An Observer-Specific, Full-Season, Strip-Map Method for Censusing Songbird Communities

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 730-740 ◽  
Author(s):  
John T. Emlen
Keyword(s):  
Detection Threshold ◽  
Bird Community ◽  
Early Morning ◽  
Breeding Bird ◽  
Threshold Distance ◽  
Area Of Interest ◽  
Simple Detection ◽  
Territory Holder ◽  
The Moment ◽  
Species Specific

Abstract In this paper I describe and demonstrate a strip-map census method designed to provide a complete record of the composition and density of a temperate-zone breeding bird community through a period covering the peaks of breeding activity of all resident species and individuals. A route transecting the area of interest is laid out, flanked on each side by an unmarked strip of a width equal to the distance at which birds can be detected (the detection-threshold distance). All birds detected during uniform listening periods on frequent, closely scheduled, early morning traverses of the route are recorded with appropriate symbols at the moment of detection on simple line maps of the route. Because species differ in the distance at which their calls and songs can be heard and observers differ in their hearing acuity, each observer has an observer-specific strip width for each species. These strip widths are determined directly from the distribution of all detection points on the census maps at the end of the season. Multiplied by the length of the strip, they give the area of the strip for each species. The accumulations of detection-point clusters on summary maps for each species are interpreted as the territories of individual birds. Densities within the study area or segments of it are determined by dividing the number of equivalent territories (Σ wholes plus fractions) within the species-detection strip by the area of the strip. Song frequencies are determined for each individual territory holder by multiplying the proportion of listening periods during which the bird was heard by the proportion of that bird's territory that fell within the species' detectability strip. The method provides a continuous record, divisible into segments of any desired length, of the density, song activity, and distribution of individuals of each species through its breeding season. The detection-threshold distance and song-frequency values obtained can be used as species-specific conversion factors for translating simple detection counts to bird densities.

scholarly journals Die Entwicklung der Brutvögel in der Waldbrandfläche bei Leuk

2018 ◽  
Vol 169 (5) ◽  
pp. 299-307
Author(s):  
Livio Rey ◽  
Alain Jacot
Keyword(s):  
Large Scale ◽  
Bird Species ◽  
Bird Community ◽  
Future Research ◽  
Conservation Action ◽  
Breeding Bird ◽  
Fire Event ◽  
Positive Effects ◽  
Priority Species ◽  
Species Specific

Temporal changes of the breeding bird community in the burnt forest of Leuk Wildfires and windstorms are dynamic processes that can heavily impact habitats and alter their species compositions. Especially species of open and semi-open habitats can benefit from such disturbances, among them several bird species. In this study, we investigated the species-specific changes of the breeding bird community in the burnt forest of Leuk between 2006 and 2016, starting three years after the wildfire of 2003. Several species increased or decreased significantly in abundance after the fire event. A few species showed a complex reaction, where territory numbers increased after the fire, reaching a maximum after a few years and subsequently decreased. Interestingly, many of these bird species (e.g., Eurasian Wryneck, Common Redstart) are threatened and are priority species for conservation action. They may have benefitted from the first, open successional stages with a high proportion of bare ground, but are expected to decrease in abundance with the ongoing densification of the vegetation layers. Our study demonstrates that a large-scale forest fire can promote threatened bird species of open and semi-open habitats also in temperate regions. To what extent forestry measures, grazing or controlled fires can imitate the positive effects of wildfires is an open question and should be part of future research in the combined fields of forestry and conservation biology.

Evaluating Riparian Restoration Success: Long-Term Responses of the Breeding Bird Community in California’s Lower Putah Creek Watershed

2018 ◽  
Vol 36 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Kristen E. Dybala ◽  
Andrew Engilis ◽  
John A. Trochet ◽  
Irene E. Engilis ◽  
Melanie L. Truan
Keyword(s):  
Bird Community ◽  
Riparian Restoration ◽  
Breeding Bird ◽  
Restoration Success ◽  
Creek Watershed ◽  
Putah Creek

Religious and Mystical Experiences as Artifacts of Temporal Lobe Function: A General Hypothesis

1983 ◽  
Vol 57 (3_suppl) ◽  
pp. 1255-1262 ◽  
Author(s):  
Michael A. Persinger
Keyword(s):  
Temporal Lobe ◽  
Early Morning ◽  
Religious Experiences ◽  
General Hypothesis ◽  
Intrinsic Reward ◽  
Reinforcement History ◽  
Body Experiences ◽  
Cultural Experiences ◽  
Specific Stimulation ◽  
Species Specific

Mystical and religious experiences are hypothesized to be evoked by transient, electrical microseizures within deep structures of the temporal lobe. Although experiential details are affected by context and reinforcement history, basic themes reflect the inclusion of different amygdaloid-hippocampal structures and adjacent cortices. Whereas the unusual electrical coherence allows access to infantile memories of parents, a source of god expectations, specific stimulation evokes out-of-body experiences, space-time distortions, intense meaningfulness, and dreamy scenes. The species-specific similarities in temporal lobe properties enhance the homogeneity of cross-cultural experiences. They exist along a continuum that ranges from “early morning highs” to recurrent bouts of conversion and dominating religiosity. Predisposing factors include any biochemical or genetic factors that produce temporal lobe lability. A variety of precipitating stimuli provoke these experiences, but personal (life) crises and death bed conditions are optimal. These temporal lobe microseizures can be learned as responses to existential trauma because stimulation is of powerful intrinsic reward regions and reduction of death anxiety occurs. The implications of these transients as potent modifiers of human behavior are considered.

Diurnal variability of frontal dynamics, instability, and turbulence in a submesoscale upwelling filament

2021 ◽  
Author(s):  
Jen-Ping Peng ◽  
Lars Umlauf ◽  
Julia Dräger-Dietel ◽  
Ryan P. North
Keyword(s):  
Solar Radiation ◽  
Early Morning ◽  
Shear Instability ◽  
Surface Boundary ◽  
Surface Boundary Layer ◽  
Diurnal Variability ◽  
Frontal Dynamics ◽  
The Stability ◽  
The Moment ◽  
The Impact

AbstractRecent high-resolution numerical simulations have shown that the diurnal variability in the atmospheric forcing strongly affects the dynamics, stability, and turbulence of submesoscale structures in the surface boundary layer (SBL). Field observations supporting the real-ocean relevance of these studies are, however, largely lacking at the moment. Here, the impact of large diurnal variations in the surface heat flux on a dense submesoscale upwelling filament in the Benguela upwelling system is investigated, based on a combination of densely-spaced turbulence microstructure observations and surface drifter data. Our data show that during nighttime and early-morning conditions, when solar radiation is still weak, frontal turbulence is generated by a mix of symmetric and shear instability. In this situation, turbulent diapycnal mixing is approximately balanced by frontal restratification associated with the cross-front secondary circulation. During daytime, when solar radiation is close to its peak value, the SBL quickly restratifies, the conditions for frontal instability are no longer fulfilled, and SBL turbulence collapses except for a thin wind-driven layer near the surface. The drifter data suggest that inertial oscillations periodically modulate the stability characteristics and energetics of the submesoscale fronts bounding the filament.

scholarly journals The Role of Weather during the Greek–Persian “Naval Battle of Salamis” in 480 B.C.

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 838 ◽  
Author(s):  
Christos Zerefos ◽  
Stavros Solomos ◽  
Dimitris Melas ◽  
John Kapsomenakis ◽  
Christos Repapis
Keyword(s):  
Sea Breeze ◽  
Weather Conditions ◽  
Early Morning ◽  
Area Of Interest ◽  
Open Sea ◽  
Early Afternoon ◽  
Wind Climatology ◽  
South Sea ◽  
Diurnal Wind

The Battle of Salamis in 480 B.C. is one of the most important naval battles of all times. This work examines in detail the climatically prevailing weather conditions during the Persian invasion in Greece. We perform a climatological analysis of the wind regime in the narrow straits of Salamis, where this historic battle took place, based on available station measurements, reanalysis and modeling simulations (ERA5, WRF) spanning through the period of 1960–2019. Our results are compared to ancient sources before and during the course of the conflict and can be summarized as follows: (i) Our climatological station measurements and model runs describing the prevailing winds in the area of interest are consistent with the eyewitness descriptions reported by ancient historians and (ii) The ancient Greeks and particularly Themistocles must have been aware of the local wind climatology since their strategic plan was carefully designed and implemented to take advantage of the diurnal wind variation. The combination of northwest wind during the night and early morning, converging with a south sea breeze after 10:00 A.M., formed a “pincer” that aided the Greeks at the beginning of the clash in the morning, while it brought turmoil to the Persian fleet and prevented them to escape to the open sea in the early afternoon hours.

scholarly journals Circadian Variation of Migraine Attack Onset: A Review of Clinical Studies

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Daniel Baksa ◽  
Kinga Gecse ◽  
Sahel Kumar ◽  
Zsuzsanna Toth ◽  
Zsofia Gal ◽  
...  
Keyword(s):  
Migraine Attack ◽  
Circadian Variation ◽  
Early Morning ◽  
Sleep Stages ◽  
Shift Workers ◽  
Late Night ◽  
Diurnal Distribution ◽  
Pubmed Search ◽  
Migraine Triggers ◽  
The Moment

Several studies suggested that migraine attack onset shows a circadian variation; however, there has not been an overview and synthesis of these findings. A PubMed search with keywords “migraine” AND “circadian” resulted in ten studies directly investigating this topic. Results of these studies mostly show that migraine attacks follow a monophasic 24-hour cyclic pattern with an early morning or late night peak while other studies reported an afternoon peak and also a biphasic 24-hour cycle of attacks. The identified studies showed methodological variation including sample size, inclusion of medication use, comorbidities, and night or shift workers which could have contributed to the contradictory results. Several theories emerged explaining the diurnal distribution of migraine attacks suggesting roles for different phenomena including a morning rise in cortisol levels, a possible hypothalamic dysfunction, a circadian variation of migraine triggers, sleep stages, and a potentially different setting of the circadian pacemaker among migraineurs. At the moment, most studies show an early morning or late night peak of migraine attack onset, but a significant amount of studies reveals contradictory results. Further studies should investigate the arising hypotheses to improve our understanding of the complex mechanism behind the circadian variation of migraine attacks that can shed light on new targets for migraine therapy.

scholarly journals Riparian Bird Community Structure in Portland, Oregon: Habitat, Urbanization, and Spatial Scale Patterns

The Condor ◽  
2003 ◽  
Vol 105 (2) ◽  
pp. 288-302 ◽  
Author(s):  
Lori A. Hennings ◽  
W. Daniel Edge
Keyword(s):  
Native Species ◽  
Forest Canopy ◽  
Urban Canopy ◽  
Canopy Cover ◽  
Bird Community ◽  
Metropolitan Region ◽  
Road Density ◽  
Breeding Bird ◽  
Bird Abundance ◽  
Neotropical Migrant

Abstract In 1999, we surveyed breeding bird and plant communities along 54 streams in the Portland, Oregon, metropolitan region to link bird community metrics with structural and spatial characteristics of urban riparian areas. Canonical correspondence analysis produced two explanatory axes relating to vegetation and road density. Total and non-native bird abundance was higher in narrow forests. Native bird abundance was greater in narrow forests surrounded by undeveloped lands; native species richness and diversity were greater in less-developed areas. Native resident and short-distance-migrant abundance was higher in narrow forests, and diversity was positively associated with developed lands. Neotropical migrant abundance, richness, and diversity were greater in open-canopied areas with fewer roads. We examined spatial relationships by regressing bird variables on satellite-derived forest canopy cover, area of undeveloped lands, and street density in a series of 50-m buffers within a 500-m radius around study sites. Non-native bird abundance decreased with increasing canopy cover within 450 m, but most other relationships were strongest at smaller scales (50–100 m). Our results suggest that increasing urban canopy cover is the most valuable land management action for conserving native breeding birds. A hierarchical scheme for Neotropical migrant conservation might include increasing forest canopy within 450 m of streams to control non-native species and cowbirds; reducing street density within a 100-m radius of streams; and conserving or planting onsite native trees and shrubs. Estructura de Comunidades Riparias de Aves en Portland, Oregon: Hábitat, Urbanización y Patrones de Escala Espacial Resumen. Censamos las comunidades de aves reproductivas y plantas a lo largo de 54 arroyos en el área metropolitana de Portland, Oregon en 1999 para conectar medidas de comunidades de aves con características estructurales y espaciales de zonas riparias urbanas. Análisis de correspondencia canónica produjeron dos ejes explicativos relacionados con la vegetación y la densidad de carreteras. La abundancia total de aves y la de aves no nativas fueron mayores en bosques estrechos. La abundancia de aves nativas fue mayor en bosques estrechos rodeados por terrenos rurales y la riqueza y diversidad de especies fueron mayores en áreas menos desarrolladas. La abundancia de residentes nativas y migratorias de corta distancia fue mayor en bosques estrechos y su diversidad estuvo asociada positivamente con terrenos desarrollados. La abundancia, riqueza y diversidad de las migratorias neotropicales fueron mayores en áreas de dosel abierto y con pocas carreteras. Examinamos las relaciones espaciales mediante regresiones entre variables de aves y la cobertura del dosel derivada de imágenes satelitales, el área de terrenos sin desarrollar y la densidad de calles en una serie de áreas de 50 m de ancho en un radio de 500 m alrededor de los sitios de estudio. La abundancia de aves no nativas disminuyó con aumentos en la cobertura del dosel hasta 450 m, pero la mayoría de las demás relaciones fueron más fuertes a escalas menores (50–100 m). Nuestros resultados sugieren que el incremento de la cobertura del dosel en áreas urbanas es la estrategia de manejo más valiosa para conservar las aves nativas que se reproducen en el área. Un esquema jerárquico para la conservación de las migratorias neotropicales podría incluir aumentar la cobertura de bosque a menos de 450 m de los arroyos para controlar a las especies no nativas y a los Molothrus, reducir la densidad de calles dentro de un radio de 100 m alrededor de los arroyos y conservar o plantar árboles y arbustos nativos.

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