Amy Kuenzi

Montana Tech, Biology, Faculty Member

Followers

Following

Co-authors

Public Views

Rafael Avila-Flores

Universidad Juárez Autónoma de Tabasco

Texas State University

Tyla Holsomback

Nancy Mcintyre

Colleen Jonsson

University of Tennessee Knoxville

Carl Dick

Western Kentucky University

Interests

Uploads

Papers by Amy Kuenzi

Species diversity concurrently dilutes and amplifies transmission in a zoonotic host–pathogen system through competing mechanisms

Proceedings of the National Academy of Sciences of the United States of America, Jul 16, 2018

Download

Heterospecific competitors and seasonality can affect host physiology and behavior: key factors in disease transmission

Ecosphere, Jun 1, 2021

Ecological and environmental factors can influence the transmission of infectious diseases. They ... more Ecological and environmental factors can influence the transmission of infectious diseases. They can accomplish this via effects on host susceptibility and exposure to infection, which are governed by host physiology and behavior, respectively. To better inform disease control, more information is needed about how extrinsic factors affect physiological and behavioral processes that determine transmission. We investigated how heterospecific competitors and seasonality may influence host susceptibility and intraspecific contact rates using a directly transmitted disease system, the North American deer mouse (Peromyscus maniculatus)-Sin Nombre hantavirus (SNV) system. In grasslands of western Montana, USA, deer mice compete with dominant voles (Microtus spp.) and shrews (Sorex spp.) and experience a seasonal temperate climate. Higher SNV transmission occurs primarily during spring/summer, when changes in physiology and behavior may serve as influential contributors. We hypothesized that (1) voles, and to a lesser extent shrews, will induce chronic stress, suppress immunity, and may change contact rates of deer mice; and (2) during spring/summer, deer mice may experience chronic stress, suppressed immunity, and higher contact rates, which may help explain the reported seasonality in SNV transmission. Over two years, we trapped small mammals at four grids in western Montana. Deer mice were sampled for feces and blood and evaluated for scar numbers, demography, and body condition scores (BCSs). We evaluated stress physiology with fecal corticosterone metabolites (FCMs), neutrophil/lymphocyte (N/L) ratios and BCSs, immunity with white blood cell (WBC) counts, and contact rates with scar numbers. We found that shrew density was negatively associated with stress response FCMs, suggestive of chronic stress. Additionally, although complex interactions existed, shrew and vole densities were negatively associated with BCSs, but differentially with scar numbers. N/L ratios were higher in spring/summer, whereas WBC counts were lower in summer, suggestive of chronic stress and suppressed immunity, respectively. Our results suggest that (1) heterospecific competitors may differentially influence disease transmission via stress physiology and contact rates, and that (2) chronic stress, suppressed immunity, and higher contact rates may help explain why higher SNV transmission has been previously reported during spring/summer in Montana. Our findings may extend to other directly transmitted disease systems.

Download

Interspecific Comparison of Hantavirus Prevalence in Peromyscus Populations from a Fragmented Agro-Ecosystem in Indiana, Usa

Journal of Wildlife Diseases, 2018

Download

Short Communication Increased Detection of Sin Nombre Hantavirus RNA in Antibody-Positive Deer Mice from Montana, USA: Evidence of Male Bias in RNA Viremia

Hantaviruses are widespread emergent zoonotic agents that cause unapparent or limited disease in ... more Hantaviruses are widespread emergent zoonotic agents that cause unapparent or limited disease in their rodent hosts, yet cause acute, often fatal pulmonary or renal infections in humans. Previous laboratory experiments with rodent reservoir hosts indicate that hantaviruses can be cleared from host blood early in the infection cycle, while sequestered long term in various host organs. Field studies of North American deer mice (Peromyscus maniculatus), the natural reservoir of Sin Nombre hantavirus, have shown that viral RNA can be transiently detected well past the early acute infection stage, but only in the minority of infected mice. Here, using a non-degenerate RT-PCR assay optimized for SNV strains known to circulate in Montana, USA, we show that viral RNA can be repeatedly detected on a monthly basis in up to 75% of antibody positive deer mice for periods up to 3-6 months. More importantly, our data show that antibody positive male deer mice are more than twice as likely to have detectable SNV RNA in their blood as antibody positive females, suggesting that SNV-infected male deer mice are more likely to shed virus and for longer periods of time.

Download

COMMUNITY ECOLOGY- ORIGINAL PAPER A temporal dilution effect: hantavirus infection in deer mice and the intermittent presence of voles in Montana

The effect of intermittently occurring, non-reservoir host species on pathogen transmission and p... more The effect of intermittently occurring, non-reservoir host species on pathogen transmission and prev-alence in a reservoir population is poorly understood. We investigated whether voles, Microtus spp., which occur intermittently, influenced estimated standing antibody prevalence (ESAP) to Sin Nombre hantavirus (SNV, Bunyaviridae: Hantavirus) among deer mice, Peromyscus maniculatus, whose populations are persistent. We used 14 years of data from central Montana to investigate whether ESAP among deer mice was related to vole presence or abundance while controlling for the relation-ship between deer mouse abundance and ESAP. We found a reduction in deer mouse ESAP associated with the presence of voles, independent of vole abundance. A number of studies have documented that geographic locations which support a higher host diversity can be associated with reductions in pathogen prevalence by a hypothesized dilution effect. We suggest a dilution effect may also occur in a temporal dimensi...

Interspecific Comparison of Hantavirus Prevalence in Peromyscus Populations from a Fragmented Agro-Ecosystem in Indiana, Usa

Journal of wildlife diseases, 2018

Comparatively little is known about hantavirus prevalence within rodent populations from the Midw... more Comparatively little is known about hantavirus prevalence within rodent populations from the Midwestern US, where two species of native mice, the prairie deer mouse ( Peromyscus maniculatus bairdii) and the white-footed mouse ( Peromyscus leucopus noveboracensis), are dominant members of rodent communities. We sampled both species in central Indiana and tested individuals for presence of hantavirus antibodies to determine whether seroprevalence (percent of individuals with antibodies reactive to Sin Nombre virus antigen) differed between species, or among different habitat types within fragmented agro-ecosystems. Prevalence of hantavirus antibodies varied significantly between species, with seroprevalence in prairie deer mice (21.0%) being nearly four times higher than in white-footed mice (5.5%). Seroprevalence was almost eight times higher within the interior of row-crop fields (37.7%) occupied solely by prairie deer mouse populations, relative to field edges (5.2%) or adjacent fo...

Download

Species diversity concurrently dilutes and amplifies transmission in a zoonotic host-pathogen system through competing mechanisms

Proceedings of the National Academy of Sciences of the United States of America, Jul 16, 2018

In this era of unprecedented biodiversity loss and increased zoonotic disease emergence, it is im... more In this era of unprecedented biodiversity loss and increased zoonotic disease emergence, it is imperative to understand the effects of biodiversity on zoonotic pathogen dynamics in wildlife. Whether increasing biodiversity should lead to a decrease or increase in infection prevalence, termed the dilution and amplification effects, respectively, has been hotly debated in disease ecology. Sin Nombre hantavirus, which has an ∼35% mortality rate when it spills over into humans, occurs at a lower prevalence in the reservoir host, the North American deermouse, in areas with higher small mammal diversity-a dilution effect. However, the mechanism driving this relationship is not understood. Using a mechanistic mathematical model of infection dynamics and a unique long-term, high-resolution, multisite dataset, it appears that the observed dilution effect is a result of increasing small-mammal diversity leading to decreased deermouse population density and, subsequently, prevalence (a result ...

Download

Tick‐, mosquito‐, and rodent‐borne parasite sampling designs for the National Ecological Observatory Network

Ecosphere, 2016

Parasites and pathogens are increasingly recognized as significant drivers of ecological and evol... more Parasites and pathogens are increasingly recognized as significant drivers of ecological and evolutionary change in natural ecosystems. Concurrently, transmission of infectious agents among human, livestock, and wildlife populations represents a growing threat to veterinary and human health. In light of these trends and the scarcity of long‐term time series data on infection rates among vectors and reservoirs, the National Ecological Observatory Network (NEON) will collect measurements and samples of a suite of tick‐, mosquito‐, and rodent‐borne parasites through a continental‐scale surveillance program. Here, we describe the sampling designs for these efforts, highlighting sampling priorities, field and analytical methods, and the data as well as archived samples to be made available to the research community. Insights generated by this sampling will advance current understanding of and ability to predict changes in infection and disease dynamics in novel, interdisciplinary, and co...

Download

Toward a Mechanistic Understanding of Environmentally Forced Zoonotic Disease Emergence: Sin Nombre Hantavirus

BioScience, 2015

Understanding the environmental drivers of zoonotic reservoir and human interactions is crucial t... more Understanding the environmental drivers of zoonotic reservoir and human interactions is crucial to understanding disease risk, but these drivers are poorly predicted. We propose a mechanistic understanding of human-reservoir interactions, using hantavirus pulmonary syndrome as a case study. Crucial processes underpinning the disease's incidence remain poorly studied, including the connectivity among natural and peridomestic deer mouse host activity, virus transmission, and human exposure. We found that disease cases were greatest in arid states and declined exponentially with increasing precipitation. Within arid environments, relatively rare climatic conditions (e.g., El Niño) are associated with increased rainfall and reservoir abundance, producing more frequent virus transmission and host dispersal. We suggest that deer mice increase their occupancy of peridomestic structures during spring-summer, amplifying intraspecific transmission and human infection risk. Disease incidence in arid states may increase with predicted climatic changes. Mechanistic approaches incorporating reservoir behavior, reservoir-human interactions, and pathogen spillover could enhance our understanding of global hantavirus ecology, with applications to other directly transmitted zoonoses.

Download

Hantavirus Transmission in Sylvan and Peridomestic Environments

Bulletin of Mathematical Biology, 2009

Bat Distribution and hibernacula use in west-central Nevada

were 111e TOost (:ammon~lJe{;ies C"dprnrcd. These sJX~ies art' apparently hroadly dhtributed thro... more were 111e TOost (:ammon~lJe{;ies C"dprnrcd. These sJX~ies art' apparently hroadly dhtributed throughout west central "twada, occurring in a variety ofhabihl.l types. We captured EudenM maculatum at 2 localities. 111est' reprcsclll the 1st l.:nowll records of Ihis species in Esmeralda COlmLy. I\cvada. Mine adits wcn~surveyed for hibernating hats from Dccelllb~r J994, throu~h 1:'cbruary 1905. \\'e determined the presence of 3 hibemating species: C. touJtlsendii, M. ciliolabrum, i111d P. hesperus. Bats were present in 19 of 70 mines (27%) W~surveyed i1t eJeV'"Jtions ranging from 1.500 III to 2460 Ill. C. townsendii walt the most comlllon species eTl("oullh~J1:X.l. Our study provides some mtlch~ne{.'(lcd haseline data on Inll dilitl'.ihuhofl and use of miues for hihernacl.11a in west cent tal Nevada.

Download

A study design to provide information for the bird-aircraft strike hazard programs

Bird-aircraft strikes are a major concern to the entire aviation community. We developed a study ... more Bird-aircraft strikes are a major concern to the entire aviation community. We developed a study to provide the Navy with infomation concerning avian use of agricultural lands on and near selectedNava1 bases in Arizona, California, and Nevada. With this knowledge a management program can be implemented to reduce hazardous bird-aircraft stikes. Permanent census points were established for observing flight patterns of birds at each base. In addition, transect lines were used to observe habitat use by birds in and around agricultural fields on each base. Habitat types and an estimated percent of that habitat within a 200-mradius were recorded. Habitat classifications that were more specific than those used in the current Wildlife Habitat Relationships (WHR) system (data base) were given. Percent usage of habitats was estimated for 2 study sites and compared with the WHR system. Habitat use differed by species and crop type. These differences tended to be overlooked when using the WHR classifications. Our study design can be used for determinining the species composition and abundance of birds on a seasonal basis and relating that to crop types and crop phenology. Expansion of the current Wildlife Habitat Relationship (WHR) Data Base to include more specific agricultural habitat classifications is suggested.

Download

Habitat Use and Abundance Trends of Rodents in Southeastern Arizona

The Southwestern Naturalist, 2002

We evaluated habitat use, abundance trends, and potential relationships between biotic and abioti... more We evaluated habitat use, abundance trends, and potential relationships between biotic and abiotic conditions and characteristics of rodent assemblages in southeastern Arizona. In May 1995 we established 3 sampling webs in the semidesert grassland at the Santa Rita Experimental Range, Pima County, Arizona. Mark-release trapping was conducted for 3 nights monthly through December 1999. Drought conditions occurred in 1995, moderate rainfall fell during 1996 through 1998, and heavy rainfall fell in 1999. The same pattern of rodent abundance was observed on all 3 webs. With the exception of white-throated woodrats (Neotoma albigula), rodents in our study responded numerically to increased rainfall. Additionally, the pattern of changes in abundance was similar for all species and sexes within species on all 3 sampling webs. There were, however, significant differences in the absolute abundance of many species among the webs. Differences among webs in rodent abundance were related to differences in plant associations among the webs. We found substantial temporal and age-related differences in habitat use for several species. The riparian area was strongly related to the occurrence of brush mice (Peromyscus boylii), white-footed mice (P. leucopus), and woodrats. Our results have specific ramifications in relatively fine-scale planning for restoration of desert plant communities.

Effects of Sampling Blood on Survival of Small Mammals

Journal of Mammalogy, 1997

We assessed mortality due to handling and survival of small mammals that had been anesthetized an... more We assessed mortality due to handling and survival of small mammals that had been anesthetized and then bled through the orbital sinus during a I-year study in southeastern Arizona. Rates of return and mortality due to handling were not significantly different between treatment and control for any species. Estimates of survival based on Connack-Jolly-Seber capture-recapture models indicated no significant difference (P < 0.05) in survival for white-throated woodrats (Neotoma albigula) and combined species of mice in the genus Peromyscus. However, for pocket mice (Chaetodipus) mean rates of survival were significantly lower for animals that had been bled. Removing samples of blood from wild rodents appears to have little effect on survival for most species. Lower survival in pocket mice may be due to the effects of anesthesia or the combined effects of bleeding and anesthesia on this desert-adapted animal.

Download

California ground squirrels at Concord Naval Weapons Station: alternatives for control and the ecological consequences

Ear Tags Versus Passive Integrated Transponder (Pit) Tags for Effectively Marking Deer Mice Ear Tags Versus Passive Integrated Transponder (Pit) Tags for Effectively Marking Deer Mice

We examined whether passive integrated transponder (PIT) tags were a more effective marking techn... more We examined whether passive integrated transponder (PIT) tags were a more effective marking technique for a long-term population study of deer mice (Peromyscus maniculatus marking technique for a long-term population study of deer mice (Peromyscus maniculatus marking technique for a long-term population study of deer mice ( ) than ear tags. We compared the number of PIT tags lost to ear tags lost in a population of individuals that received both types of markers. A total of 194 deer mice received both PIT and ear tags and 56.7 percent of these animals were recaptured at least once during the study. We found that PIT tags performed poorly as a marking technique for a mark-recapture study of deer mice using our methods of implantation. The percentage of recaptured individuals that lost PIT tags (31.8%) was significantly higher than the percentage that lost ear tags (8.2%). We recommend further study to determine if alternative tag placement techniques may increase PIT tag retention in this species.

Download

Detection of bats by mist-nets and ultrasonic detectors

Wildlife Society Bulletin

We conducted short-term bat surveys as part of an inventory program at 23 sites in 12 mountain ra... more We conducted short-term bat surveys as part of an inventory program at 23 sites in 12 mountain ranges of west-central Nevada during the summer of 1994. With this information, we compared the number of bat species identified through direct capture in mistnets with the number detected ultrasonically by their echolocation calls. The average number of species detected per site did not differ between the 2 techniques, but neither technique identified all of the bat species present at all sites. Because both mist-netting and ultrasonic detection may incompletely sample bat communities, we advise using both techniques when conducting surveys for bat species presence. Large declines in populations of some North American bat species have been documented (Humphrey 1978, Tuttle 1979, Richter et al. 1993), and 7 species or subspecies of bats are federally listed as endangered (U.S. Fish and Wildl. Serv. 1994). Additional species are thought to be in decline, but lack of baseline data (McCracken 1988), combined with problems in surveying bat populations (Davis et al. 1962, Humphrey 1971), make accurate censuses difficult.

Download

Diets of Desert Mule Deer

Journal of Range Management, 1997

... PAUL R. KRAUSMAN, AMY J. KUENZI, RICHARD C. ETCHBERGER, KURT R. RAUTENSTRAUCH, LEONARD L. ORD... more

Diets of Three Predators at Concord Naval Weapons Station, Contra Costa County, California

Northwestern Naturalist, 1998

... IVETTE LOREDO San Luis National Wildlife Refuge Complex, Los Banos, California 93635 USA ... ... more

Translocation as a Nonlethal Alternative for Managing California Ground Squirrels

The Journal of Wildlife Management, 1997

To evaluate the efficacy of translocation as a nonlethal management alternative, we determined tr... more To evaluate the efficacy of translocation as a nonlethal management alternative, we determined trapability, post-release survival, site fidelity, and homing ability of experimentally translocated California ground squirrels (Spermophilus beecheyi). Trapability of squirrels was low (0.04 captures/trap-day). Most squirrels (71-79%) survived until ?18 days after translocation; mortality was highest shortly after release, and was attributed mostly to predation. Of those squirrels that survived but did not return home, 85% established a new home range, but most settled away from the release site. Homing success decreased with translocation distance. Our data do not support the hypothesis that homing results from navigation, but they do support the hypothesis that homing results from piloting when squirrels are inside their area of familiarity, perhaps extended by visual detection of distant landmarks, and random search when outside. Translocation probably is infeasible for control of squirrels over large areas because of low trapability, but shows potential for smaller localities. Squirrels, however, must be translocated far enough (ca. 1,500 m) to prevent homing, and lack of fidelity to the release site may result in squirrels settling in undesirable locations.

Download

Species diversity concurrently dilutes and amplifies transmission in a zoonotic host–pathogen system through competing mechanisms

Proceedings of the National Academy of Sciences of the United States of America, Jul 16, 2018

Download

Heterospecific competitors and seasonality can affect host physiology and behavior: key factors in disease transmission

Ecosphere, Jun 1, 2021

Download

Interspecific Comparison of Hantavirus Prevalence in Peromyscus Populations from a Fragmented Agro-Ecosystem in Indiana, Usa

Journal of Wildlife Diseases, 2018

Download

Short Communication Increased Detection of Sin Nombre Hantavirus RNA in Antibody-Positive Deer Mice from Montana, USA: Evidence of Male Bias in RNA Viremia

Download