Cape gray mongoose
The Cape gray mongoose called the small gray mongoose, is a small mammal native to South Africa and southern Namibia. It is a small species, it is a dark grey colour with a darker tip of the tail. The legs are a darker grey than the rest of the body, it has a typical elongated mongoose body-shape. The ears are situated on the sides of the head; the tail is bushy. The teeth show adaptations for both crushing; the Cape grey mongoose feeds on insects and small rodents, but will eat birds, small reptiles, other invertebrates, fruit. They have been known to eat garbage as well, it is predominantly insectivorous but carnivorous. Insects and other arthropoda such as spiders are caught on the ground and held down with the forefeet and eaten. Larger prey such as rodents are killed with a bite to the head. Large prey items are held down with the forefeet and torn into bite size pieces with the teeth. Small rodents, in particular Otomys and Rhabdomys, are their most important dietary component. On occasion, immature hares or the young of small antelopes such as Cape grysbok may be attacked.
Until a few decades ago, the species was thought to be endemic to the Cape Province, but it is now known to occur in much of the rest of South Africa and in the west, northwards to southern Angola. It is not yet clear how continuous the range is, nor how much of this wider presence is due to extension of its range, its density in areas where the species is established, ranges from one mongoose per 60 hectares to one per two hectares. It inhabits macchia-type vegetation, semi-desert scrub and forest. However, it is not found in the grassland biome, they live in close association with man under the floors of outbuildings, live on the fringe of suburbia. When habituated to human presence, they may tolerate close approach; the Cape grey mongoose is diurnal. When not breeding, it is solitary, but litter remains together in a family party at least until late adolescence, they live in overlapping home ranges of 5-68 ha, with the males having larger ranges than the females. However, it is not clear whether this species is territorial or not, or whether it might be more social than believed.
They are poor diggers so they utilize piles of rocks, deserted burrows and hollows in tree trunks for shelter when there is not sufficient bush cover. They are spotted by humans when they cross roads. Litters of 1 – 3 young are born from August to December and are hidden in burrows, rock crevices or tree hollows. At birth, the pups are furred but their eyes and ears are closed, only opening after about a fortnight; the young remain in the breeding burrow until they are weaned, leave when they are capable of independence
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus encounter one another. An interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation; such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation does not imply secondary contact, speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may not interbreed. Four main types of population pairs exist in nature. Sympatric populations contrast with parapatric populations, which contact one another in adjacent but not shared ranges and do not interbreed. Allopatric populations isolated from one another by geographical factors may experience genetic—and phenotypic—changes in response to their varying environments.
These may drive allopatric speciation, arguably the dominant mode of speciation. The lack of geographic isolation as a definitive barrier between sympatric species has yielded controversy among ecologists and zoologists regarding the validity of the term; as such, researchers have long debated the conditions under which sympatry applies with respect to parasitism. Because parasitic organisms inhabit multiple hosts during a life cycle, evolutionary biologist Ernst Mayr stated that internal parasites existing within different hosts demonstrate allopatry, not sympatry. Today, many biologists consider parasites and their hosts to be sympatric. Conversely, zoologist Michael J. D. White considered two populations sympatric if genetic interbreeding was viable within the habitat overlap; this may be further specified as sympatry occurring within one deme. Others question the ability of sympatry to result in complete speciation: until many researchers considered it nonexistent, doubting that selection alone could create disparate, but not geographically separated, species.
In 2003, biologist Karen McCoy suggested that sympatry can act as a mode of speciation only when "the probability of mating between two individuals depend on their genotypes, dispersed throughout the range of the population during the period of reproduction". In essence, sympatric speciation does require strong forces of natural selection to be acting on heritable traits, as there is no geographic isolation to aid in the splitting process. Yet, recent research has begun to indicate that sympatric speciation is not as uncommon as was once assumed. Syntopy is a special case of sympatry, it means the joint occurrence of two species in the same habitat at the same time. Just as the broader term sympatry, "syntopy" is used for close species that might hybridise or be sister species. Sympatric species occur together in the same region, but do not share the same localities as syntopic species do. Areas of syntopy are of interest because they allow to study how similar species may coexist without outcompeting each other.
As an example, the two bat species Myotis auriculus and M. evotis were found to be syntopic in North America. In contrast, the marbled newt and the northern crested newt have a large sympatric range in western France, but differ in their habitat preferences and only occur syntopically in the same breeding ponds; the lack of geographic constraint in isolating sympatric populations implies that the emerging species avoid interbreeding via other mechanisms. Before speciation is complete, two diverging populations may still produce viable offspring; as speciation progresses, isolating mechanisms – such as gametic incompatibility that renders fertilization of the egg impossible – are selected for in order to increase the reproductive divide between the two populations. Sympatric groups show a greater ability to discriminate between their own species and other related species than do allopatric groups; this is shown in the study of hybrid zones. It is apparent in the differences in levels of prezygotic isolation in both sympatric and allopatric populations.
There are two main theories regarding this process: 1) differential fusion, which suggests that only populations with a keen ability to discriminate between species will persist in sympatry. Reinforcement is the process. In sympatry, reinforcement increases species discrimination and sexual adaptation in order to avoid maladaptive hybridization and encourage speciation. If hybrid offspring are either sterile or less-fit than non-hybrid offspring, mating between members of two different species will be selected against. Natural selection decreases the probability of such hybridization by selecting for the ability to identify mates of one's own species from those of another species. Reproductive character displacement strengthens the reproductive barriers between sympatric species by encouraging the divergence of traits that are crucial to reproduction. Divergence
A chordate is an animal constituting the phylum Chordata. During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, a post-anal tail: these five anatomical features define this phylum. Chordates are bilaterally symmetric; the Chordata and Ambulacraria together form the superphylum Deuterostomia. Chordates are divided into three subphyla: Vertebrata. There are extinct taxa such as the Vetulicolia. Hemichordata has been presented as a fourth chordate subphylum, but now is treated as a separate phylum: hemichordates and Echinodermata form the Ambulacraria, the sister phylum of the Chordates. Of the more than 65,000 living species of chordates, about half are bony fish that are members of the superclass Osteichthyes. Chordate fossils have been found from as early as the Cambrian explosion, 541 million years ago. Cladistically, vertebrates - chordates with the notochord replaced by a vertebral column during development - are considered to be a subgroup of the clade Craniata, which consists of chordates with a skull.
The Craniata and Tunicata compose the clade Olfactores. Chordates form a phylum of animals that are defined by having at some stage in their lives all of the following anatomical features: A notochord, a stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, in wholly aquatic species this helps the animal to swim by flexing its tail. A dorsal neural tube. In fish and other vertebrates, this develops into the spinal cord, the main communications trunk of the nervous system. Pharyngeal slits; the pharynx is the part of the throat behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. Post-anal tail. A muscular tail that extends backwards behind the anus. An endostyle; this is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus.
It stores iodine, may be a precursor of the vertebrate thyroid gland. There are soft constraints that separate chordates from certain other biological lineages, but are not part of the formal definition: All chordates are deuterostomes; this means. All chordates are based on a bilateral body plan. All chordates are coelomates, have a fluid filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm; the following schema is from the third edition of Vertebrate Palaeontology. The invertebrate chordate classes are from Fishes of the World. While it is structured so as to reflect evolutionary relationships, it retains the traditional ranks used in Linnaean taxonomy. Phylum Chordata †Vetulicolia? Subphylum Cephalochordata – Class Leptocardii Clade Olfactores Subphylum Tunicata – Class Ascidiacea Class Thaliacea Class Appendicularia Class Sorberacea Subphylum Vertebrata Infraphylum incertae sedis Cyclostomata Superclass'Agnatha' paraphyletic Class Myxini Class Petromyzontida or Hyperoartia Class †Conodonta Class †Myllokunmingiida Class †Pteraspidomorphi Class †Thelodonti Class †Anaspida Class †Cephalaspidomorphi Infraphylum Gnathostomata Class †Placodermi Class Chondrichthyes Class †Acanthodii Superclass Osteichthyes Class Actinopterygii Class Sarcopterygii Superclass Tetrapoda Class Amphibia Class Sauropsida Class Synapsida Craniates, one of the three subdivisions of chordates, all have distinct skulls.
They include the hagfish. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or all deuterostomes, are by their tails". Most craniates are vertebrates; these consist of a series of bony or cartilaginous cylindrical vertebrae with neural arches that protect the spinal cord, with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, are therefore not regarded as vertebrates, but as members of the craniates, the group from which vertebrates are thought to have evolved; however the cladistic exclusion of hagfish from the vertebrates is controversial, as they ma
The Pousargues's mongoose known as the African tropical savannah mongoose, is a mongoose native to Central Africa. It is listed as data deficient on the IUCN Red List as little is known about its distribution and ecology. Up to the late 20th century, it was known from only around 30 zoological specimens in natural history museum collections; the Pousargues's mongoose is brown with face. Its tail is bushy, its front feet have strong claws, its body length is between 33 cm with a 16 -- 23 cm long tail. In 1893, Eugène de Pousargues first described the Pousargues's mongoose on the basis of zoological specimens collected in 1892 near the Kémo River; the type locality corresponds to the former French garrison founded by the Dybowski Mission close to the settlement of Fort de Possel. It is named in honor of Jean Dybowski, it was subordinated to the genus Crossarchus. It is the only species in the genus Dologale. A genetic study focused on Carnivora highlighted the Pousargues’s mongoose to be the sister-species of the genus Helogale.
The Pousargues’s mongoose ranges from northern Democratic Republic of the Congo, South Sudan, Central African Republic to western Uganda. Mongooses sighted and recorded by a camera-trap in 2011 and 2012 in the Central African Republic were preliminarily identified as Pousargues's mongoose. In 2013, a group of Pousargues's mongooses was observed near Lake Albert in Uganda’s Semliki Wildlife Reserve. In 2016, an individual was photographed in Garamba National Park. Field research for the collection of basic data on its ecology is indispensable for designing adequate conservation measures
Laurasiatheria is a clade of placental mammals that originated on the northern supercontinent of Laurasia 99 million years ago. The clade includes shrews, even-toed ungulates, bats, odd-toed ungulates and carnivorans, among others. Laurasiatheria was discovered on the basis of the similar gene sequences shared by the mammals belonging to it; the Laurasiatheria clade is based on DNA sequence analyses and retrotransposon presence/absence data. The name comes from the theory that these mammals evolved on the supercontinent of Laurasia, after it split from Gondwana when Pangaea broke up, it is a sister group to Euarchontoglires. Laurasiatheria includes the following extant taxa: Eulipotyphla, having subsumed: Erinaceomorpha: hedgehogs and gymnures the remaining families of Soricomorpha: moles, solenodons Chiroptera: bats Perissodactyla: odd-toed ungulates including horses and rhinoceroses Artiodactyla: even-toed ungulates including camels, ruminants and cetaceansCetacea: whales and porpoises Ferae containing the orders: Pholidota: pangolins Carnivora: cats, bears and others Uncertainty still exists regarding the phylogenetic tree for extant laurasiatherians due to disagreement about the placement of Chiroptera and Perissodactyla.
Based on morphological grounds, Chiroptera had long been classified in the superorder Archonta until genetic research instead showed their kinship with the other laurasiatherians. The studies conflicted in terms of the exact placement of Chiroptera, with it being linked most to groups such as Eulipotyphla, Ferae or with Perissodactyla and Ferae in the Pegasoferae proposal. A recent study found that "trees reconstructed for the 1,608-gene data set support a basal position for Eulipotyphla and a more apical position for Chiroptera" and concluded that "Pegasoferae does not appear to be a natural group." The most recent study supports the conclusions of Zhou et al. using a large genomic dataset, placing Eulipotyphla as a basal order and Chiroptera as sister to Cetartiodactyla, with maximal support for all nodes of their phylogenetic tree. The exact position of Perissodactyla remains less certain, with some studies linking it with Ferae into a proposed clade Zooamata while others unite it with Cetartiodactyla into Euungulata, a clade of'true ungulates'.
A 2013 study by Tsagkogeorga, et al. suggests that the carnivores, cetaceans and ungulates form an ancient clade. This is supported by a study by Morgan, et al. that suggests that Eulipotyphla are the earliest diverging clade within the Laurasiatheria. Laurasiatheria is posited to include several extinct orders and superorders. At least some of these are considered wastebasket taxa lumping together several lineages based on superficial attributes and assumed relations to modern mammals. In some cases, these orders have turned out to either be paraphyletic assemblages, or to be composed of mammals now understood not to be laurasiatheres at all. Meridiungulata Condylarthra Dinocerata Mesonychia Creodonta Gondwanatheria Data related to Laurasiatheria at Wikispecies
Lake Tsimanampetsotsa is a moderately alkaline lake in the Toliara Province, in the southwestern part of Madagascar. It is located at around 24°07′S 43°45′E; the lake is protected within a national park and as a Ramsar site. The Ramsar site has a total area of 456 km2; the lake Tsimanampetsotsa is a part of the Tsimanampetsotsa National Park. The name of the lake in Malagasy means "lake without dolphins", it is a sacred place for worship and rituals. Local taboos prevent water pollution. Swimming and the utilisation of pirogues is prohibited. Water and some plants from the lake are used in traditional medicine The lake is about 20 km long, about 2 km wide and is quite shallow, it is situated in a collapse area of the Mahfaly Plateau, in a closed evaporite basin with cliffs of Eocene marine limestone to the east and a wide strip of alluvium, capping low outcrops of limestone to the west. The area is covered by sand deposits of Quaternary origin. In pre-history, there was a paleolake here complete with overland drainage.
The lake was much greater in size and depth, as evidenced by strand lines that ring the outer edges of the basin. The water is “sodic” mineralised and moderately alkaline with high concentrations of ammonia and phosphate. Salt concentrations approach that found in seawater, becoming somewhat diluted during the rainy season; the lake may be directly connected to the sea, but this is a matter of conjecture that has not been verified. The eastern part of the lake receives some freshwater flow and so has lower salt concentrations than the western part; the basin is shallow resulting in dramatic variation in the surface area of the lake with small changes in water level. Water levels can drop during the dry season, resulting in a broad exposed area of seasonal hypersaline flats around a shrunken lake. Lake Tsimanampetsotsa is in an area with a semi-arid climate, it is in the lowest precipitation region in Madagascar. In addition, rainfall amount and location is unpredictable. There are no surface rivers here and the lake has no inlet or outlet.
Lake levels are tied to rainfall, along with some underground flow from aquafers located further inland. There is a network of groundwater that surfaces at the foot of the Mahfaly Plateau, with three permanent springs and numerous seeps and intermittent springs. Lake levels rise with sufficient rainfall, drop when water evaporates faster than it is being replenished. Emergent plant species able to grow in the sodic water include southern flat-sedge. Glasswort is one of the few species that can tolerate extreme salinity, so it is found alone on saline sites. Other salt-tolerant species move onto the flats as the water levels recede including Salsola littoralis, Atripex perrieri, as well as some grasses and the golden leather fern; the introduced species beach sheoak can be found in small stands along the east shore. High phosphate concentrations, originating from erosion, are thought to be the main factor limiting the diversity of aquatic fauna. There are no fish. Invertebrates belonging to four taxonomic groups have been documented.
Taxonomic richness decreased to 11 taxa in August. The eastern part of the lake had more species the western part because of the lower salt concentrations; the crustaceans were the most widespread species. The aquatic fauna documented in Lake Tsimanampetsotsa is as follows: Annelida, family Glossiphoniidae. Gastropoda species: Planorbis planorbis, Georissa petiti and Potamopyrgus sp.. Crustacea species: Grandidierella mahafalensis and Halmyrapseudes thaumastocheles. Insects found included: flies. More than 34 bird species are recorded from the lake area. Greater flamingos are at times present in large numbers and nest on the lake. Lesser flamingos have be seen here; the lake and saline flats constitute an important habitat for many threatened water bird species, such as Madagascan plover and supports a breeding colony of Madagascan grebe. Loewen, M. A. Samonds, K. E. and Ramarolahy, M. F. 2001. Lake Tsimanampetsotsa, A Modern Alkaline Playa Lake In Madagascar; the Geological Society of America, Annual Meeting, November 5-8, 2001
Alfred Grandidier was a French naturalist and explorer. From a wealthy family, at the age of 20, he and his brother, Ernest Grandidier, undertook a voyage around the world. At first they were led by the astronomer and physicist Pierre Jules César Janssen, but when Janssen fell sick and had to return to France after about six months, the brothers continued the journey, they visited South America in 1858 and 1859 and in particular the Andes, Chile, Bolivia and Brazil. During this voyage they gathered a significant collection of specimens which were analyzed, in 1860, by Ernest; the two brothers parted ways after this. Ernest Grandidier went to China and collected a vast number of specimens which are now in the Louvre and the Guimet museum. Alfred travelled to India, reaching it in 1863, he was prevented by a severe attack of fever. Grandidier travelled to Zanzibar to recuperate, remaining some time and making important collections and publishing an account of his findings, he visited the island of Réunion and in 1865 made his first visit to Madagascar.
He became devoted to the study of the island, revisiting in 1866 and 1868. He returned permanently to France in 1870. During his explorations he crossed the island three times, travelling 3000 kilometers in the interior and 2500 along the coast, he made observations which resulted in the production of a map of the island used in future expeditions. After returning to France he began to work on his great work, L'Histoire physique, naturelle et politique de Madagascar; this work was undertaken in cooperation with others such as Alphonse Milne-Edwards and Leon Vaillant. This work ran to 40 volumes, the final volumes published posthumously by his son Guillaume Grandidier, he described about 50 new species of amphibians. Alfred Grandidier's work drew the attention of the French government to Madagascar, which it would annex at the end of 1890, he was elected to the French Academy of Sciences in 1885 and was the president of the French Geographical Society from 1901 to 1905. The Royal Geographical Society awarded him their Founder's Gold Medal in 1906.
Oplurus grandidieri, a species of lizard, Xenotyphlops grandidieri, a species of snake, were named in his honor by French herpetologist François Mocquard. The mineral grandidierite, discovered in Madagascar was named in his honor. Partial list. Grandidier A. "Description de quatre espèces nouvelles de Lepidopteres decouvertes sur la cote sud-oust de Madagascar ". Revue et Magasin de Zoologie Pure et Appliquee 19: 272–275. Grandidier A. Histoire physique, naturelle et politique de Madagascar. Volumes 18 & 19. Paris: Imprimerie Nationale. Grandidier A. "Histoire naturelle des lepidopteres ". Histoire Physique, Naturelle et Politique de Madagascar 18: i-v, 1–364. Category:Taxa named by Alfred Grandidier Obituary in The Auk 39: 453. Gallica has several digitised on line digitised works by Grandidier. Aluka – Cookies are absent/required at www.aluka.org The Grandidier library and photograph collection