Now showing items 17037-17056 of 39116

    • HAANE’ BITS'Ą́Ą́DÉÉ’: The Process of Diné Education

      Fox, Mary Jo Tippeconnic; Begay, Waylon Nakai; Shirley, Valerie; Zepeda, Ofelia (The University of Arizona., 2020)
      This critical Indigenous qualitative study seeks to examine Diné (Navajo) students’ struggle with success in American mainstream postsecondary institutions. The aim of this research is to explore Diné graduate college student narratives about mainstream higher education and their overall purpose for attending graduate school. The heart of this research is driven by the question: What is the main purpose Diné college students attend mainstream postsecondary institutions in the United States? Two additional questions served as guides: 1.) In what ways is Diné identity & culture important at mainstream postsecondary institutions? 2.) How can mainstream postsecondary institutions incorporate more culturally based frameworks to promote American Indian student success? This study uses the unique framework of Sa’ąh Naagháí Bik’eh Hózhóón (SNBH) philosophy of balance and harmony with the Ałchi Silah (Duality) paradigm identified in Diné Philosophy to examine the overall experiences of Diné college students. In addition, this study draws upon the theoretical framework of Tribal Critical Race Theory (TribalCrit) to map out the depth and scope colonialism and neocolonialism imposes on the experiences of Diné college students in the educational environment of policies and practices, theories(stories) and school traditions of mainstream postsecondary institutions. The specific connection to student success for Diné college students is the deconstruction and reconstruction of the Diné identity in relation to the cultural landscape of U.S. mainstream universities and colleges. A narrative based inquiry (storytelling) approach is utilized to uncover successes, obstacles, and misunderstood factors of mainstream higher education in the U.S. for Diné college students. This study proposes and recommends a Diné centered epistemology to reclaim Diné identity from the hold of 21st century colonialism. A Diné centered epistemology provides within mainstream postsecondary institutions, a space where Diné identity and Diné Philosophy can flourish and benefit Diné people and surrounding communities. A space where a Diné definition of success and education can be envisioned, shared, and honored. The findings of the study emphasize that funding and academic support is needed for not just Navajo college students, but all Indigenous students. In addition, the findings illustrate a real need for an Indigenous designed space within mainstream postsecondary institutions. A site where Natives could have prayer ceremonies and collaborate alongside Native healers and leaders to create curriculum that highlights Indigenous languages and cultures. A place that houses strategic academic guidance from well-informed Indigenous teachers and leaders who work closely with Native Nation (re)Building concepts. A site that resolves inter-tribal conflicts and lets Indigenous peace and unity emerge.
    • DE HAAS - VAN ALPHEN EFFECT IN QUENCHED PLATINUM CRYSTALS.

      Vuillemin, Joseph; BOUFELFEL, ALI. (The University of Arizona., 1987)
      The oscillatory de Haas-van Alphen (DHVA) magnetization has been studied in Pt crystals containing more than 100 ppm vacancies. Magnetic fields as high as 75 kG were used. The oscillations were observed at temperatures as low as 0.45 k, and found to be strongly attenuated by the vacancies in this concentration range. The emphasis of this work is on the measurement of this attenuation for the purpose of studying conduction electron scattering due to single vacancies. Dingle (scattering) temperatures due to vacancies are reported for four cyclotron orbits with the field in a (110) plane, along with a new measurement of the cyclotron effective mass (m* = 2.31 ± 0.03) for the electron orbit 33° away from <100>. Vacancies were generated by quenching Pt single crystals from temperatures as high as 1730 °C in air, using a technique which minimizes the induced strain. The vacancy contribution to the electron scattering rate was separated by measuring the Dingle temperature in both quenched and annealed specimens which had been subjected to the same quenching process. The results suggest that there is only a moderate variation in this scattering rate over the s-p-like electron sheet of the Fermi surface. However, the scattering rate for the d-like open hole sheet, which contacts the Brillouin zone, is about 49% larger than that for the electron sheet. This anisotropy is attributed mainly to the lattice distortion around a vacancy and to the difference between the hole and electron wave-function symmetries.
    • A HABITAT ANALYSIS OF SPRING-SUMMER ELK RANGE ON THE APACHE-SITGREAVES NATIONAL FOREST, ARIZONA.

      DelGiudice, Glenn D. (Glenn David) (The University of Arizona., 1982)
    • Habitat Fragmentation in Small Vertebrates from the Sonoran Desert in Baja California

      Culver, Melanie; Munguia-Vega, Adrian; Rodriguez-Estrella, Ricardo; Nachman, Michael W.; Shaw, William W.; Culver, Melanie (The University of Arizona., 2011)
      Land conversion is one of the greatest threats to terrestrial ecosystems around the world, and understanding its impacts on the biota is crutial for the management and conservation of species in and around human-modified landscapes, particularly in those where local declines can quickly translate into the extinction of endemic species or Evolutionary Significant Units.I investigated how habitat loss and fragmentation impacted dispersal and extinction risk in three small vertebrates (a phrynosomatid lizard Urosaurus nigricaudus, and two heteromyid rodents Chaetodipus arenarius and Dipodomys simulans), in a highly fragmented agricultural valley from the Sonoran Desert in the Baja California Peninsula, Mexico, where reptiles and rodents show high endemism and phylogenetic diversity. After reconstructing the history of habitat loss at the valley during the last 60 years, my approach involved the development and genotyping of 10 DNA microsatellite loci in 800 individuals from the three species that were sampled from continuous and fragmented habitat and analyzed using various population genetic methods.Although genetic diversity was not significantly affected by habitat loss and fragmentation, I observed an increase in genetic structure, relatedness, the spatial scale of individual movement and reversal of sex-biased dispersal in the three species, compared to continous habitat. I found evidence of a large and spatially localized extinction debt in the lizard, that showed individual dispersal restricted to<400 m in the fragmented habitat, while the two heteromyids seemed capable of dispersing over distances of few kilometers. Several observations supported a higher extinction risk in kangaroo rats compared to pocket mice. Continuous areas surrounding the fragmented landscape where identified as important sources of individuals to habitat fragments located nearby. Even the vegetation associated with a narrow wash across the fragmented landscape appeared to act as a corridor as high levels of dispersing individuals were inferred in the three species over a scale of several kilometers. This study provided an approach to evaluate the effects of distinct landscape features in preventing or allowing individual dispersal in multiple co-distributed species towards their conservation in human-modified landscapes.
    • HABITAT SELECTION BY COUES WHITE-TAILED DEER IN RELATION TO GRAZING INTENSITY.

      Brown, Mark Timothy. (The University of Arizona., 1984)
    • Habitat selection by elf owls and western screech-owls in the Sonoran Desert

      Morrison, Michael L.; Hardy, Paul Christopher, 1969- (The University of Arizona., 1997)
      Little is known about habitat selection by elf owls (Micrathene whitneyi) and western screech-owls (Otus kennicottii). From 1994 to 1996 in the Sonoran Desert, I used point counts and nest searches to examine habitat selection by both species at multiple spatial scales. The abundance of both species had a positive association with percent cover of washes and mesquite (Prosopis spp.) at the scale of the study area. At both the scale of the study area and the nesting area, elf owls selected areas with high densities of mature saguaros (Carnegiea gigantea) and saguaro cavities. Elf owls nested only in woodpecker cavities in saguaros, whereas western screech-owls nested in both saguaro cavities and in natural cavities in mesquite. Western screech-owls nested nearly exclusively in gilded flicker (Colaptes chrysoides) cavities when they nested in saguaros. Patterns of nest cavity selection by elf owls suggest they may choose cavities that provide thermoregulatory advantages. I give management recommendations based on my findings.
    • Habitat selection by mountain sheep in Mojave Desert scrub

      Krausman, Paul R.; Berner, Louis Robert, 1963- (The University of Arizona., 1992)
      I identified habitat use by 12-18 mountain sheep (Ovis canadensis nelsoni) in a 320-ha enclosure between June 1990 and June 1991 on the Desert National Wildlife Refuge, Nevada. The enclosure included 9 vegetation associations and 5 slope classes. I used a non-mapping technique and line transects to determine availability of vegetation associations and slope classes, and species composition, respectively. I determined use of habitats by mountain sheep with instantaneous sampling. Mountain sheep used midslopes and draw associations on the west side of the study area, and slope classes of 36-80% more than expected based on availability. I tested Hansen's (1980) habitat evaluation model on the study area. The model was >98% accurate in predicting mountain sheep use of habitat. Habitat use by mountain sheep in the enclosure was similar to habitat use of free-ranging mountain sheep.
    • Habitat selection by the elegant trogon (Trogon elegans) at multiple scales.

      Hall, Linnea Suzanne.; Mannan, R. William; Matter, William J.; Schwalbe, Cecil R.; Calder, William A.; Block, William M. (The University of Arizona., 1996)
      In this dissertation I discuss several facets of the ecology of the elegant trogon (Trogon elegans). In Chapter 1, I assessed habitat selection by the trogon from 1993 to 1995 at three spatial scales (those of the mountain and canyon, home range, and microsite scales). At the broadest (inter-mountain and inter-canyon) scale, trogons were positively associated with cover by sycamore, pinyon, and juniper vegetation, and the abundances of three bird species. At the intermediate scale, radio-tagged trogons in the Huachuca and Santa Rita mountains used both upland and riparian areas, and selectively used sites with dense vegetation within those areas. At the microsite scale, nest sites of trogons were primarily located in sycamore trees in riparian areas. Successful nests could be discriminated from unsuccessful nests on the basis of three variables. Adult trogons used trees that were mostly dead for several behaviors besides nesting, and males foraged from sycamore and oak trees. Across all three scales, trogons were associated with variables describing sycamores, junipers, pines, and oaks, indicating that these trees were important to elegant trogon habitat use in Arizona. In Chapter 2, I discussed the behavior and phenology of nesting elegant trogons in the Chiricahua, Huachuca, and Santa Rita mountains in 1993-1994. I described the average durations and characteristics of nest advertisement, incubation, brooding, nestling attendance, and fledgling attendance behaviors. Elegant trogons in Arizona had different behaviors from other members of Neotropical Trogonidae, especially in regards to their durations of incubation and feeding. In Chapter 3, I present analyses of disturbance records collected while observing trogons in 1993-1995, and the finding that elegant trogons did not react strongly to most contacts with humans. However, on some occasions trogons reacted long enough to humans to potentially impact their productivity at nest sites. Therefore, some protection of nesting trogons may be warranted. In general, management of trogons in Arizona will require consideration of whole watersheds, including the condition of riparian water tables and upland vegetation.
    • A Habitat Suitability Analysis of Texas Horned Lizards in Texas and New Mexico

      Sanchez Trigueros, Fernando; Piehler, Reid (The University of Arizona., 2021-05)
      The Texas Horned Lizard (Phrynosoma cornutum) is a state-protected lizard native to the American Southwest. To rebuild the Texas Horned Lizard population, they are bred in captivity and released into the wild. Identifying factors that impact habitat suitability is vital to finding the proper areas for release and reintroduction. Environmental and human factors were examined in Texas and New Mexico counties native to the Texas Horned Lizard, as well as counties without known sightings, to determine which factors most impact habitat suitability. Four statistical and geospatial software packages were used to map, analyze, and evaluate 24 potential variables and it was discovered that elevation, road density, natural gas pipeline density, seasonal rainfall, land use category, and proximity to Red Harvester Ants are all statistically significant to Texas Horned Lizard habitat suitability at a 95% confidence level. Texas Horned Lizards are most prevalent in counties with low elevation, high percentage of open water or snow, low precipitation levels, and native habitats for Red Harvester Ants. Horned Lizards are also less prevalent where road density or natural gas pipeline density is high. No significant difference was detected in habitat suitability relative to Imported Fire Ants as suggested in previous studies. To protect viable environments for Texas Horned Lizard reintroduction, pipeline and road construction should be limited in the most suitable regions: eastern and southern New Mexico, the southern Gulf Coast, the Texas Panhandle, Edwards Plateau, and along the Rio Grande.
    • Habitat Suitability Criteria for Nonnative Species and Relationships between Fish Populations and Flow Regime in Four Arizona Streams

      Bonar, Scott A.; Lee, Larissa N.; Guertin, D. Phillip; Bogan, Michael T. (The University of Arizona., 2018)
      Nonnative species invasions and streamflow alteration are two of the primary causes of native fish depletion in the southwestern U.S. Previous research in Arizona has focused on the habitat needs of native species, without understanding the habitat selection of nonnative species. Additionally, fish populations and streamflow can vary significantly throughout a single Arizona stream, so it is important to understand how spatially variable flows affect fish assemblages. This research has two objectives: 1) to define suitable habitat for nonnative species, and 2) to explore the relationships between the distributions of various fish species throughout time and space in four Arizona streams. Four streams in the Mogollon Rim region of Arizona were sampled during summer base flow conditions (May – October) of 2017 to collect information on fish distributions and habitat conditions. A 20-year dataset from fish sampling in the Verde River by the Arizona Game and Fish Department was used to examine temporal shifts in fish assemblages as they relate to streamflow. Streamflow data from USGS stream gages, the USGS StreamStats application, and the National Hydrography Dataset (NHD) provided metrics to characterize streamflow throughout the study sites. These metrics included estimates of 2-year flood flows, 10-year flood flows, 100-year flood flows, mean annual flows, mean channel velocity, stream power at mean flow, and stream power at 2-year flood flow. I defined suitable habitat for seven nonnative species across these four streams, and results indicated that nonnative species were generally using warmer temperatures and shallower depths compared to available habitat, but many habitat results varied by species. Relationships between streamflow characteristics and species assemblages also varied by species. I found that certain native species, like Sonora Sucker, consistently demonstrated positive relationships with spatial flow characteristics across all four streams, demonstrating a preference for areas with higher velocities, flow, and power. Results for other species were more variable by stream, and differences often split the four study streams into similarities among Tonto Creek and the Verde River, the two larger systems dominated by nonnative species, as opposed to the Blue River and Eagle Creek, the two smaller systems dominated by nonnative species. These results can inform decision-makers and fisheries managers in streamflow allocation, habitat restoration, and nonnative species removals.
    • Habitat Suitability Criteria for Zuni Bluehead Sucker Catostomus discobolus yarrowi and Navajo Nation Genetic Subunit Bluehead Sucker Catostomus discobolus and Comparing Efficiency of AFS Standard Snorkeling Techniques to eDNA Sampling Techniques

      Bonar, Scott A.; Ulibarri, Roy M.; Bonar, Scott A.; Mata, Melissa; Matter, William (The University of Arizona., 2016)
      I quantified habitat selection for the endangered Zuni Bluehead Sucker Catostomus discobolus yarrowi and the Navajo Nation Genetic Subunit (NNGS) Bluehead Sucker Catostomus discobolus - a recent taxon described from genetic information. Both taxa are found in northern Arizona and New Mexico border regions. I examined fish [≥50 millimeters (mm) total length (TL)] selection of microhabitat conditions (i.e., water velocity, substrate size, overhead cover, water depth, instream cover, and mesohabitat conditions [i.e., pool, run riffle], during summer base flow conditions for NNGS Bluehead Suckers, and during both summer base flow and high spring flow conditions for Zuni Bluehead Suckers in six streams). Electrofishing, seining, and snorkeling were used to evaluate fish occupancy. From this information, I developed stream specific habitat suitability criteria (HSC) and then generalized HSC for each taxon, and tested transferability of the generalized HSC to individual streams. Zuni Bluehead Suckers and NNGS Bluehead Suckers occupied similar habitats: low velocity pools; sand, silt, and pebble substrate; high percent of instream cover; and water temperatures ranging from 2-21°C. However, Zuni Bluehead Suckers selected for low (0-25%) overhead cover where as NNGS Bluehead Sucker selected for high (0-75%) overhead cover. This was likely due to the source of instream cover–aquatic macrophytes that required sunlight in the Zuni Bluehead Sucker streams, and large woody debris falling from overhead branches in the NNGS Bluehead Sucker streams. Suggestions for managers includes maintaining existing cover or artificially construct additional instream cover; promote overhead cover (e.g., maintaining large trees along streams) and pool mesohabitats. In addition to this work I also tested the new method of environmental DNA (eDNA) to further help conservation efforts for these taxa. Environmental DNA has typically been used to detect invasive species in aquatic environments through water samples. I compared the efficacy of eDNA methodology to American Fisheries Society standard snorkeling surveys to detect presence of a rare fish species. My study site included three streams on the Navajo Nation in northern Arizona and northern New Mexico containing Navajo Nation Genetic Subunit Bluehead Sucker Catostomus discobolus and the Zuni Bluehead Sucker Catostomus discobolus yarrowi. To determine sample sites, I first divided entire wetted area of streams into 100-m consecutive reaches. I systematically selected 10 of those reaches for snorkel and eDNA surveys. Water samples were taken in 10-m sections within each 100-m reach, and fish presence via snorkeling was noted in each 10-m section as well. Water samples were collected at the downstream starting point of each reach, and continued upstream in each section 5 to 8 m ahead of the snorkeler. A qPCR was run on each individual water sample in quadruplicate to test for sucker presence or absence. I was able to positively detect both species with eDNA sampling techniques in two out of three streams. Snorkeling resulted in positive detections of both species in all three streams. In streams where fish were detected with eDNA sampling, snorkeling detected fishes at 11-29 sites per stream, where as eDNA detected fish at 3-12 sites per streams. My results suggested that AFS standard snorkeling was more effective at detecting target fish species than eDNA. To improve eDNA sampling, the amount of water collected and tested should be increased. Additionally, filtering water on site may improve eDNA techniques for detecting fish. Future research should focus on standardizing eDNA sampling to provide a widely operational sampling tool similar to electrofishing, netting, and hydroacoustics.
    • Habitat use and life history of the Mount Graham red squirrel

      Smith, Norman S.; Froehlich, Genice Frances, 1953- (The University of Arizona., 1990)
      I studied habitat use by 9 radio-collared Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis) during the summers of 1988 and 1989 in the Pinaleno Mountains, Arizona. My 2 study areas represented an Engelmann spruce (Picea engelmannii)/corkbark fir (Abies lasiocarpa) association on High Peak and a Douglas-fir (Pseudotsuga menziesii) association on Merrill Peak. I trapped 9 squirrels in 33,400 trap hours, and calculated the seasonal home range for 4 animals, 2 in each study area. Hidden density was 0.54 and 0.2 middens/ha, respectively, but seasonal home range size (x = 3.62 ha) did not vary between habitats. Squirrel numbers decreased on both study areas between 1988 and 1989. I concluded that preference for habitat characteristics in midden areas explained lower densities in the mixed conifer vegetation. Squirrels fed mainly on cones and mushrooms, depending on season and availability. Mt. Graham red squirrels may breed twice/year.
    • Habitat use and preference of Gila topminnow

      Matter, William J.; Forrest, Robert Eugene, 1965- (The University of Arizona., 1992)
      The Gila topminnow (Poeciliopsis occidentalis occidentalis) is federally and state listed as endangered. My objectives were to quantify microhabitat use and preference of topminnow in the field and test responses to controlled laboratory settings. In Cienega Creek, topminnow preferred stream margins where the water was calm, shallow, and contained aquatic vegetation. Topminnow were always near the water surface. Water temperature averaged 1-2 C warmer in areas occupied by fish. In outdoor pools, groups of topminnow consistently preferred cover provided over no cover and selected the upper 1/3 of the water column. Plastic strips, elicited the strongest response and styrofoam sheets elicited the weakest response. Topminnow did not show a consistent preference for cover when tested singly in aquaria, but showed a strong preference for calm water. Responses of topminnow to tests in aquaria were not in concordance with behavior observed in Cienega Creek or in tests conducted in outdoor pools.
    • Habitat use and selection by Merriam's turkeys in the Prescott National Forest, Arizona

      Mannan, R. William; Stone, Sylvia Beth, 1968- (The University of Arizona., 1993)
      Habitat use of Merriam's turkey (Meleagris gallopavo merriami) was characterized in the Prescott National Forest, Arizona, between March 1991 and August 1992. Roost sites were generally found in canyons or on hillsides, and contained a large number of ponderosa pine trees, and Gambel oak seedlings and trees. Turkeys fed on juniper berries, generally in small groups of large juniper trees within ponderosa pine stands. Turkeys fed on acorns in stands of Gambel oak on hillsides. Turkeys feeding on grass/forb vegetation tended to be on flat areas with a large amount of forb and grass cover. Turkeys loafed under Gambel oak, in areas with large amounts of Gambel oak growth near openings, on hillsides or in canyons. Turkeys also loafed under juniper trees; these areas had a large basal area of alligator juniper and high numbers of Gambel oak seedlings.
    • Habitat use by breeding male Northern Goshawks in northern Arizona

      Bright-Smith, Donald Joseph (The University of Arizona., 1994)
      I radio-tagged and followed 5 and 9 male Northern Goshawks (Accipiter gentilis atricapillus) during the breeding seasons of 1991 and 1992, respectively, to evaluate their use of different forest conditions in managed ponderosa pine (Pinus ponderosa) forests. Sufficient data for habitat analyses were collected for 11 birds. Minimum convex polygon home-ranges averaged 1,758 ha (SD = 500 ha, range 896-2528 ha) and harmonic mean home ranges averaged 1,530 ha (SD = 477 ha, range 859-2,321 ha). I compared use (i.e., number of hawk locations) and availability (i.e., % of area of home range) for three different forest conditions (canopy closure, edge, and diversity) generated from LANDSAT data. Most (≥6) of the 11 birds used the categories in the three overlays in proportion to their availability. Six of the 11 birds used at least one category on one of the overlays nonrandomly. When the categories of canopy closure were ranked for each bird on the basis of relative preference, these ranks increased with increasing canopy closure.
    • HABITAT USE BY DESERT MULE DEER (ASPECT, ELEVATION, SLOPE, ARIZONA)

      Ordway, Leonard L. (The University of Arizona., 1985)
    • Habitat use by desert mule deer and collared peccary in an urban environment

      Krausman, Paul R.; Bellantoni, Elizabeth Susan, 1958- (The University of Arizona., 1991)
      I examined movements and habitat use by desert mule deer (Odocoileus hemionus crooki) and collared peccary (Dicotyles tajacu) in the Rincon Mountain District of Saguaro National Monument (SNM) from February 1988 through December 1989. Movements and habitat use by mule deer were closely associated with the distribution of free-standing water during the driest seasons of the year. Deer responded to losses of ephemeral water sources in SNM by leaving the monument to obtain water. Four of 5 peccary herds supplemented their natural diet by visiting houses and/or restaurants on a daily or twice daily basis. The addition of water and supplemental food sources was a deliberate effort by homeowners to attract wildlife onto their property. The current pattern of habitat islands interspersed with low density housing (1 house/2-4 ha) is an effective and highly desirable buffer zone between the monument and the more heavily developed urban areas 3.2 km west of the park.
    • HABITAT USE BY ELK, MULE DEER, AND CATTLE IN ARIZONA.

      Wallace, Mark Christopher, 1954- (The University of Arizona., 1984)
    • Habitat use by endangered masked bobwhites and other quail on the Buenos Aires National Wildlife Refuge, Arizona

      DeStefano, Stephen; King, Nina Monique, 1958- (The University of Arizona., 1998)
      Masked bobwhites used sites with more structural diversity than what was available on the Buenos Aires National Wildlife Refuge during 1994-96. Selected habitat variables that adequately predicted habitat use by masked bobwhites included percent herbaceous canopy cover, structure at 15 cm and 2 m, forb richness, and season. Masked bobwhite used more structural diversity than Gambel's and scaled quail. Gambel's quail had broader habitat tolerances than either masked bobwhite or scaled quail. Selected habitat variables that revealed differences among masked bobwhites, Gambel's quail, and scaled quail included percent woody canopy cover, structure at 15 cm, forb richness, and season. A historic perspective revealed that masked bobwhites used sacaton grasses that grew along the floodplains as important escape cover. I believe that we need to restore the integrity of the grassland ecosystems including the floodplain if we are to recover masked bobwhite quail.
    • Habitat use by fishes of the San Bernardino National Wildlife Refuge

      Maughan, O. Eugene; Maes, Ronnie Andrew (The University of Arizona., 1995)
      I quantified microhabitat conditions used by Yaqui chub (Gila purpurea), Yaqui topminnow (Poeciliopsis occidentalis sonoriensis), and beautiful shiner (Cyprinella lutrensis) on the San Bernardino National Wildlife Refuge, Arizona. Different species and different lifestages used different microhabitats. Smaller fish selected shallower water than adults. Yaqui topminnow and Yaqui chub showed seasonal variation in microhabitats used. Yaqui topminnows were found closer to cover when in the presence of beautiful shiners. Close proximity to cover may indicate a negative interaction. Yaqui chubs did not use microhabitats differently when in the presence of the other two species. Microhabitats used by Yaqui chubs in the ponds and Leslie Creek did not differ. Yaqui chub preferred pools with little or no flow. Management of aquatic environments on the refuge should focus on vegetative thinning. Stocking of beautiful shiner with Yaqui topminnow should be postponed until further research is conducted on the interactions between the two species.