Vicugna vicugna vicugna

• Main Authors: Wilson, Don E., Mittermeier, Russell A.
• Format: Text
• Language: unknown
• Published: Zenodo 2011
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Mammalia; Artiodactyla; Camelidae; Vicugna; Vicugna vicugna; Patagonia; Argentina; Argentine; Molina; Pampa; Lynx; Tierra del Fuego
• Online Access: https://dx.doi.org/10.5281/zenodo.5719733; https://zenodo.org/record/5719733

3. Vicuna Vicugna vicugna French: Vigogne / German: Vikunja / Spanish: Vicuna Other common names: Argentine Vicuna (vicugna), Peruvian Vicufa (mensalis) Taxonomy. Camelus vicugna Molina, 1782, Chile, “abondano nella parte della Cordigliera spettante alle Provincie de Coquimbo, e di Copiap6” (Cordilleras of Coquimbo and Copiapo in northern Chile). The separation of the Vicuna and the Guanaco (Lama guanicoe) occurred 2-3 million years ago. Palaeontological evidence suggests the genus Vicugna evolved from Hemiauchenia, a North American immigrant to South America, in the lowlands east of the Andes some two million years ago, with widespread distribution as recently as 10,000-13,000 years ago in lowland grasslands of Bolivia, Paraguay, Patagonia, and Tierra del Fuego. Then 9000-12,000 years ago, during the last Pleistocene glacial advance and the subsequent establishment of the Holocene climate, Vicugna moved from its lowland distribution to its present day, high-elevation habitat. Today, two subspecies are recognized, distinguished on the bases of genetics, habitat, and morphology. Northern subspecies mensalis is closely related to the domestic Alpaca (V. pacos). Subspecies and Distribution. V. v. vicugna Molina, 1782 — W Bolivia, NW Argentina, and NE Chile from 18° S to 29° S. V. v. mensalis Thomas, 1917 — SE Peru, W Bolivia, and NE Chile from 9° S to 19° S. Ecuador has a small population (c.3000) introduced from Peru, Chile, and Bolivia in the 1980s. Descriptive notes. Head-body 125-190 cm,tail 15-25 cm, shoulder height 85-90 cm; weight 38-45 kg. The body color of the soft, woolly coat is pale cinnamon to reddishbrown, with insides of the legs and underside white. There is a bib of coarse white hairs 20-30 cm long on the chest at the base of the neck in the northern subspecies, which is short to almost unnoticeable in the southern subspecies. The body is slender with a long neck. The head is small and wedge-shaped; the ears are slender and pointed. The Vicuna has unique rodent-like incisors. Males and females weigh approximately the same, look alike, and are sexually indistinguishable in the field. Southern subspecies vicugna, sometimes called the “ Argentine Vicuna,” is ¢.15% larger (c.45 kg vs. 38 kg), length of molars longer, taller at the withers, substantially shorter chest-bib hair, lighter colored, larger white underside countershading, and in general exhibits higher levels of genetic diversity than the northern subspecies mensalis, sometimes referred to as “Peruvian Vicuna.” Vicuna wool (often called fiber) is among the finest in the world at 12-5 + 1-5 microns (Cashmere goat fibers measure 14-19 microns; Chiru, Pantholops hodgsonii fiber is 9-12 microns). The shorn fleeces of 30,391 Vicunas in Peru averaged 220 g/animal. With its silky texture, Vicuna woolis highly prized, retailing for US $ 250/0z in the USA and in 2004 selling at wholesale for US $ 566,/kg from certified liveshorn animals. World prices for Vicuna wool ranged from US $ 350/kg to US $ 900/kg over the past decade, promoting reference to it as the “Gold of the Andes.” The adaptations responsible for the animal’s outstanding physical endurance at high altitudes include lightweight insulating fleece, which protects against cold and the sun’s ultraviolet light, and high blood-oxygen affinity (highest of all mammals investigated). Full saturation of the blood with oxygen occurs at the lower partial pressure of oxygen that is found at high altitudes. The Vicuna’s heart muscle capillary densities are exceptionally high for a mammal of its body size. Its ability to load and unload oxygen is improved by a relatively high oxygen transfer conductance because ofits small red blood cells, and it has low blood viscosity due to a relative low percentage of red blood cells. Both are advantageous for maximum cardiac output. The Vicuna’slife span is 20 years, with a maximum age of 24 years and nine months recorded in captivity. Habitat. Vicunas are restricted to the Puna and Altoandina biogeographic provinces of the Andes.The Vicuna is the highest-altitude ungulate in all of South America, living in a unique montane zone from 3200 m to 4800 m above sea level called the Puna, a high-altitude, equatorial grassland that is above the tree line but below the snow line. Summer precipitation is typically in the form of rain or hail, rarely snow. It is a dry and cold environment with summer nights hovering close to freezing. Winter nights plummet well below freezing, 10-20°C below the daytime highs. Two distinct habitats with different levels of precipitation can be found within this dry-Andean ecosystem: the high-elevation moist or semi-humid high-Andean Puna and the lower elevation dry or semi-arid Puna habitat. The dry Puna is an extremely dry belt called the Andean Dry Diagonal, a north-west/south-east transition zone between two major hemispheric wind belts centered at the junction of north-west Argentina, south-west Bolivia, and north-east Chile. Within the Dry Diagonalthere is essentially no precipitation, no lakes, and no glacier formation. The distribution of subspecies vicugna is within the Dry Diagonal. Subspecies mensalis is found to the north of it. From a landscape perspective the Puna is characterized by peaks and pronounced slopes, the typical elevated plain that defines the region (Puna or Altiplano), and the intermediate piedmont fringes of smooth slopes. Vicunas use the habitats within the Puna and piedmont zones. The most common habitats in the Puna are xerophytic shrub steppes that are often mixed with an understory of sparse short grasses and forbs (typically not an important habitat for Vicunas); bunchgrass steppes (variable importance); open rocky areas with sparse vegetation (not important); short grass and forb areas on lower slopes, gentle slopes, and plains (important); and wetlands of short plants with high ground cover associated with high ground water, surface water, streams, and lagoons, regionally called bofedales, mojadales, and vegas (important). Bofedales (around 4500 m elevation in Peru) are perennially green sedge communities typically dominated by Eleocharis albracteata and Carex ecuadorica with vegetative cover of ¢.22% grasses, 42% sedges and reeds, and 33% forbs, and a crude protein content of 12%. Short-grass forb areas on lowerslopes (around 3190 m in Peru) are dominated by the grass species Festuca dolichophylla and Muhlenbergia fastigiata with a vegetative cover of 66% grass, 13% sedges and reeds, and 6% forbs, and a crude protein content of 10%. Food and Feeding. As with other ungulate herbivores, Vicuna habitat and forage selection is based not only upon availability, but heavily influenced by climate (wet vs. dry years), population density (high vs. low), and the social status and ranking of individual animals (high vs. low). Thus for studies done at different locations, landscapes, and animal densities,it is not surprising to see variable results. For example in Peru at the Pampa Galeras National Reserve, Vicunas were observed to be strict grazers on grasses and forbs, whereas in Argentina at the Laguna Blanca National Park, Vicunas showed some diet plasticity by being grazers on grasses 16-19% ofthe time and browsers on shrubs 59-72% of the time with two grasses (Panicum chlorolewcum and Distichlis spp-) representing nearly 50% of the diet. Feeding preference in productive habitats dominated by grasses has been documented in several areas of the Vicuna’s distribution. Of the two main habitats (grass steppe and vegas) at the Ulla-Ulla Vicuna Reserve in Bolivia, Vicunas preferred vegas. In the San Guillermo Biosphere Reserve of Argentina Vicunas were more abundant on the grassland plains. In Pampa Galeras National Reserve Vicunas preferred to forage in grass steppe communities characterized by Festuca nigesens or by Calamagrostis vicunarum, the latter being the dominant species in the vegetative type known as Excrement Influenced Vegetation (EIV). EIV is the result of long-term defecation-urination by Vicunas on dung piles; the resulting fertilization and accumulation of organic matter accelerates soil and plant succession over a long period of time. The third sere is an isolated “putting-green,” an island of short, abundant plants in rocky terrain downhill from a single or series of dung piles. The top soil is deeper and the plants grow thickly, close to the ground. EIV covered 18% of the total surface area of Pampa Galeras National Reserve, andits third sere had the highest productivity and was the most preferred forage vegetation. The general pattern of Vicuna habitat selection for grass-dominated communities, especially those of high nutritional value, is consistent with the results of diet studies that found Vicunas forage mainly on grasses (Poaceae) and grass-like sedges (Ciperaceae). When Vicunas coexisted with domestic livestock (sheep, goats, donkeys) in Argentina, they were spatially segregated, had a high overlap in diets, and used preferred habitatless than expected. The native Vicuna and exotic domestic animals coexisted because Vicunas were able to utilize suboptimal habitats while herders kept livestock in the richest habitats. A sympatric population of Vicunas and Guanacos in the San Guillermo Biosphere Reserve, Argentina, revealed that the diet of both species was similar, but Guanacos utilized more tall grasses and Vicuna fed more on forbs and short grasses. Breeding. Vicunas are strong seasonal breeders. Males reach sexual maturity at 3-5 years of age, and become reproductive after obtaining a feeding territory and recruiting females. Most females first mate as two-year-olds. Breeding is almost an unnoticeable event except for a short chase before mating, because the prolonged copulation takes place with the mating pair in sternal recumbency. Females show no unusual behavior to indicate they are in estrus and males do not persistently smell the female’s hindquarters as is common in other ungulates. There is no prolonged preoccupation or tending that ungulate males traditionally show for females in heat, because a territorial male has exclusive and immediate access to females within his territory. In Pampa Galeras National Reserve mating was observed from the end of February to the end of May, but peaked in April (3 matings/100 hours of observation), followed by May (1-8) and March (1-3). Almost all matings were in the morning and within the family group’s feeding territory. Gestation averages c.11-3 months (330-350 days). Females within a few weeks of parturition are visibly pregnant. At the start of the birth season at Pampa Galeras over a three year period, a high percentage of females two years of age or older were pregnant: 85%, 95%, and 85%. The non-pregnant females were mostly two-year-olds because only 20% of one-year-olds mated. Rectal palpation by experienced veterinarians of captive adult Vicunas in Puno (Peru) revealed 99% of females pregnant. Most (90%) births occurred from the last week of February through the first week of April with 75% of the births in March. February is the reported peak birth season for subspecies vicugna in Argentina and Chile. Nearly all (96%) births occurred in the morning and within the feeding territory. Females give birth to one offspring, with twins not reported or observed. Morning births are likely a behavioral adaptation to the stormy weather typical of Andean afternoons. In summer and early autumn, daily storms regularly start around noon. Young born during the afternoon storms of rain and hail would not be able to dry their soft-insulating wool before entering the nearfreezing nights. Wet newborns would have little chance for survival. A female aboutto give birth separated herself 15-25 m from the group. During the usual one-hour labor the female looked back to inspect her hindquarters, laid down and stood intermittently, changed positions, and walked a few steps every few minutes. Parturition occurred while the female stood. The labor and birthing behaviors were subtle and not easily noticed, as females commonly continued to feed during the process— surely to avoid attracting potential predators in this wide-open habitat. The mother immediately smelled and inspected the head and muzzle of the newborn, but licking did not occur (thus no assistance with the newborn’s thermoregulation) nor was the afterbirth eaten (the latter two behaviors common in other ungulates). Other members of the group frequently came over to smell and inspect the newborn. Newborns weighed 4-6 kg, were on their feet and able to walk in a wobbly way 15-20 minutes after birth, and began nursing when they were 30-45 minutes old. Vicuna young are “followers” as opposed to “hiders” and stay close to their mothers, especially in the first few months. Most young are weaned during the dry season in July and August, when they are 4-6 months old. During the first four months after birth 10-30% of newborns died. The cause was undetermined, but predation by Culpeos (Pseudalopex culpaeus) and Pumas (Puma concolor) was suspected. Reproductive success as measured in August by the ratio of young to adult females ranged 35-70 young per 100 females in different regions of the Pampa Galeras National Reserve. In Chile, density dependency seemed to be operating: the more females in a family group the lower the number of young per female. Very little research has been conducted on the physiology of Vicuna reproduction, but a noteworthy study on reproduction in captive male Vicunas in the Puna of northern Chile found higher levels of plasma testosterone, large testessize, greater size of seminiferous tubules, and large diameters of Leydig cell nuclei beginning in February, a month before the summer breeding season started. In the winter month of August spermatogenesis was in the regressive phase. Both findings suggested photoperiod as the mechanism for when males are sexually effective. Insight can be gained from studies on the Vicuna’s domesticated descendent, the Alpaca: an experimental study on Alpacas demonstrated that the continuous association of females and males exerted an inhibiting effect on male sexual activity. After continuous association of two weeks, there was no mating activity by the male even though receptive females were present. However, when mature males were separated from females and reunited at two week intervals, mating occurred. These observations shed light on why nonpregnant Vicunas (and other cameloids) are not bred during non-breeding seasons of the year. Activity patterns. During a year-round, 3-5-yearfield study in Pampa Galeras National Reserve, home to a population of the northern subspecies mensalis, Vicuna family groups showed a predictable daily activity pattern in the large open valleys they occupied. Having spent the night on the upperflat ridges in small sleeping territories, within an hour after sunrise they moved as a group down to their daytime feeding territories. They spent the day on these lower slopes or flat plains, feeding at a constant rate. The sleeping territories, on higher ground, were warmer at night than feeding territories and were away from the streambeds where nocturnal predators hunted. The adult male Vicuna in the family group actively defended both territories by challenging and chasing away trespassing Vicunas. If human disturbance did not cause an early retreat back up the slope, the group returned to its sleeping territory in mid- to late afternoon. In the winter dry season, when small springs on the slopes dried up, groups left their feeding territory and moved to the center of the valley floor to drink from streams. Solo males holding a territory showed similar patterns. Male groups moved randomly and unpredictably through the area. In a separate study at Pampa Galeras National Reserve conducted during the March—-May breeding season, females spent significantly more time grazing than males (54 vs. 45 minutes/hour) and lactating females fed more than non-lactating females (56 vs. 53 minutes/hour). In general females fed 91% of the time; territorial males fed 75% of the time. In Salinas y Aguada Blanca National Reserve above Arequipa, Peru, there was a positive correlation between frequency of alert behavior per adult and the number of offspring in the family group, and at the Laguna de Pozuelos Biosphere Reserve in Argentina, solitary Vicunas spent more time standing and being vigilant and less time foraging than did members of groups. In Abra Pampa (Argentina), territorial males spent more time being vigilant and less time feeding as the size of their family group increased, but not more time in territorial defense (walking, running). At the Laguna Blanca Reserve in Argentina, which is extremely arid, daily activity patterns during the dry season were similar to the patterns of family groups at Pampa Galeras in the same season, with morning feeding on slopes, midday movement to a river on the flat, and a return to the slope and more feeding in the afternoon. At Pampa Galeras there was no significant difference between the amount of time males spent in territorial behavior and the number of female group members or the total group size. Studies at Laguna Blanca on the other subspecies, however, found a substantial decrease in amount of time males spent foraging when the number of females in their group increased. Movements, Home range and Social organization. All Vicuna populations of both subspecies studied to date were sedentary and non-migratory. However, as described above, daily activity patterns and movements are greatly influenced by the need to drink water. Several studies have shown that water distribution and availability can have a major effect on local movement of Vicunas. Despite being well adapted to living in arid conditions, the Vicuna is an obligate drinker and needs to drink often, especially in the dry season when it seeks water daily. Visits to small streams often include water bathing accompanied by dust bathing in dust bowls. The home range of a family group encompasses the area where the group is typically found, thatis,its sleeping territory, feeding territory, and the space in between, as well as those areas it commonly moves through during the dry season on its way to drinking water. The two territories are defended by the male and exclusively occupied by the family group, but the balance of the home range is not;it overlaps and is shared with other groups. These are neutral zones, especially the corridors that groups move through on their way to water. The social units ofVicuna are family groups, male groups, and solo males. A characteristic family group is composed of one adult male, 3-4 females, and two juveniles. Although the permanent territorial family group is the classic Vicuna social unit occupying good habitat containing semi-permanent water, other groups found within Vicuna populations may include marginal territorial family groups occupying secondary habitat types without water, and temporary mobile family groups that lack a territory. Permanentterritorial family groups occupy a year-round feeding territory averaging 18-4 ha (2-56 ha), and sleeping territory averaging 2-6 ha. This is highly unusual for an ungulate. Territorial males defend their sites passively (standing guard near borders) and actively (walking towards, chasing, fighting, biting, etc.) multiple times daily. The territorial system is based upon resource-defense polygyny in which the territorial male defends food resources essential to females. This attracts females to the site, providing them with guaranteed forage in a food-limited environment, within which : Published as part of Don E. Wilson & Russell A. Mittermeier, 2011, Camelidae, pp. 206-246 in Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona :Lynx Edicions on pages 238-240, DOI: 10.5281/zenodo.5719719