| water balance of merriam's kangaroo rat, dipodomys merriami, during cold exposure. | | 1975 | 237660 |
| wheel running of kangaroo rats, dipodomys merriami, as related to food deprivation and body composition. | kangaroo rats deprived of food ran themselves to death in 48 h in wheel cages. despite the loss of 14.5% of body weight the ratio of water to protein was the same after the run as it was in control rats. metabolic measurements at rest and in the running wheel and weight loss in the 48-h run were used to estimate fuels used and water expended. two-thirds of the initial amount of fat and 9% of the protein were metabolized. the terminal mean percentage of body fat was about twice that observed in r ... | 1978 | 627494 |
| an analysis of sandbathing and grooming in the kangaroo rat (dipodomys merriami). | the sandbathing and grooming behaviour of ten kangaroo rats (dipodomys merriami) were recorded on sand and woodchip substrates after periods of 0, 1, 5 and 10 days without sand. sandbathing is restricted to the sandy substrate. grooming occurs on both, but with a higher frequency on sand. increases in both grooming and sandbathing occur with increasing sand deprivation, but the temporal patterning does not change. d. merriami tends to alternate sandbathing components in contrast to other dipodom ... | 1976 | 937766 |
| auditory systems of heteromyidae: postnatal development of the ear of dipodomys merriami. | serial histological sections of kangaroo rats of postnatal ages 0-, 3-, 7-, 10-, and 14-days were prepared and studied. at birth the middle ear is mostly filled with mesenchyme and small in size, having only a small hypotympanum and a very small epitympanic recess. during the first postnatal two weeks, much of the hypertrophy found in the adult middle ear develops. because an entotympanic element is nev er formed, the previously called entotympanic chamber is here renamed the hypotympanum. the e ... | 1975 | 1142445 |
| projections of the trapezoid body and the superior olivary complex of the kangaroo rat (dipodomys merriami). | glass micropipettes filled with 2 m sodium cyanide were used to physiologically locate and iontophoretically damage the nucleus of the trapezoid body (ntb), the medial superior olive (mso), and the lateral superior olive (lso). mechanical lesions were made in the trapezoid body as it leaves the cochlear nuclei. after a 3- to 10-day survival time the projections and terminal degeneration were traced with the fink-heimer and nauta-gygax stains. the ventral cochlear nucleus (vcn) projects via the t ... | 1975 | 1192176 |
| responses of merriam's kangaroo rats, dipodomys merriami, to various levels of carbon dioxide concentration. | | 1973 | 4145439 |
| central auditory system of the kangaroo rat, dipodomys merriami. | | 1968 | 4185131 |
| ultrastructural changes in the neural lobe of the hypophysis of the kangaroo rat (dipodomys merriami) following intraperitoneal injection of hypertonic sodium chloride. | | 1969 | 4185961 |
| histo-pathological changes in cold-exposed kangaroo rats, dipodomys merriami. | | 1971 | 4397890 |
| energy metabolism and body water turnover rates of two species of free-living kangaroo rats, dipodomys merriami and dipodomys microps. | | 1971 | 4397891 |
| blood composition in normothermic and hyperthermic kangaroo rats dipodomys merriami and laboratory rats rattus norvegicus. | | 1972 | 4405342 |
| importance of green vegetation for reproduction in the kangaroo rat, dipodomys merriami merriami. | | 1973 | 4706256 |
| comparative developmental osteology in three species of desert rodents, peromyscus eremicus, perognathus intermedius, and dipodomys merriami. | | 1973 | 4744935 |
| vocalization in merriam's kangaroo rat. | | 1974 | 4833191 |
| projection of the cochlea to cochlear nuclei in merriam's kangaroo rat. | | 1971 | 5134323 |
| ascending and descending projections of the inferior colliculus in the kangaroo rat (dipodomys merriami). | | 1971 | 5148388 |
| daily cycles of hibernation in the kangaroo rat, dipodomys merriami. | | 1971 | 5156357 |
| distribution of the intrarenal monoaminergic nerves in the kidneys of the desert rat (dipodomys merriami) and the white rat (rattus norvegicus). | | 1969 | 5344888 |
| organ weights and serum total cholesterol in the kangaroo rat (dipodomys merriami). | | 1969 | 5351971 |
| energy expenditure of running kangaroo rats dipodomys merriami. | | 1970 | 5515607 |
| natural free-running period in vertebrate animal populations. | regression analysis (analysis of covariance) is contrasted with the conventional "mean period length" for estimating the length of period of the spontaneous activity frequency (free-running period) in population samples of gila monsters (heloderma suspectum) and kangaroo rats (dipodomys merriami) in the sonoran desert. the mean period length in each population does not differ significantly from 24:00 hours (p > .05) and it does not differ significantly (p > .05) between the species studied; the ... | 1967 | 6021681 |
| hormonal regulation of sandbathing in male kangaroo rats (dipodomys merriami). | detection of reproductive status from chemical signals at sandbathing loci was examined in merriam's kangaroo rat. castrated and intact males were attracted similarly to the sandbathing loci of four classes of scent donors: intact males, castrated males, estrous females, and nonestrous females. this suggested that reproductive status was not communicated to males at sandbathing loci. in a control test, castrated males were attracted to disturbed sand that contained no olfactory cues whereas inta ... | 1983 | 6626088 |
| natural space-use patterns and hippocampal size in kangaroo rats. | the size of the hippocampus, a forebrain structure that processes spatial information, correlates with the need to relocate food caches by passerine birds and with sex-specific patterns of space use in microtine rodents. the influences on hippocampal anatomy of sexual selection within species, and natural selection between species, have not yet been studied in concert, however. here we report that natural space-use patterns predict hippocampal size within and between two species of kangaroo rats ... | 1994 | 7987661 |
| prevalence of cutaneous evaporation in merriam's kangaroo rat and its adaptive variation at the subspecific level. | previous estimates suggested that ventilatory evaporation constitutes the major source of water loss in kangaroo rats (dipodomys spp.). we quantified rates of water loss in merriam's kangaroo rat (dipodomys merriami) and demonstrate the degree to which acclimation to a particular thermal and hydric environment plays a role in the intraspecific variation in water loss evident in this species. we draw the following conclusions: (1) that water loss varies intraspecifically in merriam's kangaroo rat ... | 2000 | 10648219 |
| unappreciated tolerance to high ambient temperatures in a widely distributed desert rodent, dipodomys merriami. | a long-held assertion has been that nocturnality is an escape mechanism for many nocturnal desert rodents because of limited tolerances to heat. to test this claim, we used a treadmill to examine the tolerances to high ambient temperatures (t(a)'s) of one subspecies of desert rodent, merriam's kangaroo rat, dipodomys merriami merriami, from contrasting environments. we simultaneously measured body temperature (t(b)), evaporative water loss, and metabolic rates at an ecologically relevant speed ( ... | 2000 | 11121354 |
| absence of aquaporin-4 water channels from kidneys of the desert rodent dipodomys merriami merriami. | recently, we found that aquaporin-4 (aqp4) is expressed in the s3 segment of renal proximal tubules of mice but not in rat proximal tubules. because mice have relatively larger papillae than rats, it was proposed that the renal distribution of aqp4 in various species could be related to their maximum urinary concentrating ability. therefore, kidneys and other tissues of merriam's desert kangaroo rat, dipodomys merriami merriami, which produce extremely concentrated urine (up to 5,000 mosmol/kgh( ... | 2001 | 11292621 |
| integration of genotoxicity and population genetic analyses in kangaroo rats (dipodomys merriami) exposed to radionuclide contamination at the nevada test site, usa. | we examined effects of radionuclide exposure at two atomic blast sites on kangaroo rats (dipodomys merriami) at the nevada test site, nevada, usa, using genotoxicity and population genetic analyses. we assessed chromosome damage by micronucleus and flow cytometric assays and genetic variation by randomly amplified polymorphic dna (rapd) and mitochondrial dna (mtdna) analyses. the rapd analysis showed no population structure, but mtdna exhibited differentiation among and within populations. genot ... | 2001 | 11351431 |
| developmental and acclimatory contributions to water loss in a desert rodent: investigating the time course of adaptive change. | understanding the evolution of physiological traits requires considering three nonexclusive mechanisms that underlie phenotypes and cause their change over different time scales: acclimation, developmental plasticity, and natural selection for genetically fixed traits. physiological adjustments to changes in the desiccating potential of the environment were investigated with one subspecies of common desert rodent, dipodomys merriami merriami (merriam's kangaroo rat). we raised young whose parent ... | 2001 | 11765976 |
| the effects of thyroxine on metabolism and water balance in a desert-dwelling rodent, merriam's kangaroo rat (dipodomys merriami). | desert-dwelling mammals such as merriam's kangaroo rat (dipodomys merriani) need to conserve both energy and water to survive desert conditions characterized by aridity and low productivity. the thyroid hormone thyroxine increases both basal metabolic rate and urinary water loss in mammals. increases in basal metabolism and urinary water loss are likely to be detrimental to d. merriami, therefore the regulation of this hormone may be important. to examine the effects of thyroxine in this species ... | 2002 | 11824400 |
| effect of predation risk on selectivity in heteromyid rodents. | variations in predation risk affect the costs of foraging and may therefore warrant different foraging decisions. one class of models ("higher requisite profit") predicts that foragers should become more selective when predation risk increases, as low-profitability items that do not cover the increased costs are dropped from the diet. an alternative class of models ("reduced finickiness") predicts that foragers should become less selective when predation risk increases, because selectivity requi ... | 2003 | 12914997 |
| merriam's kangaroo rats (dipodomys merriami) voluntarily select temperatures that conserve energy rather than water. | desert endotherms such as merriam's kangaroo rat (dipodomys merriami) use both behavioral and physiological means to conserve energy and water. the energy and water needs of kangaroo rats are affected by their thermal environment. animals that choose temperatures within their thermoneutral zone (tnz) minimize energy expenditure but may impair water balance because the ratio of water loss to water gain is high. at temperatures below the tnz, water balance may be improved because animals generate ... | 2003 | 13130431 |
| growth and development of merriam's kangaroo rat, dipodomys merriami. | | 1959 | 13809779 |
| response of the kangaroo rat (dipodomys merriami mearns) to single whole-body x-irradation. | | 1960 | 14398991 |
| low-frequency distortion product otoacoustic emissions in two species of kangaroo rats: implications for auditory sensitivity. | low-frequency distortion-product otoacoustic emissions were measured in two species of kangaroo rats to test the prediction that a large footdrumming species (e.g., dipodomys spectabilis) would have greater distortion-product otoacoustic emission amplitude than a small non-footdrumming species (e.g., dipodomys merriami), indicating better hearing sensitivity at low frequencies. equal-level (65 db spl) stimulus tones ( f(1), f(2)), presented over a ( f(1)) range of 200-1000 hz, were used to evoke ... | 2004 | 14648101 |
| effects of trichloroethylene and perchloroethylene on wild rodents at edwards air force base, california, usa. | effects of inhalation of volatilized trichloroethylene (tce) or perchloroethylene (pce) were assessed based on the health and population size of wild, burrowing mammals at edwards air force base (ca, usa). organic soil-vapor concentrations were measured at three sites with aquifer contamination of tce or pce of 5.5 to 77 mg/l and at two uncontaminated reference sites. population estimates of kangaroo rats (dipodomys merriami and d. panamintinus) as well as hematology, blood chemistry, and histop ... | 2004 | 15378993 |
| direct calorimetry reveals large errors in respirometric estimates of energy expenditure. | knowledge of animal energetics is based largely upon indirect calorimetry, which is estimation of metabolic heat production by an organism from measurement of indices such as oxygen consumption or carbon dioxide production. remarkably, indirect calorimetry has been validated by comparison to direct measurements of metabolic heat production (direct calorimetry) only for highly restricted conditions, primarily with a few species of medium-to-large mammals. taxa with differing physiologies are litt ... | 2005 | 15767305 |
| cache decision making: the effects of competition on cache decisions in merriam's kangaroo rat (dipodomys merriami). | caching food is an economic, decision-making process that requires animals to take many factors into account, including the risk of pilferage. however, little is known about how food-storing animals determine the risk of pilferage. in this study, the authors examined the effect of a dominant competitor species on the caching and behavior of merriam's kangaroo rat (dipodomys merriami). the authors found that, as with conspecific competitors, kangaroo rats did not alter caching in response to the ... | 2005 | 15982162 |
| behavioural syndromes in merriam's kangaroo rats (dipodomys merriami): a test of competing hypotheses. | behavioural syndromes, correlations of behaviours conceptually analogous to personalities, have been a topic of recent attention due to their potential to explain trade-offs in behavioural responses, apparently maladaptive behaviour and limits to plasticity. using merriam's kangaroo rats (dipodomys merriami), we assessed the explanatory power and generality of hypothesized syndrome structures derived from the literature and the natural history of the species. several aspects of functionally dist ... | 2007 | 17623643 |
| milk analysis of the kangaroo rat, dipodomys merriami. | the milk of dipodomys merriami has an average water content of 50.42 percent, which is low compared with milk from other mammals. the fat content is about 23.48 percent. the significance of these values is discussed in terms of the animal's water balance. | 1963 | 17842340 |
| chihuahuan desert kangaroo rats: nonlinear effects of population dynamics, competition, and rainfall. | using long-term data on two kangaroo rats in the chihuahuan desert of north america, we fitted logistic models including the exogenous effects of seasonal rainfall patterns. our aim was to test the effects of intraspecific interactions and seasonal rainfall in explaining and predicting the numerical fluctuations of these two kangaroo rats. we found that logistic models fit both data sets quite well; dipodomys merriami showed lower maximum per capita growth rates than dipodomys ordii, and in both ... | 2008 | 18831180 |
| wild rodents (dipodomys merriami) used as biomonitors in contaminated mining sites. | mining is one of the most important industrial activities globally; however, mining processes have critical environmental impacts, as mining is a major source of metals and metalloids that contribute significantly to the pollution of soil, sediment, water and air. heavy metals can impact the health of exposed human populations and nonhuman receptors. this study focused on arsenic because its genotoxicity is well-known. previously, we proposed a methodology to evaluate and integrate risk from a s ... | 2010 | 20390846 |
| thomas george lee - implantation and early development of north american rodents. | a century ago thomas g. lee amassed an unparalleled collection of developmental series of north american rodents such as the thirteen-lined ground squirrel, the plains pocket gopher and merriam's kangaroo rat. he was the first to describe the initial attachment of the squirrel blastocyst to the antimesometrial side of the uterus. the full potential of lee's material was not realized until after his death, when it came into the possession of mossman. the latter relied heavily on lee's collection ... | 2010 | 20947162 |
| architecture of kangaroo rat inner medulla: segmentation of descending thin limb of henle's loop. | we hypothesize that the inner medulla of the kangaroo rat dipodomys merriami, a desert rodent that concentrates its urine to over 6000 mosm/kg water, provides unique examples of architectural features necessary for production of highly concentrated urine. to investigate this architecture, inner medullary nephron segments in the initial 3000 μm below the outer medulla were assessed with digital reconstructions from physical tissue sections. descending thin limbs of henle (dtls), ascending thin li ... | 2012 | 22237592 |
| minimal metabolism, summit metabolism and plasma thyroxine in rodents from different environments. | rodents were live-trapped in three environments (desert, intermediate and coastal) in southern california, usa, chosen because of the taxonomic overlap of species. upon capture, blood samples were taken and plasma thyroxine concentrations were measured. four species (dipodomys merriami, perognathus fallax, peromyscus eremicus and peromyscus californicus) were returned to the laboratory for measurement of minimal and summit rates of metabolism. heteromyid rodents had significantly lower plasma th ... | 2010 | 2863060 |
| nematofauna of rodents of the families heteromyidae and cricetidae from the mexican plateau. | as a part of an ongoing project to inventory the helminth parasites of rodents in mexico, 85 specimens of 2 families of rodents were collected from the mexican plateau: cricetidae ( neotoma sp., neotoma leucodon , onychomys arenicola , peromyscus sp., peromyscus eremicus , and reithrodontomys sp.) and heteromyidae ( chaetodipus sp., chaetodipus eremicus , chaetodipus hispidus , dipodomys merriami , dipodomys ordii , dipodomys ornatus, dipodomys spectabilis , liomys irroratus , perognathus sp., a ... | 2017 | 27788020 |
| assessment of mercury concentrations in small mammals collected near las vegas, nevada, usa. | mercury concentrations in liver and hair tissue were determined for five species of small mammals captured near las vegas, nevada, usa. these data were then used to evaluate the suitability of using hair as a noninvasive technique for determining body burdens of mercury. a total of 104 small mammals were captured and analyzed; four main species were examined and included: dipodomys merriami, chaetodipus penicillatus, peromyscus eremicus, and neotoma lepida. mean mercury concentrations were highe ... | 2006 | 17091502 |
| kangaroo rats change temperature when investigating rattlesnake predators. | predator presence causes acute stress in mammals. a prey animal's stress response increases its chance of survival during life-threatening situations through adaptive changes in behavior and physiology. some components of the physiological stress response can lead to changes in body surface temperatures. body temperature changes in prey could provide information about prey state to predators that sense heat, such as pit vipers. we determined whether wild rodents undergo a stress-induced change i ... | 2017 | 28188761 |
| rattlesnakes are extremely fast and variable when striking at kangaroo rats in nature: three-dimensional high-speed kinematics at night. | predation plays a central role in the lives of most organisms. predators must find and subdue prey to survive and reproduce, whereas prey must avoid predators to do the same. the resultant antagonistic coevolution often leads to extreme adaptations in both parties. few examples capture the imagination like a rapid strike from a venomous snake. however, almost nothing is known about strike performance of viperid snakes under natural conditions. we obtained high-speed (500 fps) three-dimensional v ... | 2017 | 28084400 |
| genetic consequences of postglacial range expansion in two codistributed rodents (genus dipodomys) depend on ecology and genetic locus. | how does range expansion affect genetic diversity in species with different ecologies, and do different types of genetic markers lead to different conclusions? we addressed these questions by assessing the genetic consequences of postglacial range expansion using mitochondrial dna (mtdna) and nuclear restriction site-associated dna (rad) sequencing in two congeneric and codistributed rodents with different ecological characteristics: the desert kangaroo rat (dipodomys deserti), a sand specialist ... | 2015 | 25413968 |
| architecture of vasa recta in the renal inner medulla of the desert rodent dipodomys merriami: potential impact on the urine concentrating mechanism. | we hypothesize that the inner medulla of the kangaroo rat dipodomys merriami, a desert rodent that concentrates its urine to over 6,000 mosmol/kg h(2)o, provides unique examples of architectural features necessary for production of highly concentrated urine. to investigate this architecture, inner medullary vascular segments in the outer inner medulla were assessed with immunofluorescence and digital reconstructions from tissue sections. descending vasa recta (dvr) expressing the urea transporte ... | 2012 | 22914749 |
| the roles of competition and environmental heterogeneity in the maintenance of behavioral variation and covariation. | many models of selection predict that populations will lose variation in traits that affect fitness. nonetheless, phenotypic variation is commonly observed in natural populations. we tested the influences of competition and spatial heterogeneity on behavioral variation within and among populations of merriam's kangaroo rats (dipodomys merriami) and tested for the differential expression of trait correlations. we found that populations of d. merriami exhibited more aggression at sites with more c ... | 2012 | 22834374 |
| does weather shape rodents? climate related changes in morphology of two heteromyid species. | geographical variation in morphometric characters in heteromyid rodents has often correlated with climate gradients. here, we used the long-term database of rodents trapped in the sevilleta national wildlife refuge in new mexico, usa to test whether significant annual changes in external morphometric characters are observed in a region with large variations in temperature and precipitation. we looked at the relationships between multiple temperature and precipitation variables and a number of mo ... | 2009 | 18843477 |
| the effects of owl predation on the foraging behavior of heteromyid rodents. | researchers have documented microhabitat partitioning among the heteromyid rodents of the deserts of north america that may result from microhabitat specific predation rates; large/bipedal species predominate in the open/risky microhabitat and small/quadrupedal species predominate in the bush/safer microhabitat. here, we provide direct experimental evidence on the role of predatory risk in affecting the foraging behavior of three species of heteromyid rodents: arizona pocket mouse (perognathus a ... | 1988 | 28312021 |
| the influence of ambient temperature, seed composition and body size on water balance and seed selection in coexisting heteromyid rodents. | the water balance of three different sized coexisting species of heteromyid rodents (dipodomys merriami ca. 39 g;perognathus fallax ca. 23 g;perognathus longimembris ca. 9 g) was assessed while consuming two different diets (either wheat or hulled sunflower) at ambient temperatures of 15-30°c. the metabolism of wheat as the sole food source was calculated to provide a greater metabolic water production (mwp) than the consumption of sunflower seed because of their different composition. the state ... | 1988 | 28312426 |
| effects of chemical smokes on flora and fauna under field and laboratory exposures. | various types of obscurant smokes are used routinely in training by the u.s. army. because continued routine use of the smokes could be detrimental to the native flora and fauna at training sites, a preliminary biological and chemical field study of fogoil, hexachloroethane, and tank diesel smokes was conducted. smoke plumes were sampled and chemically analyzed at distances of 15-150 m from the smoke source where tradescantia clones 4430 and 03 and the native plant ambrosia dumosa and the native ... | 1987 | 2440659 |
| role of urine in coordinating reproduction in a desert rodent (dipodomys merriami). | detection of reproductive status from chemical signals in the urine of a desert rodent was examined. intact and castrated male and estrous (induced) and nonestrous (ovariectomized) female dipodomys merriami were tested for their preferences for various combinations of water and urine from intact males, estrous females, castrated males, and nonestrous females. intact and castrated males were also tested for their responses to urine from females at different stages of the reproductive cycle: proes ... | 1985 | 4039824 |
| experimental field evidence of interspecific aggression between two species of kangaroo rat (dipodomys). | the competitive coexistence of heteromyid rodents has been primarily ascribed to differential utilization of resources such as microhabitats and seeds. an examination of the use of space by the kangaroo rat dipodomys merriami indicates this species is aggressively subordinate to a larger species, dipodomys spectabilis and is excluded from the larger species home range during the crtical fall harvesting season. these experiments suggest that interspecific aggression may be involved in the coexist ... | 1983 | 25024151 |
| microhabitat use in coexisting desert rodents-the role of population density. | among some species of sonoran desert rodents microhabitat differences are density dependent. i studied the differences in microhabitat use among four species of heteromyid rodents (dipodomys merriami, perognathus amplus, p. baileyi, and p. penicillatus) at low and at high population densities. microhabitats are defined by the abundance and size distribution of desert shrubs. during a period of low population density the rodent species showed substantial microhabitat differentiation. following a ... | 1981 | 28309046 |
| eimeria chihuahuaensis sp.n. and other coccidia from dipodomys spp. in el paso county, texas. | dipodomys merriami mearns and dipodomys ordi woodhouse were surveyed for coccidia in el paso county, texas. infections with eimeria chobotari, eimeria dipodomysis and eimeria balphae were 24.8%, 4.4%, and 11%, respectively, for d. ordi. dipodomys merriami had an infection level of 23.8% with e. chobotari. four animals concurrently harbored e. chobotari and e. balphae or e. dipodomysis or a new species eimeria chihuahuaensis. male and female host infection levels were not significantly different. ... | 1980 | 7218182 |
| morphological study of the desert heteromyid kidney with emphasis on the genus perognathus. | the renal morphology of three species of desert dwelling perognathus rodents were compared to dipodomys and two species of sympatric cricetid rodents. perognathus has a highly adapted unipolar kidney capable of urine concentration up to 7,500 mosm/kgh2o. two major modifications were observed in these kidneys. (1) there is elongation of both the inner and outer medulla. when the thickness of the regions in p. penicillatus are factored by kidney weight it is found that the outer medulla is 3.8 and ... | 1979 | 475010 |
| aerobic and anaerobic metabolism during activity in small rodents. | analysis of oxygen consumption and lactic acid formation during five minutes of maximal activity by the rodents microtus montanus (cricetidae) and dipodomys merriami (hetermyidae) indicates that: (1) anaerobiosis provides approximately 10% of total energy utilized during the 5-minute activity period; (2) anaerobiosis may account for as much as one-third of total energy utilized during the first 30 seconds of activity. in addition, these data indicate at least one species of lizard may be capable ... | 1979 | 381568 |
| a functional analysis of ankle extension in the ricochetal rodent (dipodomys merriami). | | 1977 | 578082 |
| rainfall and fluctuating plant populations in relation to distributions and numbers of desert rodents in southern nevada. | fluctuations in rainfall and size of desert rodent and plant populations for each of five consecutive years were documented on 68 sites in mojave, great basin, and transition desert communities of central-southern nevada. post-reproduction rodent densities in the summer usually followed the seasonal patterns of winter annual success the previous spring, in turn directly related to the success of germination the preceding autumn.in the "dipodomys merriami environment", at the lower elevations wit ... | 1976 | 28308851 |
| perturbation analysis of competition and overlap in habitat utilization between dipodomys ordii and dipodomys merriami. | the populations of two coexisting species of dipodomys (heteromyidae, rodentia) were manipulated on 10, large, unenclosed, trapping grids. these manipulations revealed that, although many kangaroo rats are established residents in an area, a large number are transient individuals who quickly occupy vacated habitats. on plots from which residents had been removed, transients settled at rates of up to 5% of carrying capacity per day. these immigrants were invariably of the same species that was re ... | 1975 | 28308827 |
| chromosome banding and dna replication studies on a cell line of dipodomys merriami. | | 1974 | 4141958 |
| kangaroo rats revisited: re-evaluating a classic case of desert survival. | kangaroo rats are the archetypical organisms for mammalian survival in north american deserts, yet there are contradictions in the data surrounding their physiology and ecology. the traditional view has been that these nocturnal rodents have little tolerance to high temperatures (e.g., >30°c), reside in cool, humid burrows to escape the heat of the day, and nearly exclusively rely on a dry, carbohydrate-rich diet from which they metabolically derive most of their water supply. to test this view, ... | 2002 | 28466177 |
| food caching and differential cache pilferage: a field study of coexistence of sympatric kangaroo rats and pocket mice. | ecologists studying sympatric heteromyid rodents have sought evidence for species differences in primary foraging abilities and preferences and/or behavioural responses to predation risk in order to explain coexistence. the present field study was conducted to test the hypothesis that another factor may be involved, namely differences in caching patterns, which may result in differences in vulnerability to pilferage. we examined differences between kangaroo rats (dipodomys merriami) and pocket m ... | 2001 | 28547403 |
| is species richness driving intra- and interspecific interactions and temporal activity overlap of a hantavirus host? an experimental test. | high species diversity of the potential animal host community for a zoonotic pathogen may reduce pathogen transmission among the most competent host, a phenomenon called the "dilution effect", but the mechanisms driving this effect have been little studied. one proposed mechanism is "encounter reduction" where host species of low-competency decrease contact rates between infected and susceptible competent hosts, especially in directly transmitted diseases. we conducted an experiment in outdoor e ... | 2017 | 29141047 |
| can we predict the success of a parasite to colonise an invasive host? | to understand whether a parasite can exploit a novel invasive host species, we measured reproductive performance (number of eggs per female per day, egg size, development rate and size of new imagoes) of fleas from the negev desert in israel (two host generalists, synosternus cleopatrae and xenopsylla ramesis, and a host specialist, parapulex chephrenis) when they exploited either a local murid host (gerbillus andersoni, meriones crassus and acomys cahirinus) or two alien hosts (north american h ... | 2018 | 29797081 |
| intercontinental test of constraint-breaking adaptations: testing behavioural plasticity in the face of a predator with novel hunting strategies. | constraint-breaking adaptations are evolutionary tools that provide a mechanism for incumbent-replacement between species filling similar ecological roles. in common-garden experiments, we exposed populations of two desert rodents to two different viper species, testing their ability to adjust to novel predators that use different hunting strategies. we aimed to understand whether both predators and prey with constraint-breaking adaptations actually manifest comparative advantage over their coun ... | 2020 | 32271948 |
| functional connectivity and home range inferred at a microgeographic landscape genetics scale in a desert-dwelling rodent. | gene flow in animals is limited or facilitated by different features within the landscape matrix they inhabit. the landscape representation in landscape genetics (lg) is traditionally modeled as resistance surfaces (rs), where novel optimization approaches are needed for assigning resistance values that adequately avoid subjectivity. also, desert ecosystems and mammals are scarcely represented in lg studies. we addressed these issues by evaluating, at a microgeographic scale, the effect of lands ... | 2019 | 30680126 |
| uterine receptivity in merriam's kangaroo rat (dipodomys merriami). | the uterine surface undergoes significant remodeling, termed the "plasma membrane transformation," during pregnancy to allow for implantation of the blastocyst and formation of the placenta in viviparous amniote vertebrates. unlike other species within the superorder euarchontoglires, which have a hemochorial (highly invasive) placenta, kangaroo rats (dipodomys spp.) exhibit a less invasive endotheliochorial placenta. we characterized the changes that occur to membrane molecules and the cellular ... | 2018 | 30288962 |
| molecular detection of leptospira interrogans and borrelia burgdorferi in wild rodents from mexico. | leptospirosis and lyme borreliosis are zoonotic emerging diseases of global importance and wide distribution. the aim of this study was to detect by molecular testing to leptospira interrogans and borrelia burgdorferi sensu lato in wild rodents from nuevo leon, quintana roo, and campeche, mexico. this study is the first in report to chaetodipus nelsoni, dipodomys merriami, and peromyscus eremicus infected with l. interrogans in mexico. besides, chaetodipus hispidus, heteromys gaumeri, heteromys ... | 2020 | 32639187 |