Summit rat | |
---|---|
on a pitcher of Nepenthes rajah | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Muridae |
Genus: | Rattus |
Species: | R. baluensis |
Binomial name | |
Rattus baluensis (Thomas, 1894) | |
The summit rat (Rattus baluensis) is a species of rodent in the family Muridae. It is found only on Mount Kinabalu and Mount Tambuyukon, [2] Malaysia, and has been recorded at altitudes of 2,040 to 2,477 m on Mt. Tambuyukon and 2,670 to 3,426 m on Mt. Kinabalu. [1] [3] They are most abundant in higher altitude dwarf forest and montane scrubland. [4] The rat populations from these two peaks were connected in the Holocene. However, nowadays they are genetically isolated despite being 18 km apart. [5] With current predictions of Global warming, the suitable habitat for Rattus baluensis is expected to shift around 500 m upwards. This will put the population in Mount Tambuyukon at risk. However, the population in Mount Kinabalu will likely survive in its upper slopes. [5] Genetic analysis situate its origin in a local population of Rattus tiomanicus from northern Borneo at around 300-400 thousand years ago. [3]
The summit rat has a mutualistic relationship with a species of giant pitcher plant, Nepenthes rajah . Like the treeshrew Tupaia montana , it defecates into the plant's traps while visiting them to feed on sweet, fruity secretions from glands on the pitcher lids. [6] [7]
Mount Kinabalu is the highest mountain in Borneo and Malaysia. With an elevation of 4,095 metres (13,435 ft), it is the third-highest peak of an island on Earth, the 28th highest peak in Southeast Asia, and 20th most prominent mountain in the world. The mountain is located in Ranau district, West Coast Division of Sabah, Malaysia. It is protected as Kinabalu Park, a World Heritage Site.
Nepenthes rajah is a carnivorous pitcher plant species of the family Nepenthaceae. It is endemic to Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Malaysian Borneo. Nepenthes rajah grows exclusively on serpentine substrates, particularly in areas of seeping ground water where the soil is loose and permanently moist. The species has an altitudinal range of
Mount Tambuyukon or Tamboyukon is a mountain located at the West Coast and Kudat divisions of Sabah, Malaysia. It is considered the third-highest mountain in the country with height at 2,579 metres (8,461 ft), lying north of the highest Mount Kinabalu.
Nepenthes villosa, or the villose pitcher-plant, is a tropical pitcher plant endemic to Mount Kinabalu and neighbouring Mount Tambuyukon in northeastern Borneo. It grows at higher elevations than any other Bornean Nepenthes species, occurring at elevations of over 3,200 m (10,500 ft). Nepenthes villosa is characterised by its highly developed and intricate peristome, which distinguishes it from the closely related N. edwardsiana and N. macrophylla.
Nepenthes burbidgeae, also known as the painted pitcher plant or Burbidge's Pitcher-Plant, is a tropical pitcher plant with a patchy distribution around Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Borneo.
Nepenthes tentaculata, or the fringed pitcher-plant, is a tropical pitcher plant with a wide distribution across Borneo and Sulawesi. It grows at altitudes of 400–2550 m.
Nepenthes × kinabaluensis, or the Kinabalu pitcher-plant, is the natural hybrid between N. rajah and N. villosa. It was first collected near Kambarangoh on Mount Kinabalu, Borneo by Lilian Gibbs in 1910 and later mentioned by John Muirhead Macfarlane as "Nepenthes sp." in 1914. Although Macfarlane did not formally name the plant, he noted that "[a]ll available morphological details suggest that this is a hybrid between N. villosa and N. rajah". It was finally described in 1976 by Shigeo Kurata as N. × kinabaluensis. The name was first published in Nepenthes of Mount Kinabalu, but was a nomen nudum at the time as it lacked an adequate description and information on the type specimen. The name was subsequently published validly by Kurata in 1984.
Nepenthes lowii, or Low's pitcher-plant, is a tropical pitcher plant endemic to Borneo. It is named after Hugh Low, who discovered it on Mount Kinabalu. This species is perhaps the most unusual in the genus, being characterised by its strongly constricted upper pitchers, which bear a greatly reduced peristome and a reflexed lid with numerous bristles on its lower surface.
Nepenthes edwardsiana, or the splendid pitcher-plant, is a carnivorous tropical pitcher plant endemic to Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Malaysian Borneo. It is considered one of the most spectacular of all Nepenthes, producing some of the largest pitchers and the most highly developed peristome ribs of any species in the genus.
Nepenthes fusca, or the dusky pitcher-plant, is a tropical pitcher plant endemic to Borneo. It is found throughout a wide altitudinal range and is almost always epiphytic in nature, primarily growing in mossy forest.
Nepenthes macrovulgaris, or the serpentine pitcher-plant, is a tropical pitcher plant endemic to Borneo. It is a lowland plant that typically grows at altitudes ranging from 300 to 1200 m in sub-montane forest clearings and mossy forest. Its range is restricted to ultramafic habitats, including Mount Kinabalu, Mount Tambuyukon, the Danum Valley, the Tawai Range, the Meliau Range and Mount Silam, all in Sabah, Malaysian Borneo. Pitchers grow to around 25 cm high and range in colour from green to brown, with the speckled form being the most common.
Nepenthes stenophylla, or the narrow-leaved pitcher-plant, is a tropical pitcher plant endemic to Borneo. The species produces attractive funnel-shaped pitchers up to 25 cm high. It is listed as Least Concern on the IUCN Red List. Nepenthes stenophylla belongs to the loosely defined "N. maxima complex", which also includes, among other species, N. boschiana, N. chaniana, N. epiphytica, N. eymae, N. faizaliana, N. fusca, N. klossii, N. maxima, N. platychila, and N. vogelii.
Nepenthes macrophylla, the large-leaved pitcher-plant, is a tropical pitcher plant known only from a very restrictive elevation on Mount Trusmadi in Sabah, Malaysian Borneo.
Nepenthes muluensis, or the Mulu pitcher-plant, is a tropical pitcher plant endemic to Borneo. It grows in highland habitats at elevations of 1700 to 2400 m above sea level.
Nepenthes × trusmadiensis, or the Trus Madi Pitcher-Plant, is a natural hybrid of two famous Bornean pitcher plant species: N. lowii and N. macrophylla. It is restricted to Mount Trus Madi, where both of its parent species are sympatric.
The mountain treeshrew is a treeshrew species within the Tupaiidae. It is endemic to Borneo and inhabits montane forests in Sarawak and Sabah, Malaysia, and Kalimantan, Indonesia.
The black-footed shrew is a species of mammal in the family Soricidae. It is endemic to northern and central Sulawesi, Indonesia where it lives on the floor of the tropical forests. The International Union for Conservation of Nature has assessed its conservation status as being of "least concern".
The Kinabalu shrew is a species in the family Soricidae. It is endemic to the mountain Mount Kinabalu on Borneo, and its sister peak, Mount Tambuyukon.
The Bornean shrew is a species of mammal in the family Soricidae. It is found only on Borneo, throughout most of the island; it may or may not be present in Brunei.