Salanoia durrelli
Encyclopedia
Salanoia durrelli, also known as Durrell's vontsira, is a Madagascan
mammal in the family Eupleridae
of the order Carnivora
. It is most closely related to the brown-tailed mongoose
(Salanoia concolor), with which it forms the genus Salanoia
. The two are genetically similar, but morphologically distinct, leading scientists to recognize them as separate species. After an individual was observed in 2004, the animal became known to science and S. durrelli was described as a new species in 2010. It is found only in the Lac Alaotra
area.
A small, reddish-brown carnivore, Salanoia durrelli is characterized by broad feet with prominent pads, reddish-buff underparts, and broad, robust teeth, among other differences from the brown-tailed mongoose. In the only two weighed specimens, body mass was 600 g and 675 g (21 and 24 oz). It is a marsh-dwelling animal that may feed on crustaceans and mollusks. The Lac Alaotra area is a threatened ecosystem, and S. durrelli may also be endangered by competition with introduced species
.
(DWCT) during a survey of bamboo lemur
s (Hapalemur) in the Lac Alaotra
area, the largest wetland
s of Madagascar. The animal was captured, photographed, and then released, but examination of the photograph showed that it could not be identified with any known species of Malagasy carnivoran (family Eupleridae
). Therefore, two specimens were caught in 2005 by the DWCT. One was killed to facilitate additional morphological comparisons. In 2010, it was formally described as Salanoia durrelli in a paper by conservationist Joanna Durbin and a team of scientists from the Climate, Community & Biodiversity Alliance
, Nature Heritage, the Natural History Museum
, Conservation International
, and the DWCT. The specific name, durrelli, honors Gerald Durrell
, a noted conservationist and the founder of the DWCT. Previously, local villagers had already reported the presence of a small carnivoran at Alaotra, and it was speculated that the animal was the closely related brown-tailed mongoose
(Salanoia concolor).
Salanoia durrelli was placed in the genus Salanoia
, which previously included only the brown-tailed mongoose of eastern Madagascar. S. durrelli shows substantial morphological differences from the brown-tailed mongoose, but the mitochondrial DNA
of the two species is very similar. The discoverers chose to recognize the Lac Alaotra population as a separate species in view of its significant morphological differentiation. The observed morphological distinctiveness might be result of adaptation
s to life in the Alaotra wetlands, similar to the Alaotra bamboo lemur species, Hapalemur alaotrensis, which is also recognized as a distinct species despite being genetically close to the more widespread Hapalemur griseus.
-like carnivoran. It is reddish-brown overall, paler than the brown-tailed mongoose. The head and nape
are speckled. The underparts are reddish-buff, not brownish as in the brown-tailed mongoose. Most of the tail is similar in color to the body, but the tip is yellowish-brown. The inner side of the well-furred external ear (pinna) is reddish-buff. The broad feet are naked below, with the naked skin buff on the forefeet and dark brown on the hindfeet, and show prominent pads. Each of the five digits on the fore- and hindfeet bears a long, dark brown claw. There are rows of stiff hairs along the outer margins of the feet. In contrast, the brown-tailed mongoose has narrower feet with more poorly developed pads. In S. durrelli, the fur is long and soft.
In the holotype
specimen, a female, the head and body length was 310 mm (12.2 in), the tail length was 210 mm (8.3 in), the hindfoot length was 66.8 mm (2.63 in), the ear length was 17.5 mm (0.69 in), and the body mass was 675 g (24 oz). In another specimen, a male which was captured and released, the head and body length was about 330 mm (13 in), the tail length was about 175 mm (6.9 in), and the body mass was 600 g (21 oz). Based on these limited data, S. durrelli may be slightly smaller than the brown-tailed mongoose.
The skull generally resembles that of the brown-tailed mongoose, but the rostrum (front part) is broad and deep, the nasal bone
s are broad and short, and the region of the palate
is broad. The mandible
(lower jaw) is robust and shows a high, steeply rising coronoid process
(a projection at the back of the bone). Statistical analysis of measurements of the skulls and teeth strongly separates S. durrelli from specimens of the brown-tailed mongoose.
Salanoia durrelli has a more robust dentition
than the brown-tailed mongoose; the teeth have larger surface areas. The first and second upper incisor
s are smaller than the third, which is separated by a pronounced diastema
(gap) from the canine tooth
. The canine is more robust than in the brown-tailed mongoose. The first upper premolar
is small, but the second and third are larger; these two teeth are shorter and broader than in the brown-tailed mongoose. The fourth premolar is large, as is the first molar. The second upper molar is less than one-third the size of the first, and is more highly reduced than that of the brown-tailed mongoose, which is about two-thirds the size of the first molar. The first lower incisor is smaller than the other two. The lower canine, premolars, and first molar are well-developed. The second molar is broad, but smaller than in the brown-tailed mongoose.
s, rather than the insects that the more gracile-toothed brown-tailed mongoose eats. Indeed, the two specimens of S. durrelli were captured using traps baited with fish and meat. S. durrelli is similar in many respects to the larger mainland African marsh mongoose
(Atilax paludinosa), a carnivorous wetland-dweller that also uses mats of vegetation to eat and sleep on.
such as exotic fish, plants, the black rat
(Rattus rattus), and the small Indian civet
(Viverricula indica), another small carnivoran. A bird restricted to the area, the Alaotra grebe
(Tachybaptus rufolavatus), was recently declared extinct and the population of the bamboo lemur fell by about 30% from 1994 to 1999. As a narrowly distributed species with a small population, S. durrelli is likely to be threatened by degradation of its habitat and perhaps competition with the small Indian civet and the black rat, but its conservation status
has not yet been formally assessed. The DWCT is working to conserve the Lac Alaotra area and the region has been designated as a protected area
.
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
mammal in the family Eupleridae
Eupleridae
The family Eupleridae is a group of carnivorans endemic to Madagascar and comprising 10 known species in seven genera. Probably the best known species is the Fossa , in the subfamily Euplerinae...
of the order Carnivora
Carnivora
The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...
. It is most closely related to the brown-tailed mongoose
Brown-tailed Mongoose
The brown-tailed mongoose, Malagasy brown-tailed mongoose, or salano is a species of mammal in the Eupleridae family. It is endemic to Madagascar. Its natural habitat is subtropical or tropical dry forests...
(Salanoia concolor), with which it forms the genus Salanoia
Salanoia
Salanoia is a genus of euplerid carnivoran with two currently described species found in Madagascar. They are mongoose-like, which is reflected in the older versions of their English names, for example brown-tailed mongoose which is now called brown-tailed vontsira. The name Salanoia is derived...
. The two are genetically similar, but morphologically distinct, leading scientists to recognize them as separate species. After an individual was observed in 2004, the animal became known to science and S. durrelli was described as a new species in 2010. It is found only in the Lac Alaotra
Lake Alaotra
Lake Alaotra is the largest lake in Madagascar, located in Toamasina Province, in the northern central plateau. Its basin is composed of shallow freshwater lakes and marshes surrounded by areas of dense vegetation. It forms the center of the island's most important rice-growing region...
area.
A small, reddish-brown carnivore, Salanoia durrelli is characterized by broad feet with prominent pads, reddish-buff underparts, and broad, robust teeth, among other differences from the brown-tailed mongoose. In the only two weighed specimens, body mass was 600 g and 675 g (21 and 24 oz). It is a marsh-dwelling animal that may feed on crustaceans and mollusks. The Lac Alaotra area is a threatened ecosystem, and S. durrelli may also be endangered by competition with introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
.
Taxonomy
An individual Salanoia durrelli was observed swimming in 2004 by the Durrell Wildlife Conservation TrustDurrell Wildlife Conservation Trust
Durrell Wildlife Conservation Trust is a conservation organisation with a mission to save species from extinction.Gerald Durrell founded the Jersey Wildlife Preservation Trust as a charitable institution in 1963 with the Dodo as its symbol...
(DWCT) during a survey of bamboo lemur
Bamboo lemur
The bamboo or gentle lemurs are the lemurs in genus Hapalemur. They are medium sized primates that live exclusively on Madagascar...
s (Hapalemur) in the Lac Alaotra
Lake Alaotra
Lake Alaotra is the largest lake in Madagascar, located in Toamasina Province, in the northern central plateau. Its basin is composed of shallow freshwater lakes and marshes surrounded by areas of dense vegetation. It forms the center of the island's most important rice-growing region...
area, the largest wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s of Madagascar. The animal was captured, photographed, and then released, but examination of the photograph showed that it could not be identified with any known species of Malagasy carnivoran (family Eupleridae
Eupleridae
The family Eupleridae is a group of carnivorans endemic to Madagascar and comprising 10 known species in seven genera. Probably the best known species is the Fossa , in the subfamily Euplerinae...
). Therefore, two specimens were caught in 2005 by the DWCT. One was killed to facilitate additional morphological comparisons. In 2010, it was formally described as Salanoia durrelli in a paper by conservationist Joanna Durbin and a team of scientists from the Climate, Community & Biodiversity Alliance
Climate, Community & Biodiversity Alliance
The Climate, Community & Biodiversity Alliance is an initiative led by Conservation International, CARE, The Nature Conservancy, Rainforest Alliance, and the Wildlife Conservation Society to promote the development of land management activities that simultaneously deliver significant benefits for...
, Nature Heritage, the Natural History Museum
Natural History Museum
The Natural History Museum is one of three large museums on Exhibition Road, South Kensington, London, England . Its main frontage is on Cromwell Road...
, Conservation International
Conservation International
Conservation International is a nonprofit organization headquartered in Arlington, Virginia, which seeks to ensure the health of humanity by protecting Earth's ecosystems and biodiversity. CI’s work focuses on six key initiatives that affect human well-being: climate, food security, freshwater...
, and the DWCT. The specific name, durrelli, honors Gerald Durrell
Gerald Durrell
Gerald "Gerry" Malcolm Durrell, OBE was a naturalist, zookeeper, conservationist, author and television presenter...
, a noted conservationist and the founder of the DWCT. Previously, local villagers had already reported the presence of a small carnivoran at Alaotra, and it was speculated that the animal was the closely related brown-tailed mongoose
Brown-tailed Mongoose
The brown-tailed mongoose, Malagasy brown-tailed mongoose, or salano is a species of mammal in the Eupleridae family. It is endemic to Madagascar. Its natural habitat is subtropical or tropical dry forests...
(Salanoia concolor).
Salanoia durrelli was placed in the genus Salanoia
Salanoia
Salanoia is a genus of euplerid carnivoran with two currently described species found in Madagascar. They are mongoose-like, which is reflected in the older versions of their English names, for example brown-tailed mongoose which is now called brown-tailed vontsira. The name Salanoia is derived...
, which previously included only the brown-tailed mongoose of eastern Madagascar. S. durrelli shows substantial morphological differences from the brown-tailed mongoose, but the mitochondrial DNA
Mitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
of the two species is very similar. The discoverers chose to recognize the Lac Alaotra population as a separate species in view of its significant morphological differentiation. The observed morphological distinctiveness might be result of adaptation
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
s to life in the Alaotra wetlands, similar to the Alaotra bamboo lemur species, Hapalemur alaotrensis, which is also recognized as a distinct species despite being genetically close to the more widespread Hapalemur griseus.
Description
Salanoia durrelli most closely resembles the brown-tailed mongoose, which is a small, gracile mongooseMongoose
Mongoose are a family of 33 living species of small carnivorans from southern Eurasia and mainland Africa. Four additional species from Madagascar in the subfamily Galidiinae, which were previously classified in this family, are also referred to as "mongooses" or "mongoose-like"...
-like carnivoran. It is reddish-brown overall, paler than the brown-tailed mongoose. The head and nape
Nape
The nape is the back of the neck. In technical anatomical/medical terminology, the nape is referred to by the word nucha, which also gives the adjective corresponding to "nape" in English, "nuchal"....
are speckled. The underparts are reddish-buff, not brownish as in the brown-tailed mongoose. Most of the tail is similar in color to the body, but the tip is yellowish-brown. The inner side of the well-furred external ear (pinna) is reddish-buff. The broad feet are naked below, with the naked skin buff on the forefeet and dark brown on the hindfeet, and show prominent pads. Each of the five digits on the fore- and hindfeet bears a long, dark brown claw. There are rows of stiff hairs along the outer margins of the feet. In contrast, the brown-tailed mongoose has narrower feet with more poorly developed pads. In S. durrelli, the fur is long and soft.
In the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen, a female, the head and body length was 310 mm (12.2 in), the tail length was 210 mm (8.3 in), the hindfoot length was 66.8 mm (2.63 in), the ear length was 17.5 mm (0.69 in), and the body mass was 675 g (24 oz). In another specimen, a male which was captured and released, the head and body length was about 330 mm (13 in), the tail length was about 175 mm (6.9 in), and the body mass was 600 g (21 oz). Based on these limited data, S. durrelli may be slightly smaller than the brown-tailed mongoose.
The skull generally resembles that of the brown-tailed mongoose, but the rostrum (front part) is broad and deep, the nasal bone
Nasal bone
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose.Each has two surfaces and four borders....
s are broad and short, and the region of the palate
Palate
The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...
is broad. The mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
(lower jaw) is robust and shows a high, steeply rising coronoid process
Coronoid process of the mandible
The mandible's coronoid process is a thin, triangular eminence, which is flattened from side to side and varies in shape and size....
(a projection at the back of the bone). Statistical analysis of measurements of the skulls and teeth strongly separates S. durrelli from specimens of the brown-tailed mongoose.
Salanoia durrelli has a more robust dentition
Dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, the characteristic arrangement, kind, and number of teeth in a given species at a given age...
than the brown-tailed mongoose; the teeth have larger surface areas. The first and second upper incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s are smaller than the third, which is separated by a pronounced diastema
Diastema (dentistry)
Diastema is a space or gap between two teeth. Many species of mammals have diastemata as a normal feature, most commonly between the incisors and molars.-In humans:...
(gap) from the canine tooth
Canine tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, fangs, or eye teeth, are relatively long, pointed teeth...
. The canine is more robust than in the brown-tailed mongoose. The first upper premolar
Premolar
The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...
is small, but the second and third are larger; these two teeth are shorter and broader than in the brown-tailed mongoose. The fourth premolar is large, as is the first molar. The second upper molar is less than one-third the size of the first, and is more highly reduced than that of the brown-tailed mongoose, which is about two-thirds the size of the first molar. The first lower incisor is smaller than the other two. The lower canine, premolars, and first molar are well-developed. The second molar is broad, but smaller than in the brown-tailed mongoose.
Distribution, habitat, and behavior
Salanoia durrelli has been recorded at Andreba, a marshy area at 750 m (2460 ft) above sea level on the eastern coast of Lac Alaotra. The nearest occurrence of the brown-tailed mongoose is about 55 km (35 mi) from Alaotra. The first observed specimen was swimming; it may have fled from human activity on the shore. The two others were caught on mats of floating vegetation. Thus, S. durrelli occurs in a marsh habitat—quite different from the forest-dwelling brown-tailed mongoose. S. durrelli may use its robust dentition to feed on prey with hard parts, such as crustaceans and molluscs, in addition to small vertebrateVertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s, rather than the insects that the more gracile-toothed brown-tailed mongoose eats. Indeed, the two specimens of S. durrelli were captured using traps baited with fish and meat. S. durrelli is similar in many respects to the larger mainland African marsh mongoose
Marsh Mongoose
The Marsh Mongoose, or Water Mongoose, is a medium-sized mammal but a large mongoose. Weight can range from , with an average range of . From the head to the base of the tail, these animals range from , with the tail adding . It is a member of the mongoose family and the only member of its genus...
(Atilax paludinosa), a carnivorous wetland-dweller that also uses mats of vegetation to eat and sleep on.
Conservation status
The unique habitat of Lac Alaotra is threatened by pollution, destruction of marshes for the construction of rice fields, overfishing, and introduced speciesIntroduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
such as exotic fish, plants, the black rat
Black Rat
The black rat is a common long-tailed rodent of the genus Rattus in the subfamily Murinae . The species originated in tropical Asia and spread through the Near East in Roman times before reaching Europe by the 1st century and spreading with Europeans across the world.-Taxonomy:The black rat was...
(Rattus rattus), and the small Indian civet
Small Indian Civet
The Small Indian Civet or Rasse is a species of civet found across south and South-east Asia as well as in the Indonesian archipelago. The Assamese name Johamaal refers to its glandular odour similar to a scented rice variety called Joha...
(Viverricula indica), another small carnivoran. A bird restricted to the area, the Alaotra grebe
Alaotra Grebe
The Alaotra Grebe , also known as Delacour's Little Grebe or Rusty Grebe, was a grebe endemic to Lake Alaotra and surrounding lakes in Madagascar. The last sighting was in 1985 and the species was declared extinct in 2010...
(Tachybaptus rufolavatus), was recently declared extinct and the population of the bamboo lemur fell by about 30% from 1994 to 1999. As a narrowly distributed species with a small population, S. durrelli is likely to be threatened by degradation of its habitat and perhaps competition with the small Indian civet and the black rat, but its conservation status
Conservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...
has not yet been formally assessed. The DWCT is working to conserve the Lac Alaotra area and the region has been designated as a protected area
Protected area
Protected areas are locations which receive protection because of their recognised natural, ecological and/or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the enabling laws of each country or the regulations of the international...
.
Literature cited
- BirdLife International. 2010. Species factsheet: Tachybaptus rufolavatus. BirdLife International website. Downloaded on August 3, 2010.
- Durbin, J., Funk, S.M., Hawkins, F., Hills, D.M., Jenkins, P.D., Moncrieff, C.B. and Ralainasolo, F.B. 2010. Investigations into the status of a new taxon of Salanoia (Mammalia: Carnivora: Eupleridae) from the marshes of Lac Alaotra, Madagascar (subscription required). Systematics and Biodiversity 8(3):341–355.
- Garbutt, N. 1999. Mammals of Madagascar. Pica Press, 320 pp. ISBN 1873403526
- Garbutt, N. 2007. Mammals of Madagascar: A Complete Guide. A & C Black, 304 pp. ISBN 978-0-7136-7043-1
- Geoffroy Saint-Hilaire, I. 1839. Notice sur deux nouveaux genres de mammifères carnassiers, les Ichneumies, du continent African, et les Galidies, de Madagascar. Magasin de Zoologie (2)1:1–39 (in French).
- Gill, V. 2010. New carnivorous mammal species found in Madagascar. BBC News. Downloaded on October 16, 2010.
- Mutschler, T., Randrianarisoa, A.J. and Peistner, A.T.C. 2001. Population status of the Alaotran gentle lemur Hapalemur griseus alaotrensis (subscription required). Oryx 35(2):152–157.