1 Module # 7 Component # 4 Carnivora This component covers a brief introduction to the Order Carnivora. The most prominent members of this Order have all been described individually in detail. Please look out for separate components dealing with: Lion Leopard Cheetah Spotted Hyaena Wild dog Suricates
2 Introduction Carnivores all share one main characteristic - the possession of carnassial teeth (the last upper premolar and the first lower molar). These teeth fit together perfectly to provide a shearing surface to tear flesh. The typical dental formula of a carnivore is: I 3/3, C 1/1, P 4/4, M 3/3 = a total of 44 teeth. However, the cheetah s dental formula is: I 3/3, C 1/1, P 3/2, M 1/1 = a total of 30 teeth. They have 3 incisors on both sides of the upper and lower jaw, one canine on both sides of the upper and lower jaw, three premolars on each side of the upper jaw but only two premolars on each side of the lower jaw and one molar on both sides of the upper and lower jaw. When this group of mammals was classified, it was thought that all members known and those that would later be described would be meat or flesh eaters. The name carnivore derives from caro, the Latin for flesh, and voro, the Latin for eat. Some present-day carnivores such as the Giant panda have adapted to eat either mixed or even largely vegetarian diets. Eating meat has been their diet in the past and when these animals encounter carrion in the wild, they will scavenge. Another anomaly is the African civet that, while certainly classified as a carnivore, mostly follows a herbivorous diet supplemented by occasional insects.
3 Carnivores are, however, mostly meat eaters and are therefore also killers. Three main techniques are used by them in this process: Strangulation is a favoured method of the larger members who, after they have brought their prey down either apply a choke-hold on the prey s trachea (windpipe), or secure a biting grip over the animal s muzzle. Prey dies from suffocation. Lions, leopard and cheetah among others practise this method. The dentition of some members is not conducive to strangulation and they kill by biting down on the back of the neck of their victims severing their spinal cords. This is seen in the African wild cat. Some of the smaller members show less finesse and kill their prey by biting it repeatedly and shaking it violently. Suricates are an excellent example of practitioners of this technique. Carnivores share another characteristic - the fusion of bones in the foot. The scaphoid, lunar and central bones are fused together to form the scapho-lunar bone. This development provides a firm basis for flexion for climbing as well as grappling with prey. In addition, the penis of members of all families of carnivores, apart from the family hyaenidae, contains an elongate bony structure known as the baculum. The baculum functions to prolong copulation to increase reproductive success. Due to their hunting lifestyle, most carnivores also possess enhanced sensual acuity. This is particularly true of their vision, smell and hearing.
4 Several of the larger carnivores are either nocturnal or crepuscular and therefore have evolved the ability to see quite well in very low light conditions. They achieve this through their pupils that can dilate extraordinarily well. This is further enhanced by the presence of a tapetum. This is a reflective layer at the back of their eye socket that nature has specifically designed to gather all available light. The presence of a tapetum is not a specific carnivore characteristic but is common to many mammals. The Serval, while a nocturnal hunter, uses its keen sense of hearing rather than sight to hunt. It walks along road verges listening for insects or small rodents in the thick grass. When it identifies a sound, it leaps onto it to make its kill. Carnivore Families endemic to Southern Africa include: Felidae Canidae Viverridae Mustelidae Hyaenidae Otariidae Phocidae - cats - foxes, wilddog and jackals - civets, genets, mongooses and suricates - otters, badgers, weasels and polecats - hyeanas - fur seals (not examined in this course) - true seals (not examined in this course) The remainder of the component will highlight specific family characteristics, but will not deal with individual species accounts.
5 Family Felidae Members of this family (the felids) are the most carnivorous of the order. They are characterised by: round heads upstanding ears digitigrade feet muscular slender bodies soft padded feet with fur growing between both toes and pads retractile claws except for cheetah who have non-retractile claws long distinctive tails Felids have large eyes with binocular and colour vision which adapt to darkness rapidly. Their ears are large and their sense of hearing acute. Their sense of smell is less developed compared to canids. The facial whiskers (vibrissae) are long, stiff and sensitive and help with hunting at night. The tongue is coated with sharp-pointed papillae which lacerate food and aid in grooming. Although there is no uniformity among the tails of this group, the tail is usually a good indicator of the mood of the animal. This seems to be true from the domestic cat to the leopard. Examples of this family that occur in Southern Africa are: Lion Leopard Cheetah African wild cat Serval Caracal Black-footed cat - Panthera leo - Panthera pardus - Acinonyx jubatus - Felis silvestris lybica - Leptailurus serval - Caracal caracal - Felis nigripes
6 Family Canidae Members of this family are characterised by: long legs digitigrade feet with five toes on the front foot and four toes on the hind foot non-retractile claws long muzzles well-developed jaws bushy tails conspicuous ears Canids have flattened molars in front of the carnassials, indicating a diet which is not purely carnivorous. All the jackals have a high proportion of vegetation and insects in their diet, while the bat eared fox is almost exclusively insectivorous. All species will, however, take carrion when available. The long duration of copulation in canids is due to the presence of erectic folds on the penis which when swollen prevent retraction. The African wild dog is the least typical canid. It is exclusively carnivorous, has a short powerful muzzle and has lost the fifth digit on the front foot. Other than the wild dog, members of this group are still quite abundant outside of formal conservation areas, playing a vital and active role in many different ecosystems. This has been gauged from the significant numbers of these animals that are killed by cars on our national roads. In addition, some farmers consider jackal as vermin, thus frequently shot or poisoned. Happily, though, these species are resident in our national parks and reserves gaining the protection due to them. The wild dog is one such resident and is also a conservation success story as related in component # 15, please go there for more fascinating information. Examples of this family that occur in Southern Africa are: Sidestriped jackal - Canis adustus Black Backed jackal - Canis mesomelas Bat-eared fox - Otocyon megalotis Cape fox - Vulpes chama African wild dog - Lycaon pictus
7 Family Viverridae This is one of the most diverse of the carnivore families exhibiting no less than 16 species. They have some features in common with cats, but differ in their shorter legs, the length of their muzzles and the fact that they do not have rounded heads. They are characterised by: well-developed anal glands feet varying from digitigrade to nearplantigrade their canine teeth which are relatively small and the fact that they are omnivorous feeders, their food consisting of: Termites, wild fruit, frogs, spiders, fish, scorpions, millipedes, centipedes, agamas, skinks, bats, shrews, butterflies, gerbils, rats, mice, snakes (including highly venomous species), geckos, birds, scrub hares, beetles, locusts, ants, bees, wasps, antlions, lizards, snails, grass, eggs, crabs, seeds, earthworms and chameleons. Because these mammals can subsist on such a wide variety of foods, they can radiate widely into most terrestrial habitats. Their vision is excellent as is their hearing due to a highly developed inner ear. Examples of this family that occur in Southern Africa are: African civet Small-spotted genet Large-spotted genet Suricate (meerkat) Selous mongoose Meller s mongoose Yellow mongoose Bushy tailed mongoose White tailed mongoose Small grey mongoose Large grey mongoose Slender mongoose Water mongoose Banded mongoose Dwarf mongoose - Civettictis civetta - Genetta genetta - Genetta tigrina - Suricata suricatta - Paracynictis selousi - Rhynchogale melleri - Cynictis penicillata - Bdeogale crassicauda - Ichneumia albicauda - Galerella pulverulenta - Herpestes ichneumon - Galerella sanguinea - Atilax paludinosus - Mungos mungo - Helogale parvula Of these the suricate has been chosen for a detailed study. Look out for it in this Module, component # 19.
8 Family Mustelidae The mustelids are a large, widely distributed and mixed group of mammals. They all have: short legs well-developed anal glands long bodies Their feet and dentition show considerable variety - some are digitigrade others plantigrade, some have four toes and some five and the claws may or may not be retractile. Most mustelids are completely carnivorous and fierce hunters, preferring fresh flesh. The honey badger, however, feeds on honey and bee larvae and the otters on crabs and fish. The anal glands are an important feature of most mustelids. When frightened, or threatened most mustelids will discharge a powerful-smelling fluid called musk. A little musk is excreted with the faeces. The reproductive habits of the mustelids are unusual. The sexes live separately, rarely meeting, and are hostile towards each other when they do. During the mating season the male seizes the female by the scruff of her neck and may drag her about forcibly before mounting her. Copulation is repeated and prolonged. The penis is stiffened by a baculum. It seems female mustelids can only be induced to ovulate by vigorous copulation. Prolonged mating makes the pair vulnerable but this risk is outweighed by advantage of certain fertilisation. Examples of Southern African mustelids are: Cape clawless otter Spotted-necked otter Honey badger Striped weasel Striped polecat - Aonyx capensis - Hydrictis maculicollis - Mellivora capensis - Poecilogale albinucha - Ictonyx striatus Although Mustelidae maintain stable populations they are seldom seen.
9 Family Hyaenidae Members of this family are characterised by: thickset muzzles large ears powerful jaws non-retractile claws anal pouches The anal pouches are one of the most distinctive features of all hyenids. The pouch lies between the rectum and the base of the tail and can be turned inside out. It is particularly large in the Brown hyaena which discharges two distinct secretions from different glands lining the pouch. Hyenids bare a resemblance to canids but based on comparative anatomy, their closest relatives are the Viverridae. Their dog-like characteristics are probably an evolved adaptation to their open habitats. Hyaenas, mainly scavengers, have the most incredible digestive systems - they can consume indigestible items such as bone, hooves, horns, ligaments and hair. These are regurgitated in pellets. Spotted hyaena have big heads, large bone-crushing premolars and the carnassial teeth are used almost exclusively for slicing and shearing meat. The corresponding premolars, in brown hyaenas, are smaller as their food includes insects, wild fruit and eggs. The famous hermaphroditism of the spotted hyaena refers to the genitals being identically masculine in both sexes until puberty, when the female urogenital opening and the mammae enlarge. However, the presence of the male penis is not a penis at all, but rather an enlarged clitoris. This is retained. It is thought that female hyaenas evolved as such to achieve dominance so that they could compete with the males for food. Both species of hyaena possess well-developed forequarters, a sloping backline and a dorsal mane. There is some taxonomic debate as to whether the aardwolf belongs to its own unique family. For this course, we have included it with the other two species. The aardwolf is a shy, nocturnal creature seldom seen. Its diet mainly consists of harvester termites. The aardwolf appears to locate termites by sound. Because of the sticky saliva that covers their tongues, they can lick up a great number at a time. Hyenids that occur in Southern Africa: Spotted hyaena Brown hyaena Aardwolf - Crocuta crocuta - Hyaena brunnea - Proteles cristata