Southwestern Kansas Research Articles

Five million years of pocket gopher history in the Meade Basin of southwestern Kansas and northwestern Oklahoma

ABSTRACT The Meade Basin record of pocket gophers extends from the latest Miocene (Buis Ranch local fauna) to modern time. A primitive species with hypsodont but rooted cheek teeth, Pliogeomys buisi, characterizes the late Hemphillian. Another species of Pliogeomys, P. louderbachi, is described here as a new species from the early Blancan. It is intermediate in dental and mandibular morphology between Pliogeomys and Geomys. The Geomys minor (= G. smithi) lineage displays a stepped dwarfing trend prior to its extinction, whereas the G. jacobi lineage demonstrates an overall pattern of stasis in size. G. jacobi is replaced by G. quinni at the end of the Pliocene, within which there is a significant directional size increase. A late Pliocene immigrant, the new species G. floralindae, appears in the Sanders assemblage. It is briefly replaced by an indeterminate small species in the Nash 72 local fauna. G. tobinensis is found in the Cudahy local fauna. Morphologically modern G. bursarius appears in the Meade Basin during the early Rancholabrean. A small, primitive species, Geomys adamsi, appears only during the early Pliocene at Fox Canyon, and transient Thomomys appear at various times during the Pleistocene, both apparently during cold intervals. A phylogenetic analysis suggests two clades, one uniting Pliogeomys russelli and Geomys adamsi and another including the remaining Meade Basin geomyines. Enhanced species turnover and the last push for modern mandibular morphology is most pronounced in sediments younger than about 2.6 million years ago, corresponding to the first global cooling heralding the Pleistocene.

Milking the Plains: Movement of Large Dairy Operations Into Southwestern Kansas*

Western Kansas has an historical identification with cattle, with a focus on cattle ranching and more specifically since the 1950s, beef‐cattle feedlots. Since the mid‐1990s large dairy operations have moved into southwestern Kansas. Today more than twenty large dairies house more than 70,000 milk cows. These operate as confined feeding operations similar to beef‐cattle feedlots. Regional advantages for the dairy industry include affordable land with wide‐open space, local residents' cattle‐ and dairy‐friendly attitudes, and other factors. Regional promoters have actively recruited dairies, and a dairy‐business support system has emerged. The prospects for continued expansion of dairies in southwestern Kansas are unclear; despite the locational advantages and the possibility that the industry may continue to relocate here, as did the cattle‐feeding industry several decades ago, further moves into the area may depend on continued resources availability and additional infrastructure development.

TESTING EVOLUTIONARY DYNAMICS ON FIRST LOWER MOLARS OF PLIOCENE OGMODONTOMYS (ARVICOLIDAE, RODENTIA) FROM THE MEADE BASIN OF SOUTHWESTERN KANSAS (USA): A LANDMARK-BASED APPROACH

Landmark- and semilandmark-based geometric morphometrics were used to explore morphological variation in the occlusal surface and linea sinuosa (enamel-dentine junction) of first lower molars (m1s) of Ogmodontomys sawrockensis and O. poaphagus from the Meade Basin in southwestern Kansas. Morphological differences between the two species were determined in an effort to explore interspecific variation and to test the power of landmark geometry of dental variation for species discrimination. Significant differences were found between O. sawrockensis and O. poaphagus in both occlusal surface and the linea sinuosa patterns. Multivariate tests demonstrate that the most significant morphological changes occurred at the presumed O. sawrockensis-O. poaphagus speciation event. An intraspecific multivariate analysis of O. poaphagus m1s, however, also identified directional evolutionary tendencies in shape of both the occlusal surface and linea sinuosa.

Grazing Effects on Yield and Quality of Hard Red and Hard White Winter Wheat

Six hard red (2137, Jagalene, Jagger, OK101, Stanton, and Thunderbolt) and six hard white (Burchett, Lakin, NuFrontier, NuHills, NuHorizon, and Trego) winter wheat (Triticum aestivum L.) varieties were evaluated for grain yield and quality in southwestern Kansas in 2004 and 2005. Cattle commonly graze wheat in this region from late November to mid March in a dual‐purpose system. The experimental design was a randomized complete block with split‐plot treatment arrangement. Main plots were grazed or ungrazed, and subplot treatments were wheat varieties. Yield was not affected by color. Yield was reduced 23% when grazed beyond wheat jointing. NuHorizon yielded less when grazed. Test weight was 4 kg m−3 greater among red varieties in 2004 and 4 kg m−3 greater among white varieties in 2005. Grazing did not affect test weight. Color and grazing did not affect protein concentration. White varieties sprouted more than red varieties, but Burchett sprouted less than Stanton. Grazing did not affect sprouting. Kernel diameter was 0.1 mm greater among red than white varieties. Grazing reduced kernel diameter 0.1 mm in 2004. Kernel hardness was 4% greater among white than red varieties. Grazing increased kernel hardness 3% in 2005. Seed weight was 5% greater among red than white varieties. Grazing reduced seed weight 4%. Both red and white wheat can be used in a dual‐purpose system with no substantial affects on yield or quality. Producers should select varieties on the basis of their system and environment because certain varieties responded better to grazing and environmental conditions than others.

Modelling the morphology and evolution of the linea sinuosa (crown–root junction) in arvicolid rodents; a test with Pliocene Ogmodontomys from Kansas, USA

The linea sinuosa of 39 specimens of Pliocene Ogmodontomys sawrockensis and Ogmodontomys poaphagus from the Meade Basin of southwestern Kansas, USA, was deconstructed into eight enamel segments, representing the major peaks and troughs that characterized Ogmodontomys. Coordinates for the positions of the major peaks and troughs were determined from standard Cartesian coordinate drawings, and then scaled for uniformity. Descriptive statistics for the amplitude (vertical) and drift (lateral) variation were calculated for each coordinate. A modified cubic spline analysis showed that accurate representations of the linea sinuosa, both of individuals and species, could be generated given these coordinate data. Comparisons of individual coordinates by analyses of variance distinguished O. sawrockensis from O. poaphagus, and the same coordinates were statistically distinguishable when the samples of O. sawrockensis were combined and tested against the combined samples of O. poaphagus by Student's t-tests. A mosaic of evolutionary trends, predominantly in peak morphology, was documented for Ogmodontomys from early through middle Pliocene time. Principal components analysis of coordinate data distinguished the linea sinuosa pattern of Ogmodontomys from a small sample of Pliomys lenki. This combined statistical approach offers a new and relatively simple quantitative method to model the form and evolution of the arvicolid linea sinuosa, thereby leading to more accurate phylogenetic and biostratigraphic reconstructions.

The Edgerton Structure: A Possible Meteorite Impact Feature in Eastern Kansas

Recognized meteorite impact features are relatively rare in the U.S. Midcontinent region, but recently with increased interest and research, the number has increased dramatically. We add another possibility to the growing list, the Edgerton structure in northwestern Miami County, Kansas. The feature is elliptical (∼5.5 × 6.5 km, slightly elongated east-west) with radial surface drainage. The feature was first observed on hillshade maps of digitized topography of 7.5 minute quadrangles. Subsequent magnetic profiles show a higher magnetic value in the center of the ellipse with higher values around the edges; this shape is characteristic of an impact feature. Depth to the anomalous body is estimated to be about 1 km, which puts it in the Precambrian crystalline basement under a cover of Paleozoic sediments. There are no deep boreholes in the vicinity and no seismic profiles are available. If it is an impact structure, it will be the second such feature documented in Kansas, the first being the Brenham meteorite crater at Haviland in Kiowa County in southwestern Kansas. It would be older than the other impact structures identified in the Midcontinent—Manson in Iowa, Ames in Oklahoma, Haswell Hole in Colorado, and possibly Belton in Missouri and Merna in Nebraska. There are at least two other prospective impact features in Kansas: the Goddard ring west of Wichita and Garden City ellipse north-west of Garden City.

Mosaic evolution in first lower molars of Pliocene Ogmodontomys (Rodentia: Arvicolidae) from the Meade Basin of southwestern Kansas (USA)

Mosaic evolution in first lower molars of Pliocene Ogmodontomys (Rodentia: Arvicolidae) from the Meade Basin of southwestern Kansas (USA)

An Atmospheric Soliton Observed with Doppler Radar, Differential Absorption Lidar, and a Molecular Doppler Lidar

Abstract Airborne Leandre II differential absorption lidar (DIAL), S-band dual-polarization Doppler radar (S-Pol), and Goddard Lidar Observatory for Winds (GLOW) Doppler lidar data are used, in conjunction with surface mesonet and special sounding data, to derive the structure and dynamics of a bore and associated solitary wave train (soliton) that were generated in southwestern Kansas during the International H20 Project (IHOP_2002). Vertical cross sections of S-Pol reflectivity, S-Pol radial velocity, and DIAL water vapor mixing ratio show a stunning amplitude-ordered train of trapped solitary waves. DIAL data reveal that the leading wave in the soliton increasingly flattened with time as the soliton dissipated. A method is developed for using the GLOW Doppler winds to obtain the complex two-dimensional vertical circulation accompanying the dissipating soliton. The results show multiple circulations identical in number to the oscillations seen in the S-Pol and DIAL data. The leading updraft occurred precisely at the time that the bore passed over the GLOW facility, as well as when the photon count values suddenly ramped up (suggesting lifting of the low-level inversion by the bore). Additional evidence in support of the validity of the results is provided by the fact that layer displacements computed using the derived vertical motions agree well with those implied by the changes in height of the DIAL mixing ratio surfaces. The depth and speed of propagation of the bore seen in the DIAL and surface mesoanalyses were shown to be consistent with the predictions from bore hydraulic theory. Analysis of National Center for Atmospheric Research (NCAR) Integrated Sounding System (ISS) data shows that a highly pronounced curvature in the profile of bore-relative winds, related to the existence of a very strong low-level jet, effectively trapped the upward leakage of solitary wave energy below 3 km. This finding explains the trapped lee wave–type structures seen in the DIAL, GLOW, and S-Pol data.

The giant resin bee making its way west: First record in Kansas (Hymenoptera: Megachilidae)

The invasive giant resin bee (Megachile sculpturalis Smith) was first discovered in North America in 1994. A 2005 study provided the first predictive ecological niche model for any bee species and concluded that M. sculpturalis, then confined to the eastern United States, would eventually spread as far south as southern Florida, as far north as southern Ontario and Nova Scotia, and as far west as South Dakota, western Kansas, and northwestern Texas. Herein I provide the first record of M. sculpturalis from northeastern Kansas, documenting that the species has indeed continued its westward expansion in North America and the new available records entirely correspond to the earlier predictions.

Rodent community change at the Pliocene–Pleistocene transition in southwestern Kansas and identification of the Microtus immigration event on the Central Great Plains

A dense fossil rodent database and new paleomagnetic data from the Meade Basin of southwestern Kansas document the transition from a Pliocene community characterized by cricetids of southern aspect and archaic arvicolids with rooted molars to a Pleistocene community with cricetids of temperate aspect and arvicolids with ever-growing molars. This new information suggests a revised date for the Blancan–Irvingtonian North American Land Mammal Age boundary between 2.06 and 1.95 Ma, coincident with the extinction of the Sigmodon minor lineage and the immigration of Microtus. Carbon and oxygen isotope compositions of paleosol carbonates indicate the faunal changes occurred during the final expansion of C 4 grasses in the Great Plains to modern abundance and a strong cooling trend reflecting the end of the early Pliocene warm interval and onset of northern hemisphere glaciation. Although extinctions balance originations through the study period, pulses of enhanced extinction and origination occurring near the Pliocene–Pleistocene boundary strongly suggest environmental change as the likely forcing mechanism for rodent community compositional shifts. The Meade Basin rodent sequence provides the most complete history of any terrestrial vertebrate group in North America for this period of time.

The effect of fire-induced soil hydrophobicity on wind erosion in a semiarid grassland: Experimental observations and theoretical framework

Aridland ecosystems are often susceptible to degradation resulting from disturbances like fires and grazing. By exposing the soil surface to the erosive action of winds, these disturbances contribute to the redistribution of soil nutrients associated with grassland-to-shrubland conversions and to the formation of a heterogeneous landscape. Wind erosion maintains the local heterogeneities in nutrient and vegetation distribution in arid landscapes through the removal of nutrient-rich soil from the intercanopy areas and the subsequent deposition of soil onto vegetation patches. Even though wind erosion and disturbances like fires strongly interact with each other and determine vegetation patterns in arid landscapes, very few studies have addressed these interactions. Using soil samples collected after a wildfire event at the Cimarron National Grasslands in southwestern Kansas, we demonstrate through a series of wind-tunnel experiments, laboratory measurements, and theoretical analyses how wind erosion can be enhanced by fire-induced water repellency. Results from the wind-tunnel experiments show that in semiarid grasslands fires can cause a decrease in the threshold velocity of wind erosion thereby, enhancing the post-burn erosion of (hydrophobic) soils. Further, a generalized process-based theoretical equation was derived to explain the decrease in threshold friction velocity in water-repellent soil for the case of soil particles modeled as asymmetrical cones.

Late Quaternary eolian sand depositional record for southwestern Kansas: Landscape sensitivity to droughts

Eolian deposits and landforms are ubiquitous in western Kansas, particularly south of the Arkansas River with the presence of a stabilized dune field. Stratigraphic studies and associated optical dating reveal a complex depositional history for this dune field spanning the late Quaternary. The oldest eolian deposits from ca. 16 to 12 ka completely or partially bury high terraces with ages of ca. 16 and 33 ka. It is unknown whether these eolian deposits reflect regional aridity and/or a change in sediment availability with the transition of the Arkansas River from a single channel to a braided system. There is pervasive evidence for episodic eolian erosion and deposition ca. 9.8 to 6.3 ka, generally coincident with loess deposition on upland surfaces [Olson, C.G., Nettleton, W.D., Porter, D.A., Brasher, B.R., 1997. Middle Holocene aeolian activity on the High Plains of west-central Kansas. Holocene, 7(3): 255–261], and thus it is inferred to reflect regional aridity. Sites within the dune field show a sequence of eolian sands and weak buried soils, reflecting either dune migration or sand sheet accretion at ca. 1490, 430, 380–320, 180, and 70 yr ago, which correspond well with continental-scale droughts in the tree-ring record. Eolian sand in the Arkansas River dune field may be derived principally with variability in fluvial activity and in climate during the late Pleistocene to the middle Holocene, with substantial reactivation of eolian systems during decadal-scale drought variability in the past 2000 yr.

Presence of the Evening bat (Nycticeius humeralis) in westernmost Kansas

The evening bat, Nycticeius humeralis, is an austral species (Armstrong, Choate, and Jones 1986) that ranges from the southeastern United States north to the southern Great Lakes region and west to the central Great Plains (Watkins 1972). In Kansas, the species was known from just four counties (Clay, Douglas, Jewell, and Johnson) in the northeast when Jones, Fleharty, and Dunnigan (1967) reviewed the distributional status of bats in the state. Birney and Rising (1968) subsequently reported specimens of the evening bat from Franklin and Ford counties, the latter in southwestern Kansas, and Kunz, Choate, and George (1980) reported specimens from Barber and Comanche counties in south-central Kansas. Sparks and Choate (2000) added more than a dozen counties, most in north-central Kansas, to the known range of the species in the state and opined that this tree-dwelling species, which previously was rare at the western limit of its range, was becoming increasingly common in riparian corridors. They concluded that the lack of forested habitats in much of western Kansas in the past possibly restricted the range of the evening bat to the eastern twothirds of the state (Sparks and Choate 2000), but that growth of forested habitats along watercourses was enabling this species to expand westward.

Remote Sensing-Measured Impacts of the Conservation Reserve Program (CRP) on Landscape Structure in Southwestern Kansas

Changes in landscape structure caused by the introduction of the U.S. Conservation Reserve Program (CRP) were examined. Using imagery-derived land cover maps for the pre- and post-CRP enrollment periods, we identified regions of cropland that had been converted to CRP in a six-county area in southwestern Kansas. The major impact of CRP in the study area has been the reversal of an overall trend of grassland fragmentation. The introduction of CRP has substantially modified the spatial structure of the southwest Kansas landscape, generally with important positive implications for wildlife habitat, by changing the count, size, shape, interior areas, and connectivity of grassland patches. The authors also concluded that CRP enrollments had a strong spatial association with the distribution of points of water diversion for irrigation.

Rio Grande Wild Turkey Habitat Selection in the Southern Great Plains

ABSTRACT We recorded telemetry locations from 1,129 radiotagged turkeys (Meleagris gallopavo intermedia) on 4 study areas in the Texas Panhandle and southwestern Kansas, USA, from 2000 to 2004. Analyses of telemetry locations indicated both sexes selected riparian vegetative zones. Females did not select grazed or nongrazed pastures for daily movements. However, females did select nongrazed pastures for nest sites on 2 study areas and males selected for grazed pastures at one study area during the breeding season. We compared nest sites (n = 351) to random sites using logistic regression, which indicated height of visual obstruction, percent canopy cover, and percent bare ground provided the highest predictive power (P ≤ 0.003) for characteristics describing nest‐site selection. Nest‐site vegetative characteristics between vegetative zones differed primarily in composition: upland zone nest sites had more (P ≤ 0.001) shrubs and riparian zone nest sites had more (P ≤ 0.001) grass. There were no differences in measured nest site vegetative characteristics between pasture types, but there were differences between available nesting cover in grazed and nongrazed pastures. Random plots in grazed pastures had less grass cover (P ≤ 0.001) and more bare ground (P = 0.002). Because of cattle impacts on average grass height and availability, grazing would likely have the highest impact on nesting in riparian zones due to turkey use of grass as nesting cover. An appropriate grazing plan to promote Rio Grande turkey nesting habitat would include grazing upland zones in the spring, when it likely has little impact on nesting‐site selection, and grazing riparian zones following breeding season completion. Grazing at light to moderate intensities with periods of rest did not affect male turkey pasture use and may have continued to maintain open areas used by male turkeys for displaying purposes.

The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl (review)

Reviewed by: The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl by Timothy Egan George O’har The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl. By Timothy Egan. New York: Houghton Mifflin, 2006. Pp. 340. $28.95. The Worst Hard Time was the winner of the 2006 National Book Award for nonfiction. And while the work is directed toward a popular rather than an academic audience, it is well researched and benefits from a knowledge of the relevant scholarship. The narrative employed by Timothy Egan as a frame for his forty-year (1901–39) tale of the dust bowl is the by-now-familiar explanation of what happened in that storm-cursed corridor extending from the Texas and Oklahoma panhandles up into southwestern Kansas and southeastern Colorado, about a hundred million acres of land. Prior to Hurricane Katrina, the windstorms that ripped across the dust bowl during the Great Depression and ruined the lives of thousands of settlers and “sodbusters” were considered the greatest natural disaster to hit the United States. Even after Katrina, these storms may still hold the record for the human misery and environmental devastation they left in their wake. In each case, Katrina and the dust bowl, misery was exacerbated by human ineptitude, although the degree to which that was the case, especially regarding the dust bowl, is open to debate. Egan’s position is best summed up by Melt White, one of the survivors he interviewed: “God didn’t create this land here to be plowed up. He created it for Indians and buffalo. Folks raped this land. Raped it bad” (p. 9). Egan’s version of the settlement of the High Plains is hardly the tale told by Walter Prescott Webb in The Great Plains (1931). Yet Egan admires the fortitude of the settlers and farmers, especially those who stayed behind to fight bad luck and weather. Overall, though, he is skeptical about the enterprise—farming on the arid plains—and more caught up in what might be called the dark side of empire and technology. His tale is a cautionary one. Settlement of the plains by Anglo Americans, most of them farmers, was driven largely by land speculation and the post–Civil War extension of the railroads into the territories. The Homestead Acts of 1862 and 1909 also played a significant role. Between 1880 and 1925,“roughly two-hundred million acres” were homesteaded, and of that number, “nearly half was considered marginal for farming” (p. 56). Farming methods and machinery that worked well in the humid eastern half of the nation (east of the 98th meridian) had to be modified in order for them to be effective in the windy, arid, treeless plains. The disc plow, barbed wire, dry farming, windmills, and the siphoning of the aquifer, a well-known saga to students of Webb, made it possible to grow wheat. Then the weather turned bad, and the land failed. Dry to begin with, the soil was only made worse when plows ripped up the native grasses—by the roots, so they could not be replenished. Areas the size of entire states back east were stripped bare, and then high winds, drought, and [End Page 872] loose soil brought on a disaster almost biblical in scope: plagues of grasshoppers, spiders, air that literally stuck to your skin. While the particulars may not be known to the general reader, the larger story—giant dust clouds said to be ten thousand feet high, haunted faces staring out at the camera, shacks covered up to their roofs with dirt—has become part of American folklore. Egan remarks that the archaeological record indicates that Native Americans were farming on the plains as far back as “the time of Christ” (p. 122). Deep deposits of wind-blown soils show up in the record as well, which tells us that dust storms are a constant feature of life on the plains. During the Depression, dust storms also struck areas of the plains where native grasses had barely been disturbed. So the extent to which land-use practices of a particular moment in time exacerbated...

Niche Partitioning by Lesser Prairie-chicken Tympanuchus pallidicinctus and Ring-necked Pheasant Phasianus colchicus in Southwestern Kansas

We conducted this 2-year study to determine if lesser prairie-chickens Tympanuchus pallidicinctus and ring-necked pheasants Phasianus colchicus used the same habitats where their ranges overlapped in southwestern Kansas. Telemetry locations of 50 transmitter-equipped lesser prairie-chickens and 28 pheasants were used to monitor habitat use by the two species. Additionally, vegetation characteristics at 39 nest sites of lesser prairie-chickens were compared to those at 14 pheasant nest sites. Morisita's Index of niche overlap detected moderate similarities of habitat mixes used by lesser prairie-chickens and pheasants, but location data showed that spatial use of those habitats differed. Vegetation structure around nest sites of the two species differed significantly indicating selection of different habitat for nesting birds, and lesser prairie-chickens nested far from the outer edges of native prairie whereas pheasants nested nearer the outer edges. Despite the modest amount of similarity in mixes of habitats used by lesser prairie-chickens and ring-necked pheasants, we conclude that the two species occupy separate niches given the current extent of habitat in southwestern Kansas. However, if additional habitat loss or fragmentation occurs pheasants may gain competitive advantage over lesser prairie-chickens. Thus, we recommend maintaining and conserving large blocks of native habitat as well as the connectivity between them as a management strategy for maintaining populations of lesser prairie-chickens.

Age‐Specific Survival and Probable Causes of Mortality in Female Lesser Prairie‐Chickens

ABSTRACT Long‐term population declines and habitat reductions have increased concern over the status of the lesser prairie‐chicken (Tympanuchus pallidicinctus). Robust estimates of demographic parameters are essential for identifying population declines and planning effective management. We evaluated the effects of age and season on the survival of female lesser prairie‐chickens at 2 sites in southwestern Kansas, USA. Using telemetry data from a 7‐year field study (from 1997 to 2003), we estimated seasonal (Apr—Sep) and annual (Apr—Mar) survival. We also examined daily survival rates of females attending nests during the 26‐day incubation period and young during the 14‐day early brood‐rearing period. We evaluated the probable mortality causes of radiomarked birds by examining evidence at recovery sites. We captured 227 female lesser prairie‐chickens (87 yearlings, 117 ad, and 23 age undetermined) and fitted them with radiotransmitters. Estimates of 12‐month survival were lower among yearlings (Ŝ12 = 0.429, SE = 0.117) and adults at site I (Ŝ12 > = 0.302, SE = 0.080) than among yearlings (Ŝ12 = 0.588, SE = 0.100) and adults at site II (Ŝ12 > = 0.438, SE = 0.083). The patterns in timing of mortality and age‐specific 6‐month survival were consistent with those of 12‐month estimates at site I from 1998 to 2002, with a peak in mortality during May and June. Females tending to nests or to prefledged chicks had lower daily survival (DŜRtend = 0.993, SE = 0.001) than females not involved in these activities (DŜRfailedbreeder = 0.997, SE = 0.002). We recorded 92 mortalities from April 1997 to March 2003, and 59% and 11% were attributed to predation by mammals and raptors, respectively. Our research suggests that predation during the nesting season can have a major impact on lesser prairie‐chicken demography, and conservation efforts should focus on enhancing female survival during the nesting and brood‐rearing seasons.

Latent Heat Flux Profiles from Collocated Airborne Water Vapor and Wind Lidars during IHOP_2002

Abstract Latent heat flux profiles in the convective boundary layer (CBL) are obtained for the first time with the combination of the Deutsches Zentrum für Luft- und Raumfahrt (DLR) water vapor differential absorption lidar (DIAL) and the NOAA high resolution Doppler wind lidar (HRDL). Both instruments were integrated nadir viewing on board the DLR Falcon research aircraft during the International H2O Project (IHOP_2002) over the U.S. Southern Great Plains. Flux profiles from 300 to 2500 m AGL are computed from high spatial resolution (150 m horizontal and vertical) two-dimensional water vapor and vertical velocity lidar cross sections using the eddy covariance technique. Three flight segments on 7 June 2002 between 1000 and 1300 LT over western Oklahoma and southwestern Kansas are analyzed. On two segments with strong convection, the latent heat flux peaks at (700 ± 200) W m−2 in the entrainment zone and decreases linearly to (200 ± 100) W m−2 in the lower CBL. A water vapor budget analysis reveals that this flux divergence [(0.9 ± 0.4) g kg−1 h−1] plus the advection (0.3 g kg−1 h−1) are nearly balanced by substantial CBL drying [(1.5 ± 0.2) g kg−1 h−1] observed by airborne and surface in situ instruments, within the limits of the overall budget rms error of 0.5 g kg−1 h−1. Entrainment of dry air from aloft and net upward humidity transport caused the CBL drying and finally inhibited the initiation of deep convection. All cospectra show significant contributions to the flux between 1- and 10-km wavelength, with peaks between 2 and 6 km, originating from large eddies. The main flux uncertainty is due to low sampling (55% rmse at mid-CBL), while instrument noise (15%) and systematic errors (7%) play a minor role. The combination of a water vapor and a wind lidar on an aircraft appears as an attractive new tool that allows measuring latent heat flux profiles from a single overflight of the investigated area.

Fossil Passerines From the Early Pliocene of Kansas and the Evolution of Songbirds in North America

AbstractSeven living species of passerines are identified or tentatively identified from the early Pliocene Fox Canyon locality (4.3–4.8 mya), Rexroad Formation, Meade Basin, southwestern Kansas. All seven species occur in Kansas today, primarily as winter residents or transients, and their migratory behavior may extend to the early Pliocene as well. A review of all known passerines from the Neogene of North America indicates that many modern taxa began to appear in the early Pliocene, much earlier than previously believed. This fossil evidence agrees with some mitochondrial DNA analyses for the estimated age of divergence for living species of longspurs (Calcarius lapponicus and C. mccownii), but similar estimates for the divergence of C. ornatus using cytochrome-b analyses is at least 3 my younger than indicated by the fossil evidence. The fossil songbirds, as well as other vertebrate taxa from the Meade Basin, also indicate a paleoenvironment of short-grass prairie and shrubland with wetlands and ponds nearby, similar to that found in the area today. This prairie-steppe habitat first appeared in the Meade Basin by the early Pliocene and remained relatively stable until the Pleistocene, when it periodically appeared and disappeared with climate change. High seasonal productivity associated with this habitat in the early Pliocene may have promoted migratory behavior and speciation events in songbirds during a period of relative climatic stasis.Paserinos Fósiles del Plioceno Temprano de Kansas y la Evolución de las Aves Canoras en Norte América