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Migratory silvereyes treated with a strong magnetic pulse shift their headings by approximately 90°, indicating an involvement of magnetite-based receptors in the orientation process. Structures containing superparamagnetic magnetite have been described in the inner skin at the edges of the upper beak of birds, while single-domain magnetite particles are indicated in the nasal cavity. To test which of these structures mediate the pulse effect, we subjected migratory silvereyes, Zosterops l. lateralis, to a strong pulse, and then tested their orientation, while the skin of their upper beak was anaesthetized with a local anaesthetic to temporarily deactivate the magnetite-containing structures there. After the pulse, birds without anaesthesia showed the typical shift, whereas when their beak was anaesthetized, they maintained their original headings. This indicates that the superparamagnetic magnetite-containing structures in the skin of the upper beak are most likely the magnetoreceptors that cause the change in headings observed after pulse treatment.

Previous experiments have shown that a short, strong magnetic pulse caused migratory birds to change their headings from their normal migratory direction to an easterly direction in both spring and autumn. In order to analyse the nature of this pulse effect, we subjected migratory Australian silvereyes, Zosterops lateralis, to a magnetic pulse and tested their subsequent response under different magnetic conditions. In the local geomagnetic field, the birds preferred easterly headings as before, and when the horizontal component of the magnetic field was shifted 90° anticlockwise, they altered their headings accordingly northwards. In a field with the vertical component inverted, the birds reversed their headings to westwards, indicating that their directional orientation was controlled by the normal inclination compass. These findings show that although the pulse strongly affects the magnetite particles, it leaves the functional mechanism of the magnetic compass intact. Thus, magnetite-based receptors seem to mediate magnetic 'map'-information used to determine position, and when affected by a pulse, they provide birds with false positional information that causes them to change their course.

Migratory Australian silvereyes (Zosterops lateralis) were tested under monochromatic light at wavelengths of 424 nm blue and 565 nm green. At a low light level of 7 × 1015 quanta m-2 s-1 in the local geomagnetic field, the birds preferred their seasonally appropriate southern migratory direction under both wavelengths. Their reversal of headings when the vertical component of the magnetic field was inverted indicated normal use of the avian inclination compass. A higher light intensity of 43 × 1015 quanta m-2 s-1, however, caused a fundamental change in behaviour: under bright blue, the silvereyes showed an axial tendency along the east-west axis; under bright green, they showed a unimodal preference of a west-northwesterly direction that followed a shift in magnetic north, but was not reversed by inverting the vertical component of the magnetic field. Hence it is not based on the inclination compass. The change in behaviour at higher light intensities suggests a complex interaction between at least two receptors. The polar nature of the response under bright green cannot be explained by the current models of light-dependent magnetoreception and will lead to new considerations on these receptive processes.

Previous studies have shown that a magnetic pulse affected the orientation of passerine migrants for a short period only: for about 3 days, the birds' headings were deflected eastward from their migratory direction, followed by a phase of disorientation, with the birds returning to their normal migratory direction after about 10 days. To analyze the processes involved in the fading of the pulse effect, migratory birds were subjected to a second, identical pulse 16 days after the first pulse, when the effect of that pulse had disappeared. This second pulse affected the birds' behavior in a different way: it caused an increase in the scatter of the birds' headings for 2 days, after which the birds showed normal migratory orientation again. These observations are at variance with the hypothesis that the magnetite-based receptor had been fully restored, but also with the hypothesis that the input of this receptor was ignored. They rather indicate dynamic processes, which include changes in the affected receptor, but at the same time cause the birds to weigh and rate the altered input differently. The bearing of these findings on the question of whether single domains or superparamagnetic particles are involved in the magnetite-based receptors is discussed.

To guide the decision-making for the case definition and guidelines, a literature search was performed by a Cochrane Collaboration professional search person for Guillain-Barré syndrome and other peripheral neuropathies in the context of immunization (MEDLINE 1976-2006; search terms included among others \"Guillain-Barré syndrome\", \"acute inflammatory demyelinating polyradiculoneuropathy\", \"peripheral neuropathy\", \"peripheral demyelination\", \"vaccine\", and \"immunization\"). First described by French neurologists Guillain, Barré, and Stohl in 1916, understanding of the disorder has increased tremendously in the past 2 decades [5]. 0 Healthy 1 Minor symptoms or signs of neuropathy but capable of manual work/capable of running 2 Able to walk without support of a stick (5m across an open space) but incapable of manual work/running 3 Able to walk with a stick, appliance, or support (5m across an open space) 4 Confined to bed or chair bound 5 Requiring assisted ventilation (for any part of the day or night) 6 Death

In view of the finding that cryptochrome 1a, the putative receptor molecule for the avian magnetic compass, is restricted to the ultraviolet single cones in European Robins, we studied the orientation behaviour of robins and Australian Silvereyes under monochromatic ultraviolet (UV) light. At low intensity UV light of 0.3 mW/m², birds showed normal migratory orientation by their inclination compass, with the directional information originating in radical pair processes in the eye. At 2.8 mW/m², robins showed an axial preference in the east–west axis, whereas silvereyes preferred an easterly direction. At 5.7 mW/m², robins changed direction to a north–south axis. When UV light was combined with yellow light, robins showed easterly ‘fixed direction’ responses, which changed to disorientation when their upper beak was locally anaesthetised with xylocaine, indicating that they were controlled by the magnetite-based receptors in the beak. Orientation under UV light thus appears to be similar to that observed under blue, turquoise and green light, albeit the UV responses occur at lower light levels, probably because of the greater light sensitivity of the UV cones. The orientation under UV light and green light suggests that at least at the level of the retina, magnetoreception and vision are largely independent of each other.

Geographic relocations of migratory passerines have shown that adults can compensate for physical displacements; juveniles on their first migration, however, use an innate clock-and-compass strategy and are unable to compensate for displacement. We examined the effects of changes in magnetic inclination and intensity on orientation of adult and juvenile Australian Silvereyes (Zosterops l. lateralis) to learn if geomagnetic cues are used by a migratory passerine for geographic positioning. Silvereyes, captured in breeding areas in Tasmania, were physically transported to a location along their migratory route and assessed for orientation during autumn migration. Adults and juveniles exhibited seasonally appropriate, northeasterly orientation (19° and 23° east of magnetic North, respectively) when tested under the natural geomagnetic field. Birds were then exposed to changes in the magnetic field that simulated either southern (SimS) or northern (SimN) locations near the beginning and end, respectively, of their migratory route. Inexperienced juveniles continued to show seasonally appropriate orientation (3° and 358°, respectively) in both SimS and SimN magnetic fields. Adults, in contrast, exhibited changes in orientation but only when the experimental magnetic field was consistent with a geographical displacement that should require compensatory orientation (i.e., SimN). Adults exposed to a SimS magnetic field continued to show seasonally-appropriate orientation to the North (0°). However, adults exposed to magnetic fields simulating locations beyond their wintering areas (SimN) altered their orientation significantly, orienting bimodally and perpendicular (123°–303°) to their seasonally appropriate migratory direction. These results are consistent with the presence of an age- or experience-dependent magnetic geographic position sense in migratory Australian Silvereyes.

Rainbow lorikeets ( Trichoglossus haematodus ) have successfully adapted to urban environments and are today abundant in many Australian cities. Here they often form noisy communal roosts and may damage infrastructure. While extensive studies on problem birds (mainly passeriforms) and their roosts have been conducted in other parts of the world, no detailed studies exist in Australia, where non-passeriform birds (e.g. parrots) can cause problems. This study investigates the roosting preferences of rainbow lorikeets in Sydney (Australia) and establishes the site characteristics that typify these roosts. Lorikeets preferred three exotic tree species, namely the plane tree ( Platanus spp. including Platanus x hybrida ), Canary Island palm ( Phoenix canariensis ) and Norfolk Island pine ( Araucaria heterophylla ). They were also common in brush boxes ( Lophostemon confertus ), a tree native to Queensland, Australia. Rainbow lorikeets commonly roosted in tall trees with thick trunks and medium density foliage and the trees next to their roost trees were of the same species. Roosting trees were often in areas of high anthropogenic disturbance and close to streetlights.

Young domestic chicks of two strains, ISA brown layers and White Leghorn X Australorps, were trained to associate a magnetic anomaly with food. This was done by feeding them in their housing boxes from a dish placed above a small coil that produced a magnetic anomaly roughly six times as strong as the local geomagnetic field. Unrewarded tests began on day 9 after hatching. In a square arena, two corresponding coils were placed underneath two opposite corners. One coil, the control coil, was double-wrapped producing no net magnetic field, while the other in the opposite corner produced a local magnetic anomaly similar to that experienced during feeding. The chicks favoured the corner with the anomaly from day 10 after hatching onward. Both strains of chickens showed this preference, indicating that they could sense the local changes in the magnetic field.

Since the 1970s, populations of the Australian White Ibis ( Threskiornis molucca ) have dramatically increased in many Australian urban centres. Managers of ibis are currently focusing on limiting this bird’s reproductive success in order to reduce population sizes or at least halt further increases in urban areas. Here we use data on nesting success and survival for three populations of ibis around greater Sydney to develop an age-structured population model. The estimated growth rate for all populations combined was about 1.5 % per year and for individual sites were more variable at −1, −7, and 9 %. For all populations, growth rates were most sensitive (based on elasticity analyses) to the survival of adults and least sensitive to fecundity, especially of 3 year olds. Further exploration of the importance of fecundity rates, which are relatively poorly known for these populations, suggests that rates of <0.4 fledglings per nest per year is very likely to lead to a population decline ( λ less than lower bound of 95 % CI). Conversely, positive population growth is nearly assured ( λ greater than upper bound of 95 % CI) for fecundities of >0.7 fledgling per nest per year. The results suggest that ibis from other locations (probably their traditional breeding areas in inland Australia) have immigrated into urban environments as estimated growth rates cannot account for current population sizes. Management strategies must take these findings into account and also consider that ibis are declining in their traditional habitats to avoid exacerbating their decline at a regional scale.