Otomi Research Articles

The 100,000\u201377,000-Year Old Middle Stone Age Micromammal Sequence from Blombos Cave, South Africa: Local Climatic Stability or a Tale of Predator Bias?

In this paper, we present a case study of the micromammal sequence from Marine Isotope Stage 5 (130,000–71,000 YBP) at Blombos Cave on the southern Cape coast of South Africa. Our analyses of the micromammal assemblage from 100,000 to 76,000 YBP shed light on micromammal taxonomic distributions, local palaeoenvironments, and site formation processes at this renowned Middle Stone Age site. Taphonomic analyses indicate that spotted eagle owls (Bubo africanus) were the main predator species responsible for accumulating the micromammals, but with contributions from barn owls (Tyto alba). In addition, the micromammal bones have been subjected to a range of post-depositional processes, some of which are associated with microbial actions likely resulting from human or animal activities in the cave. We have recorded three species in the archaeological assemblage that do not occur in the Blombos area today. These are the Hottentot golden mole (Amblysomus hottentotus), Duthie’s golden mole (Chlorotalpa duthieae), and Laminate vlei rat (Otomys laminatus). The biodiversity indices based on micromammal species suggest that local vegetation consisted of different habitats that could sustain a diverse small mammal population. During MIS 5c/5b, the diversity of species declined, but there was still a mosaic of vegetation habitats present in the local area. On a larger temporal scale, climate conditions were slightly more humid than at present, and winter rainfall was seemingly greater. The amount of winter rainfall would have been similar to locations currently c. 50–150 km further west of Blombos Cave. However, based on micromammal proxies, there were seemingly no major fluctuations visible in climate or vegetation composition during the entire 24,000-year period. We suggest that the explanation could be multifaceted, two potential factors being predator bias derived from the owls’ preference for generalist micromammal species or an actual reflection of local stable climatic and environmental conditions in the Blombos area.

The cryptic case of Otomys sloggetti (Sloggett’s vlei rat): Interpreting murid molar morphology in the fossil record

Vlei rats (Family: Muridae; Subfamily: Otomyinae) have a widespread distribution in southern Africa. They are favoured prey of barn and spotted eagle owls, and frequently become associated with archaeological deposits when the owls roost in cave sites. The phylogeny of several Otomyinae species is enigmatic, and Otomys sloggetti (Sloggett’s vlei rat) is no exception. This species has been referred to as the ‘ice rat’ and present distribution ranges are seemingly limited to mountainous areas, at high altitude, in Lesotho Drakensberg and the Karoo. It was thus surprising and unexpected when specimens closely resembling Otomys sloggetti (identification was based on molar morphology) were found in several archaeological sites on the south and west coasts of South Africa, and also in modern owl pellet assemblages – all extralimital to the current reported distribution. However, further examination of and comparison between these specimens, as well as extensive differences observed between comparative Otomys sloggetti specimens from museum collections, highlighted potential problems associated with the common practice of using tooth morphology to identify fossil murid species. We identified six molar morphotypes from the fossil and modern material, all of which bore a morphological resemblance to O. sloggetti. The material discussed in this paper suggests that cryptic, undescribed vlei rat species, or subspecies, have been in the past, and may yet be, co-occurring with modern populations of O. karoensis and O. irroratus. Phylogenetic studies need to be done in conjunction with morphological studies, as, currently, the relationship between the huge variation seen in interspecific morphology with genetics is little understood, different Otomys species are not always distinguishable morphologically, and considerable chromosomal polytypes have been found. Our findings highlight the need for extensive cladistic and genetic research on the Otomyinae.
 Significance:
 Mice and shrews from fossil sites are frequently used by archaeologists as indicators of past climatic and environmental conditions. Research into the species present in fossil assemblages is usually done on a single site basis and intersite comparisons are rare. The taxonomic conundrums presented by a vlei rat found in several South African archaeological sites indicates that such comparisons could result in the re-evaluation of identifications, and/or indicate the presence of cryptic species/subspecies. Phylogenetic studies are needed in conjunction with morphological studies, as the relationship between variations in interspecific tooth morphology (used to identify taxa) with genetics is little understood. This in turn will help to elucidate the relationship between morphology, biogeography and local adaptations.

Rodents and other micromammals from the Pleistocene strata in Excavation 1 at Wonderwerk Cave, South Africa: A work in progress

This preliminary report concerns the micromammalian remains recovered from the Pleistocene strata in Excavation 1 at Wonderwerk Cave by Peter B. Beaumont during the 1980s and early 1990s. Because of the large size of the samples (170 656 specimens representing a minimum of 71 304 individuals), identification has so far only been taken to the generic level. Remains belonging to 34, and possibly 36, genera in five Orders have been identified, and there could be as many as 48 species represented. The uneven horizontal distribution of material throughout the excavation indicates probable roost or nest sites of Barn owls (Tyto alba), which is the most likely predator responsible for their accumulation. There is also considerable vertical variation in the amount of material in the different levels, which indicates that the predators were not consistently present in the area throughout the period represented by the deposits. In the majority of the samples, Gerbillinae (Gerbilliscus, gerbils) are best represented when supra-generic groupings are used. This suggests that conditions were reasonably arid during the periods represented by the samples but not necessarily throughout the entire period spanned by the deposits. When original groupings (genus and above) are considered, Otomyinae (Otomys spp., vlei rats) predominate in nearly half the samples. Secondarily important prey taxa are shrews (Soricidae), rats and mice (Murinae) and elephant shrews (Macroscelididae). This implies some variation in environmental conditions over time but more detailed interpretations must await further analysis. In particular it is imperative to identify the species of Gerbilliscus and Otomys before progress can be made. A range of techniques is now available to assist with interpreting the samples to their full potential once this has been done.

Biomes, geology and past climate drive speciation of laminate-toothed rats on South African mountains (Murinae: Otomys)

Abstract Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).

Past, present, and future distribution of Afromontane rodents (Muridae: Otomys) reflect climate-change predicted biome changes

AbstractClimate change constitutes a potential threat to montane biodiversity, particularly in low-altitude, tropical mountains; however, few data exist for the Afromontane taxa. In South Africa, the temperate grassland and fynbos biomes are mostly associated with the Great Escarpment and the high-lying central plateau. Varying contractions of the grassland and fynbos biomes are predicted under different climate scenarios by 2050. Animal taxa adapted to these biomes should suffer similar range declines and can be used to independently test the vegetation models. We constructed MaxEnt models from 271 unique locality records for three species of montane and submontane vlei rats that are closely associated with grassland (

Letters for an indomitable language. Typography and colonial edition in Otomi

Si la edición colonial tiene una particularidad en la Nueva España, ésta se refiere a la producción impresa en lenguas indígenas ya que a diferencia de otros virreinatos la edición en las lenguas nativas de México se realizó enteramente en prensas locales. De todas las lenguas en las que se produjeron libros es probablemente el idioma otomí el que más retos impuso a los talleres coloniales. En este ensayo se presenta un recorrido por las cuatro ediciones impresas que se realizaron en esa lengua a lo largo del periodo colonial, centrando nuestra atención en las tres del siglo xviii , que por su naturaleza tipográfica y editorial permiten apreciar los procesos de composición y cuidado del texto a los que estuvieron sometidos los textos.

Temporal changes in cranial size in South African vlei rats (Otomys): evidence for the ‘third universal response to warming’

Using museum collections and recently collected specimens we studied geographical and temporal (from 1906 to 2013) changes in skull size of two sibling species of rodents, Otomys auratus and O. angoniensis, in northern South Africa occupying distinct temperate grassland (O. auratus) and subtropical savanna (O. angoniensis) biomes. We hypothesised that cranial size should vary in space and time within species according to Bergmann's Rule, which predicts an inverse relationship between body size and temperature. We used the greatest length of the skull (GLS) as a robust indicator of body size. Cranial size of both O. auratus and O. angoniensis decreased significantly over the past 100 years, as expected given historical evidence of warming across northern South Africa since the 1950s. In terms of geographical patterns, GLS was inversely correlated with both latitude and longitude in O. auratus but these trends were correlated with annual rainfall rather than mean annual temperature. Conversely, cranial size of O. angoniensis was weakly positively correlated with longitude but with no climatic variables. Our results demonstrate rapid morphological changes in two herbivorous South African rodents over the past 100 years. Whilst the general decline in size with time in relation to increased temperature is consistent with Bergmann's Rule, multiple drivers may underlie geographical trends in the two species.

Cellobiohydrolase activity in the digestive tract of two African rodent species, the African grass rat Arvicanthis niloticus and vlei rat Otomys helleri

Cellobiohydrolase activity (CBHA) of endosymbionts in the digestive tract of two African rodent species differing in its morphology and in feeding specialization--Arvicanthis niloticus and Otomys helleri--has been studied as a characteristic of their physiological and ecological adaptation to phytophagy A statistically significant correlation of CBHA with obesity has been revealed in A. niloticus, with the CBHA level being significantly higher in corpus ceci than in ampulla ceci. The possible morphophysiological and ecological significance of the observed features of symbiotic digestion are discussed.

POST-ZYGOTIC REPRODUCTIVE ISOLATION IN THE AFRICAN VLEI RAT OTOMYS IRRORATUS (MURIDAE: OTOMYINAE)

ABSTRACT Post-zygotic reproductive isolating mechanisms among three chromosomally distinct, allopatric populations (Committee's Drift, Hogsback, Karkloof) of the vlei rat Otomys irroratus (Brants, 1827) were studied by means of laboratory breeding trials. Data from intrapopulation pairings, all of which produced young, provided a baseline for assessment of the reproductive performance of interpopulation, backcross, and hybrid cross pairings. Although 83.3% of interpopulation cross pairings produced young, overall reproductive success tended to be impaired: progeny of both the Committee's Drift × Hogsback and Committee's Drift × Karkloof pairings experienced increased pre-weaning mortality, while the tertiary (weaning) sex ratio of Committee's Drift × Karkloof hybrids (10: 24) significantly favored females. Backcross and hybrid cross breeding were severely impaired: respectively, 26.4% and 11.1 % of pairs produced litters, and almost all of the Hogsback-cross hybrids that survived to sexual maturity were s...

GENETIC VARIATION IN THE AFRICAN RODENT SUB-FAMILY OTOMYINAE (MURIDAE). IV: CHROMOSOME G-BANDING ANALYlS OF OTOMYS IRRORATUS AND O. ANGONIENSIS

ABSTRACT Chromosome G-banding analysis was carried out on 30 specimens of Otomys irroratus from six South African localities and eight specimens of O. angoniensis from three localities. While O. angoniensis appeared chromosomally conservative, extensive variation was detected between populations of O. irroratus in the number of heterochromatic short arms. The results obtained were compared with those of our previous study. This species could be divided into three major cytotype groups: group A with mostly acrocentric chromosomes, group B with at least seven large autosomes carrying heterochromatic short arms, and group C in which only four pairs of large autosomes are biarmed. Within group A, three populations carried a tandem fusion between chromosomes 7 and 12, while another population displayed two pairs of unique supernumerary autosomes. The banding patterns of O. irroratus and O. angoniensis ciaomosomes were compared, and five homologous sequences were tentatively identified between the two species. ...

ECOLOGICAL DATA ON MICROMAMMALS COLLECTED BY BARN OWLS TYTO ALBA IN THE WEST COAST NATIONAL PARK, SOUTH AFRICA

ABSTRACT Barn owls Tyto alba catch large numbers of micromammals and incidentally accumulate information concerning their prey. Here an outline is given of the contribution of barn owls to micro-distributional studies at five closely situated roosts in the West Coast National Park, southwestern South Africa. Seasonal variation in proportions of species and a positive correlation between mean mass of individual in monthly samples and rainfall at Geelbek B reflect the influence of rainfall on vegetation cover. Strong, but possibly spurious, correlations exist between various climatic factors and proportions of young in the vlei rat Otomys irroratus population at different times of the year. High incidences of co-occurrences of different species in owl pellets suggest possible co-habitation of the species concerned while co-occurrences of adult and perinatal O. irroratus provide reproductive information.

GENETIC VARIATION IN THE AFRICAN VLEI RAT OTOMYS IRRORATUS (MURIDAE: OTOMYINAE)

ABSTRACT Starch gel electrophoresis was used to analyse genetic variation at 24 enzyme and protein loci in 12 South African populations of vlei rats Otomys irroratus. Mean heterozygosity ([Hbar]: 0.071) was relatively high for a mammal. Allelic variation within populations conformed to Hardy-Weinberg expectations, and the mean value for Wright's F IS statistic (0.048) indicated no evidence of inbreeding within populations. There was significant local differentiation in allelic frequencies (Wright's F ST = 0.375). However, genetic distances between populations were low (mean for Nei's D = 0.034), and cluster analysis of genetic distances failed to identify groups consistent with geographical position or karyotypic differences between populations. A single population (Hogsback, eastern Cape), bearing a chromosomal tandem fusion and demonstrating a high measure of reproductive isolation, showed no allozymic differences from other populations, suggesting that chromosomally-mediated speciation may precede phen...

The Diet of Caracal,Caracal caracal, in Two Areas of the Southern Cape, South Africa as Determined by Scat Analysis

Caracal (Caracal caracal) diet in southern Africa has primarily been quantified in protected areas dominated by natural vegetation. Here we present data on the diet of caracal ranging in two coastal landscapes (George and Vleesbaai, South Africa) with considerable anthropogenic modification (pine plantation and agricultural land). In terms of the corrected frequency of occurrence (CFO), rodents dominated the diet (>70%) and the vlei rat (Otomys irroratus) formed the bulk in terms of volume of the rodents recorded in the diet at both sites. Bushbuck (Tragelaphus scriptus) formed an important component of the diet in George (11.4% CFO) while small carnivores comprised 11.6% CFO in Vleesbaai. Although our results are relevant in light of the extensively modified vegetation of this part of South Africa's coastal region, they are unlikely to represent the full extent of the diet in Vleesbaai, as farmers in this region regularly report livestock losses attributed to caracal.

Surgical treatment for pain after brachial plexus avulsion

Objective To study dorsal root entry zone -otomy (DREZotomy) for the treatment of pain after brachial plexus avulsion. Methods 58 patients suffering from intractable pain after brachial plexus avulsion were treated by DREZotomy in a state of general anesthesia.The patients' ages ranged from 30 to 71 years old.The patients' pain duration was form 6 months to 50 years.The pain intensity was quantified by visual analog scale (VAS).Results All patients were relieved of their preoperative pain after the operation.The short - term (6 months) follow - up results indicated a satisfactory pain relief in 87.9％ of patients.At 12 months after DREZotomy,the excellent or good effect was showed in 84.5％ of patients,whereas at 24 months in 80.0％.There was no serious complication.Conclusions DREZotomy is an effective and safe treatment for patients with pain after brachial plexus avulsion. Key words: Brachial plexus avulsion; Pain; Dorsal root entry zone; Microsurgery

Cryptic speciation in the southern African vlei ratOtomys irroratuscomplex: evidence derived from mitochondrial cytband niche modelling

The vlei rat Otomys irroratus has a wide distribution in southern Africa with several datasets indicating the presence of two putative species (O. irroratus and O. auratus). In the present study we use mitochrondrial cyt b data (∼950 bp) from 98 specimens (including museum material) collected throughout the range of the species to determine the geographical limits of the two recognized species, and we link this to niche modelling to validate these species. Phylogenetic analysis of the DNA sequence data, using maximum parsimony, neighbour joining and Bayesian inference, retrieved two divergent statistically well-supported clades. Clade A occurs in the Western and Eastern Cape while Clade B occurs in the Free State, KwaZulu-Natal, Northern Cape and Mpumalanga provinces of South Africa and Zimbabwe. Mean sequence divergence between the two clades (A and B) was 7.0% and between sub-clades comprising clade B it was 4.8%; the two clades diverged during the Pleistocene. Within Clade A the mean sequence divergence among specimens was 1.91%. Niche modelling revealed that the incipient species occupy distinct bioclimatic niches associated with seasonality of precipitation. Our data allow insightful analysis into the factors that could have led to cladogenesis within this rodent. More significantly, the new data enable us to pinpoint the Eastern Cape province as a contact zone for the divergent species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104, 192–206.

Chromosomal Polymorphisms in African Vlei Rats, Otomys irroratus (Muridae: Otomyini), Detected by Banding Techniques and Chromosome Painting: Inversions, Centromeric Shifts and Diploid Number Variation

Pericentric inversions are important for evolutionary biology because of their potential role in speciation. They may result in reproductive isolation due to illegitimate pairing of homologues at meiosis which leads to the production of aneuploid gametes (containing deletions or duplications of chromosomal segments), and consequently mediate chromosomal divergence. In this study, we describe the prevalence of pericentric inversions in the African vlei rat, Otomys irroratus (OIR). The species is characterized by intraspecific chromosomal variation (2n = 23–32) across its distribution in southern Africa. Here, we analyzed 55 individuals collected from 7 localities in South Africa by G- and C-banding and chromosome painting with flow sorts of Myotomys unisulcatus. Of the 55 specimens that were analyzed, 47% contained inversions or centromeric shifts on 4 autosomes (OIR1, 4, 6 and 10) which were present singly in specimens (i.e. none of the specimens contained all 4 inversions concurrently). These inversions were found in both homozygous and heterozygous state over a wide geographic range suggesting that they are floating polymorphisms. Given the potential role of inversions in post-mating isolation (through production of aneuploid gametes), the prevalence of inversions as floating polymorphisms in the vlei rats suggests that they are probably retained in the population through suppression of recombination in the inverted regions of the chromosomes.

Mating strategy predicts the occurrence of the Bruce effect in the vlei rat Otomys irroratus

[The Bruce effect is a phenomenon in which pregnant females terminate their pregnancies when exposed to strange males, and is hypothesised to be a female counter-strategy to infanticide risk. Since uncertain paternity decreases the incidence of infanticide, we tested the prediction that the Bruce effect would occur in mating systems where paternity is more certain (polygyny) rather than in mating systems where paternity is less certain (promiscuity). Using populations of the vlei rat Otomys irroratus that were either polygynous or promiscuous in nature, we studied the Bruce effect in captivity. Pregnancy termination almost always occurred in polygynous females but never in promiscuous females ( N = 10 per population). We expected that the signal–receptor (male–female) system of pregnancy termination is present in polygynous but not promiscuous populations and predicted an absence of the Bruce effect in encounters between individuals of different mating systems. This occurred in promiscuous females. However, 50% of polygynous females terminated their pregnancies, indicating that males of both mating strategies might carry signals to disrupt pregnancy but only polygynous females respond to these signals. The Bruce effect may be an adaptive response to infanticide risk in polygynous populations, although studies of free-living populations would be important to confirm our findings., The Bruce effect is a phenomenon in which pregnant females terminate their pregnancies when exposed to strange males, and is hypothesised to be a female counter-strategy to infanticide risk. Since uncertain paternity decreases the incidence of infanticide, we tested the prediction that the Bruce effect would occur in mating systems where paternity is more certain (polygyny) rather than in mating systems where paternity is less certain (promiscuity). Using populations of the vlei rat Otomys irroratus that were either polygynous or promiscuous in nature, we studied the Bruce effect in captivity. Pregnancy termination almost always occurred in polygynous females but never in promiscuous females ( N = 10 per population). We expected that the signal–receptor (male–female) system of pregnancy termination is present in polygynous but not promiscuous populations and predicted an absence of the Bruce effect in encounters between individuals of different mating systems. This occurred in promiscuous females. However, 50% of polygynous females terminated their pregnancies, indicating that males of both mating strategies might carry signals to disrupt pregnancy but only polygynous females respond to these signals. The Bruce effect may be an adaptive response to infanticide risk in polygynous populations, although studies of free-living populations would be important to confirm our findings.]

Democratic Republic of S�o Tom� and Pr�ncipe: Selected Issues

Democratic Republic of S�o Tom� and Pr�ncipe: Selected Issues

Preliminary observations on the diet of leopards (Panthera pardus) from a conservation area and adjacent rangelands in the Baviaanskloof region, South Africa

Pastoralists on rangelands adjacent to the Baviaanskloof Provincial Nature Reserve, Eastern Cape, report stock losses through predation by leopards (Panthera pardus). This leads, in certain cases, to persecution of the leopards. This study attempted to quantify livestock depredation by leopards by comparing leopard diet within and outside the reserve. Leopard scats from both areas were analysed for prey items. A total of 18 prey taxa was identified, including small to medium-sized ungulates, rodents, birds and a felid. The mountain reedbuck was the most frequently utilized prey, followed by vlei rat, bushbuck, rock hyrax and grysbok. Baboons, although abundant throughout the study area, were not utilized by these leopards. There was a significant difference in the frequency of prey items between the reserve and the rangeland samples in terms of the relative contribution of the prey taxa. Medium-sized and small ungulates were heavily utilized in the reserve, whilst the diet in rangelands was composed largely of small mammals (including small ungulates). Only two scats contained the remains of domestic animals, indicating that <5% of the diet comprised this prey category, and suggesting that leopards in the study area do not preferentially prey on livestock.

Preliminary observations on the diet of leopards (Panthera pardus) from a conservation area and adjacent rangelands in the Baviaanskloof region, South Africa

ABSTRACT Pastoralists on rangelands adjacent to the Baviaanskloof Provincial Nature Reserve, Eastern Cape, report stock losses through predation by leopards (Panthera pardus). This leads, in certain cases, to persecution of the leopards. This study attempted to quantify livestock depredation by leopards by comparing leopard diet within and outside the reserve. Leopard scats from both areas were analysed for prey items. A total of 18 prey taxa was identified, including small to medium-sized ungulates, rodents, birds and a felid. The mountain reedbuck was the most frequently utilized prey, followed by vlei rat, bushbuck, rock hyrax and grysbok. Baboons, although abundant throughout the study area, were not utilized by these leopards. There was a significant difference in the frequency of prey items between the reserve and the rangeland samples in terms of the relative contribution of the prey taxa. Medium-sized and small ungulates were heavily utilized in the reserve, whilst the diet in rangelands was compo...