Songbird Inventory for Arkansas Post National Memorial

Two geographically separate units of Arkansas Post National Memorial were surveyed via fixed-radius plots to document songbird species composition, richness, and diversity by migratory status and nesting guild. At the Memorial Unit, 60 species vere recorded with the Brown-headed Cowbird, Red-winged Blackbird, and Northern Cardinal being most common. individuals of these three species comprised 30% of the total number of birds recorded despite representing only 5% of the species encountered. About 2 1/2 times more resident birds were recorded than migratory birds. However, species richness and diversity of resident and migratory species were similar. The number of individuals, species richness, and diversity of canopy nesting species were greater than other nesting guilds. At the Osotouy Unit, 42 species were recorded with the most common species encountered being the Indigo Bunting, Carolina Wren, and Yellow-billed Cuckoo. Individuals of these 3 species comprised 30% of the total number of birds recorded despite representing only 7% of the species encountered. About 50% fewer resident birds were recorded than migratory birds. Migratory birds represented approximately 40% more species than resident birds. Likewise, diversity was greater for migratory species than for resident species. As in the Memorial Unit, the number of individuals, species richness, and diversity of canopy-nesting species were greater than other nesting guilds. No federal or state threatened or endangered species were documented, but 8 species currently tracked by the Arkansas Natural Heritage Commission were documented. These results have implications for future park management activities, particularly in respect to potential development plans at the Osotouy Unit

Assessment of Thermal Infrared Detection Rates Using White-Tailed Deer Surrogates

As thermal infrared imaging technology has improved, it has increasingly been used for estimating sizes of wildlife populations. The greatest bias of thermal infrared surveys is the lack of known detection rates to adjust for visibility bias. As with visual surveys, a measure of detection rate is needed to provide unbiased estimates. We assessed the detection rate of white-tailed deer (Odocoileus virginianus) using a thermal infrared sensor (1.2 - 5.9 /an) from an aerial platform. Similar characteristics between thermal signatures of people and deer allowed us to use people in a reclined or horizontal position as surrogates for deer. We conducted a census of 2.56 km2 within which 20 people were randomly placed. We detected 75.0% of the people (n = 20) across the area and 93.8% of the people (n= 16) when the effect of water was taken into consideration. Thermal signatures of people and deer occupying flooded areas were likely masked by the surrounding thermal signature of water. We found the method worked well in bottomland hardwood forests under dry conditions. As with visual aerial population counting methods, detection rates for an area should be developed to provide unbiased estimates

Discovery of superthermal hydroxyl (OH) in the HH211 outflow

We present a 5-37 micron infrared spectrum obtained with the Spitzer Space Telescope toward the southeastern lobe of the young protostellar outflow HH211. The spectrum shows an extraordinary sequence of OH emission lines arising in highly excited rotational levels up to an energy E/k~28200K above the ground level. This is, to our knowledge, by far the highest rotational excitation of OH observed outside Earth. The spectrum also contains several pure rotational transitions of H2O (v=0), H2 (v=0) S(0) to S(7), HD (v=0) R(3) to R(6), and atomic fine-structure lines of [Fe II], [Si II], [Ne II], [S I], and [Cl I]. The origin of the highly excited OH emission is most likely the photodissociation of H2O by the UV radiation generated in the terminal outflow shock of HH211.Comment: ApJ Letters, in pres

Long-Term White-Tailed Deer Harvest Trends for the Southcentral United States

White-tailed deer herd size across the southcentral states continues to increase. Concurrent with this increase has come a total harvest level increase for most states. Southcentral states have increased bag limits on antlerless deer to insure that herd health is maintained as herd sizes approach total carrying capacity. Harvest growth rates, however, show irregularities from year to year. The cyclic pattern of harvest (and population) growth rate is of shorter duration than would be expected in a large ungulate population. An exogenous influence is suspected. Cyclic patterns in harvest growth rates move opposite the growth rate of epizootic hemorrhagic disease incidence in southcentral counties. Initial results suggest causality between disease incidence and harvest growth rate. As herds approach carrying capacity on many southern sites, management challenges increase

Effects of Retained Pine and Hardwood Basal Areas on Percent Cover of Plants Utilized by Bobwhite Quail

Percent cover of seven forage species utilized by bobwhite quail (Colinus virginianus) was determined before thinning and 2 and 4 years after thinning a 35-year-old loblolly pine-hardwood stand. Combinations of three loblolly pine (15, 18, and 21 m2/ha) and three hardwood (0, 3.5, and 7 m2/ha) basal areas were replicated three times. Percent cover was determined for American beautyberry (Callicarpa americana), blackberry (Rubus spp.), tick trefoil (Desmodium spp.), lespedeza (Lespedeza spp.), panic grass (Panicum spp.), yellow wood sorrel (Oxalis stricta), and three-seeded mercury (Acalypha spp.). Percent cover of American beautyberry and blackberry increased with time. Tick trefoil and panic grass were negatively related to time after thinning. However, lespedeza, yellow wood sorrel, and three-seeded mercury were not influenced significantly by time after thinning. Blackberry and panic grass were negatively related to pine basal area, while all other plant species were not affected. Three-seeded mercury was the only species not negatively related to hardwood basal area. Canopy cover and relative light intensity in the understory demonstrated an inverse relationship

Freshly Formed Dust in the Cassiopeia A Supernova Remnant as Revealed by the Spitzer Space Telescope

We performed Spitzer Infrared Spectrograph mapping observations covering nearly the entire extent of the Cassiopeia A supernova remnant (SNR), producing mid-infrared (5.5-35 micron) spectra every 5-10". Gas lines of Ar, Ne, O, Si, S and Fe, and dust continua were strong for most positions. We identify three distinct ejecta dust populations based on their continuum shapes. The dominant dust continuum shape exhibits a strong peak at 21 micron. A line-free map of 21 micron-peak dust made from the 19-23 micron range closely resembles the [Ar II], [O IV], and [Ne II] ejecta-line maps implying that dust is freshly formed in the ejecta. Spectral fitting implies the presence of SiO2, Mg protosilicates, and FeO grains in these regions. The second dust type exhibits a rising continuum up to 21 micron and then flattens thereafter. This ``weak 21 micron'' dust is likely composed of Al2O3 and C grains. The third dust continuum shape is featureless with a gently rising spectrum and is likely composed of MgSiO3 and either Al2O3 or Fe grains. Using the least massive composition for each of the three dust classes yields a total mass of 0.02 Msun. Using the most-massive composition yields a total mass of 0.054 Msun. The primary uncertainty in the total dust mass stems from the selection of the dust composition necessary for fitting the featureless dust as well as 70 micron flux. The freshly formed dust mass derived from Cas A is sufficient from SNe to explain the lower limit on the dust masses in high redshift galaxies.Comment: 8 figures: Accepted for the publication in Ap

Conceptual Basis for an Index of Forest Integrity for Upland Coastal Plain Ecosystems

Following the recent trend to manage natural resources for sustainability, ecologists, resource managers and policymakers are beginning to think of the management of forest ecosystems in terms of ecosystem health or ecosystem integrity. Biologists are increasingly recognizing that use of chemical assays in assessing the condition of an ecosystem has limited value, and that biological factors, e.g., species diversity and composition, can be useful characters in the analysis of biotic integrity. An index of biotic integrity (IBI) has been developed for riverine ecosystems in the Midwest U.S., using fish species diversity, indicator population analysis, trophic structure assessment, and physiological abnormalities in fish as measurable surrogates for biotic integrity . This paper explores the development of an analogous index of forest integrity (IFI) to be applied to the upland coastal plain forests of southern Arkansas and northern Louisiana. The IFI developed here includes sampling and analysis of population trends of dominant plant taxa, plant species diversity, and horizontal and vertical vegetative structure at midstory, shrub and detritus levels