| 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 |
| permanent genetic resources added to molecular ecology resources database 1 january 2009-30 april 2009. | this article documents the addition of 283 microsatellite marker loci to the molecular ecology resources database. loci were developed for the following species: agalinis acuta; ambrosia artemisiifolia; berula erecta; casuarius casuarius; cercospora zeae-maydis; chorthippus parallelus; conyza canadensis; cotesia sesamiae; epinephelus acanthistius; ficedula hypoleuca; grindelia hirsutula; guadua angustifolia; leucadendron rubrum; maritrema novaezealandensis; meretrix meretrix; nilaparvata lugens; ... | 2009 | 21564911 |
| no evidence for proteolytic venom resistance in southern african ground squirrels. | many mammalian species that interact with venomous snakes show resistances to venoms. the family sciuridae has several north american members that harass venomous snakes and show proteolytic resistances in their sera. we examined sera collected from an african ground squirrel (xerus inauris) against two sympatric venomous snakes (bitis arietans and naja annulifera) and found no support for proteolytic resistance. our results add to our understanding of the risks in predator defense within the fa ... | 2012 | 22728461 |
| effect of mating activity and dominance rank on male masturbation among free-ranging male rhesus macaques. | the adaptive function of male masturbation is still poorly understood, despite its high prevalence in humans and other animals. in non-human primates, male masturbation is most frequent among anthropoid monkeys and apes living in multimale-multifemale groups with a promiscuous mating system. in these species, male masturbation may be a non-functional by-product of high sexual arousal or be adaptive by providing advantages in terms of sperm competition or by decreasing the risk of sexually transm ... | 2013 | 24187414 |
| the evolution of urgency-based and functionally referential alarm calls in ground-dwelling species. | a major evolutionary force driving functionally referential alarm calls is the need for different strategies to escape various predator types in complex structured habitats. in contrast, a single escape strategy appears to be sufficient in less-structured open habitats, and under such conditions urgency-dependent alarm calls may be favored. nevertheless, some species, such as meerkats (suricata suricatta), have evolved functionally referential alarm calls despite living in open areas, using only ... | 2009 | 19199527 |
| mating tactics of male cape ground squirrels, xerus inauris: consequences of year-round breeding. | the cape ground squirrel is a highly social, tropical ground squirrel that does not hibernate, suggesting that female receptivity could be scattered throughout the year. males in this species are very social, living in all-male bands. i studied the mating tactics of male cape ground squirrels to examine the effects of year-round female receptivity and male grouping on these tactics and on the degree of intrasexual competition. female breeding was highly irregular and unpredictable, and the avera ... | 1998 | 9787037 |
| use of the sun as a heading indicator when caching and recovering in a wild rodent. | a number of diurnal species have been shown to use directional information from the sun to orientate. the use of the sun in this way has been suggested to occur in either a time-dependent (relying on specific positional information) or a time-compensated manner (a compass that adjusts itself over time with the shifts in the sun's position). however, some interplay may occur between the two where a species could also use the sun in a time-limited way, whereby animals acquire certain information a ... | 2016 | 27580797 |
| caching in the presence of competitors: are cape ground squirrels (xerus inauris) sensitive to audience attentiveness? | when social animals cache food close to their burrow, the potential for an audience member to observe the event is significantly increased. as a consequence, in order to reduce theft it may be advantageous for animals to be sensitive to certain audience cues, such as whether they are attentive or not to the cache event. in this study, observations were made on three groups of cape ground squirrels (xerus inauris) in their natural habitat when they cached provisioned food items. when individuals ... | 2016 | 26242609 |
| behavioural correlates of urbanisation in the cape ground squirrel xerus inauris. | urbanisation critically threatens biodiversity because of habitat destruction and novel selection pressures. some animals can respond to these challenges by modifying their behaviour, particularly anti-predator behaviour, allowing them to persist in heavily transformed urban areas. we investigated whether the anti-predator behaviour of the cape ground squirrel xerus inauris differed in three localities that differed in their level of urbanisation. according to the habituation hypothesis, we pred ... | 2012 | 23052820 |
| immunological sex differences in socially promiscuous african ground squirrels. | differences in how males and females respond to foreign antigens are common across taxa. such sexual differences in the immune system are predicted to be greater in species with high promiscuity and sociality as these factors increase the likelihood of disease transmission. intense sperm competition is thought to further this sexual dichotomy as increased investment in spermatogenesis likely incurs additional immunological costs. xerus inauris, a ground squirrel found throughout southern africa, ... | 2012 | 22715391 |
| seasonal patterns of body temperature daily rhythms in group-living cape ground squirrels xerus inauris. | organisms respond to cyclical environmental conditions by entraining their endogenous biological rhythms. such physiological responses are expected to be substantial for species inhabiting arid environments which incur large variations in daily and seasonal ambient temperature (t(a)). we measured core body temperature (t(b)) daily rhythms of cape ground squirrels xerus inauris inhabiting an area of kalahari grassland for six months from the austral winter through to the summer. squirrels inhabit ... | 2012 | 22558324 |
| determination of an optimal dose of medetomidine-ketamine-buprenorphine for anaesthesia in the cape ground squirrel (xerus inauris). | the optimal dose of medetomidine-ketamine-buprenorphine was determined in 25 cape ground squirrels (xerus inauris) undergoing surgical implantation of a temperature logger into the abdominal cavity. at the end of anaesthesia, the squirrels were given atipamezole intramuscularly to reverse the effects of medetomidine. the mean dose of medetomidine was 67.6 +/- 9.2microg/kg, ketamine 13.6 +/- 1.9 mg/kg and buprenorphine 0.5 +/- 0.06 microg/kg. induction time was 3.1 +/- 1.4 min. this produced surg ... | 2011 | 22135922 |
| the adaptive function of masturbation in a promiscuous african ground squirrel. | studies of animal mating systems increasingly emphasize female multiple mating and cryptic sexual selection, particularly sperm competition. males under intense sperm competition may manipulate sperm quantity and quality through masturbation, which could waste sperm and decrease fertility. i examined the factors influencing masturbation by male cape ground squirrels (xerus inauris) in light of a number of functional hypotheses. | 2010 | 20927404 |
| winter body temperature patterns in free-ranging cape ground squirrel, xerus inauris: no evidence for torpor. | the body temperature (t(b)) of cape ground squirrels (xerus inauris, sciuridae) living in their natural environment during winter has not yet been investigated. in this study we measured abdominal t(b) of eight free-ranging cape ground squirrels over 27 consecutive days during the austral winter. mean daily t(b) was relatively stable at 37.0 ± 0.2°c (range 33.4 to 40.2°c) despite a marked variation in globe temperature (t(g)) (range -7 to 37°c). lactating females (n = 2) consistently had a signi ... | 2010 | 20396893 |
| the relative roles of the parasol-like tail and burrow shuttling in thermoregulation of free-ranging cape ground squirrels, xerus inauris. | as small arid-zone mammals, cape ground squirrels (xerus inauris) are unusual in being diurnally active. it is postulated that they remain active during the day by using their parasol-like tails to shade their bodies whilst foraging. however, no studies have continuously measured body temperature to determine the effect of using the tail as a parasol, relative to other thermoregulatory behaviours, such as burrow retreat. we caught four free-ranging cape ground squirrels (673+/-36 g) and surgical ... | 2009 | 19041951 |
| alternative reproductive tactics in male cape ground squirrels xerus inauris. | in some animal societies, males vary in the strategies and tactics that they use for reproduction. explanations for the evolution of alternative tactics have usually focussed on extrinsic factors such as social status, the environment or population density and have rarely examined proximate differences between individuals. anecdotal evidence suggests that two alternative reproductive tactics occur in cooperatively breeding male cape ground squirrels. here we show that there is strong empirical s ... | 2008 | 18325548 |
| energetic costs of parasitism in the cape ground squirrel xerus inauris. | parasites have been suggested to influence many aspects of host behaviour. some of these effects may be mediated via their impact on host energy budgets. this impact may include effects on both energy intake and absorption as well as components of expenditure, including resting metabolic rate (rmr) and activity (e.g. grooming). despite their potential importance, the energy costs of parasitism have seldom been directly quantified in a field setting. here we pharmacologically treated female cape ... | 2007 | 17613450 |
| effects of storage treatment on fecal steroid hormone concentrations of a rodent, the cape ground squirrel (xerus inauris). | fecal steroid analysis is an increasingly common non-invasive technique used in both captive and field studies to measure an animal's approximate hormonal levels and corresponding physiological state. fecal collection in the field necessitates storage and transportation methods that will prevent the degradation of hormonal metabolites by fecal bacteria. to determine the most stable and therefore preferred method of storage, 48 fecal samples were collected from six captive female cape ground squi ... | 2007 | 16914150 |
| phylogeny and historical biogeography of african ground squirrels: the role of climate change in the evolution of xerus. | we used phylogenetic and phylogeographical methods to infer relationships among african ground squirrels of the genus xerus. using bayesian, maximum-parsimony, nested clade and coalescent analyses of cytochrome b sequences, we inferred interspecific relationships, evaluated the specific distinctness of cape (xerus inauris) and mountain (xerus princeps) ground squirrels, and tested hypotheses for historical patterns of gene flow within x. inauris. the inferred phylogeny supports the hypothesized ... | 2005 | 16029477 |
| trade-offs between immunity and testosterone in male african ground squirrels. | the immunocompetence handicap hypothesis (ichh) proposes that testosterone has both beneficial effects on male reproductive potential and negative effects by suppressing the immune system. however, support for the ichh has been variable and an alternative hypothesis suggests that testosterone may be acting indirectly via cortisol to suppress immunity (the stress-linked ichh). a third hypothesis is that increased energetic investment in immunity results in the suppression of testosterone. we test ... | 2018 | 29941613 |