Temperature change is an important departure cue in nocturnal migrants: controlled experiments with wild-caught birds in a proof-of-concept study.

The decision-making process of migrating birds at stopover sites is a complex interplay of the innate migration program and both intrinsic and extrinsic factors. While it is well studied how variation in precipitation, wind and air pressure influence this process, there is less evidence of the effects of temperature changes on the departure decision. Thus, we lack knowledge on how the predicted changes due to global climate change in temperature alone may affect the decision-making process during migration.

A quasi-experimental approach using telemetry to assess migration-strategy-specific differences in the decision-making processes at stopover.

Background: Migrant birds travel between their breeding areas and wintering grounds by alternating energetically and physiologically demanding flights with periods of rest and fuelling, so-called stopovers. An important intrinsic factor influencing the decision to resume migration is the amount of energy stores available for the next flight. Correlative studies with free-flying birds and experimental studies with caged birds have shown that the amount of energy stores affects the day-to-day, within-day and the directional decision of departure.

Stopover departure decisions in songbirds: do long-distance migrants depart earlier and more independently of weather conditions than medium-distance migrants?

Background: Songbirds following distinct migration strategies (e.g. long- vs.

Cues, corticosterone and departure decisions in a partial migrant.

Most migrating birds make multiple stopovers to fuel and/or rest. The decision to resume migration from stopover is based on various cues, such as time within the season and wind conditions. There are hints that the strength of these departure cues shapes corticosterone level, which in its turn appears to regulate the timing of departure.

Baseline corticosterone levels are higher in migrating than sedentary common blackbirds in autumn, but not in spring.

Corticosterone at baseline levels is thought to be mainly involved in the regulation of uptake, storage and release of energy, processes central to avian migration. Consequently, corticosterone levels are thought to be upregulated during migration, but the temporal pattern of its secretion during migration is not well defined. For example, although it appears that corticosterone levels decrease from flight to stopover, it is unknown if levels at stopover are still elevated and it is largely unclear how these levels compare to non-migratory life-history stages.

Corticosterone predicts nocturnal restlessness in a long-distance migrant.

The decision made by migrating birds to stop refueling and to depart from stopover depends on cues from innate rhythms, intrinsic factors such as fuel reserves, and extrinsic factors such as weather conditions. The physiological mechanism behind this decision, however, is largely unexplored. The transition from refueling to flight involves an increase in both locomotion and energetic demands.

Migratory restlessness in captive individuals predicts actual departure in the wild.

In captivity, migratory birds show increased activity during the time that they would normally migrate. The phenology and intensity of such 'migratory restlessness' has been shown to mirror species- and population-specific migration patterns observed in the wild and has consequently been used as a proxy for the motivation to migrate. Many studies doing so, however, were aiming to explain among-individual variation in migratory behaviour or traits, and not species- or population-specific traits.

Improving the ablation efficiency of excimer laser systems with higher repetition rates through enhanced debris removal and optimized spot pattern.

Purpose: To evaluate the reasons for the required increased radiant exposure for higher-repetition-rate excimer lasers and determine experimentally possible compensations to achieve equivalent ablation profiles maintaining the same single-pulse energies and radiant exposures for laser repetition rates ranging from 430 to 1000 Hz.

Setting: Schwind eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany.