Orientation In Birds

If it is true that science proceeds from a romantic through a scientific to a technological stage, then research on bird orientation is certainly on its move from its first to its second grade, and recent developments in radiotelemetry and satellite tracking of migrating birds might already indicate the advent of the third stage. At this juncture, Orientation in Birds is a timely account. Even though the study of animal migration in general, and bird navigation in particular, has produced a literature of impressive proportions, the threads provided by the plethora of research papers, review articles and symposiums volumes have not yet been knitted into a theoretical fabric. This is partly due to our still incomplete understanding of fundamen tal topics in avian navigation. The answer to the most intriguing question of how a bird displaced to "unknown" territory finds its way back home is as obscure now as it was a few decades ago. Whether and how birds solve this problem by using far ranging grid-maps or more local familiar-area maps, as has been proposed off and on, is still a matter of heated debates. These debates frequently center around provocative hypotheses - let alone the question about the physical (topographic, magnetic, infrasonic, olfactory) parameters which might constitute such maps.

P. Berthold and E. Gwinnd Bird migration is an intriguing aspect of the living world - so much so that it has been investigated for as long, and as thoroughly, as almost any other natural phenomenon. Aristotle, who can count as the founder of scientific ornithology, paid very close attention to the migrations of the birds he ob served, but it was not until the reign of Friedrich II, in the first half of the 13th century, that reliable data began to be obtained. From then on, the data base grew rapidly. Systematic studies of bird migration were introduced when the Vogelwarte Rossitten was founded, as the first ornithological biological observation station in the world (see first chapter "In Memory of Vogelwarte Rossitten"). This area later received enormous impetus when ex perimental research on the subject was begun: the large-scale bird-ringing experiment initiated in Rossitten in 1903 by Johannes Thienemann (who was inspired by the pioneering studies of C. C. M. Mortensen), the experiments on photoperiodicity carried out by William Rowan in the 1920s in Canada and retention and release experiments performed by Thienemann in the 1930s in Rossitten, the first experimental study on the orientation of migratory birds. After the Second World War, migration research, while continuing in the previous areas, also expanded into new directions such as radar ornithology, ecophysiology and hormonal control mechanisms, studies of evolution, ge netics, telemetry and others.

How migratory birds can navigate home from their wintering grounds to their breeding sites over hundreds and thousands of kilometres has been an admired mystery over more than a century. Profound advances towards a solution of this problem have been achieved with a model bird, the homing pigeon. This monograph summarizes our current knowledge about pigeon homing, about the birds' application of a sun compass and a magnetic compass, of a visual topographical map within a familiar area and -- most surprisingly -- of an olfactory map using atmospheric chemosignals as indicators of position in distant unfamiliar areas.

Biological effects of magnetic fields have been studied in many animals and plants. The magnetic fields were of a wide intensity range and, as alternating fields, of a wide frequency range and of a variety of impulse shapes. Effects on the cellular level, on bio chemical processes, growth and development, interactions with physiology, sensory input, reflexes and rhythm control, to name just a few, have been reported. Numerous magnetically induced changes in behavior have also been described. Recently, the amount of literature covering biological effects of magnetic fields has been rapidly increasing. By now it has grown to such an extent that it can no longer be covered in one volume. Most reviews specialize and focus on particular aspects and/or types of fields or effects. For example, the book edited by MARET et al. (1986) gives an overview on biological effects of steady magnetic fields, MISAKIAN et al. (1993) reviewed those of extremely low frequency magnetic fields, focusing on in vitro effects. BERN HARD (1992) reported on 'electromagnetic smog' in view of pos sible effects on human health and well-being, and a series of papers edited by AMEMIYA (1994) summarizes Japanese research on effects of electromagnetic fields ranging from extern ely low to ultra-high frequencies. TENFORDE (1979) and ADEY (1981) sum marized and discussed tissue interactions, REITER (1993a) neu roendocrine and neurochemical changes associated with various kinds of electromagnetic fields. The book edited by KIRSCHVINK et al.

Considers all aspects of research since experimentation began on the subject in 1925

This book reviews all major models and hypotheses concerning the mechanisms supposed to underlie the process of navigation in vertebrates. It covers data on all major model groups of vertebrates studied in the context of animal navigation, such as migratory birds, homing pigeons, sea turtles, subterranean mammals and some migratory fish species. Some other – less studied – groups, e.g., whales, have also been touched. The first part of the book describes different sources of navigational information, with their specific navigational mechanisms known or supposed to be employed by animals for navigational goals. The second part discusses possible functions of these mechanisms in different vertebrates and in the context of different navigational tasks, ranging from short-range navigation, often performed by animals within as small an area as several square meters, to long-distance global-scale migrations performed by many birds and some sea turtles during their lifespan.