The meerkat (Suricata suricatta) or suricate is a small mongoose found in southern Africa. It is characterised by a broad head, large eyes, a pointed snout, long legs, a thin tapering tail and a brindled coat pattern. The head-and-body length is around 24–35 cm (9.4–13.8 in), and the weight is typically between 0.62 and 0.97 kg (1.4 and 2.1 lb). The coat is light grey to yellowish brown with alternate, poorly defined light and dark bands on the back. Meerkats have foreclaws adapted for digging and have the ability to thermoregulate to survive in their harsh, dry habitat. Three subspecies are recognised.
Description & appearance
The meerkat is a small mongoose of slim build characterised by a broad head, large eyes, a pointed snout, long legs, a thin tapering tail and a brindled coat pattern. It is smaller than most other mongooses except the dwarf mongooses (genus Helogale) and possibly Galerella species. The head-and-body length is around 24–35 cm (9.4–13.8 in), and the weight has been recorded to be between 0.62–0.97 kg (1.4–2.1 lb) without much variation between the sexes (though some dominant females can be heavier than the rest). The soft coat is light grey to yellowish brown with alternate, poorly defined light and dark bands on the back. Individuals from the southern part of the range tend to be darker. The guard hairs, light at the base, have two dark rings and are tipped with black or silvery white; several such hairs aligned together give rise to the coat pattern. These hairs are typically between 1.5 and 2 cm (0.59 and 0.79 in), but measure 3–4 cm (1.2–1.6 in) on the flanks.
Its head is mostly white and the underparts are covered sparsely with dark reddish brown fur, with the dark skin underneath showing through. The eyes, in sockets covering over 20% of the skull length, are capable of binocular vision. The slim, yellowish tail, unlike the bushy tails of many other mongooses, measures 17 to 25 cm (6.7 to 9.8 in), and is tipped with black. Females have six nipples. The meerkat looks similar to two sympatric species—the banded and the yellow mongooses. The meerkat can be told apart from the banded mongoose by its smaller size, shorter tail and bigger eyes relative to the head; the yellow mongoose differs in having a bushy tail and lighter coat with an inner layer of yellow fur under the normal brown fur.
The meerkat has 36 teeth with the dental formula of 3.1.3.23.1.3.2. It is well adapted for digging, movement through tunnels and standing erect, though it is not as capable of running and climbing. The big, sharp and curved foreclaws (slightly longer than the hindclaws) are highly specialised among the feliforms, and enable the meerkat to dig efficiently. The black, crescent-like ears can be closed to prevent the entry of dirt and debris while digging. The tail is used to balance when standing upright. Digitigrade, the meerkat has four digits on each foot with thick pads underneath.
The meerkat has a specialised thermoregulation system that helps it survive in its harsh desert habitat. A study showed that its body temperature follows a diurnal rhythm, averaging 38.3 °C (100.9 °F) during the day and 36.3 °C (97.3 °F) at night. As the body temperature falls below the thermoneutral zone, determined to be 30–32.5 °C (86.0–90.5 °F), the heart rate and oxygen consumption plummet; perspiration increases sharply at temperatures above this range. Additionally, it has a basal metabolic rate remarkably lower than other carnivores, which helps in conserving water, surviving on lower amounts of food and decreasing heat output from metabolic processes. During winter, it balances heat loss by increasing the metabolic heat generation and other methods such as sunbathing.
Distribution & habitat
The meerkat occurs in southwestern Botswana, western and southern Namibia, northern and western South Africa; the range barely extends into southwestern Angola. It lives in areas with stony, often calcareous ground in a variety of arid, open habitats with little woody vegetation. It is common in savannahs, open plains and rocky areas beside dry rivers in biomes such as the Fynbos and the Karoo, where the mean yearly rainfall is below 600 mm (24 in). The average precipitation reduces to 100 to 400 mm (3.9 to 15.7 in) towards the northwestern areas of the range. It prefers areas with short grasses and shrubs common in velds , such as camelthorn in Namibia and Acacia in the Kalahari. It is absent from true deserts, montane regions and forests. Population densities vary greatly between places, and are significantly influenced by predators and rainfall. For instance, a study in the Kgalagadi Transfrontier Park, where predation pressure is high, recorded a lower mean meerkat density relative to a ranch with lower occurrence of predators; in response to a 10% decrease in rainfall over a year, the density fell from 0.95 to 0.32/km2 (2.46 to 0.83/sq mi). Food
The meerkat is primarily an insectivore, feeding heavily on beetles and lepidopterans; it can additionally feed on eggs, amphibians, arthropods (such as scorpions, to whose venom they are immune), reptiles, small birds (such as the southern anteater-chat), plants and seeds. Captive meerkats include plenty of fruits and vegetables in their diet, and also kill small mammals by biting the backs of their skulls. They have also been observed feeding on the desert truffle Kalaharituber pfeilii. Meerkats often eat citron melons and dig out roots and tubers for their water content.
Mongooses spend nearly five to eight hours foraging everyday. Like other social mongooses, meerkats in a pack will disperse within 5 m (16 ft) of one another and browse systematically in areas within their home range without losing visual or vocal contact. Some individuals stand sentry while the rest are busy foraging. Meerkats return to an area only after a week of the last visit so that the food supply is replenished sufficiently. They hunt by scent, and often dig out soil or turn over stones to uncover hidden prey. Meerkats typically do not give chase to their prey, though they may pursue geckos and lizards over several metres. Food intake is typically low during winter. Reproduction
Meerkats breed throughout the year with seasonal peaks, typically during months of heavy rainfall; for instance, maximum births occur from January to March in the southern Kalahari. Generally only dominant individuals breed, though subordinate members can also mate in highly productive years. Females become sexually mature at two to three years of age. Dominant females can have up to four litters annually (lesser for subordinate females), and the number depends on the amount of precipitation. Mating behaviour has been studied in captive individuals. Courtship behaviour is limited; the male fights with his partner, getting hold of her by her snout. He will grip the nape of her neck if she resists mounting, and hold her down by grasping her flanks during copulation.
After a gestation of 60 to 70 days, a litter of three to seven pups is born. Pups weigh around 100 g (3.5 oz) in the first few days of birth; the average growth rate for the first three months is 4.5 g (0.16 oz) per day, typically the fastest in the first month. A 2019 study showed that growth and survival rates of pups might decrease with increase in temperature. Infants make continuous sounds that resemble bird-like tweets, that change to a shrill contact call as they grow older. Young pups are kept securely in a den, from where they emerge after around 16 days, and start foraging with adults by 26 days. The nonbreeding members of the pack help substantially with juvenile care, for instance they feed the pups and huddle with them for warmth. A study showed that nearly half of the litters of dominant females, especially those born later in the breeding season were nursed by subordinate females, mostly those that were or recently had been pregnant. Sex biases have been observed in feeding; for instance, female helpers feed female pups more than male pups unlike male helpers who feed both equally. This is possibly because the survival of female pups is more beneficial to female helpers as females are more likely to remain in their natal pack. Some helpers contribute to all activities more than others, though none of them might be specialised in any of them. Sometimes helpers favour their own needs over those of pups and decide not to feed them; this behaviour, known as "false-feeding", is more common when the prey is more valued by the meerkat.
The father remains on guard and protects his offspring, while the mother spends a lot of time foraging to produce enough milk for her young. Mothers give out shrill, repetitive calls to ensure their pups follow them and remain close together. Unable to forage themselves, young pups vocalise often seeking food from their carers. Like many species, meerkat pups learn by observing and mimicking adult behaviour, though adults also engage in active instruction. For example, meerkat adults teach their pups how to eat a venomous scorpion by removing the stinger and showing the pups how to handle the creature. The mother runs around with prey in her mouth, prompting her pups to catch it. Pups become independent enough to forage at around 12 weeks of age. Meerkats are estimated to survive for five to 15 years in the wild; the maximum lifespan recorded in captivity is 20.6 years.
Females appear to be able to discriminate the odour of their kin from that of others. Kin recognition is a useful ability that facilitates cooperation among relatives and the avoidance of inbreeding. When mating occurs between meerkat relatives it often results in negative fitness consequences (inbreeding depression), that affect a variety of traits such as pup mass at emergence from the natal burrow, hindleg length, growth until independence and juvenile survival. These negative effects are likely due to the increased homozygosity or higher genetic similarity among individuals that arise from inbreeding and the consequent expression of deleterious recessive mutations.