Bird migration research today: some achievements and new challenges

Abstract

This review deals with the topics of bird migration research that have seen significant progress in the recent years. In these fields, earlier views have been significantly re-considered. They include the manifestation of migration, i.e. length of migratory flights, their speed, duration of stopovers, flight altitude, which taken together form the spatio-temporal realization of migration. New data on this array of research questions make it possible to ask new questions about physiological adaptations that make such flights possible, and factors that govern these processes. Significant progress is also evident in the study of long-distance orientation and navigation of migrating birds. However, it mainly concerns the mechanisms of magnetoreception and use of magnetic cues for orientation. Besides, students of bird migration could not ignore the ‘-omics’ revolution, which, like the studies of the manifestation of migration, was mainly caused by technological advances, mainly by the advent of next generation sequencing techniques. The new data obtained by these methods raised the hope to sort out the genetic basis of endogenous control of bird migration. However, the gap between the expectations and the actual results remains. To close this gap, new research into the molecular and cellular mechanisms that underlie migratory behavior is necessary. The results available now mainly refer to the processes that are relatively well understood, mainly the mechanisms of energy turnover and stress response.