A comparison of point-count and area-search surveys for monitoring site occupancy of the Coastal California Gnatcatcher (Polioptila californica californica)

Abstract As evidence for global insect population declines continues to amass, several studies have indicated that Orthoptera (grasshoppers, crickets, and katydids) are among the most threatened insect groups. Understanding Orthoptera populations across large spatial extents requires efficient survey protocols, however, many previously established methods are expensive and/or labor-intensive. One survey method widely employed in wildlife biology, the aural point count, may work well for crickets and katydids (suborder: Ensifera) because males produce conspicuous, species-specific mating calls. We conducted repeated point count surveys across an urban-to-rural gradient in central Pennsylvania. Occupancy analyses of ten focal species indicated that, although detection probability rates varied by species from 0.43 to 0.98, detection rates compounded over five visits such that all focal species achieved cumulative > 0.90. Factors associated with site occupancy varied among species with some positively associated with urbanization (e.g., Greater Anglewing, Microcentrum rhombifolium), some negatively associated with urbanization (e.g., Sword-bearing Conehead, Neoconocephalus ensiger), and others exhibiting constant occupancy across a habitat gradient (e.g., Common True Katydid, Pterophylla camellifolia). Our community-level analysis revealed that different species’ habitat associations interacted such that intermediate levels of urbanization (i.e., suburbs) hosted the highest number of species. Implications for insect conservation Ultimately, our analyses clearly support the concept that aural point counts paired with static occupancy modeling can serve as an important tool for monitoring night-singing Orthoptera populations. Applications of point count surveys by both researchers and citizen scientists may improve our understanding Ensifera populations and help in the global conservation of these threatened insects.

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Monitoring site occupancy for American mink in its native range

Journal of Wildlife Management ◽

10.1002/jwmg.294 ◽

2011 ◽

Vol 76 (4) ◽

pp. 824-831 ◽

Cited By ~ 14

Author(s):

Robert L. Schooley ◽

Lisa A. Cotner ◽

Adam A. Ahlers ◽

Edward J. Heske ◽

Jeffrey M. Levengood

Keyword(s):

American Mink ◽

Site Occupancy ◽

Monitoring Site ◽

Native Range

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Monitoring important coastal sites for bottlenose dolphin in Cardigan Bay, UK

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315409000885 ◽

2009 ◽

Vol 89 (5) ◽

pp. 1033-1043 ◽

Cited By ~ 9

Author(s):

Chris Pierpoint ◽

Liz Allan ◽

Holly Arnold ◽

Peter Evans ◽

Sarah Perry ◽

...

Keyword(s):

Marine Mammals ◽

Bottlenose Dolphins ◽

Coastal Zone Management ◽

Site Occupancy ◽

Cost Effective ◽

County Council ◽

Monitoring Site ◽

Positive Trend ◽

Site Use ◽

Boat Traffic

From 1994–2007 Ceredigion County Council and a network of shore-based, volunteer observers monitored levels of boat traffic and the occurrence of bottlenose dolphins Tursiops truncatus at seven sites on the coast of Cardigan Bay, Wales. We report high rates of site use and site occupancy by this species during the summer: at Mwnt for example, dolphins were recorded in >80% of 2 hours' observation periods; and at New Quay Harbour dolphins were present in >30% of all 15-minute intervals. At Mwnt and Aberporth there was a significant annual trend for increasing sighting rates; at Ynys Lochtyn a positive trend was only marginally non-significant; at New Quay Bird's Rock the trend was ambiguous but appeared stable over the seven most recent years. Although trends in site use may not reflect population trends in the wider region, these data were consistent with recent abundance estimates that indicate that the number of bottlenose dolphins using Cardigan Bay is stable or slightly increasing. Average group size at our study sites was small (<3 animals), which contrasts with observations of larger schools of the same population elsewhere in their range. The predominant behaviour in coastal Cardigan Bay is demersal foraging, often by solitary animals in shallow near-shore habitats. There was evidence that boat traffic suppressed site use by dolphins at New Quay Harbour, the busiest monitoring site: sighting rates fell when high numbers of boats were present and sighting rates were higher in 2007 than in previous years, when boat use was reduced due to poor weather during the main tourist season. This study demonstrates that networks of volunteer observers can provide a cost-effective, non-invasive means of gathering data on marine mammals for the purposes of coastal zone management.

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High-resolution structure determination by ALCHEMI

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074707 ◽

1983 ◽

Vol 41 ◽

pp. 178-181 ◽

Cited By ~ 1

Author(s):

Peter G. Self ◽

Peter R. Buseck

Keyword(s):

Site Occupancy ◽

Real Space ◽

Unit Cell ◽

Bragg Angle ◽

Electron Current ◽

High Resolution Structure ◽

Beam Incident ◽

Crystallographic Planes ◽

Electron Beam Incident ◽

Resolution Structure

ALCHEMI (Atom Location by CHanneling Enhanced Microanalysis) enables the site occupancy of atoms in single crystals to be determined. In this article the fundamentals of the method for both EDS and EELS will be discussed. Unlike HRTEM, ALCHEMI does not place stringent resolution requirements on the microscope and, because EDS clearly distinguishes between elements of similar atomic number, it can offer some advantages over HRTEM. It does however, place certain constraints on the crystal. These constraints are: a) the sites of interest must lie on alternate crystallographic planes, b) the projected charge density on the alternate planes must be significantly different, and c) there must be at least one atomic species that lies solely on one of the planes.An electron beam incident on a crystal undergoes elastic scattering; in reciprocal space this is seen as a diffraction pattern and in real space this is a modulation of the electron current across the unit cell. When diffraction is strong (i.e., when the crystal is oriented near to the Bragg angle of a low-order reflection) the electron current at one point in the unit cell will differ significantly from that at another point.

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Zone-axis ALCHEMI for the rapid assessment of site occupancies in garnets

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144905 ◽

1986 ◽

Vol 44 ◽

pp. 706-707

Author(s):

M.T. Otten ◽

P.R. Buseck

Keyword(s):

Single Crystals ◽

Rapid Assessment ◽

Site Occupancy ◽

Zone Axis ◽

Synthetic Compounds ◽

X Ray ◽

Large Group ◽

Crystallographic Planes

ALCHEMI (Atom Location by CHannelling-Enhanced Microanalysis) is a TEM technique for determining site occupancies in single crystals. The method uses the channelling of incident electrons along specific crystallographic planes. This channelling results in enhanced x-ray emission from the atoms on those planes, thereby providing the required site-occupancy information. ALCHEMI has been applied with success to spinel, olivine and feldspar. For the garnets, which form a large group of important minerals and synthetic compounds, the channelling effect is weaker, and significant results are more difficult to obtain. It was found, however, that the channelling effect is pronounced for low-index zone-axis orientations, yielding a method for assessing site occupancies that is rapid and easy to perform.

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Site occupancy in gamma alumina

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100165732 ◽

1996 ◽

Vol 54 ◽

pp. 654-655

Author(s):

C. A. Bateman ◽

A.Z. Ringwelski ◽

R.W. Broach

Keyword(s):

Spinel Structure ◽

Site Occupancy ◽

Unit Cell ◽

Neutron Diffraction Data ◽

Gamma Alumina ◽

Tetrahedral Sites ◽

Powder Neutron Diffraction ◽

Cation Sites ◽

Powder Neutron Diffraction Data ◽

Insufficient Number

Gamma (γ) alumina is referred to as a defect spinel because it has a tetragonally distorted spinel structure (AB2O4) and an insufficient number of cations to fill all cation sites. In the spinel structure, the oxygen lattice is cubic close packed with A- and B-site cations in tetrahedral and octahedral coordination, respectively. The 2l⅓ Al atoms per unit cell of γ alumina can distribute themselves across 16 octahedral and 8 tetrahedral sites.The literature differs on where the 2⅔ cation vacancies per unit cell are located. Wilson and McConnell proposed that the vacancies in γ alumina, as first formed by calcining boehmite, are predominantly on the tetrahedral lattice but, with further heat treatment, move to occupy random positions on both octahedral and tetrahedral lattices. One study using NMR showed that the vacancies lay exclusively on the tetrahedral lattice, independent of the calcination temperature. A more-recent study using Rietveld refinement of powder neutron diffraction data suggested that both octahedral and tetrahedral lattices were partially occupied.

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MÖSSBAUER STUDY OF HYDROGEN DIFFUSION AND INTERSTITIAL SITE OCCUPANCY IN57Co : PdHxAND57Fe : PdHx

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19792222 ◽

1979 ◽

Vol 40 (C2) ◽

pp. C2-635-C2-638

Author(s):

F. Pröbst ◽

F. E. Wagner ◽

M. Karger ◽

G. Wortmann

Keyword(s):

Hydrogen Diffusion ◽

Site Occupancy ◽

Interstitial Site ◽

Mössbauer Study

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SITE OCCUPANCY OF Fe ATOM IN RFe4+xAl8-x (R = Gd, Er, Y) AND THEIR MAGNETIC PROPERTIES

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19888172 ◽

1988 ◽

Vol 49 (C8) ◽

pp. C8-381-C8-382

Author(s):

T. Kamimori ◽

W. L. Liu ◽

H. Kadomatsu ◽

M. Goto ◽

H. Fujiwara

Keyword(s):

Magnetic Properties ◽

Site Occupancy

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Structural/Property Relationships for Optical Materials

MRS Proceedings ◽

10.1557/proc-329-215 ◽

1993 ◽

Vol 329 ◽

Author(s):

Vivien D.

Keyword(s):

Crystal Structure ◽

Optical Properties ◽

Electronic Structure ◽

Chemical Composition ◽

Field Strength ◽

Optical Materials ◽

Site Occupancy ◽

Laser Materials ◽

Crystal Field Strength ◽

The Matrix

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.

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A Crystallographic Study of Bis[S-benzyl-5-bromo-2-oxoindolin-3-ylidenemethanehydrazonthioate] Disulfide Solvated with Dimethylsulfoxide

Scientific Research Journal ◽

10.24191/srj.v9i2.9410 ◽

2012 ◽

Vol 9 (2) ◽

pp. 87

Author(s):

Mohd Abdul Fatah Abdul Manan ◽

M. Ibrahim M. Tahir ◽

Karen A. Crouse ◽

Fiona N.-F. How ◽

David J. Watkin

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Solvent Molecule ◽

Site Occupancy ◽

Unit Cell Parameters ◽

Intermolecular Hydrogen Bonds ◽

Triclinic Space Group ◽

Cell Parameters ◽

Crystallographic Study ◽

Thiol Form

The crystal structure of the title compound has been determined. The compound crystallized in the triclinic space group P -1, Z = 2, V = 1839 .42( 18) A3 and unit cell parameters a= 11. 0460( 6) A, b = 13 .3180(7) A, c=13. 7321 (8) A, a = 80.659(3 )0, b = 69 .800(3 )0 and g = 77 .007 (2)0 with one disordered dimethylsulfoxide solvent molecule with the sulfur and oxygen atoms are distributed over two sites; S101/S102 [site occupancy factors: 0.6035/0.3965] and 0130/0131 [site occupancy factor 0.3965/0.6035]. The C22-S2 l and C 19-S20 bond distances of 1. 779(7) A and 1. 788(8) A indicate that both of the molecules are connected by the disulfide bond [S20-S21 2.055(2) A] in its thiol form. The crystal structure reveals that both of the 5-bromoisatin moieties are trans with respect to the [S21-S20 and CI 9-Nl 8] and [S20-S21 and C22-N23] bonds whereas the benzyl group from the dithiocarbazate are in the cis configuration with respect to [S21-S20 and C19-S44] and [S20-S21 and C22-S36] bonds. The crystal structure is further stabilized by intermolecular hydrogen bonds of N9-H35···O16 formed between the two molecules and N28-H281 ···O130, N28-H281 ···O131 and C4 l-H4 l l ···O 131 with the solvent molecule.

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