Abundance and Habitat Use of Winter Raptors on a Reclaimed Surface Mine in Southeastern Ohio

Author Institution: Department of Biology, Muskingum UniversityNumerous studies have documented the benefits of reclaimed surface mines to breeding grassland birds, but few studies have focused on the use of such grasslands by winter raptors. I surveyed birds of prey along a driving transect on and around a 3,700 ha reclaimed surface mine in east-central Ohio from early January through mid-April 2009. My objective was to use these survey data to assess the relative abundance of migratory and winter resident raptors, as well as to examine potential habitat associations, perching preferences and morning versus afternoon activity patterns in each species. I sighted 382 total birds; red-tailed (Buteo jamaicensis) and rough-legged hawks (B. lagopus) had the greatest index of relative abundance followed by American kestrels (Falco sparverius) and northern harriers (Circus cyaneus). Numbers of rough-legged hawks, the only purely migratory species in this region, declined from January through April, while numbers of red-tailed hawks and harriers increased. Rough-legged hawks, kestrels and harriers were found in open grasslands at a rate greater than expected by chance alone, whereas red-tailed hawks were found disproportionately more often along forest edges. Most rough-legged hawks and harriers were observed soaring rather than perched, while approximately equal numbers of red-tailed hawks were observed soaring or perched in large trees. Most kestrels were observed on utility wires or in small trees. That moderate to high numbers of obligate grassland raptors were observed in this study, support previous findings that reclaimed surface mines provide important winter habitat for these species

Quantum Tunneling Detection of Two-photon and Two-electron Processes

We analyze the operation of a quantum tunneling detector coupled to a coherent conductor. We demonstrate that in a certain energy range the output of the detector is determined by two-photon processes, two-electron processes and the interference of the two. We show how the individual contributions of these processes can be resolved in experiments.Comment: 4 pages, 4 figure

Abundance and Habitat Associations of Winter and Spring Birds on a Reclaimed Surface Mine (The Wilds) in Ohio, USA

Several studies have examined how grassland birds use reclaimed surface mines during the breeding season, but few studies have documented how these birds use these areas during the winter and early spring months. Using point counts, birds occupying a reclaimed surface-mine site in southeastern Ohio were surveyed from late December 2020 to April 2021. The primary objective was to document bird abundance and species richness across a temporal gradient spanning from late December 2020 through April 2021. Additionally, bird species composition was examined in habitat patches dominated by cool-season plants and in a single warm-season plot dominated by switchgrass (Panicum virgatum). A total of 1,452 bird sightings were made consisting of 40 species in 7 orders. Songbirds (order Passeriformes) comprised 60% of all sightings, and most of these (53%) were Red-winged Blackbirds (Agelaius phoeniceus), Eastern Meadowlarks (Sturnella magna), and Song Sparrows (Melospiza melodia). Thirty-nine species were observed on cool-season sites versus 13 species in the switchgrass plot. Species including returning Eastern Meadowlarks, Henslow's Sparrows (Centronyx henslowii), and Field Sparrows (Spizella pusilla) were common on the cool-season plots, but uncommon or absent in the switchgrass plot. Conversely, the switchgrass plot had more wintering American Tree Sparrows (Spizelloides arborea) and returning Swamp Sparrows (Melospiza georgiana). Return rates of long-distance migratory species fell within the time frames for these species as obtained from previous studies in this region. The diverse habitat structure of the cool-season portions of this study site attracted some winter species, including birds of prey, as well as several returning migratory species

Tunneling into Multiwalled Carbon Nanotubes: Coulomb Blockade and Fano Resonance

Tunneling spectroscopy measurements of single tunnel junctions formed between multiwalled carbon nanotubes (MWNTs) and a normal metal are reported. Intrinsic Coulomb interactions in the MWNTs give rise to a strong zero-bias suppression of a tunneling density of states (TDOS) that can be fitted numerically to the environmental quantum-fluctuation (EQF) theory. An asymmetric conductance anomaly near zero bias is found at low temperatures and interpreted as Fano resonance in the strong tunneling regime.Comment: 4 pages, 4 figure

Lissajous curves and semiclassical theory: The two-dimensional harmonic oscillator

The semiclassical treatment of the two-dimensional harmonic oscillator provides an instructive example of the relation between classical motion and the quantum mechanical energy spectrum. We extend previous work on the anisotropic oscillator with incommensurate frequencies and the isotropic oscillator to the case with commensurate frequencies for which the Lissajous curves appear as classical periodic orbits. Because of the three different scenarios depending on the ratio of its frequencies, the two-dimensional harmonic oscillator offers a unique way to explicitly analyze the role of symmetries in classical and quantum mechanics.Comment: 9 pages, 3 figures; to appear in Am. J. Phy

Identification of Coulomb blockade and macroscopic quantum tunneling by noise

The effects of Macroscopic Quantum Tunneling (MQT) and Coulomb Blockade (CB) in Josephson junctions are of considerable significance both for the manifestations of quantum mechanics on the macroscopic scale and potential technological applications. These two complementary effects are shown to be clearly distinguishable from the associated noise spectra. The current noise is determined exactly and a rather sharp crossover between flux noise in the MQT and charge noise in the CB regions is found as the applied voltage is changed. Related results hold for the voltage noise in current-biased junctions.Comment: 6 pages, 3 figures, epl.cls include

Inverse proximity effect in superconductors near ferromagnetic material

We study the electronic density of states in a mesoscopic superconductor near a transparent interface with a ferromagnetic metal. In our tunnel spectroscopy experiment, a substantial density of states is observed at sub-gap energies close to a ferromagnet. We compare our data with detailed calculations based on the Usadel equation, where the effect of the ferromagnet is treated as an effective boundary condition. We achieve an excellent agreement with theory when non-ideal quality of the interface is taken into account.Comment: revised, 7 pages, 3 figure

High Frequency Quantum Admittance and Noise Measurement with an On-chip Resonant Circuit

By coupling a quantum detector, a superconductor-insulator-superconductor junction, to a Josephson junction \textit{via} a resonant circuit we probe the high frequency properties, namely the ac complex admittance and the current fluctuations of the Josephson junction at the resonant frequencies. The admittance components show frequency dependent singularities related to the superconducting density of state while the noise exhibits a strong frequency dependence, consistent with theoretical predictions. The circuit also allows to probe separately the emission and absorption noise in the quantum regime of the superconducting resonant circuit at equilibrium. At low temperature the resonant circuit exhibits only absorption noise related to zero point fluctuations, whereas at higher temperature emission noise is also present.Comment: 15 pages, 15 figure