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The surface of dry or wet asphalt roads reflects partially linearly polarized light, the degree of linear polarization p of which depends on the darkness and roughness of asphalt: the darker and/or the smoother the asphalt, the higher the p of light reflected from it. If the asphalt is sunlit and the direction of view is parallel to the solar-antisolar meridian, then the direction of polarization

It seems a travesty to reiterate exactly what we mean by ‘Mesopotamia’. The tautological qualities of Greek mésos (‘middle’, ‘in between’) and potamós (‘stream’, ‘river’) often rule out further elaboration of its origins and the assumed self-evident nature of its current application. Yet regional concepts are not stable. Their delineation may be defined according to a complex set of attributes not

Accelerated biodiversity loss has destabilized functional links within and between ecosystems. Species that cross different ecosystems during migration between breeding and nonbreeding sites are particularly sensitive to global change because they are exposed to various, often ecosystem-specific, threats. Because these threats have lethal and nonlethal effects on populations, many migratory specie

BACKGROUND: The degree to which avian migrants revisit the same sites to replicate routes from previous years has received more and more attention as the possibilities of tracking small to medium-size birds over multiple annual cycles have improved. Repeated measurements of individuals with an appropriate sampling resolution can potentially inform about their navigation and migration strategies an

Anthropogenic activities threaten many wildlife populations by increasing mortality rates, making it crucial to identify the locations and causes of mortality to inform conservation actions. Technological advancements, such as GPS satellite tracking, enable precise recording of wildlife movements. High-resolution data from such devices can facilitate rapid carcass recovery and provide insights int

Robins captured as passage migrants by the Baltic Sea in Sweden at Falsterbo and Ottenby Bird Observatories, respectively, differ with respect to body mass, fat load and orientation behaviour. Relatively more birds with large visual fat deposits are captured at Ottenby than at Falsterbo, but robins at Falsterbo carry more fat than robins at Ottenby. Robins with small fat loads at Ottenby probably

The possibility that albatrosses use a geomagnetic bi-coordinate map for long-distance navigation at sea was investigated by evaluating how five different geomagnetic parameters (i.e. total field intensity, horizontal and vertical field intensity, inclination and declination) vary in areas where foraging albatrosses have been recorded by satellite telemetry in the Southern Ocean. Our objective was

The Eleonora's Falcon Falco eleonorae breeds on islands and islets in the Mediterranean region and feeds its young on migratory birds caught in the air. The breeding season is scheduled to coincide with the peak of bird migration. Between 12 and 20 September 1997 we measured flight tracks of falcons within a range of 4 km from their breeding cliffs on Isola di San Pietro 6 km off the south-west co

The moult of Barred Warblers Sylvia nisoria was studied during three winter seasons in southeastern Kenya at a southward passage site (Ngulia) and a wintering site (Mtito Andei). Most Barred Warblers migrating through Ngulia in November had yet to commence winter moult. These birds probably moulted subsequently in winter in northern Tanzania. In December, birds were found in heavy moult at Mtito A

The orientation of juvenile marsh warblers during autumn migration was investigated at two widely different latitudes, in Sweden and in Kenya, by cage experiments in manipulated magnetic fields during the twilight period after sunset. The objective was to compare responses by birds exposed to different geomagnetic conditions, particularly to the shift in magnetic inclination between the northern a

A male common swift Apus apus was equipped with a light logger on August 5, 2010, and again captured in his nest 298 days later. The data stored in the light logger enables analysis of the fascinating travel it made in this time period. The state of the art algorithm for geolocation based on light loggers consists in computing first sunrise and sunset from the logged data, which are then converted

Extensive ringing data from a coastal site (Falsterbo Bird Observatory) in southwesternmost Sweden were used to investigate the occurrence of reverse autumn migration among 20 passerine bird species oF widely different migration categories. The data demonstrate that reverse migration is a widespread and regular phenomenon among nocturnal as well as diurnal migrants and among irruptive migrants, te

The aim of this study was, by analysing recoveries and resightings of Caspian Terns Hydroprogne caspia ringed in Sweden, (1) to identify areas of importance during their migration and wintering, (2) to investigate the annual routines of migration and wintering of different age categories, and (3) to investigate how human activities, especially shooting, have affected survival of Caspian Terns over

Migratory naive birds are thought to find the migration route from their natal site to a specific wintering area by either clock-and-compass orientation or goal area navigation. These two alternative hypotheses were tested by extensive longitudinal displacements of juvenile wheatears, hatched in northeastern Siberia, on their first autumn migration towards the wintering area in East Africa. Orient

Sleep is a universal and complex state and it is widely agreed that this state is present in every animal species. However, the evolutionary origins of sleep remain ignored or misunderstood, which has led researchers to study, in various species, this common behaviour of all living organisms. Sleep is commonly studied at various levels under laboratory conditions, using tethered devices which reco

Brent geese, Branta bernicia hrota, were equipped with satellite transmitters on a spring stop-over site in Iceland. The brent geese deposit heavy fuel reserves for long-distance flights across the high Greenland ice-cap to breeding destinations in north Canada. Satellite tracking of brent geese on this journey serves the twofold purpose of testing specific predictions about: (i) size-dependent po

Stopover duration and fat accumulation were studied during autumn migration at two sites near Ottenby, Oland, SE Sweden in 1985 and 1986. Post juvenile moult was scored on juvenile birds. In several of the species fat class and body mass increased with day of season (thrush nightingale Luscinia luscinia, barred warbler Sylvia nisoria, and whitethroat S. communis), while in the lesser whitethroat S