Southern Pudu

The southern pudu is a small South American deer native to the Valdivian temperate forests of south-central Chile and adjacent Argentina, and the third smallest deer in the world. It stands 35 to 45 cm (14 to 18 in) tall at the shoulder and weighs 6.4 to 13.4 kg (14 to 30 lb). Its coat is dark chestnut-brown and tufts at the front, covering the short antlers, which are 5.3 to 9 cm (2.1 to 3.5 in) long and curve back. It lives in mature and disturbed forests with a dense understory, from sea level to 1,700 m, and prefers open spaces with rich vegetation for feeding.

About the southern pudu

The southern pudu is a tiny, stocky deer from the temperate rainforests of southern Chile and neighboring Argentina, standing only 35 to 45 cm (14 to 18 in) at the shoulder. It is one of the smallest deer in the world, slightly larger than its sister species, the northern pudu. Its coat is dark reddish brown.

Its scientific name is Pudu puda. In the Mapuche language, Mapudungun, it is called püdü, and in Spanish pudú. Accounts rank it as either the second- or the third-smallest deer in the world. Either way it weighs only 6.4 to 13.4 kg (14 to 30 lb), with females about 1 kg (2.2 lb) lighter than males.

A pudu is built low and compact. The legs are short, the rump is not raised, the snout is short and the ears are rounded rather than pointed. The tail is tiny, just 30 to 40 mm (1.2 to 1.6 in) long, and hidden in the fur. The hooves are slender, each with a scent gland tucked into a deep pocket between the toes.

The fur is dark red-brown to chestnut, varying between animals and seasons. It is stiff and fairly sparse, made of long, hollow hairs, and it tufts forward over the forehead, partly covering the antlers. Pudus molt in spring and fall. Fawns carry three rows of pale spots on the back, which fade by eight weeks old.

Only males grow antlers, and they are simple, short spikes of 5.3 to 9 cm (2.1 to 3.5 in) that curve back. They first appear when a buck is 9 to 12 months old, grow mainly in July, are polished by November and are shed in the southern summer. Apart from antlers and a little extra weight in males, the sexes look much alike. Southern pudus also have large, visible scent glands in front of the eyes, which are not visible in northern pudus.

Behavior and diet

Southern pudus are mostly solitary, secretive and sedentary. They are active both day and night, typically resting and grooming in the middle of the day and moving about in the morning, late afternoon and evening. They seem to dislike heat, being more active on windy days and sheltering in shade or valleys when it is warm. They also play, skipping, running and play-fighting.

Each pudu uses a network of trails to reach feeding areas. They prefer forest edges and clearings with plenty of small, growing plants and are highly selective about what they eat. As browsers, they eat the leaves of ferns, trees, vines, herbs and shrubs, plus twigs, buds, berries and fruit, and they will stand on their hind legs or on fallen logs to reach food. Like other deer they are ruminants with four-chambered stomachs, and a meal takes about 30 hours to pass through.

Smell rules their world. Pudus sniff, chew and lick objects to investigate them, then curl the lip in a flehmen response. They mark objects by rubbing the glands in front of their eyes against them, especially when courting, showing dominance or under stress.

Pudus are territorial. In captivity they form hierarchies led by a dominant male, and two males of similar size will fight; a male may even kill an intruding male. Displays include pointing the antlers, arching the back and making the eye glands throb. Home ranges have been measured anywhere from 2 to 200 hectares (5 to 494 acres).

The mating season runs from April to June, and females can breed again from November to January if they did not conceive. Gestation is long for such a small deer, about seven months. Most fawns are born in the southern spring, usually one per year, though twins are not unusual. Newborns stand about 20 cm (8 in) tall and weigh under 1 kg (2.2 lb), can stand right after birth, and are cared for only by the mother. They are weaned at around two months and independent at about eight months, then leave to find their own home range.

Range and habitat

The southern pudu lives in the Valdivian temperate forests of south-central Chile and the neighboring part of southwestern Argentina. Its range runs roughly from the Maule River in the north to Chiloé province in the south, and pudus are more numerous on Chiloé Island than on mainland Chile. The Chiloé population appears to have been isolated for more than 200,000 years and may be a separate subspecies.

It lives in both mature and disturbed forest, as long as there is a dense understory, and feeds in more open, plant-rich spots. In the Chilean Coast Range it uses evergreen broadleaf and alerce forests, sometimes even eucalyptus plantations. In the southern Andes it is tied to bamboo thickets and Nothofagus forest. It stays below about 1,700 m (5,600 ft), lower than the northern pudu. The climate is wet, with 2 to 4 m (79 to 157 in) of rain a year.

Pudus also help other animals. The tunnels they keep open through dense undergrowth let small creatures move about hidden from predators.

Southern pudu vs northern pudu

The two pudus are sister species and look very similar.

Conservation status

The southern pudu is listed as Near Threatened on the IUCN Red List (Silva-Rodríguez, Pastore and Jiménez, 2016). It is also on Appendix I of CITES. Populations have not been well studied, but the evidence suggests they are declining and number in the thousands.

Threats include habitat loss to human land use, roadkill, hunting for meat and fur, the trade in skins, parasites and disease, and introduced deer: chital compete with pudus and displace them, and red deer damage the forest and its plants. Domestic dogs are a growing problem: they attack and kill pudus, spread disease and compete for resources. Because pudus tire quickly, they rely on hiding in tunnels and burrows rather than outrunning predators. Their main natural predator is the cougar, or puma, and pudus are one of the most important prey animals for Chilean pumas.

Genetics adds risk. Pudu populations across Chile are strongly isolated from each other, so a sharp drop in any one population would cost genetic diversity that neighbors could not replace. Captive breeding programs have been set up in Chile, and controlling feral dogs has been suggested as one way to help.