Africa Rodents of South Africa: Diversity and Identification

South Africa is home to a staggering array of rodent species, with over 100 different types found across the country.

The diversity of rodents in South Africa can be attributed to the country's varied geography and climate, which has led to the evolution of unique species adapted to different environments.

The Vlei Rat is one of the most widespread rodents in South Africa, found in a variety of habitats including grasslands, forests, and wetlands.

The Vlei Rat's distinctive appearance, with its greyish-brown fur and long, pointed snout, makes it easily identifiable in the wild.

If this caught your attention, see: Australian Water Rat

South Africa is home to an incredible array of rodent diversity, with 35 genera of rodents currently living in the country. The Muridae family, which includes mice, rats, and gerbils, is the largest family of rodents in South Africa.

The country's rodent diversity is also reflected in its unique adaptations, such as the mole-rats of the family Bathyergidae, which have cylindrical bodies and short limbs perfect for burrowing. Dormice of the family Gliridae, on the other hand, are small nocturnal rodents that are well adapted to climbing.

Related reading: Albino Rats as Pets

Here are some of the key families and genera of rodents found in South Africa:

* FamilyGenusMuridaeAcomys, Aethomys, Dasymys, Grammomys, Mastomys, Micaelamys, Mus, Myomyscus, Otomys, Parotomys, Rattus, Rhabdomys, Thallomys, ZelotomysBathyergidaeBathyergus, Cryptomys, Fukomys, GeorychusGliridaeGraphiurusHystricidaeHystrixPedetidaePedetesPetromuridaePetromusSciuridaeGeosciurus, ParaxerusThryonomyidaeThryonomys

These families and genera represent a small fraction of the incredible diversity of rodents found in South Africa.

South Africa is home to an incredible variety of rodents, with 35 genera of rodents living in the country today.

The Muridae family is the largest family of rodents in South Africa, accounting for many diverse species such as mice, rats, and gerbils.

Mole-rats of the family Bathyergidae are burrowing rodents with distinct morphological adaptations to subterranean life, including cylindrical bodies and short limbs.

Dormice of the family Gliridae are small nocturnal rodents that are largely arboreal and well adapted to climbing.

Porcupines of the family Hystricidae are large, nocturnal rodents with quills (spines) for defense against predators.

For another approach, see: Mammary Tumors in Rats

The family Petromuridae is monospecific, containing the dassie rat (Petromus typicus) - a medium-sized rodent that inhabits rocky outcrops.

Springhares, belonging to the family Pedetidae, are nocturnal rodents that hop using their strong hind legs.

The family Nesomyidae is diverse and contains small to medium-sized morphologically varied rodents endemic to continental Africa and Madagascar.

South African squirrels of the family Sciuridae are terrestrial or semi-arboreal diurnal rodents with an elongated body and bushy tail.

Cane rats of the family Thryonomyidae are large, heavily built rodents that live in marshy areas and along riverbanks.

Here's a breakdown of the nine families of rodents found in South Africa:

The Muridae family is the largest family of rodents in South Africa, encompassing diverse species such as mice, rats, and gerbils. This family is home to many species, making it a significant part of the rodent diversity in the region.

To identify rodents to family level, the upper and lower jaws provide the main identification criteria. The keys presented in the article provide a helpful guide for this purpose.

The genus Gerbilliscus was previously included in other genera but is now recognized as a distinct group. In South Africa, three species of Gerbilliscus are currently recognized, including Gerbilliscus cometes and Gerbilliscus dolichurus.

The dental formula for Gerbilliscus species is 1-0-0-3:1-0-0-3, and the alveolar formula is 5-5-3:4-4/5-3. This information can be useful for identifying these species.

The genus Graphiurus is the only representative of the family Gliridae in sub-Saharan Africa. Five species of Graphiurus are currently described in South Africa.

Here's a summary of the subfamilies and genera mentioned in the article:

Understanding the different families and genera of rodents in South Africa can be a valuable tool for researchers and enthusiasts alike. By familiarizing yourself with these key concepts, you can better appreciate the diversity of rodents in the region.

In Malawi, farmers store their produce in various containers, including woven polypropylene bags, metal silos, and plastic buckets. Farmers in both districts use these containers to store grains for several months, with an average storage duration of 4-6 months in Lilongwe and 7-9 months in Nkhata Bay.

Farmers in Nkhata Bay consider metal silos and plastic buckets effective against rodents, while bags are the least effective method of protecting agricultural produce from rodents. In contrast, metal silos and PICS bags are not widely used in most parts of Malawi.

Farmers in Nkhata Bay use Temik powder to manage rodents, mixing it with food and applying it in areas where rodents are active. The preparation of the poison mixture is at the discretion of the individual farmer.

Domestic cats, birds of prey, and snakes are mentioned as natural enemies of rodents, with domestic cats being particularly useful in homesteads.

To identify a rodent in South Africa, you'll want to start by determining its family. The key to identifying families is found in Tables 2 and 3, which focus on the upper and lower jaws, respectively.

The first step is to count the number of cheekteeth in the adult rodent. If there are 3 cheekteeth, you'll want to refer to the key for upper jaw (Table 2). If there are 4 or 5 cheekteeth, you'll refer to the key for lower jaw (Table 3).

For example, if you're looking at the upper jaw and see that the first lobe of M has 3 cusps, you can narrow down the possibilities to Muridae. If the first lobe of M has 1 or 2 cusps, you can narrow it down to Nesomyidae.

To further narrow down the possibilities, you'll want to examine the occlusal pattern of the cheekteeth. If the occlusal surfaces are flat and simplified, you can look for one of three possible families: Bathyergidae, Hystricidae, or Pedetidae.

Here's a summary of the key characteristics for each of these families:

By following these steps and examining the characteristics of the rodent's jaws and molars, you should be able to narrow down the possibilities and identify the family to which it belongs.

African rodents can be identified by various characteristics, including their dental and alveolar patterns. The dental formula, which indicates the number of incisors, canines, premolars, and molars, is a crucial identifier. The dental formula for many African rodents is 1-0-0-3:1-0-0-3.

Intriguing read: African Pygmy Mouse

The alveolar pattern, which shows the number of alveoli (small depressions in the jawbone where teeth are rooted), is also important. For example, the alveolar formula for a specific rodent is 3-3-3:2-2/3-2/3. This means that the upper molars have three alveoli each, and the lower molars have three, two, or three alveoli each.

In terms of the shape and structure of the molars, they can be identified by the presence of cusps, cingula, and extra cusplets. For instance, the lower molars of a certain rodent have prominent and sharply defined cusps, with equal-sized posterior cingula and a longitudinal crest that connects the lobes on the labial side.

The illustrations in this study are truly impressive, with photographs of teeth and skulls taken using a Nikon digital camera D 5500.

These photographs were taken in conjunction with an AF-S Micro NIKKOR 60 mm lens and macro extension tubes, which allowed for a level of detail that's simply stunning.

The photos were then stacked using Helicon Focus 8.1.4 and edited in Adobe Photoshop CC 21.1.3, a combination that really brings out the intricate features of the dental anatomy.

By including photographs of several species in each genus description, the researchers have been able to show the intrageneric variability in dental anatomy in a way that's both informative and visually engaging.

Schematics drawings of rodent craniodental morphology were created using Adobe Photoshop CC 21.1.3 and Adobe Illustrator CC 21.0.0, which allowed for the inclusion of illustrations of some distinctive features for identification.

Distribution maps of each species have also been included, based on data from a variety of sources including the IUCN red list database and range maps from expert sources available on the Map of Life's website.

These maps were designed using R software version 4.1.0, which is a testament to the researchers' attention to detail and commitment to accuracy.

A different take: Rodent Brain Anatomy

Morphological characters are a crucial aspect of identifying rodents. The tooth cusp pattern is the most important morphological character for genus identification in rodent jaws.

The number of cheekteeth, incisor morphology, and location of the primary and secondary palatal foramina are also diagnostic characters for the upper jaw. In the lower jaw, the location of the mental foramen, muscle attachment, shape of the mandible, and projection of the mental, coronoid, and condylar processes are important.

The dental formula is a way to indicate the number of each type of tooth, with the upper and lower teeth shown consecutively. The formula is written as I-C-P-M:I-C-P-M, where I is the incisor, C is the canine, P is the premolar, and M is the molar.

The alveolar formula is similar, but it indicates the number of alveoli (the sockets where the teeth are rooted) for each type of tooth. The formula is written in a similar way to the dental formula, with the upper and lower alveolar patterns shown consecutively.

Here are some examples of dental and alveolar formulas:

The cusp pattern of the lower molars is also an important diagnostic character. The M1 and M2 have equal-sized posterior cingula, and a longitudinal crest that connects the lobes on the labial side.

Here are some key characteristics of the lower molars:

The Hystricidae family is quite fascinating. In South Africa, only the genus Hystrix occurs. It contains one modern species, H. africaeaustralis, and one fossil species, H. makapanensis. The largest African rodent is H. africaeaustralis, with long spines (quills) covering its back and flanks.

The Gliridae family is home to the African dormouse Graphiurus, a small-sized, squirrel-like rodent with impressive climbing abilities.

These rodents are predominantly arboreal, often found in trees or associated with boulders and rocky outcrops.

As a result, they have adapted to their environment, developing good climbing skills to navigate their surroundings.

Predators such as owls prey on the Graphiurus species, which has likely influenced their behavior and habitat selection.

The genus Graphiurus is part of the family Gliridae and the subfamily Graphiurinae, and is further classified as a genus of dormice.

To identify families and genera of rodents in South Africa, the first step is to determine which family a rodent belongs to. This can be done by examining the number of cheekteeth in adults, with 3 cheekteeth pointing to Muridae or Nesomyidae.

The number of cheekteeth is just the starting point, as the keys to the genera provide further details to narrow down the identification. These keys are preceded by notes on habits, habitats, and potential predators, making them a valuable resource for researchers.

To identify a rodent to the family level, the upper jaw can be examined for characteristics such as the number of cheekteeth, the shape of the first lobe of the molar, and the occlusal pattern. Table 2 provides a key to the rodent families based on these characteristics.

Identifying families and genera of rodents can be a complex process, but it starts with selecting the name of the family to which the rodent belongs. This is often done by examining the upper jaw, specifically the number of cheekteeth in adults.

The first key to identifying families is to determine the number of cheekteeth in adults. If there are 3 cheekteeth, you can proceed to the next step. If there are 4 or 5 cheekteeth, you'll need to examine the upper jaw further.

To identify the family, you'll need to examine the first lobe of the M (upper molar) and determine the number of cusps. If there are 3 cusps, the family is likely Muridae. If there are 1 or 2 cusps, the family is likely Nesomyidae.

Some families contain only one genus in South Africa, making identification easier. For example, the Gliridae family contains only one genus, making it a good starting point for identification.

Here's a table summarizing the key characteristics of each family:

Keep in mind that the precision of distribution maps can be limited due to various reasons, such as species being falsely identified in the field or in collections. Therefore, it's essential to use these maps with caution when identifying fossil specimens.

The keys to the genera are preceded by notes on the habits, preferred habitats, and potential predators, and are followed by a description of each genus and salient morphological characters. These keys can be found in Tables 4 and 5, and are a crucial step in identifying the genus of a rodent.

The Pedetidae family is quite unique, containing only the genus Pedetes. This large rodent is one of the heaviest, surpassed only by Hystrix and large specimens of Thryonomys.

Its massive size makes it a challenging prey, but eagle owls have adapted to this challenge. Specifically, Bubo africanus, Bubo capensis, and Bubo lacteus are the only nocturnal raptors capable of preying on adult Pedetes.

The Pedetidae family has undergone detailed study, with the nomenclature of its teeth being thoroughly examined in the work of Pickford & Mein.

Additional reading: Large Rodents of South America

The fossil record in South Africa is a treasure trove of information about the evolution of rodents on the continent. Published extinct taxa are identified by the symbol † in the table of rodent genera in South Africa.

The family Bathyergidae has one valid fossil genus listed for the Quaternary period. The genus Thallomys has two fossil species, Thallomys debruyni and Thallomys shortridgei, which are now extinct.

Some notable extinct rodent species include the mole rat genus Cryptomys robertsi and the porcupine species Hystrix makapanensis.

When dealing with fossilized specimens, it's essential to consider their age, as it can significantly impact the accuracy of identification.

Most rodent species reach maturity after a longer period, with larger species growing slower than smaller ones.

Species like Rhabdomys pumilio have their M and M1 teeth erupting at two weeks of age, while the M begins to erupt by four to five weeks.

The age at which species reach sexual maturity is also crucial, as most rodents leave the nest shortly after hatching or birth and disperse once they are sexually mature.

Cairo spiny mice, Acomys cahirinus, become sexually mature and leave the nest at the age of 2–3 months.

In older specimens, wear on the occlusal surface can obscure or obliterate the cusp pattern, making identification more challenging.

At a most advanced stage of wear, molars can be reduced to flattened, ovoid lobes with exposed dentine.

South Africa is home to a rich fossil record of rodents, with many species dating back to the Quaternary period. The family Bathyergidae, which includes mole-rats, has one additional valid fossil genus listed for this time period.

The fossil record of the genus Thallomys, which includes the acacia rat or tree rat, is marked by the presence of a single extinct species, Thallomys debruyni. This species is now extinct.

A total of 36 genera of rodents are currently found in South Africa, with one additional valid fossil genus listed for the Quaternary period. This includes the giant pouched rat, Cricetomys ansorgei, which belongs to the family Nesomyidae.

The fossil record of the family Petromuridae is limited to a single genus, Petromus, which includes the dassie rat (Petromus typicus). This species is still found in rocky outcrops today.

A list of fossil genera found in South Africa includes:

The presence of these fossils provides valuable insights into the evolution and distribution of South African rodents over time.

The cranium of Hystrix africaeaustralis is featured in Fig 107, with a scale bar of 2 cm. This species can be found in South Africa.

The cranium is a vital part of a rodent's anatomy, and it's essential to understand its structure. Fig 1 provides a comprehensive schematics and nomenclature of rodent cranium, which includes the foramen magnum, tympanic bulla, and zygomatic arch.

The angular process is a process at the posterior lower corner of the mandible that serves for muscular attachment. This is also referred to as the processus angularis.

Hypsodonty is a characteristic of teeth with high crowns. The article doesn't provide further information on this, but it's worth noting that it's an interesting aspect of rodent anatomy.

The Bathyergus genus is known for its distinctive cheekteeth, which are rooted and have simple occlusal surfaces, either ring or 8-shaped.

Bathyergus cheekteeth are a key identification feature, and can be distinguished from other genera by their rooted nature and simple occlusal patterns.

The mandible of Bathyergus is hystricognath, which means it has a distinctive shape and structure that sets it apart from other rodents.

In terms of dental formula, Bathyergus has a formula of 1-0-0-3:1-0-0-3, with an alveolar formula of 5-5-3:4-4/5-3.

Here are some key characteristics of Bathyergus cheekteeth:

These characteristics make Bathyergus cheekteeth a valuable tool for identifying this genus and distinguishing it from others.

Let's take a closer look at the fossil record of Hystrix africaeaustralis, as shown in Fig 108.

The upper incisors of Hystrix africaeaustralis are large and smooth, with a proodont shape.

These incisors are a key characteristic of the species, and can be used to identify them in fossil records.

The anterior palatal foramina are short and located far forwards from the cheekteeth in Hystrix africaeaustralis.

This is in contrast to other species, where the foramina may be longer or located in a different position.

The molars of Hystrix africaeaustralis are large and tend towards hypsodonty, meaning they have a high crown-to-root ratio.

If this caught your attention, see: Large Rodents North America

This is likely an adaptation for grinding tough plant material, which was a key part of the species' diet.

Here's a breakdown of the tooth structure of Hystrix africaeaustralis:

The lower incisors of Hystrix africaeaustralis are large and ungrooved, similar to the upper incisors.

The mandible of Hystrix africaeaustralis is hystricognath, meaning it has a distinctive jaw shape.

This is a key characteristic of the species, and can be used to identify them in fossil records.

The teeth of Hystrix africaeaustralis display a characteristic occlusal pattern, with crests of enamel and folds on the labial and lingual sides.

This pattern is similar to that of other Hystrix species, and can be used to identify them in fossil records.

The African Giant Pouched Rat, also known as Petromus antiquus, has a fascinating distribution and habitat. It can be found in the Early Pliocene site of Waypoint 160.

In terms of its physical characteristics, the skull of Petromus antiquus is dorsoventrally flat with an inflated bulla. The upper incisors are plain and opisthodont, while the lower incisors are ungrooved.

Petromus antiquus has four cheekteeth that are hypsodont with deep lingual enamel infoldings. The mandible is very long and vertically compressed with a sharp angular process, showing hystricognathy.

Here are some key statistics about the distribution of Petromus antiquus:

Another species in the Petromus genus is Petromus minor, which can be found in the Late Pliocene site of Taung.

Farmers in the study area consider rodents a recurrent agricultural pest, with about 67% of respondents viewing them as a regular problem. Rodents were more likely to be seen as a problem in homesteads than in fields.

In homesteads, rodents were reported to move mainly at night, and were perceived as more problematic in monocultures than in mixed crops. The crops most frequently infested by rodents were maize and groundnuts. Rodent-contaminated food was not avoided by 59% of respondents, citing that it may be the only food available to the household.

Farmers in the study area reported encountering rodents in homesteads (72%) more frequently than in fields (26%). Rodents were also reported to damage household dwellings and property, including doors, roofs, clothing, chairs, and money.

Farmers in the study area believe that rodent populations are increasing over time, with 56% of respondents citing an abundant food supply and lack of coordinated rodent management measures as the main factors.

Rodent populations decrease when there is too much rain, a drought, or during lean times, but increase in times of rich harvests. This is a common observation in the area.

Farmers in the study area have reported occasional seasonal rodent outbreaks, which occur in the first months of the dry season, just after the end of the rainy season. These outbreaks are thought to be caused by the abundant supply of food that often accompanies bumper production years.

A large majority of respondents (95%) have detected rodent holes and runways in crop fields and newborns in homesteads and crop fields.

Most farmers (90%) believe that rodents can bite people, while 50% think they can also bite livestock. However, about 80% of respondents do not know of any diseases transmitted by rodents to humans or livestock.

Farmers' perceptions of health risks posed by rodents vary. In Nkhata Bay, all FGD participants agreed that rodents can transmit certain diseases to humans, but in Lilongwe, only half of the participants thought this was the case.

Suggestion: Diseases from Rodent Feces

Farmers in Malawi store their produce in plastic buckets, woven polypropylene bags, and metal silos.

About 84% of respondents used plastic buckets and woven polypropylene bags for storage in the house, while Khokwes were the main storage facilities outside homesteads.

Purdue Improved Crop Storage (PICS) bags were the new grain storage technology most frequently mentioned (33%), followed by metal silos (12%).

The Malawi government has approved PICS bags as an improved alternative storage option since February 2016.

Farmers used trapping (45%) and hunting (31%) as the two main methods to manage rodents in the fields.

In the homesteads, rodents were managed using Indomethacin tablets (61%), Temik powder (18%), and traps (31%).

Rodents were managed for an average of 4-6 months in Lilongwe and 7-9 months in Nkhata Bay.

Metal silos and plastic buckets were considered effective against rodents in Nkhata Bay, while bags were cited as the least effective in protecting agricultural produce from rodents.

Domestic cats, birds of prey, and snakes were mentioned as natural enemies of rodents, with domestic cats being particularly useful in homesteads.

To understand the relationships between respondents' demographic characteristics and their knowledge of rodent pests, descriptive statistics such as percentages and cross-tabulations were conducted in SPSS version 27.

Farmers in both districts indicated that they could distinguish rodent species on homesteads from those in the fields based on fur color, tail length, and body size. The field rodents were described as being gray in fur color, smaller in size, and having shorter tails than the homestead rodents.

A total of 42 rodents were caught: 22 in Nkhata Bay, and 20 in Lilongwe. The rodent species most commonly caught was the Natal multimammate mouse, Mastomys natalensis (90.5%).

Data Analysis was conducted using SPSS version 27 to understand the relationships between respondents' demographic characteristics and their knowledge of rodent pests.

Descriptive statistics such as percentages and cross-tabulations were used to analyze the data from the questionnaire survey, FDGs, and KIIs separately.

Each captured rodent was photographed from different angles for taxonomic identification using morphological keys, local names provided by farmers, and a comparison with the collections of the National Museum of Malawi.

We followed the taxonomy of Monadjem et al. (2015) and Wilson et al. (2017) for identification.

Data analysis has become an essential tool in understanding and predicting the behavior of various species.

The study of species can be greatly aided by data analysis, which allows researchers to identify patterns and trends that would be difficult to discern through other means.

Analyzing data from various sources, such as camera traps and sensor networks, has helped researchers to understand the habitat and migration patterns of species like the mountain lion.

Data analysis has also been used to identify potential threats to species, such as habitat fragmentation and climate change.

The use of data analysis in species research has led to the development of more effective conservation strategies.

For example, researchers have used data analysis to identify areas of high conservation value and to prioritize conservation efforts accordingly.