Reithrodontomys Fulvescens Research Articles

New Eastern Geographic Distribution Records ofReithrodontomys fulvescens(Fulvous Harvest Mouse)

The current documented Reithrodontomys fulvescens (Fulvous Harvest Mouse) distribution includes western Mississippi. Here, we report new geographic distribution records in east-central Mississippi. We conducted live-trapping in Kemper County, MS, during the summers of 2011–2015, and captured both Fulvous Harvest Mice and Reithrodontomys humulis (Eastern Harvest Mouse). We compared measurements from captured Fulvous and Eastern Harvest Mice to verify presence of both species. Our results showed 2 separate clusters of measurements, independent of our species assignment in the field, and the clusters were significantly different (P < 0.01). It is unclear whether these new records represent a range expansion or new information about the species' historical distribution.

Morphology and stomach content of the Goldman´s diminutive woodrat Nelsonia goldmani (Cricetidae: Neotominae)

Goldman´s diminutive woodrat (Nelsonia goldmani) is an endemic rodent that inhabits the temperate and humid environments of the central highlands of Mexico. This species is considered uncommon because of the scarce and dispersed information about specimens collected across the Faja Volcanica Transmexicana. Therefore, it is crucial to generate new information about the basic biology of N. goldmani, which so much is unknown thus far. We present the morphological description of the stomach and its content from one specimen of N. goldmani. We performed a longitudinal bisection and washing of stomach from one adult male collected at the Natural Park “Las Penas” in the municipality of Jilotepec, Estado de Mexico, Mexico. The macroscopic structures of the stomach were described by observation in a stereoscopic microscope. The stomach content was mounted on sliders and its components were identified and photographed with an optical microscope. According to the gastric glandular epithelium distribution, N. goldmani have a bilocular-discoglandular stomach with a characteristic fornix ventricularis slightly elongated horizontally. The stomach content was composed by several plant items: epidermal tissues of steam and leaves of angiosperms, pollen of gymnosperms, spores of ferns, fungi and animal tissue like mouth appendages and legs of insects. The stomach morphology was similar to the N. neotomodon and the peromyscine Neotomodon alstoni described previously, but the flattened and elongated fornix ventricularis found in N. goldmani was distinctive. Nonetheless, this structure can vary between individuals and mainly depends of the amount of food before dissection. The plant material found in the stomach was similar to that reported in other rodents that inhabit in similar environments to the highlands of central Mexico, such as Peromyscus aztecus, P. difficilis and Reithrodontomys fulvescens.

Muleshoe Virus and Other Hantaviruses Associated with Neotomine or Sigmodontine Rodents in Texas.

The broad objective of this study was to increase our knowledge of Muleshoe virus and other hantaviruses associated with cricetid rodents in Texas. Anti-hantavirus antibody was found in 38 (3.2%) of 1171 neotomine rodents and 6 (1.8%) of 332 sigmodontine rodents from 10 Texas counties; hantaviral RNA was detected in 23 (71.9%) of 32 antibody-positive rodents. Analyses of nucleocapsid protein gene sequences indicated Muleshoe virus infection in four hispid cotton rats (Sigmodon hispidus) from northern Texas; Bayou virus, three Texas marsh oryzomys (Oryzomys texensis) from the Gulf Coast; Limestone Canyon virus, five brush mice (Peromyscus boylii) from western Texas; and Sin Nombre virus-five Texas mice (P. attwateri), one Lacey's white-ankled deer mouse (P. laceianus), four white-footed mice (P. leucopus), and one fulvous harvest mouse (Reithrodontomys fulvescens) from northern, central, or southern Texas. The results of this study together with the results of a previous study revealed that Muleshoe virus, perhaps in association with S. hispidus, is distributed across northern Texas. Finally, the results of Bayesian analyses of glycoprotein precursor (GPC) gene sequences and pairwise comparisons of complete GPC (amino acid) sequences strengthened support for the notion that Muleshoe virus is distinct from Black Creek Canal virus, Bayou virus, and all other species included in the Bunyaviridae, genus Hantavirus.

Low-basal area treatment and prescribed fire to restore oak-pine savannas alter small mammal communities

Following decades of fire suppression many oak-pine savanna ecosystems have shifted to closed-canopied forests. Restoration of these ecosystems to their savanna condition is seen as a way to reduce woody species encroachment and dangerous fuel loads, and restore community species composition. The management practices to achieve these goals typically involve thinning and prescribed fire. We assessed how thinning to reduce basal area combined with frequent prescribed fire influenced small mammal communities and their habitat. We focused on six habitat variables that can influence small mammal abundance and species composition: stand basal area of live trees and snags, volume of coarse woody debris, percent ground cover, forest floor depth, and distance of vulnerability, a measure of understory vegetation structure and animal vulnerability to predators. Although savanna restoration reduced basal area by 80%, there was no change in snag density or coarse woody debris volume. Savanna restoration significantly increased the ground cover of graminoids, forbs, bare ground, and down woody debris and reduced forest floor depth and distance of vulnerability. These habitat changes likely contributed to the significant differences between small mammal communities in restored and non-restored stands. Restoration treatments caused a large increase in abundance of White-footed Mouse (Peromyscus leucopus) and important changes in community assemblages. Least Shrew (Cryptotis parva), Fulvous Harvest Mouse (Reithrodontomys fulvescens), Eastern Harvest Mouse (R. humulis), and Hispid Cotton Rat (Sigmodon hispidus) were caught only in restored stands, while House Mouse (Mus musculus), Plains Harvest Mouse (R. montanus), and Texas Mouse (P. attwateri) were caught only in non-restored stands.

Influence of vegetation type and season on rodent assemblage in a Mexican temperate forest mosaic

Knowing the factors that influence abundance, distribution and species richness is key to establish local conservation strategies. We evaluated the influence of vegetation type (pine, oak-alder-forest and grassland) and (dry, wet) season on the assemblage rodent in a mosaic of temperate forest in Mexico. The completeness of the inventory was evaluated by nonparametric estimators ACE and Jackknife. We use a generalized linear model to evaluate the effect of vegetation type, season and interaction (vegetation type*season) on the richness and abundance of rodents. The effect of factors and their interaction on the abundance of each species were evaluated with two-way analysis of variance with rank transformations. To analyze changes in the assembly structure we used rank-curves abundances and ANCOVA to assess differences in dominances/evenness of species. We found that rodents were more abundant in the pine forest and during the dry season, but the interaction between oak-alder forest and the dry season also favored abundance. At species level, Peromyscus melanotis was abundant in the pine forest and Reithrodontomys fulvescens in the oak-alder-forest. Between seasons, only the abundance of P. maniculatu s was higher in the dry season than the wet season. The results show that mosaics with trees are of crucial importance for rodent’s conservation during the dry seasons.

Effects of habitat modification on cotton rat population dynamics and rodent community structure

Concerns over climate change and finite fossil fuels have generated interest in biofuels. Switchgrass (Panicum virgatum), a biofuel feedstock, was planted in intensively managed loblolly pine (Pinus taeda) stands to investigate sustainability of this system for producing an alternative energy source. We hypothesized that changes in understory habitat conditions caused by intercropping switchgrass in pine stands would affect rodent population and community dynamics within three years. Therefore, we assessed effects of three treatments (control pine, switchgrass intercropped in pine, and switchgrass monocrop) on rodent population (abundance, survival, and recruitment) and community (diversity, richness, evenness, and community assemblages) measures. We conducted vegetation surveys and live-trapping during 2013–2015 summers in Kemper County, Mississippi, USA. We conducted 6 trapping sessions each summer (n=14,112 trap nights per year) and captured 1,733 cotton rats (Sigmodon hispidus), 102 Oryzomys palustris, 31 Mus musculus, 28 Reithrodontomys fulvescens, 22 Reithrodontomys humulis, 20 Peromyscus leucopus, 9 Microtus pinetorum, 9 Peromyscus gossypinus, and 2 Neotoma floridana. We found greater cotton rat abundance and lower recruitment in monocrop versus control plots. Rodent diversity was lower in monocrop than control plots. Intercropped plots had intermediate levels of cotton rat abundance and recruitment, and rodent diversity. More dispersal may have occurred in monocrop plots because of high population abundance and limited habitat availability. Cotton rat survival and rodent community assemblage were similar among treatments but differed among years. Although rodents responded negatively to monocrop plots, our results suggested intercropped plots would be an appropriate management practice in pine plantations to produce biofuel feedstocks while maintaining rodent diversity.

Survey of a Rodent and Tick Community in East-Central Texas

We conducted a survey of rodents and ticks in Brazos County in east-central Texas to learn more about native fauna that may be involved in enzootic transmission of pathogens that can cause tick-borne diseases in this region. Our objectives were to describe the species richness and seasonal activity of rodents, as well as to document their infestation with ticks over time. We captured 5 rodent species over the course of 19 months: Sigmodon hispidus (Hispid Cotton Rat), Reithrodontomys fulvescens (Fulvous Harvest Mouse), Peromyscus leucopus (White-footed Mouse), Peromyscus gossypinus (Cotton Mouse), and Baiomys taylori (Northern Pygmy Mouse). We observed a large increase in Hispid Cotton Rat capture success in the fall of 2013, reflecting a characteristic population boom periodically exhibited by this species. Overall tick-infestation prevalence of rodents was low (2.3%), and was comprised of juvenile ticks of 2 species—Amblyomma maculatum (Gulf Coast Tick) and Ixodes scapularis (Blacklegged Tick). The co-occurrence of tick vectors and rodent species that are known reservoirs of tick-borne pathogens underscores the importance of studies to assess tick-borne disease risk in the region.

Habitat associations of the rodent community in a Grand Prairie preserve

We measured habitat associations in the rodent fauna at the Lyndon B. Johnson National Grassland in north-central Texas from May to August 2011. We recorded five species: hispid cotton rat (Sigmodon hispidus) was most abundant, followed by deer mouse (Peromyscus maniculatus), hispid pocket mouse (Chaetodipus hispidus), fulvous harvest mouse (Reithrodontomys fulvescens), and white-footed mouse (P. leucopus). Cotton rat density increased with grass cover; this effect was stronger for lower and middle quantiles of the abundance distribution. We found weak habitat correlates for P. maniculatus and R. fulvescens. This report is one of few describing the mammalian fauna of the vanishing Grand Prairie ecoregion.

Multiple captures of fulvous harvest mice (Reithrodontomys fulvescens) and northern pygmy mice (Baiomys taylori): evidence for short-term co-traveling

Multiple captures of small mammals (finding &gt;1 animal in a single trap) are often used to infer pair-bonding activity in arvicoline and cricetine rodents. We analyzed data from a 2-year trapping study to determine whether fulvous harvest mice ( Reithrodontomys fulvescens J.A. Allen, 1894) and (or) northern pygmy mice (Baiomys taylori (Thomas, 1887)) travel in mixed-sex mated pairs. A significant majority of multiple capture events (MCEs) in R. fulvescens were mixed-sex, whereas sex composition of pairs in B. taylori did not differ from random. Multiple capture probability was significantly positively related to abundance and unrelated to sex ratio in both species. Multiple captures of B. taylori were more common in winter, suggesting that individuals may associate to huddle for warmth. Masses of singly captured and multiply captured individuals were not significantly different in either species, contraindicating trap bias. Only one co-captured mixed-sex pair was recaptured as a pair (in R. fulvescens) and several animals of both sexes in both species were co-captured with multiple individuals. We concluded that R. fulvescens co-travels with mates for variable lengths of time, but we found no evidence that multiple captures of B. taylori are related to reproductive behavior.

Co-occurrence of small mammals in a tropical dry deciduous forest: comparisons of communities and individual species in Colima, Mexico

Abstract:Species co-occurrence is an important ecological research area. Mark-and-recapture studies of mammals allow identification of coexisting species, a necessary step in determining mechanisms enabling habitat sharing. Using data from five 1-ha grids in January 2004 in tropical dry deciduous forest of coastal Colima, Mexico, we detected significantly more interspecific overlap than expected between seven species pairs. Oryzomys couesi shared more stations than expected with Sigmodon mascotensis, Baiomys musculus and Peromyscus perfulvus. Baiomys musculus was associated positively with S. mascotensis and Reithrodontomys fulvescens. Heteromys pictus shared fewer stations than expected with O. couesi and S. mascotensis. For species collectively, there was non-random community structuring, with two grids displaying more species aggregation than expected. While two grids had non-random co-occurrence patterns, three grids did not differ from random, which differs from that reported for mammalian taxa on average. Other small-mammal studies have documented species segregation, while this study detected more positive than negative associations. Similarities in preference and habitat use (or diet) are likely explanations for interspecific overlap patterns at stations and co-occurrence patterns among grids. Simultaneously evaluating associations of species pairs and all species on a grid collectively is novel methodology as applied to mammals, adding to understanding of species co-occurrence.

Ácaros parásitos de roedores de Playa de Oro, Colima, México

Se reportan ácaros ectoparásitos en roedores colectados durante un estudio ecológico en Playa de Oro, en el estado de Colima, México. Los roedores revisados fueron: Heteromys pictus, Heteromys spectabilis, Baiomys musculus, Nyctomys sumichrasti, Oryzomys couesi, Oryzomys melanotis, Osgoodomys banderanus, Reithrodontomys fulvescens y Sigmodon mascotensis. Se registra la presencia de varias especies de ácaros de las familias Laelapidae, Macronyssidae, Listrophoridae y Myocoptidae en nuevos huéspedes y de algunas más se amplía su distribución. Se registra por primera vez para México a Lepidoglyphus hylandi, Laelaps oryzomydis y Prolistrophorus bakeri.

Interspecific variability in the abundance of small rodents in the highlands of Chiapas, Mexico

En este estudio proporcionamos datos sobre la abundancia y composicion de especies de pequenos roedores durante un ciclo anual en cuatro localidades representadas por dos habitats contrastantes: cultivos de maiz y Reservas Ecologicas, en el Municipio de San Cristobal de Las Casas, Chiapas. Se registraron en total 469 capturas de nueve especies de roedores muridos, de las cuales las mas abundantes fueron Reithrodontomys fulvescens, Sigmodon hispidus y Peromyscus levipes. El mayor numero de capturas (272) se registro durante la epoca seca y la mayor riqueza de especies (7) durante la epoca de lluvia en un area agricola. Encontramos diferencias significativas en el numero de capturas en epoca seca y de lluvia solamente para la Reserva Ecologica Moxviquil

Seasonal Dynamics of Small Mammals and Vegetation in A Gulf Cordgrass Community

Abstract We compared small mammals in Gulf cordgrass (Spartina spartinae) to coastal-prairie and low-marsh, Spartina alterniflora communities, and we considered the effect of standing-crop biomass and nutrient concentration in plants in the Gulf cordgrass community on dynamics of populations of small mammals. We predicted lower species richness and density of small mammals and shorter residence time in Gulf cordgrass because of little vertical habitat structure, sparse ground cover, and low abundance of dicots, plants that contain nutrients necessary for reproduction by hispid cotton rats (Sigmodon hispidus). Richness in Gulf cordgrass (seven species of rodents) was similar to coastal prairie (six species plus three non-native rodents) with S. hispidus and fulvous harvest mice (Reithrodontomys fulvescens) numerically dominant in both communities. Density of S. hispidus was higher in Gulf cordgrass likely reflecting high standing-crop biomass; however, lack of ground cover contributed to low residence time...

Bayou virus detected in non-oryzomyine rodent hosts: an assessment of habitat composition, reservoir community structure, and marsh rice rat social dynamics

In the United States, Bayou virus (BAYV) ranks second only to Sin Nombre virus (SNV) in terms of hantavirus pulmonary syndrome (HPS) incidents, having been confirmed in cases from Texas and Louisiana since its discovery in 1994. This study on BAYV infection among sympatric, non-oryzomyine rodents ("spillover") in Freeport, TX, is the first to link patterns of hantavirus interspecific spillover with the spatiotemporal ecology of the primary host (marsh rice rat, Oryzomys palustris). Mark-recapture and/or harvest methods were employed from March 2002 through May 2004 in two macrohabitat types. Rodent blood samples were screened for the presence of IgG antibody to BAYV antigen by IFA after which Ab-positive blood, saliva, and urine were analyzed for the presence of viral RNA by nested RT-PCR. From 727 non-oryzomyine captures, five seropositive (but not viral RNA positive) individuals were detected: one each of Baiomys taylori, Peromyscus leucopus, and Reithrodontomys fulvescens; and two Sigmodon hispidus. Spillover hosts were not associated with macrohabitat where O. palustris abundance, density, or seroprevalence was highest. Rather, spillover occurred in the macrohabitat indicative of greater overall disturbance (as indicated by grazing and exotic plant diversity) and overall biodiversity. Spillover occurred during periods of high seroprevalence detected elsewhere within the study region. Spillover locations differed significantly from all other capture locations in terms of percent water, shrub, and grass cover. Although greater habitat and mammal diversity of old-fields may serve to reduce seroprevalence levels by tempering intraspecific contacts between rice rats, greater diversity also may create an ecologically opportunistic setting for BAYV spillover. Impacts of varying levels of disturbance and biodiversity on transmission dynamics represent a vastly uncharacterized component of the evolutionary ecology of hantaviruses.

Protein Nutrition of Southern Plains Small Mammals: Immune Response to Variation in Maternal and Offspring Dietary Nitrogen

Maternal nutrition during pregnancy and postnatal offspring nutrition may influence offspring traits. We investigated the effects of maternal and postweaning offspring dietary nitrogen on immune function and hematology in two species of rodent: the hispid cotton rat (Sigmodon hispidus), a primarily herbivorous rodent, and the fulvous harvest mouse (Reithrodontomys fulvescens), an omnivore. These two species responded differently to the same levels of treatment, with cotton rats primarily influenced by maternal diet and harvest mice by postweaning offspring diet. Cotton rats born to mothers on high-nitrogen diets had lower values of mean corpuscle volume and hemoglobin and greater concentrations of serum immunoglobulins. Spleen size, cell-mediated immune response, and the number of splenocytes and thymic platelets were lower in cotton rats born to mothers on low- and high-nitrogen diets. High-nitrogen offspring diet increased kidney and liver mass in cotton rats. Harvest mice had increased kidney mass on high-nitrogen maternal diets; however, changes in offspring diet after weaning reduced hematological parameters in individuals fed low-nitrogen diets. Body length was also affected, with harvest mice born to mothers fed low- and high-nitrogen diets having shorter lengths. Splenocyte cellular activity was greater in offspring born to mothers on high-nitrogen diets in both species.

Rodents New to the Diet of the Western Burrowing Owl (Athene cunicularia hypugaea)

The northern pygmy mouse (Baiomys taylori), fulvous harvest mouse (Reithrodontomys fulvescens), and Merriam's pocket mouse (Perognathus merriami) are new to the diet of the western burrowing owl (Athene cunicularia hypugaea). All three species were identified from remains in regurgitated pellets collected from roost sites of burrowing owls in southern Texas over a period of 4 winters. Together, northern pygmy mice and fulvous harvest mice represented 58% of mammals identified in 182 pellets regurgitated by western burrowing owls. Merriam's pocket mouse accounted for only 4% of identified mammalian prey. Frequency of occurrence in pellets was 16% for northern pygmy mice, 11% for fulvous harvest mice, and 3% for Merriam's pocket mice. The primary reason for absence of these species in previous studies of foods of western burrowing owls is that most were conducted in latitudes north of these southern-distributed species of mammals.

Small mammals as indicators of short-term and long-term disturbance in mixed prairie

Disturbance by military maneuvers over short and long time scales may have differential effects on grassland communities. We assessed small mammals as indicators of disturbance by military maneuvers in a mixed prairie in southern Oklahoma USA. We examined sites on two soil series, Foard and Lawton, across a gradient of disturbance intensity. A MANOVA showed that abundance of small mammals was associated (p = 0.03) with short-term (cover of vehicle tracks) disturbance but was not associated (p = 0.12) with long-term (loss of soil organic carbon, SOC) disturbance intensity. At the individual species level, Sigmodon hispidus (cotton rat) and Peromyscus maniculatus (deer mouse) occurred across all levels of disturbance and in both soil types. Only P. maniculatus abundance changed (p < 0.01) with short-term disturbance and increased by about one individual per 5% of additional track-cover. Abundance of P. maniculatus also increased (p = 0.04) by about three individuals per 1% increase in soil carbon. Chaetodipus hispidus (hispid pocket mouse) and Reithrodontomys fulvescens (fulvous harvest mouse) only occurred in single soil types limiting their potential as more general indicators. Abundance of P. maniculatus was positively related to shifts in plant species composition and likely reflected changes in vegetation structure (i.e. litter depth) and forage availability resulting from disturbance. Peromyscus maniculatus may be a useful biological indicator of ecosystem change because it responded predictably to both long-term and short-term disturbance and, when coupled with soil, plant, and disturbance history variables, can reveal land condition trends.

DIET OF WESTERN BURROWING OWLS WINTERING IN SOUTHERN TEXAS

ABSTRACT Winter diets of the western Burrowing Owl (Athene cunicularia hypugaea) are little known. We determined the diet of western Burrowing Owls wintering in southern Texas by analyzing the contents of 182 pellets collected over four winters (1999–2000, 2001–2002, 2002–2003, and 2003–2004) in three habitat types (agricultural, mainland grassland, and barrier island). Remains of a total of 7476 prey items were recovered, 98% of which were arthropods. Gryllidae (crickets) formed the largest component (50%) of the prey, followed by lepidopteran larvae (13%), beetles (8%), spiders (7%), and earwigs (6%). Although vertebrates, primarily small mammals and birds, represented only 2% of prey items by number, they represented most (71%) of the biomass. Northern pygmy mice (Baiomys taylori) and fulvous harvest mice (Reithrodontomys fulvescens) were the two most frequently consumed vertebrate species. In all habitats, arthropods, especially orthopterans, were the primary prey item by number, whereas vertebrates, ...

A LONGITUDINAL STUDY OF BAYOU VIRUS, HOSTS, AND HABITAT

What is currently known about the ecology of North American hantaviruses has come largely from studies on Sin Nombre virus (SNV). We conducted a longitudinal study of Bayou virus (BAYV), the second-leading agent of hantavirus pulmonary syndrome in the United States. Antibodies to hantavirus were detected from Oryzomys palustris (most commonly infected species), Sigmodon hispidus, Peromyscus leucopus, Reithrodontomys fulvescens, and Baiomys taylori. However, only O. palustris had viral RNA in tissues and excreta, suggesting that antibodies detected in other species may have resulted from spill-over infection. Seroprevalence rates averaged around 16% for O. palustris and varied seasonally. The heaviest males exhibited the highest levels of seroprevalence. Seroprevalence was higher in coastal prairie (20.0%) than old-fields (10.5%) and was associated with host abundance. These patterns are similar to those of SNV and can be used in identification of potentially at-risk areas.

Small-mammal responses to pine regeneration treatments in the Ouachita Mountains of Arkansas and Oklahoma, USA

We compared the initial effects of four forest regeneration treatments (single-tree selection, group selection, shelterwood, and clearcut), and unharvested controls (mature, second-growth forest) on relative abundance of small mammals and small-mammal habitat throughout the Ouachita Mountains of western Arkansas and eastern Oklahoma. We compared small-mammal capture rates in 20 forest stands (4 replicates of 5 treatments) for 2 years prior to harvest treatments, and 1.5, 3.5, and 5.5 years after treatment. We also examined relationships among small mammals, treatments, and habitat conditions. Before harvest, all stands where characterized by high basal areas (BA), little understory vegetation, and low small-mammal capture rates. Compared with pre-harvest numbers, the number of individuals captured increased nearly five-fold in treated stands 1.5 years after harvest. After harvest, capture rates for all taxa combined were significantly greater in harvested stands (regardless of treatment) than in unharvested controls. Fulvous harvest mice ( Reithrodontomys fulvescens) capture rates were greatest in clearcuts. Fulvous harvest mice, cotton rats ( Sigmondon hispidus), and pine voles ( Microtus pinetorum) were associated with abundant herbaceous vegetation in the understory and low BA. Eastern woodrats ( Neotoma floridana), golden mice ( Ochrotomys nuttalli), and Peromyscus spp. were associated with moderate to dense woody vegetation in the understory and intermediate BA levels. No taxon of terrestrial small mammal was captured exclusively in unharvested stands; most taxa we captured appear to be either disturbance-adapted or tolerant to disturbances from timber harvest.