captive animals. They form dominance hierarchies and are highly territorial. The hierarchy usually includes one dominant male, followed by subordinate males then juvenile males, with females as the most subordinate. A hierarchy exists among females as well. Dominant pudu males have higher levels of insulin-like growth factor and testosterone compared to subordinate bucks. If two males of similar size encounter one another, it often results in a fight. A male pudu will fight and kill an intruder of the same sex.

Southern pudus use submissive postures when frightened, exhausted or in the presence of dominant animals; laying down completely flat with the neck horizontal and extended, crouching with the tail down, or lowering the neck and avoiding eye contact while standing. Southern pudus can also show aggressive postures; pointing their antlers at an opponent, standing still near the opponent with the snout raised in the air, or with the head low as if preparing to butt the opponent. They use a broadside display, where the animal arches their back and shifts their weight to the hind limbs, the tail is held horizontal, the preorbital glands throb and their ears are erect. A dominant pudu will chase a submissive pudu until exhaustion while attempting to hit the opponent with their forelimbs or attempting to bite the opponent. Home range size is variable among southern pudus and has been recorded in one study as being from 16 to 26.1 hectares in size. Another study showed home ranges that varied from 2 to 200 hectares (Ramilo in Jiménez 2010).

• Key Behaviors
• cursorial
• terricolous
• crepuscular crepuscular
• motile motile
• sedentary sedentary
• solitary solitary
• territorial territorial
• dominance hierarchies dominance hierarchies

Home Range

Home range is variable among southern pudus and has been recorded in one study as being from 16 to 26.1 hectares in size. Another study showed home ranges that varied from 2 to 200 hectares (Ramilo in Jiménez 2010).

Communication and Perception

Southern pudus rely heavily on olfaction as a means of foraging and investigating. They sample the environment by sniffing, chewing and licking objects around them. Afterwards, they exhibit a flehmen response. They have large preorbital glands in deep lacrimal fossa and southern pudus mark an object by rubbing their gland against it. This can occur during a dominance display, courtship ritual, or when they are stressed. Southern pudus potentially use elimination postures as a form of communication. Males and females each have different postures when urinating or defecating, both serve to spread their scent. In captive species, a urinating female pudu will attract a male pudu and he will lick and smell the female. Pudus can also leave their scent by antler rubbing.

• Communication Channels
• visual visual
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Southern pudus use a network of trails to move to feeding areas throughout the day. They prefer to eat at the edges of forests or clearings where there are abundant small, growing plants, rather than deep within the forest. They are highly selective in what they eat. They are browser feeders and feed on leaves of ferns, trees, vines, herbs and shrubs. They can stand on the hind legs or fallen logs to reach food. Their competitors include other herbivores: European roe deer ( Capreolus capreolus ), fallow deer ( Dama dama ) and European hares ( Lepus europaeus ). Southern pudus are ruminants, with four-chambered stomachs. The mean transit time of a meal is approximately 29.9 hours. In captivity, southern pudus eat a wide variety of fruit, vegetables and fungi. Plant foods include: Gevuina avellana , Fuschia magellanica , Ugni molinae , Berberis buxifolia , Crinodendron bookerianum , Pernettya pumila , Azala species, Nothofagus species ferns, tree foliage, vines, herbs, shrubs, twigs, buds, berries, fruit, roses, plantain, and clover. Other types of foods include: alfalfa hay, cereal, and vegetables, acorns, nuts, and salt.

• Primary Diet
• herbivore herbivore
  • folivore folivore
  • lignivore

• Plant Foods
• leaves
• roots and tubers
• wood, bark, or stems
• seeds, grains, and nuts
• fruit
• flowers

• Other Foods
• fungus

Predation

The main natural predators of southern pudus main are pumas ( Puma concolor ). Southern pudus are one of the most important prey for Chilean pumas. Other predators include foxes ( Dusicyon grisseus ), spotted cats ( Felis guigna and Felis colocolo ), kod-kods ( Leopardus guigna ), domestic dogs ( Canis familiaris ), and owls ( Bubo bubo ). There has been an increase in the number of domestic dogs ( Canis familiaris ) in the range of southern pudus, increasing the instances of attack and death of pudus. Domestic dogs also interfere in the success of southern pudus via increased disease transmission and resource competition. To flee from predators, southern pudus hide in small tunnels or burrows. Because pudus tire quickly, there is little likelihood of them evading a chasing domestic dog.

Ecosystem Roles

Several parasites have been reported, including gastrointestinal nematodes, lice, flies, and ticks. Reported parasites include Sarcosystis species, Trichostrongylus axei , Oesophagostomun venulosum , Ostertagia species, Cooperia species, Nematodirus species, Cysticerces teniucollis , Linguatula serrata , Ixodes taglei , Ixodes stilesi . Southern pudus carry lice, including the species Bovicola caprae and Solenopotes binipilosus were discovered on pudus in one study. The appearance of lice on southern pudus is thought to be an accidental transmission from nearby goats.

Because southern pudus are herbivores and browsers, they impact vegetation abundance, consumption and growth. They can modify abundance of a particular tree species, and also facilitate spreading of seedlings. This could be harmful if the seedlings being distributed were from an introduced plant or tree species. If southern pudus prefer eating native species of plants and trees, this offers an opportunity for invasive species to infiltrate further as their competition is decreased. One study focused on how non-native deer influenced the spread of invasive vegetation, but additional research is needed to understand what impact southern pudu diet has on native and non-native vegetation.

Southern pudus play an important role for other small animals that inhabit the same forests. Southern pudus build and maintain tunnels in the underbrush, which allows small animals to pass through and remain undetected by predators.

• Ecosystem Impact
• disperses seeds
• creates habitat

Economic Importance for Humans: Positive

Southern pudus are used in the pet industry and in zoos in South America, North America, and Europe. There are reports of southern pudus being hunted for meat and fur, and skins being traded, both legally and illegally.

• Positive Impacts
• pet trade pet trade
• food food
• body parts are source of valuable material
• research and education

Economic Importance for Humans: Negative

Because pumas ( Puma concolor ) subsist mainly on southern pudus, declining pudu populations cause a bottom-up effect in the trophic scale and may affect ecosystems as pumas shift their diet to other prey. Southern pudus carry several ecto and endoparasites that are transmissable to humans, including gastrointestinal nematodes, lice, ticks, and flies. There are reports that southern pudus contract and die from disease, though little research has been conducted. For example, foot and mouth disease, poxvirus infection, bacterial infections, and bovine pestevirus have all been reported in southern pudus. There is a published report of a southern pudu dying from Arcanobacterium pyogenes septicemia. These diseases could have adverse effects on the populations of people who eat pudu meat.

• Negative Impacts
• injures humans
  • causes disease in humans causes disease in humans
• causes or carries domestic animal disease causes or carries domestic animal disease

Conservation Status

Population sizes of southern pudus have not been well-studied, but evidence suggests populations are in decline. It is estimated that their population is in the thousands and continuously diminishing due to the introduction of domestic dogs in their range, vehicular accidents, introduction of other cervid species, parasite infection, being hunted for their meat and fur, and habitat loss from human land use. Unfortunately, skins of southern pudus are traded, both legally and illegally.

An invasive species of deer, chital ( Axis axis ), introduced into Argentina in 1906, competes with southern pudus for resources and displaces them. Another cervid species, elk or red deer Cervus elaphus , was introduced in the early 20th century and has caused damaging effects on forest and vegetation within the southern pudu range. Because of their declining populations, captive breeding programs were established at state parks and at the University of Concepcion. In 1994-1995, 23 establishments in Chile had captive breeding programs for southern pudus. Several strategies have been suggested to maintain pudu populations, monitor their population size, understand their threats and pressures and eliminate or control those specific threats. For example, a feral dog management plan within pudu ranges would likely assist in the conservation of pudu populations.

Additional Links

Encyclopedia of Life

Contributors

Meagan Robidoux (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.

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