Banteng

The banteng, also known as the tembadau, is a species of wild bovine found in Southeast Asia and parts of Northern Australia.
The head-and-body length is between. Wild banteng are typically larger and heavier than their domesticated counterparts, but are otherwise similar in appearance. The banteng shows extensive sexual dimorphism; adult bulls are generally dark brown to black, larger and more sturdily built than adult cows, which are thinner and usually pale brown or chestnut red. There is a big white patch on the rump. Horns are present on both sexes, and are typically long. Three subspecies are generally recognised.
Banteng are active during the day as well as at night, though activity at night is more in areas frequented by humans. Herds comprise two to forty individuals, and generally a single bull. Being herbivorous, banteng feed on vegetation such as grasses, sedges, shoots, leaves, flowers, and fruits. Banteng can survive without water for long stretches during droughts, but drink regularly if possible, especially from standing water. Not much is known about the reproductive physiology of banteng, but it might be similar to that observed in taurine cattle. After a gestation of nearly 285 days, a week longer than that typically observed in taurine cattle, a single calf is born. Banteng occur in a variety of habitats throughout their range, including open deciduous forests, semi-evergreen forests, lower montane forests, grasslands, and abandoned farms.
The largest populations of wild banteng occur in Java, Cambodia, and possibly in Kalimantan and Thailand. Domesticated banteng occur in Bali and many eastern Indonesian islands, Australia, Malaysia, and New Guinea. Feral populations are found in Sabah and the Northern Territory of Australia. Domesticated populations are primarily used for their highly demanded meat, and are used as draught animals to a lesser extent. The wild banteng is classified as Critically Endangered on the IUCN Red List, and populations have decreased by more than 50% in the past few decades. Rampant poaching, habitat loss and fragmentation and susceptibility to disease are major threats throughout its range. Wild banteng are legally protected in all countries in their range, and are largely restricted to protected areas. The banteng is the second endangered species to be successfully cloned, and the first clone to survive beyond infancy.

Taxonomy and phylogeny

The banteng was first described by German naturalist Joseph Wilhelm Eduard d'Alton in 1823. "Banteng" derived from the Javanese/Sundanese name for the animal. D'Alton based his description on two skulls from Java, a male and a female; while he described the male as a banteng, he referred to the female simply as a wild ox from Java. In 1956, Dirk Albert Hooijer of the Rijksmuseum van Natuurlijke Historie, where the skulls were first brought to from Java, noted that d'Alton used the name Bibos javanicus, or Bos javanicus if Bibos is considered a subgenus, to describe the male.
Bos leucoprymnus was suggested as a synonym in 1830, but was pointed out to be a cross between a wild banteng and a domesticated individual; Hooijer wrote that he could not infer that this was the case from the original description, and, even if it were a cross, the name would not become invalid. Other names proposed for the banteng include Bos banteng and Bos bantinger. In a 1845 revision of d'Alton's description, the authors opined that both the specimens were wild oxen, referring to them as Bos sondaicus instead. They mistook the female for a young male, an error that continued in several publications by later authors.
Fossils of banteng are known from the Middle Pleistocene of Thailand along with Stegodon, gaur, wild water buffalo and other living and extinct mammals.

Subspecies

Four subspecies are generally recognised based on phenotypic differences, though some authors do not accept these, citing extensive breeding between the small remaining banteng populations and other sympatric cattle. The details of these subspecies are given below:

Javan banteng : Occurs in Java and possibly Bali.
Indochinese banteng : Occurs on the Southeast Asian mainland.
Bali cattle Wilckens, 1905: Occurs in Bali, Australia, East Timor, Malaysia, the Philippines and New Guinea
Bornean banteng : Occurs only in Borneo.

A 2015 phylogenetic study obtained the complete mitochondrial genome of the Bornean banteng. It showed that the Bornean banteng is closer to the gaur than it is to other banteng subspecies, having diverged from the gaur around. Moreover, the Bornean banteng is genetically distant from taurine cattle and zebu, indicating that the wild Bornean banteng could not have hybridised with them, and therefore might form a purebreeding line. These researchers suggested that the Bornean banteng could be an independent species. A later study in 2021 by Sindling et al., which included the genome of the closely related and now likely extinct kouprey from Cambodia, suggested that on the level of the nuclear genome, the gaur, kouprey and banteng were distinct species, but due to incomplete lineage sorting as a result of interbreeding between their ancestors, their mitochondrial genomes did not correspond to species-specific lineages. Admixture analysis suggested that East Asian zebu cattle may have ancestry derived from banteng.
Relationships of members of the genus Bos based on nuclear genomes after Sinding, et al. 2021.

Characteristics

The banteng is similar to taurine cattle, with head-and-body length between. Wild banteng are typically larger and heavier than their domesticated counterparts, but are otherwise similar in appearance. The mean shoulder height of wild Javan and Indochinese banteng is for cows and for bulls; Bornean banteng, the smallest subspecies, are shorter. Domesticated banteng cows reach at the shoulder, while the bulls are tall. In the wild cows weigh around, while bulls weigh around. Weights of domesticated individuals range from for females and from for males. The largest bulls attain between pegs with long tail, at the withers, and weigh or more.
The banteng shows extensive sexual dimorphism; adult bulls are generally dark brown to black, larger and more sturdily built than adult cows, that are thinner and usually pale brown or chestnut red. Females and juveniles additionally have a dark line running along their back. Some bulls may retain their brown colour, sometimes with white spots similar to those seen in deer. The coat of young bulls is reddish brown, and progressively attains the adult colouration starting from the front to the rear parts. Aged bulls may turn grey. The underparts are white to light brown. The face is lighter relative to the rest of the body, whitish or tawny grey at the forehead and around the eyes but darker near the black snout. There is a big white patch on the rump, poorly developed in the Indochinese banteng; the patch may serve as a guide for herds to stay together in the dark. The legs are white below the knees. The back is particularly elevated in bulls due to the unusual lengths of the thoracic vertebrae, giving the impression of a hump. Horns are typically long, and separated by thick skin at the base. Bulls have long, slender horns with sharp tips and a circular cross-section, and are smooth except for the wrinkled base. The horns of cows are short and tightly curved, pointing inward at the tips, while those of bulls arc upwards and slightly forward. The tail, measuring, ends in a black tuft.

Ecology and behaviour

Banteng are active during the day as well as at night, though activity at night is more in areas frequented by humans. They typically form herds of two to forty individuals consisting of a single bull, cows and young. Older males form groups of two or three. Banteng are timid and reclusive, and tend to be highly alert, making approach difficult. Domestic individuals get stressed easily, and need to be handled with care. They rest and seek shelter for safety in dense forests. Banteng, particularly cows and calves, walk fast and manoeuvre easily through dense cover. Predators of adult banteng include the local populations of tigers and dholes. Banteng use their strong sense of smell to detect predators and as a means of communication within a herd. Their hearing is also highly developed. Vocalisations such as roars and bellows might be common during the breeding season; calves within seven months may produce soft eng sounds. High-pitched cries are used to raise alarm.

Diet and foraging

Herbivores, banteng feed on vegetation such as grasses, sedges, shoots, leaves, flowers and fruits. They forage at night in open areas, taking breaks of two to three hours in between to ruminate and rest. They may move to forests at higher altitudes to forage during the rainy season. A study in Deramakot Forest Reserve showed the presence of several herbal seeds, bamboo and tree bark in faecal samples. A study in West Java showed that banteng grazed mostly on the grasses Axonopus compressus, Cynodon dactylon, Ischaemum muticum and P. conjugatum, and the woody shrub Psychotria malayana. Banteng can survive without water for several days during droughts, but drink regularly if possible, especially from standing water. They frequent salt licks to satisfy their salt requirements; in the absence of licks they drink sea water instead. Banteng can drink highly saline water, and have been observed feeding on seaweed in northern Australia.

Reproduction and life cycle

Not much is known about the reproductive physiology of banteng, but it might be similar to that observed in taurine cattle. Domestic banteng can become sexually mature at as early as 13 months of age, and breed after another three months. They conceive easily, with a conception rate of 80–90% recorded in northern Australia. Breeding has been observed throughout the year in captivity and in wild banteng in Myanmar, though wild individuals on Cobourg Peninsula mate mainly in October and November, and in Thailand mating peaks in May and June. After a gestation of nearly 285 days, a week longer than that typically observed in taurine cattle, a single calf is born. Males weigh at birth, while females weigh. Young are suckled for as long as 16 months, though some cows may continue nursing till the birth of their next calf. A study of wild banteng on Cobourg Peninsula showed that males become sexually mature at three to four years and females at two to four years; males attain their full-grown size five to six years, while females grow completely by three to four years. Calf mortality is high in the first six months of life, and declines quickly thereafter with increasing body size. Banteng live for as long as 26 years.