| studies on rift valley fever in some african murids (rodentia: muridae). | brains, spleens and livers of 2214 murids, 27 shrews and 7 dormice, trapped at 7 sites in rhodesia, were tested in 277 pools for the presence of rift valley fever virus. there were no isolations of rift valley fever, but 69 isolations of an unidentified virus were obtained. sixteen out of 867 sera had low-titre haemagglutination-inhibition activity against rift valley fever antigen, but only one out of 1260 sera had neutralizing antibody. the evidence suggests that murids fail to encounter infec ... | 1978 | 632561 |
| viremia and antibody response of small african and laboratory animals to crimean-congo hemorrhagic fever virus infection. | eleven species of small african wild mammals, laboratory rabbits, guinea pigs, and syrian hamsters were infected with crimean-congo hemorrhagic fever (cchf) virus. low-titered viremia followed by development of antibody was observed in scrub hares (lepus saxatilis), cape ground squirrels (xerus inauris), red veld rats (aethomys chrysophilus), white tailed rats (mystromys albicaudatus), bushveld gerbils (tatera leucogaster), striped mice (rhabdomys pumilio), and guinea pigs. the maximum viremic t ... | 1989 | 2499205 |
| the host status of the striped mouse, rhabdomys pumilio, in relation to the tick vectors of heartwater in south africa. | striped mice, rhabdomys pumilio, were trapped over a 17 month period in the thomas baines nature reserve in the eastern cape province of south africa. captured mice were placed in cages, over water, and naturally detaching ticks were collected. only 5 larvae and 1 nymph of amblyomma hebraeum were recovered from the mice. these represented less than 0.1% of the total number of ticks recovered. no amblyomma marmoreum were recovered. as the vegetation and large mammals and tortoises in the thomas b ... | 1989 | 2626267 |
| experimental plague infection in south african wild rodents. | susceptibility studies were undertaken to determine the response of some south african wild rodent species to experimental plague (yersinia pestis) infection. a degree of plague resistance was found in three gerbil species captured in the plague enzootic region of the northern cape province, these being the namaqua gerbil, desmodillus auricularis, (ld50 1 x 10(6) organisms), the bushveld gerbil, tatera leucogaster, (ld50 9.1 x 10(5)) and the highveld gerbil, t. brantsii (ld50 4 x 10(2)). animals ... | 1986 | 3701038 |
| the brown ear tick rhipicephalus appendiculatus neumann (acarina: ixodidae) and associated tick species on wild and domestic hosts at muguga, kenya. | during a study of an experimental population of rhipicephalus appendiculatus and its transmission of bovine theileriosis to cattle, some supplementary information was obtained on the role of rodents and the small carnivores in the development and maintenance of r. appendiculatus populations. observations were also made on other common tick species found on these hosts. a total of 530 individual hosts were examined during the 4-yr period, of which the majority included, among the carnivores, the ... | 1985 | 3998963 |
| studies on plague in the eastern cape province of south africa. | investigations were carried out in the area of a human plague outbreak in march 1982 at coega in the eastern cape province of south africa. trapping revealed that rodent populations were high owing primarily to a population increase of the four-striped mouse, rhabdomys pumilio. flea populations were low and had been declining in the eastern cape province since october 1981. the results of a serological survey from march to october 1982 showed haemagglutinating antibody to yersinia pestis in 0.35 ... | 1983 | 6665833 |
| plague in south african rodents 1972-1981. | sera from 3012 rodents of 24 species captured in south africa during the period 1972-81 were tested for antibody to the fraction 1 antigen of yersinia pestis by passive haemagglutination. antibodies were found in seven (0.23%) rodents of three species. these were desmodillus auricularis and tatera brantsii in the northern cape province and rhabdomys pumilio in the eastern cape province. rodents were found positive in 1972, 1974, 1975 and 1979, indicating that plague continues to circulate in rod ... | 1983 | 6868103 |
| body temperature daily rhythms in the striped mouse rhabdomys pumilio: the effects of alpha and beta blockade. | body temperature (tb) daily rhythms and the effects of alpha and beta blockade were studied in the south african diurnal striped mouse rhabdomys pumilio. eleven mice (8 males and 3 females) with a body mass of 42.7+/-7.8 g (mean +/- sd) were tested. mice were acclimated to a 13 h:11 h light-dark photoperiod at an ambient temperature of 25 degrees c. to assess the daily rhythm of pineal melatonin secretion, urinary 6-sulfatoxymelatonin (6-smt) was determined. mice displayed a robust tb daily rhyt ... | 1998 | 9618013 |
| short day length alone does not inhibit spermatogenesis in the seasonally breeding four-striped field mouse (rhabdomys pumilio). | this study was an examination of the effect of photoperiod on spermatogenesis and the accessory glands of the four-striped field mouse (rhabdomys pumilio), a seasonally breeding rodent that occurs through southern africa. adult scrotal males were exposed to either short day length (10l:14d), long day length (14l:10d), or natural photoperiod in constant-environment rooms (25 degrees c, 41% humidity; food and water ad libitum) for 8 wk in late summer, when males in the wild were spermatogenically ... | 1999 | 10330087 |
| comparative chromosome analysis (r- and c-bands) of two south african murid species, lemniscomys rosalia and rhabdomys pumilio (rodentia, murinae). | we carried out a comparative chromosome analysis (r- and c-bands) on two south african murid rodent species, lemniscomys rosalia and rhabdomys pumilio, whose banded karyotypes are reported here for the first time. the study revealed that, in spite of minor differences in diploid number and the number of autosomal arms (48 vs. 46 and 58 vs. 60, respectively), these species differ by at least 10 structural rearrangements, comprising seven robertsonian translocations (two of which share monobrachia ... | 1999 | 10640814 |
| feeding patterns of immature stages of hyalomma truncatum and hyalomma marginatum rufipes on different hosts. | in this study we examine the feeding patterns of immature stages of hyalomma truncatum and hyalomma marginatum rufipes ticks on different hosts. larvae of h. truncatum developed through a three-host pattern on two species of field mice, rhabdomys pumilio and lemniscomys rosalia. on guinea-pigs, both hyalomma species followed a mixed two-host and three-host pattern, with the latter route being preferred, since more than 70% of the fully fed larvae dropped off from their hosts. h. truncatum was a ... | 2000 | 11110240 |
| gender differences in the inhibitory effects of a reduction in ambient temperature and a reduction in food quantity on reproduction in the southern african rodent, rhabdomys pumilio. | the effects of a reduction in ambient temperature (from 26 degrees c to 15 degrees c) and a 10% reduction in daily food consumption on reproductively active male and female four-striped field mice ( rhabdomys pumilio) were investigated. in male r. pumilio, both reduced ambient temperature and a reduction in food quantity had an inhibitory effect on spermatogenesis and on size of the reproductive organs, and this was greatest when the two factors were combined and the effect of fat was removed. f ... | 2001 | 11597304 |
| chromosome painting in the african four-striped mouse rhabdomys pumilio: detection of possible murid specific contiguous segment combinations. | fluorescence in-situ hybridization was used to construct a comparative chromosome map between the laboratory mouse, mus musculus and the african four-striped mouse, rhabdomys pumilio. a high degree of homology between the species was detected using both fish and g-banding. ten mouse chromosomes (2-4, 7, 14-16, 18, 19 and the x) were retained as chromosomal arms or intact chromosome blocks. six mouse chromosome painting probes that correspond to mouse autosomes 5, 6, 8, 11, 12 and 13, produced do ... | 2003 | 12733636 |
| molecular genetics of rhabdomys pumilio subspecies boundaries: mtdna phylogeography and karyotypic analysis by fluorescence in situ hybridization. | the phylogeography of the african four-striped mouse, rhabdomys pumilio, was investigated using complete sequences of the mtdna cytochrome b gene (1140 bp) and a combination of fluorescence in situ hybridization (fish) and conventional cytogenetic banding techniques (g- and c-banding). two cytotypes (2n=46 and 2n=48) were identified by cytogenetic analysis. there is no evidence of diploid number variation within populations, difference in gross chromosome morphology or of subtle interchromosomal ... | 2003 | 12927139 |
| paternal care in the social and diurnal striped mouse (rhabdomys pumilio): laboratory and field evidence. | paternal care is rare in mammals, occurring mainly in carnivores and neotropical primates, in which the difficulties of long generation time and large individuals lead to small sample sizes. here, the authors show that paternal care can be easily studied in the four-striped mouse (rhabdomys pumilio) because (a) captive males show all the patterns of parental care as do females, with the obvious exception of nursing; (b) in the field, wild males act amicably toward juveniles and retrieve pups exp ... | 2003 | 14498808 |
| the striped mouse (rhabdomys pumilio) from the succulent karoo, south africa: a territorial group-living solitary forager with communal breeding and helpers at the nest. | the authors studied the striped mouse (rhabdomys pumilio) in the semiarid succulent karoo of south africa. mice forage alone, but they live in groups that share a common nest. groups consist of 1 to 4 breeding females, 1 to 2 breeding males, and their offspring of both sexes, which remain in their natal group even after reaching adulthood, participating in territorial defense and nest building without showing signs of reproductive activity. interactions are typically amicable and take place insi ... | 2004 | 15008671 |
| prolactin levels in paternal striped mouse (rhabdomys pumilio) fathers. | paternal behavior is associated with an increase in prolactin levels in fish, birds and mammals, including rodents. the striped mouse (rhabdomys pumilio) from southern africa shows highly developed paternal care. we investigated whether striped mouse fathers have higher prolactin levels than nonfathers, and whether there is a relationship between tactile stimulation with pups and prolactin secretion in fathers. we measured serum prolactin in 42 male striped mice assigned to one of four different ... | 2004 | 15059683 |
| mhc class ii drb variability and parasite load in the striped mouse (rhabdomys pumilio) in the southern kalahari. | major histocompatibility complex (mhc) variability is believed to be maintained by pathogen-driven selection, mediated either through heterozygous advantage or frequency-dependent selection. however, empirical support for these hypotheses under natural conditions is rare. in this study, we investigated the genetic constitution of the functionally important mhc class ii gene (drb exon 2) and the parasite load in a population of the striped mouse (rhabdomys pumilio) in the southern kalahari. fifty ... | 2005 | 15703235 |
| striped mice, rhabdomys pumilio, and other murid rodents as hosts for immature ixodid ticks as in the eastern cape province. | striped mice, rhabdomys pumilio, were trapped over a period of 17 months in the thomas baines nature reserve, and placed in cages, over water, until all the ticks they harboured had detached. the mice were then returned to the reserve. four ixodid tick species were recovered from the mice of which the larvae and nymphs of rhipicephalus follis and rhipicephalus simus were the most numerous. most larvae of r. follis detached from mice trapped from march to july, and most nymphs in march and from j ... | 2004 | 15732458 |
| effects of supplementary food on the winter inhibition of reproduction in male and female four-striped field mice (rhabdomys pumilio). | the effects of winter food supplementation on reproduction in the seasonally breeding four-striped field mouse rhabdomys pumilio were investigated at mountain zebra national park in the eastern cape province of south africa. on both control and supplemented grids, reproductive activity in females was inhibited; no pregnant females were collected and juveniles were only present in the first winter month. the provision of additional food resulted in an increase in body mass and mass of the male an ... | 2005 | 15899150 |
| circadian rhythm of locomotor activity in the four-striped field mouse, rhabdomys pumilio: a diurnal african rodent. | although humans are diurnal in behaviour, animal models used for the study of circadian rhythms are mainly restricted to nocturnal rodents. this study focussed on the circadian behaviour of a rodent from south africa that has a preference for daylight, the four-striped field mouse, rhabdomys pumilio. in order to characterise the behavioural pattern of daily activity, locomotor rhythms were studied under different light regimes using an automated data recording system. under conditions of natural ... | 2005 | 15950249 |
| small mammals as hosts of immature ixodid ticks. | two hundred and twenty-five small mammals belonging to 16 species were examined for ticks in free state, mpumalanga and limpopo provinces, south africa, and 18 ixodid tick species, of which two could only be identified to genus level, were recovered. scrub hares, lepus saxatilis, and cape hares, lepus capensis, harboured the largest number of tick species. in free state province namaqua rock mice, aethomys namaquensis, and four-striped grass mice, rhabdomys pumilio, were good hosts of the immatu ... | 2005 | 16300195 |
| light-induced fos expression in the suprachiasmatic nucleus of the four-striped field mouse, rhabdomys pumilio: a southern african diurnal rodent. | previous studies have suggested that nocturnal and diurnal species of rodents differ in their circadian responses to light including phase shifts and early gene expression. rhabdomys pumilio, the four-striped field mouse, is diurnal both in nature and in the laboratory. we studied in this species the response of the suprachiasmatic nucleus (scn) to light stimuli at different time periods using light-induced expression of fos as marker of neuronal activity. fos induction in the scn was investigat ... | 2006 | 17027762 |
| choline acetyltransferase immunoreactive cortical interneurons do not occur in all rodents: a study of the phylogenetic occurrence of this neural characteristic. | the present study was designed to provide results aimed at testing whether the interneurons with choline acetyltransferase immunoreactivity (chat), probably representing gaba interneurons, found in the cerebral cortex of the rat represent a common feature of the order rodentia. initially we verified the presence of chat immunoreactive bipolar cell bodies, axons and terminal-like fibres in pigmented (long-evans) and non-pigmented (sprague-dawley) strains of rattus norvegicus, confirming that the ... | 2006 | 17049807 |
| epifaunistic arthropod parasites of the four-striped mouse, rhabdomys pumilio, in the western cape province, south africa. | flea, lice, mite, and tick species associated with 510 rhabdomys pumilio were collected at 9 localities in the western cape province, south africa. the aims of the study were first to quantify the species richness, prevalence, and relative mean intensity of infestation of epifaunistic arthropod species associated with r. pumilio, and second to determine temporal variations in the mean abundance of the parasitic arthropods. each mouse was examined under a stereoscopic microscope and its parasites ... | 2007 | 17436941 |
| differences in prolactin levels between three alternative male reproductive tactics in striped mice (rhabdomys pumilio). | in male fishes, birds and mammals, increased prolactin secretion is thought to play a role in species showing paternal behaviours. this hypothesis was investigated in the striped mouse (rhabdomys pumilio). this paper compares serum prolactin levels in 71 free-living male striped mice following three different reproductive tactics: (i) paternal group-living breeders, (ii) alloparental philopatric group-living males, and (iii) roaming non-paternal solitary males. prolactin levels of breeding males ... | 2008 | 18230588 |
| ectoparasites of rodents in southern africa: a new species of androlaelaps berlese, 1903 (acari: parasitiformes: laelapidae) from rhabdomys pumilio (sparrman) (rodentia: muridae). | androlaelaps rhabdomysi n. sp. is described from the pelage of the endemic rodent rhabdomys pumilio (sparrman) in the western cape province, south africa. the formal taxonomic description and illustrations are derived from adults (female and male) and deutonymphs. the specimens are similar in appearance to two congeneric species a. dasymys (radford, 1939) and a. fahrenholzi (berlese, 1911), but differ in the following features: genital shield long and almost parallel-sided; metapodal shield elon ... | 2008 | 18535789 |
| searching for generality in the patterns of parasite abundance and distribution: ectoparasites of a south african rodent, rhabdomys pumilio. | we studied abundance and distribution of seven ectoparasite species (fleas chiastopsylla rossi and dynopsyllus ellobius, a louse polyplax arvicanthis, mites androlaelaps fahrenholzi and laelaps giganteus and two ticks haemaphysalis elliptica and hyalomma truncatum) exploiting the same populations of the rodent host rhabdomys pumilio in south africa. we considered three general patterns of abundance and distribution, namely (i) aggregated distribution of parasites amongst individual hosts; (ii) p ... | 2009 | 19168068 |
| testosterone levels in dominant sociable males are lower than in solitary roamers: physiological differences between three male reproductive tactics in a sociably flexible mammal. | the relative plasticity hypothesis predicts that alternative tactics are associated with changes in steroid hormone levels. in species with alternative male reproductive tactics, the highest androgen levels have usually been reported in dominant males. however, in sociable species, dominant males show amicable behaviors to gain access to females, which might conflict with high testosterone levels. we compared testosterone, corticosterone, and resting metabolic rate in male striped mice (rhabdomy ... | 2009 | 19199528 |
| cooperative breeding in groups of synchronously mating females and evolution of large testes to avoid sperm depletion in african striped mice. | testis size has been related to the mating system of both vertebrates and invertebrates. these differences are regarded as adaptive responses to sperm competition in promiscuously mating species. however, not all variation in testis size can be explained by sperm competition. here, we test the hypothesis that the evolution of large testes occurs when synchronously breeding females must be fertilized within a short period of time to avoid reproductive competition among the females. african stripe ... | 2009 | 19264699 |
| ectoparasites of rodents in southern africa: two new species of laelaps koch, 1836 (acari: laelapidae) ectoparasitic on rhabdomys pumilio (sparrman) (rodentia: muridae). | laelaps horaki n. sp. and l. radovskyi n. sp. are described from the pelage of the rodent rhabdomys pumilio (sparrman) in the western cape province, south africa. the formal taxonomic description and illustrations are derived from adults (females and males) and deutonymphs. a key to southern african species of laelaps koch, 1836 is given. | 2009 | 19337857 |
| parasite-specific variation and the extent of male-biased parasitism; an example with a south african rodent and ectoparasitic arthropods. | we asked whether the occurrence and the extent of host gender-biased parasitism vary among higher parasite taxa, among individual species within these taxa and within parasite species among localities. to answer this question, we studied prevalence, abundance, species richness and the level of aggregation of ectoparasites (ticks, mites, lice and fleas) collected from male and female striped mice (rhabdomys pumilio) in 9 localities of the western cape province of south africa. we used meta-analys ... | 2010 | 19835648 |
| reproductive competition favours solitary living while ecological constraints impose group-living in african striped mice. | 1. social groups typically form due to delayed dispersal of adult offspring when no opportunities for independent breeding exist, or the costs of dispersal are higher than the costs of remaining philopatric. ecological constraints are thought to be a main reason for group-living in animals. 2. reproductive competition within groups can induce high costs of philopatry, and is thought to be a main reason for solitary living. 3. experimental manipulation of reproductive competition is difficult. on ... | 2010 | 20059610 |
| the nasty neighbour in the striped mouse (rhabdomys pumilio) steals paternity and elicits aggression. | abstract: | 2010 | 20573184 |
| seasonal abundance of plague vector xenopsylla brasiliensis from rodents captured in three habitat types of periurban suburbs of harare, zimbabwe. | abstract the study was aimed at determining the seasonal abundance of xenopsylla brasiliensis, an important vector of plague in zimbabwe, from rodent hosts captured in selected habitat types of two periurban suburbs of harare, zimbabwe. the removal-trapping method was used to capture the rodents, from which fleas were collected and identified. percentage incidence index (pii) and specific flea index (sfi) were calculated for x. brasiliensis in relation to rodent species host. mastomys natalensis ... | 2010 | 21142965 |
| relative fitness of alternative male reproductive tactics in a mammal varies between years. | 1. in many species, males can use different behavioural tactics to achieve fertilization, so-called alternative reproductive tactics (arts). few field studies have measured fitness consequences of arts under varying environmental conditions. 2. here, we describe fitness consequences of three phenotypically plastic arts in the african striped mouse (rhabdomys pumilio) and show that relative fitness of arts differs between years. each year represents a different generation. 3. for the generation l ... | 2011 | 21418210 |
| a new species of ixodes (acari: ixodidae) from south african mammals. | abstract a new tick species belonging to the african subgenus afrixodes morel, 1966, namely, ixodes ( afrixodes ) fynbosensis n. sp., is described. the female of i. fynbosensis is easily differentiated from the other african ixodes species by a large, tapering triangular ventrolateral spur on palpal segment i. nymph and larva of i. fynbosensis can be distinguished from those of other members of afrixodes by a combination of the following characters: pointed hypostome, long auriculae, long and ac ... | 2010 | 21506796 |
| Social flexibility and social evolution in mammals: a case study of the African striped mouse (Rhabdomys pumilio). | Environmental change poses challenges to many organisms. The resilience of a species to such change depends on its ability to respond adaptively. Social flexibility is such an adaptive response, whereby individuals of both sexes change their reproductive tactics facultatively in response to fluctuating environmental conditions, leading to changes in the social system. Social flexibility focuses on individual flexibility, and provides a unique opportunity to study both the ultimate and proximate ... | 2011 | 21883591 |
| transmission of parental care behavior in african striped mice, rhabdomys pumilio. | the expression of behavior, including parental care behavior, is influenced by complex interactions of the genes of an organism and the prevailing environmental conditions. previously, we showed that the development of paternal, but not maternal, care in the african striped mouse, rhabdomys pumilio, has a significant nongenetic maternal component. here, we investigate the genetic component of parental care behavior from parents to offspring. we first measured the duration of parental care behavi ... | 2011 | 21953856 |
| Hormone levels of male African striped mice change as they switch between alternative reproductive tactics. | Alternative reproductive tactics occur when individuals of the same species follow alternative ways to maximize reproductive success. Often younger and smaller males follow tactics that result in lower fitness than that of dominant larger males. The relative plasticity hypothesis predicts that hormone levels change as males change tactics, but direct tests of this hypothesis are missing. It has been demonstrated in a number of studies that males following different tactics also differ in hormone ... | 2011 | 21968215 |
| better off alone! reproductive competition and ecological constraints determine sociality in the african striped mouse (rhabdomys pumilio). | 1. while the reasons for group-living have been studied for decades, little is known about why individuals become solitary. 2. several previous experimental studies could demonstrate that group-living can arises as a consequence of ecological constraints. 3. it has been argued that reproductive competition between group members leads to significant costs of group-living, being a main reason of solitary-living. however, so far, no studies tested experimentally whether reproductive competition can ... | 2012 | 22220746 |
| evidence for novel hepaciviruses in rodents. | hepatitis c virus (hcv) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. research is complicated by a lack of accessible small animal models. the systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. we have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and o ... | 2013 | 23818848 |
| foraging in space and time structure an african small mammal community. | we used live-trapping and foraging to test for the effect of habitat selection and diet on structuring a community of six small mammals and one bird within the soutpansberg, south africa. we established grids that straddled adjacent habitats: woodland, rocky hillside, and grassland. trapping and foraging were used to estimate abundance, habitat use, and species-specific foraging costs. the species with the highest abundance and foraging activity in a habitat, activity time, or food was considere ... | 2014 | 24648024 |
| infracommunity dynamics of chiggers (trombiculidae) parasitic on a rodent. | we studied the structure of chigger mite (trombiculidae) communities parasitic on a south african rodent, rhabdomys pumilio. we aimed to determine whether: (a) different chigger species differ in preferences for certain body areas of a host and (b) chigger assemblages among body areas of the same host individual, are structured and if so, whether the structure of these assemblages is aggregative or segregative. rhabdomys pumilio is parasitized by seven chigger species belonging to six genera. th ... | 2015 | 26303191 |
| adaptation for rodent pollination in leucospermum arenarium (proteaceae) despite rapid pollen loss during grooming. | plants are adapted for rodent pollination in diverse and intricate ways. this study explores an extraordinary example of these adaptations in the pincushion leucospermum arenarium (proteaceae) from south africa. | 2014 | 24607723 |
| arginine vasopressin plasma levels change seasonally in african striped mice but do not differ between alternative reproductive tactics. | arginine vasopressin (avp) is an important hormone for osmoregulation, while as a neuropeptide in the brain it plays an important role in the regulation of social behaviors. dry habitats are often the home of obligately sociable species such as meerkats and damaraland mole-rats, leading to the hypothesis that high plasma avp levels needed for osmoregulation might be associated with the regulation of social behavior. we tested this in a facultative sociable species, the african striped mouse (rha ... | 2014 | 24842715 |
| seasonal abundance and epidemiological indices of potential plague vectors dinopsyllus lypusus (siphonaptera: hystrichopsyllidae) and ctenophthalmus calceatus (siphonaptera: ctenophthalmidae) on rodents captured from three habitat types of hatcliffe and dzivarasekwa suburbs of harare, zimbabwe. | the seasonal abundance of dinopsyllus lypusus jordan and rothschild and ctenophthalmus calceatus waterson (potential vectors of plague in southern africa) were studied on rodent hosts captured in selected habitat types of two periurban suburbs of harare, zimbabwe. removal trapping was used to capture the rodents, from which fleas were collected and identified. prevalence (proportion of animals infested) and specific flea index (sfi = number of fleas per animal) were calculated for each species o ... | 2012 | 23270175 |
| effects of photophase illuminance on locomotor activity, urine production and urinary 6-sulfatoxymelatonin in nocturnal and diurnal south african rodents. | effects of photophase illuminance (1, 10, 100 and 330 lx of white incandescent lighting) on daily rhythms of locomotor activity, urine production and 6-sulfatoxymelatonin (6-smt; 10 versus 330 lx) were studied in nocturnal namaqua rock mice (micaelamys namaquensis) and diurnal four-striped field mice (rhabdomys pumilio). micaelamys namaquensis was consistently nocturnal (∼90-94% nocturnal activity), whereas considerable individual variation marked activity profiles in r. pumilio, but with activi ... | 2017 | 28209805 |
| effects of melatonin on heat production and enzymatic activity in diurnal and in nocturnal rodents. | 1. heat production by means of oxygen consumption (vo2), and enzymatic activity of malate dehydrogenase (mdh), lactate dehydrogenase (ldh), and glucose-6-phosphate dehydrogenase (g6pdh) were studied in diurnal (rhabdomys pumilio) as well as nocturnal (praomys natalensis) murids, as a response to melatonin treatment. 2. a significant (p less than 0.001) increase in vo2 was noticed in melatonin treated mice of both species at ambient temperatures of ta = 6 degrees c, 25 degrees c, 30 degrees c and ... | 1982 | 6120787 |
| intra- and interspecific similarity in species composition of helminth communities in two closely-related rodents from south africa. | to reveal factors responsible for spatial variation in parasite community composition we studied patterns of similarity in helminth species composition in two closely-related rodents (rhabdomys pumilio and rhabdomys dilectus) that differ in their social and spatial behaviour and live under different environmental conditions across 20 localities in south africa. we asked whether the two hosts harbour similar assemblages, whether these are more dissimilar between than within hosts and if host soci ... | 2017 | 28485256 |
| community structure of fleas within and among populations of three closely related rodent hosts: nestedness and beta-diversity. | we studied nestedness and its relationships with beta-diversity in flea communities harboured by three closely related rodent species (rhabdomys pumilio, rhabdomys intermedius, rhabdomys dilectus) at two spatial scales (within and among host populations) in south africa and asked (a) whether variation in species composition of flea communities within and among host populations follows a non-random pattern; if yes, (b) what are the contributions of nestedness and species turnover to dissimilarity ... | 2016 | 27172891 |
| active and explorative individuals are often restless and excluded from studies measuring resting metabolic rate: do alternative metabolic rate measures offer a solution? | it has often been proposed that bolder, more explorative or more active individuals also have a higher resting metabolic rate (rmr), indicating metabolic costs of these personality types. however, such individuals might often be restless and thus excluded from rmr datasets, leading to a significant sampling bias. we tested (1) whether such a bias occurs when animals are measured for a relatively common but short time period of 3h, and if so, (2) whether alternative measures of metabolic rate, th ... | 2017 | 28283463 |
| helminth parasitism in two closely related south african rodents: abundance, prevalence, species richness and impinging factors. | we investigated patterns of helminth infection in two closely related rodents (social rhabdomys pumilio occurring mainly in xeric habitats and solitary r. dilectus occurring mainly in mesic habitats) at 20 localities in different biomes of south africa and asked if between-species differences were mainly caused by difference in sociality or difference in environmental conditions of their respective habitats. helminths recovered from the gastrointestinal tract totalled 11 nematode and 5 cestode s ... | 2017 | 28281100 |
| trade-offs between reproduction and health in free-ranging african striped mice. | energy is limited and must be allocated among competing life-history traits. reproduction is considered one of the most energetically demanding life-history stages. therefore, the amount of energy an individual invests in reproduction might carry fitness costs through reduced energy allocation to other activities such as health maintenance. we investigated whether reproduction impacts health in the seasonally breeding african striped mouse (rhabdomys pumilio). we measured health in individuals t ... | 2017 | 28161790 |
| both thyroid hormone levels and resting metabolic rate decrease in african striped mice when food availability decreases. | in response to variation in food availability and ambient temperature (ta), many animals show seasonal adaptations in their physiology. laboratory studies showed that thyroid hormones are involved in the regulation of metabolism, and their regulatory function is especially important when the energy balance of an individual is compromised. however, little is known about the relationship between thyroid hormones and metabolism in free-living animals and animals inhabiting seasonal environments. he ... | 2017 | 27994044 |
| developmental mechanisms of stripe patterns in rodents. | mammalian colour patterns are among the most recognizable characteristics found in nature and can have a profound impact on fitness. however, little is known about the mechanisms underlying the formation and subsequent evolution of these patterns. here we show that, in the african striped mouse (rhabdomys pumilio), periodic dorsal stripes result from underlying differences in melanocyte maturation, which give rise to spatial variation in hair colour. we identify the transcription factor alx3 as ... | 2016 | 27806375 |
| survival is linked with reaction time and spatial memory in african striped mice. | studying the association between fitness and cognition in free-living animals is a fundamental step in the elucidation of the evolution of cognition. we assessed whether survival until the onset of the breeding season was related to reaction time or spatial memory in the african striped mouse rhabdomys pumilio, a rodent that has to survive summer drought before breeding. we tested a total of 90 individuals at the beginning of summer. female survival was related to a faster response to predation ... | 2016 | 27484646 |
| the pathophysiology of survival in harsh environments. | an individual's ability to survive harsh conditions might depend on its available energy, and also on its health, which is expected to decline as conditions deteriorate. yet, we know little about how health and energy expenditure are shaped by harsh environmental conditions in free-living vertebrates. here, we studied how african striped mice (rhabdomys pumilio) that survived summer droughts differed in their energy expenditure and health from non-survivors. specifically, we tested whether: (1) ... | 2017 | 27421847 |
| alternative reproductive tactics in female striped mice: heavier females are more likely to breed solitarily than communally. | alternative reproductive tactics (arts) are discrete reproductive phenotypes governed by decision rules called strategies. arts are fixed for life in species with alternative strategies, while tactic expression is plastic in species with a single strategy. arts have been investigated in males of many species, but few studies have tested whether the same theoretical framework applies in females. female striped mice (rhabdomys pumilio) employ three arts: communal breeders give birth in a nest shar ... | 2015 | 26250697 |
| seasonal variation in attention and spatial performance in a wild population of the african striped mouse (rhabdomys pumilio). | cognitive flexibility describes the reversible changes of cognition in response to environmental changes. although various environmental factors such as temperature, photoperiod and rainfall change seasonally, seasonal variation in cognitive performance has been reported in merely a few birds and mammals. we assessed whether cognitive performance in a wild population of african striped mice rhabdomys pumilio, from the succulent karoo semidesert of south africa, differed between summer and winter ... | 2015 | 26139344 |
| basal blood glucose concentration in free-living striped mice is influenced by food availability, ambient temperature and social tactic. | vertebrates obtain most of their energy through food, which they store mainly as body fat or glycogen, with glucose being the main energy source circulating in the blood. basal blood glucose concentration (bbgc) is expected to remain in a narrow homeostatic range. we studied the extent to which bbgc in free-living african striped mice (rhabdomys pumilio) is influenced by ecological factors with a bearing on energy regulation, i.e. food availability, abiotic environmental variation and social tac ... | 2015 | 25994012 |
| alternative reproductive tactics in female striped mice: solitary breeders have lower corticosterone levels than communal breeders. | alternative reproductive tactics (arts), where members of the same sex and population show distinct reproductive phenotypes governed by decision-rules, have been well-documented in males of many species, but are less well understood in females. the relative plasticity hypothesis (rph) predicts that switches between plastic arts are mediated by changes in steroid hormones. this has received much support in males, but little is known about the endocrine control of female arts. here, using a free-l ... | 2015 | 25828632 |
| adult neurogenesis in the four-striped mice (rhabdomys pumilio). | in this study, we investigated non-captive four-striped mice (rhabdomys pumilio) for evidence that adult neurogenesis occurs in the adult brain of animal models in natural environment. ki-67 (a marker for cell proliferation) and doublecortin (a marker for immature neurons) immunostaining confirmed that adult neurogenesis occurs in the active sites of subventricular zone of the lateral ventricle with the migratory stream to the olfactory bulb, and the subgranular zone of the dentate gyrus of the ... | 2014 | 25558241 |
| landscape characteristics influence helminth infestations in a peri-domestic rodent--implications for possible zoonotic disease. | anthropogenic habitat change often results in altered landscapes that can provide new environments where hosts, parasites and pathogens can interact. the latter can have implications for human and animal health when in close proximity to developed areas. we recorded the helminth species richness and level of infestation in the peri-domestic rodent, rhabdomys pumilio, in three different human linked landscapes. the aim was, to investigate the potential of r. pumilio to act as a reservoir host for ... | 2014 | 25159989 |
| leptin levels in free ranging striped mice (rhabdomys pumilio) increase when food decreases: the ecological leptin hypothesis. | leptin is a hormone informing the body about its fat stores, reducing appetite and foraging and as such reducing fattening of individuals. in laboratory rodents, leptin secretion is highly correlated to the amount of adipose tissue. we compared this to the alternative ecological leptin hypothesis, which based on the behavioural effects of leptin predicts that leptin levels are disassociated from adipose tissue when fattening is of evolutionary advantage to survive coming periods of low food avai ... | 2014 | 24992023 |
| experimental increase of testosterone increases boldness and decreases anxiety in male african striped mouse helpers. | males of many species can adjust their behaviors to environmental conditions by changing reproductive tactics. testosterone surges in adult breeding males typically inhibit the expression of paternal care while facilitating the expression of aggression during environmental changes. similarly, in non-breeding philopatric males of cooperatively breeding species, up-regulation of testosterone may inhibit alloparental care while facilitating dispersal, i.e. males might become bolder and more explora ... | 2014 | 24534177 |
| histology and ultrastructure of transitional changes in skin morphology in the juvenile and adult four-striped mouse (rhabdomys pumilio). | the four-striped mouse has a grey to brown coloured coat with four characteristic dark stripes interspersed with three lighter stripes running along its back. the histological differences in the skin of the juvenile and adult mouse were investigated by haematoxylin and eosin and masson trichrome staining, while melanocytes in the skin were studied through melanin-specific ferro-ferricyanide staining. the ultrastructure of the juvenile skin, hair follicles, and melanocytes was also explored. in b ... | 2013 | 24288469 |
| life history strategy influences parasite responses to habitat fragmentation. | anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. we investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, rhabdomys ... | 2013 | 23954434 |
| endocrinology of sociality: comparisons between sociable and solitary individuals within the same population of african striped mice. | the social organization of species ranges from solitary-living to complex social groups. while the evolutionary reasons of group-living are well studied, the physiological mechanisms underlying alternative social systems are poorly understood. by studying group-living and solitary individuals of the same species, we can determine hormonal correlates of sociality without the problem of confounding phylogenetic factors. the african striped mouse (rhabdomys pumilio) is a socially flexible species, ... | 2013 | 23648775 |
| remnant fragments within an agricultural matrix enhance conditions for a rodent host and its fleas. | habitat fragmentation can adversely impact biodiversity, although where remnant fragments of natural vegetation provide favourable conditions the negative effects of fragmentation may be mitigated. host-parasite systems in fragmented areas have only recently been examined, with parasites generally showing higher prevalence and richness in fragments, mediated by changes in host density. however, the effect of fragmentation on parasite body size and fecundity remains poorly investigated. thus, her ... | 2013 | 23101765 |
| the development of exploratory behaviour in the african striped mouse rhabdomys reflects a gene × environment compromise. | behaviour results from the interaction of an individual's genotype with prevailing environmental conditions, resulting in local adaptation to specific habitats. we investigated the development of exploratory behaviour in two closely-related species of african striped mice from the semi-arid succulent karoo (rhabdomys pumilio) and moist grassland (r. dilectus chakae) localities. irrespective of sex, r. pumilio displayed greater exploratory behaviour (open field) and greater use of the open arms o ... | 2012 | 22976549 |
| biome specificity of distinct genetic lineages within the four-striped mouse rhabdomys pumilio (rodentia: muridae) from southern africa with implications for taxonomy. | within southern africa, a link between past climatic changes and faunal diversification has been hypothesized for a diversity of taxa. to test the hypothesis that evolutionary divergences may be correlated to vegetation changes (induced by changes in climate), we selected the widely distributed four-striped mouse, rhabdomys, as a model. two species are currently recognized, the mesic-adapted r. dilectus and arid-adapted r. pumilio. however, the morphology-based taxonomy and the distribution boun ... | 2012 | 22728170 |
| experimental increase of testosterone levels in free-ranging juvenile male african striped mice (rhabdomys pumilio) induces physiological, morphological, and behavioral changes. | testosterone influences sexual differentiation in early development, and activates sexual maturation and sex-related behavior in males during puberty. testosterone can also influence the expression of male alternative reproductive tactics, by either organizational effects (fixed tactics) or by activational effects (plastic tactics). however, the roles of testosterone in sexual maturation and at the same time the expression of alternative reproductive tactics have been little investigated experim ... | 2012 | 22565164 |
| differential investment into testes and sperm production in alternative male reproductive tactics of the african striped mouse (rhabdomys pumilio). | males that follow alternative reproductive tactics might differ in their investment into testis development and sperm production. the resource-allocation hypothesis predicts that males following a sneaker tactic should invest more into sperm production than dominant territorial males which should invest more into mate guarding. this hypothesis is supported by studies in species where individual males cannot switch between tactics (fixed tactics). here we present the first data for a species wher ... | 2012 | 22445749 |
| maternal care in the african striped mouse rhabdomys pumilio: a behaviorally flexible phenotype that is modified by experience. | the development of maternal care in mammals can be influenced by the type and quality of maternal care received. using biparental striped mice rhabdomys pumilio, we investigated whether development of maternal care is influenced by the mother during early rearing and by an adult female's experience and that of her mate. offspring were raised in one of three treatments, by: both parents; mothers alone; and mothers separated from the father with a barrier. since female striped mice increase their ... | 2013 | 22407856 |
| insights into the complex associations between mhc class ii drb polymorphism and multiple gastrointestinal parasite infestations in the striped mouse. | differences in host susceptibility to different parasite types are largely based on the degree of matching between immune genes and parasite antigens. specifically the variable genes of the major histocompatibility complex (mhc) play a major role in the defence of parasites. however, underlying genetic mechanisms in wild populations are still not well understood because there is a lack of studies which deal with multiple parasite infections and their competition within. to gain insights into the ... | 2012 | 22389675 |
| spatial variation in gender-biased parasitism: host-related, parasite-related and environment-related effects. | the gender-biased pattern of parasite infestation has been shown to be a complicated phenomenon that cannot be explained by a single mechanism but rather involves several different mechanisms. we asked what are the factors that affect the manifestation and extent of gender-biased parasitism and studied the relationship between parasite-related (mean abundance, mean species richness and total species richness of all parasites), host-related (rodent density and proportion of reproductive males and ... | 2010 | 20550754 |
| geographical variations in heat production and dissipation within two populations of rhabdomys pumilio (muridae). | a comparative study of heat production and dissipation was carried out on rhabdomys pumilio from two extremely different climatic zones. our results show higher oxygen consumption (vo2) values for the desert population at ta = 5 degrees c when compared to the mesic population. the overall thermal conductance is also higher for the desert population. it seems as though penetration into mesic areas of r. pumilio, which originated in an arid zone, was accompanied by an increase in body mass. | 1986 | 2871964 |
| effects of the colour of photophase light on locomotor activity in a nocturnal and a diurnal south african rodent. | many physiological and behavioural responses to varying qualities of light, particularly during the night (scotophase), have been well documented in rodents. we used varying wavelengths of day-time (photophase) lighting to assess daily responses in locomotor activity in the nocturnal namaqua rock mouse (micaelamys namaquensis) and diurnal four-striped field mouse (rhabdomys pumilio). animals were exposed to three light-dark cycle regimes: a short-wavelength- (swlc, blue), a medium-wavelength- (m ... | 2019 | 31573427 |
| the topography of rods, cones and intrinsically photosensitive retinal ganglion cells in the retinas of a nocturnal (micaelamys namaquensis) and a diurnal (rhabdomys pumilio) rodent. | we used immunocytochemistry to determine the presence and topographical density distributions of rods, cones, and intrinsically photosensitive retinal ganglion cells (iprgcs) in the four-striped field mouse (rhabdomys pumilio) and the namaqua rock mouse (micaelamys namaquensis). both species possessed duplex retinas that were rod dominated. in r. pumilio, the density of both cones and rods were high (cone to rod ratio: 1:1.23) and reflected the species' fundamentally diurnal, but largely crepusc ... | 2018 | 30092025 |
| morphometric analysis of the gastrointestinal tract of four african muroid rodent species (rhabdomys dilectus, rhabdomys pumilio, aethomys chrysophilus, and lemniscomys rosalia). | several muroid rodent species are distributed throughout southern africa. some species are reportedly classified as opportunistic omnivorous rodents consuming plant, seed, and insect material. this study aims to provide a detailed morphometric analysis of the gastrointestinal tract (git) of four such omnivorous species, including stomach content analysis. fixed git specimens (n = 5 of each) of rhabdomys dilectus (mesic four-striped grass mouse), rhabdomys pumilio (xeric four-striped grass mouse) ... | 2018 | 30187940 |
| dental microwear of sympatric rodent species sampled across habitats in southern africa: implications for environmental influence. | dental microwear textures have proven to be a valuable tool for reconstructing the diets of a wide assortment of fossil vertebrates. nevertheless, some studies have recently questioned the efficacy of this approach, suggesting that aspects of habitat unrelated to food preference, especially environmental grit load, might have a confounding effect on microwear patterning that obscures the diet signal. here we evaluate this hypothesis by examining microwear textures of 3 extant sympatric rodent sp ... | 2016 | 26748948 |
| growing up in the family or growing up alone influences behavior and hormones, but not arginine vasopressin receptor 1a expression in male african striped mice. | in many species males display alternative reproductive tactics (arts). while males of different tactics differ behaviorally in the field, it is often not known whether these behavioral differences would also occur under standardized laboratory conditions, nor how arts are regulated by the brain. in the present study we kept male african striped mice (rhabdomys pumilio) in captivity either in family groups or solitary, to mimic arts observed in the field. this allowed us to study these males beha ... | 2014 | 24631307 |
| community structure of helminth parasites in two closely related south african rodents differing in sociality and spatial behaviour. | to understand the effect of social and spatial behaviour of a host on parasite community organization, we studied species co-occurrence and nestedness of assemblages of gastrointestinal helminths in two closely related rodents, solitary and mobile rhabdomys dilectus and social and territorially conservative rhabdomys pumilio, and asked whether helminth communities of the two hosts are characterized by a non-random pattern and whether the occurrence or degree of this non-randomness (a) differs be ... | 2017 | 28668982 |
| sons benefit from paternal care in african striped mice. | mammalian paternal care is rare and is often linked to enhanced fitness under particular ecological conditions. the proximate consequences of paternal care on offspring are lacking, however. here, we tested whether levels of paternal care predict the behavioural, cognitive and physiological development of sons in the naturally paternal african striped mouse (rhabdomys pumilio). we focused on sons raised in two treatments: biparental (both parents) or uniparental (mother alone) families. we recor ... | 2020 | 33098084 |
| the effect of varying laboratory conditions on the locomotor activity of the nocturnal namaqua rock mouse (micaelamys namaquensis) and the diurnal four-striped grass mouse (rhabdomys dilectus). | rodents are the most common laboratory animals all over the world, however, most studies on the effects of laboratory conditions on the behavior and physiology of the study animals have been performed on traditional laboratory animals. we investigated the effects of environmental enrichment, lighting conditions and ambient temperature cycles on the locomotor activity of wild trapped, nocturnal namaqua rock mice and diurnal four-striped grass mice. when considering the general activity of the two ... | 2020 | 32534363 |
| spectral sensitivity of cone vision in the diurnal murid rhabdomys pumilio. | an animal's temporal niche - the time of day at which it is active - is known to drive a variety of adaptations in the visual system. these include variations in the topography, spectral sensitivity and density of retinal photoreceptors, and changes in the eye's gross anatomy and spectral transmission characteristics. we have characterised visual spectral sensitivity in the murid rodent rhabdomys pumilio (the four-striped grass mouse), which is in the same family as (nocturnal) mice and rats but ... | 2020 | 32371443 |
| fat content of striped mice decreases during the breeding season but not during the food-restricted dry season. | individuals that are capable of accumulating appropriate fat stores are assumed to have selective advantages when food becomes scarce. similarly to species from temperate zones, some species inhabiting arid areas accumulate fat stores prior to periods of food limitation. yet, we have little knowledge concerning seasonal variation in body composition and the relationship between fat store size and disappearance risk in species from arid habitats. using the water dilution method, we examined the b ... | 2019 | 31727761 |
| beta diversity of gastrointestinal helminths in two closely related south african rodents: species and site contributions. | a fundamental aim of parasite ecology is to understand the mechanisms behind spatial variation in diversity and structure of parasite assemblages. to understand the contribution of individual parasite species and their assemblages to spatial variation in parasite communities, we examined species contributions to beta diversity (scbd) and local contributions to beta diversity (lcbd) of parasitic gastrointestinal helminths (nematodes and cestodes) in two closely related rodents, rhabdomys dilectus ... | 2019 | 31399870 |
| bartonellae of synanthropic four-striped mice (rhabdomys pumilio) from the western cape province, south africa. | bartonella is a species-rich bacterial genus that infects a wide variety of wild and domestic animals, including rodents. despite high levels of murid rodent diversity in africa, associated bartonella prevalence and diversity remains understudied, particularly within the southern african subregion. to address this, we sampled endemic four-striped mice, rhabdomys pumilio, from three rural and two urban localities in the western cape province, south africa. pcr screening and multilocus sequence an ... | 2019 | 30571537 |
| daily energy expenditure of males following alternative reproductive tactics: solitary roamers spend more energy than group-living males. | in many species, males follow alternative reproductive tactics (arts), where one tactic (called bourgeois) has much higher reproductive success than alternative tactics followed by males with lower competitive ability. the extent to which arts differ in energetic costs is unknown, but it is important to understand the fitness payoffs of arts. we studied male african striped mice (rhabdomys pumilio) which follow one of three arts: heavy bourgeois males defend harems of females and have 10 times h ... | 2019 | 30521878 |
| periodic patterns in rodentia: development and evolution. | mammalian periodic pigment patterns, such as spots and stripes, have long interested mathematicians and biologists because they arise from non-random developmental processes that are programmed to be spatially constrained, and can therefore be used as a model to understand how organized morphological structures develop. despite such interest, the developmental and molecular processes underlying their formation remain poorly understood. here, we argue that arvicanthines, a clade of african rodent ... | 2019 | 30506729 |
| seasonal variation in energy expenditure in a rodent inhabiting a winter-rainfall desert. | animals that spend more energy than they obtain risk entering allostatic overload, reducing survival and fitness. they are predicted to adjust their daily energy expenditure (dee) during periods of food scarcity. adjustments of dee to changes in food availability have been well-studied in species in temperate zones during winter, but less so in species enduring seasonal droughts. likely mechanisms regulating dee involve adjustments of activity and maintenance metabolism. species that experience ... | 2018 | 29948157 |
| food availability is the main driver of seasonal changes in resting metabolic rate in african striped mice (rhabdomys pumilio). | resting metabolic rate (rmr) influences energy allocation to survival, growth, and reproduction, and significant seasonal changes in rmr have been reported. according to one hypothesis, seasonal changes in rmr are mainly attributable to seasonal changes in ambient temperature (ta) and food availability. studies on species from the temperate zone indicated that food availability is the main driver. however, whether this is generally true is unknown, because studies from the tropics and subtropics ... | 2018 | 29381108 |