Search

International audience

Funder: Calico Life Sciences, LLC, The naked mole‐rat (Heterocephalus glaber) has fascinated zoologists for at least half a century. It has also generated considerable biomedical interest not only because of its extraordinary longevity, but also because of unusual protective features (e.g. its tolerance of variable oxygen availability), which may be pertinent to several human disease states, including ischemia/reperfusion injury and neurodegeneration. A recent article entitled ‘Surprisingly long survival of premature conclusions about naked mole‐rat biology’ described 28 ‘myths’ which, those authors claimed, are a ‘perpetuation of beautiful, but falsified, hypotheses’ and impede our understanding of this enigmatic mammal. Here, we re‐examine each of these ‘myths’ based on evidence published in the scientific literature. Following Braude et al., we argue that these ‘myths’ fall into four main categories: (i) ‘myths’ that would be better described as oversimplifications, some of which persist solely in the popular press; (ii) ‘myths’ that are based on incomplete understanding, where more evidence is clearly needed; (iii) ‘myths’ where the accumulation of evidence over the years has led to a revision in interpretation, but where there is no significant disagreement among scientists currently working in the field; ( iv ) ‘myths’ where there is a genuine difference in opinion among active researchers, based on alternative interpretations of the available evidence. The term ‘myth’ is particularly inappropriate when applied to competing, evidence‐based hypotheses, which form part of the normal evolution of scientific knowledge. Here, we provide a comprehensive critical review of naked mole‐rat biology and attempt to clarify some of these misconceptions.

South Africa harbours remarkable biological diversity with three of the 34 recognised global biodiversity hotspots placed within its borders. One of these is the Succulent Karoo, which together with the Nama-Karoo, forms the Greater Karoo region. Notwithstanding a paucity of studies from this region, it would appear that, although mammal diversity is low, endemism is high. Here, as part of the Karoo BioGaps project, we use a molecular approach to assess small mammal diversity and endemism in the Karoo. We focus on rock rats (Micaelamys) and elephant shrews (Elephantulus and Macroscelides). Using a DNA-informed identification approach, we reveal two, well supported, monophyletic clades of Micaelamys; one that corresponds to M. granti. Our study is the first to publish sequence data for this species. Furthermore, when unverified records are excluded, the range of M. granti is far smaller (~99 000 km2) than that given by the IUCN red list assessments (236 027 km2), which lends support to the species being a Karoo endemic. Our macrosceledid samples grouped into four well supported clades of the genera Elephantulus and Macroscelides. Very high intraspecific diversity was present within E. pilicaudus compared with other species in our study and this newly described species may harbour cryptic diversity. Our geographic analyses confirm that the range of this species, previously considered to be a Nama-Karoo endemic, extends beyond this region. This study adds more information to the nominal data currently available for the species, Elephantulus pilicaudus.Keywords: elephant shrew, Nama Karoo, rock mouse, spatial genetic structure, phylogeography, South Africa

Commercial plantations and alien tree invasions often have substantial negative impacts on local biodiversity. The effect of plantations on faunal communities in the fire-adapted fynbos vegetation of the Cape Floristic Region biodiversity hotspot is not yet well quantified. We studied small mammal community structure in alien Pinus radiata plantations and adjacent fynbos regenerating after clear-felling of plantations on the Cape Peninsula, South Africa. Small mammal sampling over 1,800 trap-nights resulted in 480 captures of 345 individuals (excluding recaptures) representing six species. Significantly more species, individuals (12 X) and biomasses (29 X) of small mammals occurred on recovering fynbos sites compared to plantations. This was commensurate with a higher diversity of plant growth forms, vegetation densities and live vegetation biomass. Only one small mammal species, the pygmy mouse (Mus minutoides), was consistently trapped within plantations. Fynbos sites were dominated by three small mammal species that are ecological generalists and early successional pioneer species, rendering the recovering fynbos slightly depauperate in terms of species richness and evenness relative to other studies done in pristine fynbos. We make three recommendations for forestry that would facilitate the restoration of more diverse natural plant communities and progressively more diverse and dynamic small mammal assemblages in a key biodiversity hotspot.

Golden moles are small, fossorial, and primarily insectivorous mammals mostly endemic to South Africa. They belong to an ancient African clade of placental mammals (Afrotheria) that likely radiated from an herbivorous ancestor. Nearly half of the 21 golden mole species are listed as threatened; but remarkably little is known about their basic biology and gastrointestinal tract (GIT) morphology. This study provides a morphometric and histochemical analysis of the GIT of seven chrysochloridae species, including three threatened taxa. Macroscopically, all species examined had simple GITs with simple, wholly glandular stomachs and no cecum. Histologically, the pylorus was dominated by parietal cells. Neutral mucin cells were found on the luminal surface and in the gastric pits, while mixed acid and neutral mucin cells were found in the proximal parts of the gastric glands. The proximal intestine had typical small intestinal histological features such as villi. Typical colonic mucosal features were absent as villi were present throughout the intestinal tract. Goblet cells were abundant and increased toward the distal intestine. These intestinal goblet cells contained mostly mixed mucins. Stomach and intestinal content analysis confirmed the presence of arthropod exoskeleton material and possible small vertebrate remnants, commensurate with a low-fibre, protein-rich diet. This may account for their simple GIT morphology, as seen convergently in other unrelated insectivorous mammals. This study provides better representation of variation in GIT morphology among chrysochloridae and within the enigmatic Afrotheria clade. Additionally, it provides a better understanding of the mucin distribution in relation to diet and phylogeny of golden moles.

Many plant–animal interactions can be challenging to directly observe, due to species being small, cryptic and/or nocturnal. Previous research on seed predation and dispersal by rodents in the Fynbos Biome of South Africa has relied on indirect evidence, as methods for directly monitoring rodent–seed interactions were not available. The aims of the study were to determine which resident small mammals scatter-hoard nuts and the geographic, seasonal and taxonomic extent of scatter-hoarding in the Fynbos Biome. We used camera traps focused on seed stations at eight sites in the Fynbos Biome to determine the responses of small mammals to tagged nut-like fruits (nuts) of seven endemic plant species belonging to the Proteaceae (n = 3), Rosaceae (n = 2), Restionaceae (n = 1) and Cupressaceae (n = 1), as well as commercial sunflower seeds. We found Acomys subspinosus and Gerbilliscus paeba scatter-hoarded nuts, which they typically carried and buried individually. Rhabdomys pumilio and Micaelamys namaquensis only consumed nuts. Leucadendron pubescens and L. loranthifolium are added to the list of known plant species that are scatter-hoarded by rodents. Nuts of Cliffortia cuneata and C. phillipsii, and the critically endangered Widdringtonia cedarbergensis, were consumed but not dispersed by small mammals, whereas nuts of Ceratocaryum argenteum were neither consumed nor scatter-hoarded by rodents (within its native range). Gerbilliscus paeba and A. subspinosus scatter-hoarded nuts aseasonally, outside of seed-fall periods. Scatter-hoarding was widespread throughout the Fynbos Biome, although it was highly localised across and within sampled sites. The absence of scatter-hoarding rodents at sites with rodent-dispersed plants remains an important aspect for future investigation.Keywords: camera traps, Fynbos Biome, Mediterranean, scatter-hoarding, seed dispersal, seed predation

Studies detailing the anatomy of the brain of the golden moles are few. A recent study indicated that in the Hottentot golden mole (a member of the Amblysominae clade), there was a broad, atypical, distribution of cholinergic interneurons in the olfactory bulb, cerebral cortex, hippocampus and amygdala. To determine whether this broad distribution of cholinergic neurons is shared by other species of golden mole, we here examine the brain of the Cape golden mole (a member of the Chrysochlorinae clade, representing the second major clade within the family Chrysochloridae). Our analyses indicates the presence of a similar widespread distribution of cholinergic interneurons in the Cape golden mole. Thus, we conclude that these features are derived morphological traits in the brains of golden moles. In addition, we describe the nuclei generally considered to be part of the typical cholinergic system in mammals. Whereas the vast majority of these generally reported cholinergic nuclei were the same as recorded in other Eutherian mammals, it was noted that the cholinergic nuclei involved in oculomotion were substantially reduced in size, or absent in the case of the abducens nucleus. In addition, there was an absence of the cholinergic medial septal nucleus, but the presence of a cholinergic lateral septal nucleus. The laterodorsal and pedunculopontine tegmental nuclei evince regions where the cholinergic neurons are densely packed. These are atypical features of the mammalian cholinergic system, which when combined with the widespread atypical distribution of cholinergic interneurons, reveals a family-specific complement of cholinergic nuclei in the Chrysochloridae.

Tadarida aegyptiaca (mean body mass 13.5 g) is a fast flying insectivorous bat that hunts in open areas for extended periods, covering extensive distances during its foraging bouts. Whole blood samples taken from the wing arteries were analysed for 2,3-diphosphoglyceric acid, oxygen affinity and pH. The mean oxygen affinity of T. aegyptiaca blood with a P50-value 38.3 mm Hg (5.1 kPa) is lower than that of similarsized bats but not as low as the P50-values of 48.5 mm Hg (6.4 kPa) in two mice species. This indicates that oxygen affinity of the blood in T. aegyptiaca and other bats is designed to facilitate both effective binding of oxygen with haemoglobin at the alveolar/blood capillary interface and oxygen offloading in the tissues. Haematocrits (54–60 %) and levels of 2,3 DPG (2.36–3.30 mM l–1) were higher, and blood pH (7.106–7.229) lower, than those reported for terrestrial species of a similar size, but within the range of values reported for other bats. We conclude that adequate delivery of oxygen to tissues with high metabolic demands during flight is facilitated primarily by an elevated haematocrit and a reduced blood pH in response to elevated levels of metabolic by-products such as 2,3-DPG (from the citrate acid cycle) and CO2 (leading to increased concentrations of H+ ions).Key words: oxygen affinity, haematocrit, 2,3-diphosphoglyceric acid, blood pH.

Distribution patterns and protection status of endemic or threatened Lagomorpha, Macroscelidea, and Rodentia were analysed using museum point locality data and a geographic information system (GIS). The study area comprised the greater South Africa (including Lesotho and Swaziland). Species richness of the target species is highest in the south-western parts of the country, and hotspots of endemism coincide with those of species richness. However, Red Data Book species hotspots are confined to the north-eastern parts of the country. One species richness hotspol in the Succulent Karoo contains no existing reserves, whereas all Red Data Book species hotspots are protected. In general, all target species are well protected within existing reserves, but those found in the Succulent and Nama-Karoo, especially the Namaqua dune molerat (Bathyergus janetta), the riverine rabbit (Bunolagus monticularis), Brants whistling rat (Parotomys brantsii), and the pygmy rock mouse (Petromyscus collinus), are threatened by a paucity of reserves in these biomes. A heuristic reserve selection algorithm was used to identify a more representative reserve system for the protection of all target species. Ten representative reserves were identified, six of which already contain existing reserves. An analysis of biome specificity of all species revealed that Myomyscus verreauxii is endemic to the fynbos, Bathyergus janetta to the Succulent Karoo, Zelotomys woosnami to the arid savanna, and Steatomys parvus to the savanna woodlands. No species are endemic to the Nama-Karoo or grasslands, although several species do show strong preferences for these habitats. It is recommended that hotspots, representative reserves, and species that are currently not protected, be awarded more protection, and that existing reserves which coincide with hotspots and representative reserves be managed for their mammal fauna. It is also recommended that the Red Data Book status of tour species, and six subspecies, should be changed.

The 2 cryptic species of multimammate mice that occur widely in South Africa were, for many decades, lumped in a single species Mastomys natalensis sensu lato. This taxon was intensively studied because these rodents play a role in the epidemiology of various zoonoses (notably bubonic plague), serve as important models for biomedical research, and also sometimes cause extensive agricultural damage. The discovery that M. natalensis sensu lato includes 2 cryptic species in southern Africa has complicated interpretation of the results of past research because previous studies may have been based on either M. coucha or M. natalensis, or even on specimens of both species. A previous study aimed at craniometrically distinguishing between these species in South Africa met with some success, but excluded subadult specimens (which constitute a large proportion of museum collections), and cautioned that intraspecific variation might hamper interspecific discrimination. We therefore studied the nature and extent of nongeographic craniological variation using 2 populations of each species. The discriminatory value of a putative diagnostic dental character (presence or absence of t3 cusp on M3) is limited because of considerable variation within and among populations of M. coucha. Sexual dimorphism is negligible in both species, whereas age-related variation is pronounced and involves mainly differences in overall size, as well as some subtle differences in the configuration of the interorbital, postpalatal, and dental regions. Multiple discriminant function analyses aimed at craniometrically distinguishing between the 2 species showed that the inclusion of subadult specimens reduced a posteriori classification accuracy below 95% confidence levels, implying that age-related variation is sufficiently pronounced to obscure interspecific craniometric differences. Future studies aimed at craniometrically distinguishing between these cryptic species will, therefore, have to statistically correct for age-related variation.

Oxygen affinity and other hematological parameters in strictly subterranean mole-rats, Cryptomys hottentotus (subspecies pretoriae) were measured immediately upon capture and after 14-21 days in captivity. The pH, hematocrit, hemoglobin (Hb) concentration, blood oxygen content, 2,3 bisphosphoglycerate (2,3 BPG) concentration and oxygen dissociation curves (ODC), as well as tonometric measurements, were determined using whole blood. Additionally ODCs were also determined for stripped hemolysates of individual animals. Compared to other mammals, blood of freshly caught animals had low pH (7.32+/-0.22), elevated hematocrits (48.4+/-3.8 %) and significantly lower P50 values for whole blood (21.1+/-1.6 mm Hg at pH 7.4) than those reported for other similar-sized fossorial and terrestrial mammals. Blood carbon dioxide content (22.4+/-3.9 mMol L(-1)), hemoglobin concentration (1.9+/-0.15 mMol L(-1)), oxygen content (164.8+/-26 mL L(-1)), bicarbonate concentrations (22.5+/-3.5 mMol L(-1)) were within the range of values reported for similar-sized mammals. We conclude that high blood-oxygen affinity, low body temperature and possibly also high hematocrit enable C. h. pretoriae to maintain an adequate oxygen supply to the tissues in a potentially hypoxic burrow atmospheres, but that the blood of this species shows no exceptional CO2 sensitivity or buffering capacity.

The large brown, round, strongly scented seeds of Ceratocaryum argenteum (Restionaceae) emit many volatiles found to be present in herbivore dung. These seeds attract dung beetles that roll and bury them. As the seeds are hard and offer no reward to the dung beetles, this is a remarkable example of deception in plant seed dispersal.

SUMMARYThe hypertrophied malleus in the middle ear of some golden moles has been assumed to be an adaptation for sensing substrate vibrations by inertial bone conduction, but this has never been conclusively demonstrated. The Cape golden mole (Chrysochloris asiatica) exhibits this anatomical specialization, and the dynamic properties of its middle ear response to vibrations were the subjects of this study.Detailed three-dimensional middle ear anatomy was obtained by x-ray microcomputed tomography (μCT) at a resolution of 12 μm. The ossicular chain exhibits large malleus mass, selective reduction of stiffness and displacement of the center of mass from the suspension points, all favoring low-frequency tuning of the middle ear response. Orientation of the stapes relative to the ossicular chain and the structure of the stapes footplate enable transmission of substrate vibrations arriving from multiple directions to the inner ear.With the long axes of the mallei aligned parallel to the surface, the animal's head was stimulated by a vibration exciter in the vertical and lateral directions over a frequency range from 10 to 600 Hz. The ossicular chain was shown to respond to both vertical and lateral vibrations. Resonant frequencies were found between 71 and 200 Hz and did not differ significantly between the two stimulation directions. Below resonance, the ossicular chain moves in phase with the skull. Near resonance and above, the malleus moves at a significantly larger mean amplitude (5.8±2.8 dB) in response to lateral vs vertical stimuli and is 180° out of phase with the skull in both cases.A concise summary of the propagation characteristics of both seismic body(P-waves) and surface (R-waves) is provided. Potential mechanisms by which the animal might exploit the differential response of the ossicular chain to vertical and lateral excitation are discussed in relation to the properties of surface seismic waves.

Comparison between the middle ear anatomy of the Cape golden mole (Chrysochloris asiatica), which exhibits a club-shaped malleus head, and the Desert golden mole (Eremitalpa granti), with a ball-shaped malleus head, suggests differences in sensitivity to airborne sound. Scanning laser Doppler vibrometric measurements of the ossicular behavior in response to both vibration and airborne sound were made in C. asiatica. Two distinct vibrational modes were observed. In response to low-frequency vibration (70-200 Hz), the malleus oscillates about the ligament of the short process of the incus, whereas in response to high-frequency airborne sound (1-6 kHz) the ossicular chain rotates about the long axis of malleus. It is proposed that the club-shaped malleus head in C. asiatica constitutes an adaptation towards bimodal hearing-sensitivity to substrate vibrations and airborne sound. Possible functional differences between these two middle ear types are discussed.

Detailed karyotype descriptions of 20 Pipistrellus-like bat species belonging to the family Vespertilionidae are presented. For the first time, chromosomal complements of four species, i.e. Pipistrellus stenopterus (2n = 32), P. javanicus (2n = 34), Hypsugo eisentrauti (2n = 42) and H. crassulus (2n = 30) are reported. A Pipistrellus kuhlii-like species from Madagascar represents a separate species distinguished from the European Pipistrellus kuhlii (2n = 44) by a diploid chromosome number of 42. Banded karyotypes are presented for the first time for Scotozous dormeri, Hypsugo capensis, Hesperoptenus blanfordi, Tylonycteris pachypus and robustula. Chromosomal evolution in the family Vespertilionidae is characterized by the conservation of entire chromosomal arms and reductions in diploid chromosome number via Robertsonian fusions. Less frequently, centric fissions, para- and pericentric inversions and centromere shifts were found to have occurred. In several cases a certain type of chromosomal change predominates in a karyotype. Examples of this are the acquisition of interstitial heterochromatic bands in Tylonycteris robustula, and centric shifts in P. javanicus, H. eisentrauti and Hesp. blanfordi. The species examined here belong to three tribes, i.e. Pipistrellini, Vespertilionini and Eptesicini, which are distinguished by chromosomal characteristics. According to our results, the species Pipistrellus (Neoromicia) capensis belongs to the Vespertilionini and not to the Pipistrellini. We therefore propose to elevate the subgenus Neoromicia to generic rank.

We studied roost microclimates, thermal preferences and temperature-related variation in body temperatures and flight abilities of M. condylurus from three roosts in man-made structures in South Af...

Urine and plasma concentrations and haematocrits were measured in free-ranging Angolan free-tailed bats (Mops condylurus) inhabiting thermally-challenging roosts in the Komatipoort region of South Africa. Samples were collected in both autumn and summer, from bats caught emerging from roosts before feeding (pre-feed- ing), and those returning after foraging (post-prandial). Post-prandial bats exhibited higher body fluid concentrations, but lower haematocrits, than individuals caught prior to feeding, reflecting raised excretory mineral and nitrogenous loads and replenishment of body water pools during nocturnal foraging. Pre-feeding concentrations of both urine (2637 ± 506 mOsm/kg; n = 16) and plasma (331.5 ± 25.9mOsm/kg; n = 24) were significantly higher in summer than autumn (urine: 2157 ± 454mOsm/kg; n = 8; plasma: 294.5 ± 35.2 mOsm/kg; n = 18) reflecting the greater dehydration stresses within hotter roost microclimates, and a moderate kidney concentrating ability in this species. Haematocrits of pre-feeding animals were not, however, influenced by season and in both instances exceeded 53%, indicative of the higher oxygen carrying capacity needed for sustained flight in volant insectivores and also the defense of the rheologica! properties of blood. The ability of Mops condylurus to withstand a thermally-challenging roost milieu reflects, in part, its tolerance to dehydration, rather than the maintenance of water balance through exceptional renal concentrating ability.

South Africa contains the majority of southern Africa's endemic mammals and hence is an important area for mammal conservation. Moreover, there is an increase in endemism, as determined by range maps, from the northern borders of the country towards the Western Cape Province. Within this area, the Cape fold mountains have a high number of endemics, particularly those which have very restricted ranges. These mountains are at the transition of the Karoo and fynbos biomes and may be a region of high species turnover. The numerous fynbos protected areas and mountain catchments, which incorporate over 30% of the Cape fold mountains, thus protect many of the endemic mammals of this area. The majority of these endemics are small mammals and many are listed in the Red Data Book, especially those restricted to the Nama-and Succulent Karoo. This is of concern, as both areas are inadequately protected by the existing protected areas. The coastal forests also contain many Red Data Book species, particularly Insectivora. These forests are, however, inadequately protected in the Port St Johns region. In this analysis data for the Insectivora were used to compare point and range data. The results indicate that patterns emerging from range maps provide a broad picture which can then be focused with the use of higher resolution data.

Geographic patterns of species richness and endemism in three mammalian orders (Chiroptera, Insectivora and Carnivora) were studied in relation to the biomes and existing protected areas of greater South Africa (including Lesotho and Swaziland). Locality data for 21500 specimens representing 124 species were analysed with a geographical information system. Species richness of Chiroptera is high in the savanna biome, particularly in the north-east of the country, owing to the marginal intrusion of 14 tropical species. Endemism in Chiroptera is low, however, with only two endemic species in the fynbos and Karoo biomes. The Carnivora display less biome specificity and endemism than the Chiroptera. Whereas the north-eastern savannas have the highest species richness, the transition between the Nama-Karoo and grassland biomes is an important southern African centre of endemism for the Carnivora, particularly the smaller species. In addition to being an important centre for species richness in the Carnivora and Chiroptera, the Kruger National Park is also particularly important for Red Dala Book species in both orders. The Insectivora display both high species richness and endemism. Species richness of the Insectivora is greatest in the mesic south-east of the country, whereas endemism is most pronounced in the forest and grassland biomes. Differences in biome specificity and endemism between these orders reflect not only phylogenetic divergence, but also variation in body size, vagility and life-history strategies. Most of South Africa's endemics are small mammals and many of them are listed in the Red Data Book. Distributions, life-history strategies and trends in man-induced habitat degradation were used to re-evaluale the protection status of the 124 species. We conclude that at least 11 endemic species are not adequately protected by existing publicly owned protected areas and consequently identify several areas which need to be added to the existing protected area system.

The Greater Maputaland-Pondoland-Albany (GMPA) region of southern Africa was recently designated as a centre of vertebrate endemism. The phylogeography of the vertebrate taxa occupying this region may provide insights into the evolution of faunal endemism in south-eastern Africa. Here we investigate the phylogeographic patterns of an understudied small mammal species assemblage ( Amblysomus ) endemic to the GMPA, to test for cryptic diversity within the genus, and to better understand diversification across the region. We sampled specimens from 50 sites across the distributional range of Amblysomus , with emphasis on the widespread A . hottentotus , to analyse geographic patterns of genetic diversity using mitochondrial DNA (mtDNA) and nuclear intron data. Molecular dating was used to elucidate the evolutionary and phylogeographic history of Amblysomus . Our phylogenetic reconstructions show that A . hottentotus comprises several distinct lineages, or evolutionarily significant units (ESUs), some with restricted geographic ranges and thus worthy of conservation attention. Divergence of the major lineages dated to the early Pliocene, with later radiations in the GMPA during the late-Pliocene to early-Pleistocene. Evolutionary diversification within Amblysomus may have been driven by uplift of the Great Escarpment c. 5-3 million years ago (Ma), habitat changes associated with intensification of the east-west rainfall gradient across South Africa and the influence of subsequent global climatic cycles. These drivers possibly facilitated geographic spread of ancestral lineages, local adaptation and vicariant isolation. Our study adds to growing empirical evidence identifying East and southern Africa as cradles of vertebrate diversity.

The standard karyotypic properties of 60 of the 73 species of bats known to occur in southern Africa, are reviewed. The karyotypes of 23 microchiropteran species are described for the first time; our results on a further 14 species are compared with earlier reports for those taxa. The previously published chromosomal information pertaining to 23 species for which we had no information, are cited. Systematic implications of observed patterns of karyotypic variation are briefly discussed. In particular, we conclude that the taxon Cistugo (currently recognised as a subgenus oiMyotis) should be afforded full generic rank; hypothesise that the karyotypes of the two species - M. (C.) seabrai and M. (C.) lesueuri - in Cistugo are probably ancestral for all vespertilionids; and question the wisdom of redefining the taxonomic limits of the genera Eptesicus and Pipistrellus until molecular data are available to resolve the dilemma posed by conflicting morphological and cytogenetic data suites.

Background Golden moles (Chrysochloridae) are small, subterranean, afrotherian mammals from South Africa and neighboring regions. Of the 21 species now recognized, some (e.g., Chrysochloris asiatica, Amblysomus hottentotus) are relatively common, whereas others (e.g., species of Chrysospalax, Cryptochloris, Neamblysomus) are rare and endangered. Here, we use a combined analysis of partial sequences of the nuclear GHR gene and morphological characters to derive a phylogeny of species in the family Chrysochloridae. Results Although not all nodes of the combined analysis have high support values, the overall pattern of relationships obtained from different methods of phylogeny reconstruction allow us to make several recommendations regarding the current taxonomy of golden moles. We elevate Huetia to generic status to include the species leucorhinus and confirm the use of the Linnean binomial Carpitalpa arendsi, which belongs within Amblysominae along with Amblysomus and Neamblysomus. A second group, Chrysochlorinae, includes Chrysochloris, Cryptochloris, Huetia, Eremitalpa, Chrysospalax, and Calcochloris. Bayesian methods make chrysochlorines paraphyletic by placing the root within them, coinciding with root positions favored by a majority of randomly-generated outgroup taxa. Maximum Parsimony (MP) places the root either between chrysochlorines and amblysomines (with Chlorotalpa as sister taxon to amblysomines), or at Chlorotalpa, with the former two groups reconstructed as monophyletic in all optimal MP trees. Conclusions The inclusion of additional genetic loci for this clade is important to confirm our taxonomic results and resolve the chrysochlorid root. Nevertheless, our optimal topologies support a division of chrysochlorids into amblysomines and chrysochlorines, with Chlorotalpa intermediate between the two. Furthermore, evolution of the chrysochlorid malleus exhibits homoplasy. The elongate malleus has evolved just once in the Cryptochloris-Chrysochloris group; other changes in shape have occurred at multiple nodes, regardless of how the root is resolved.

The Angolan free-tailed bat (Mops condylurus) uses roosts that often exceed 40 degrees C, an ambient temperature (Ta) that is lethal to many microchiropterans. We measured the physiological responses of this species at Ta's from 15 degrees to 45 degrees C. Torpor was commonly employed during the day at the lower Ta, but the bats generally remained euthermic at night, with a mean body temperature (Tb) of 35.2 degrees C. Metabolic rate reflected the pattern of Tb, increasing with falling Ta at night but decreasing during the day. Metabolic rate and evaporative losses were lower in torpid than in euthermic bats. Body temperature increased at each Ta35 degrees C and was 43 degrees C at Ta of 45 degrees C. At Ta of 40 degrees C bats increased dry thermal conductance and evaporative heat loss compared to lower Ta. At 45 degrees C dry thermal conductance was lower than at 40 degrees C and evaporative heat loss was 132% of metabolic heat production. At high Ta there was only a slight increase in metabolic rate despite the employment of evaporative cooling mechanisms and an increase in Tb. Collectively our results suggest that M. condylurus is well suited to tolerate high Ta, and this may enable it to exploit thermally challenging roost sites and to colonise habitats and exploit food sources where less stressful roosts are limiting.

Standard karyotypes and the location of nucleolar organizer regions are reported for nine species of chrysochlorids representing five genera ( Amblysomus, Calcochloris, Chlorotalpa, Chrysochloris , and Chrysospalax ). Intraspecific karyotypic variation is negligible except in Amblysomus hottentotus , which displays three allopatric cytotypes characterized by differences in diploid number (30, 34, 36) and fundamental number (56, 60, 62, 68) as well as the number and location of nucleolar organizer regions. With the exception of Calcochloris , a monotypic genus with 2n = 28, most genera display 2n = 30, but differ in fundamental number and locations of nucleolar organizer regions. Evidence that the three cytotypes in A. hottentotus represent distinct biological species is presented. Cladisdc reladonships based on chromosomal properties support the recognition of Chlorotalpa and Calcochloris as discrete genera and the subgeneric recognition of the taxon Neamblysomus for the species A . ( N .) gunningi and A . ( N .) julianae . Limited banding studies indicate that centric fissions, tandem fusions, pericentric inversions, and heterochromatic additions may have played a role in the chromosomal evolution of chrysochlorids. Karyotypic evolution in the Chry-sochloridae appears to be similar in mode and tempo to that in other fossorial Insectivora, in contrast to subterranean rodents, which are characterized by greater chromosomal diversity and karyotypic orthoselection.

Morphological variation was studied among 209 pouched mice (Saccostomus campestris, Peters, 1846) from 104 localities in the southern African subregion. Climatic variables for these localities were generated using a climatic surface model developed with data from existing meteorological stations. These estimates of temperature, rainfall and seasonal variability were strongly correlated with latitude, so that the different climatic factors covaried. External measurements (body, tail and ear length) and body mass were strongly correlated with condylo-basal skull length which was taken as a more reliable measure of body size. Geographical variation in body size was significantly correlated with latitude, temperature and seasonality although these correlations appeared to be largely the result of a positive relationship between size and rainfall. In contrast, emperature apparently had little effect on morphology as there were no clear correlations between temperature and the size of appendages (tail or ear length). Rainfall might be more important than ambient temperature as a factor influencing body size in small fossorial and semi-fossorial mammals which spend most of their lives in warm subterranean microhabitats. Meanwhile, the smaller body size of pouched mice from localities with lower rainfall may represent anadaptation to reduce total energy requirements in arid and semi-arid areas where primary production and food availability is low.