Each year an uncountable number of airborne organisms, mainly birds and insects, venture out on long journeys across the globe. In particular, the mass movements of birds have fascinated humankind for hundreds of years and inspired a wealth of increasingly sophisticated studies. The development and improvement of individual tracking devices in animal research and has provided amazing insights into such extensive journeys. Study of mass movements of biological organisms is still a challenge on continent-wide or cross-continental scales.
One tool that can effectively track and/or monitor large numbers of birds is radar technology. Radars offer many advantages over other methods such as visual counts or ringing. They’re less expensive, need less effort, offer better visibility and detectability, and are more applicable for large-scale monitoring. Networks of meteorological radars (as opposed to individual radars) seem particularly promising for large-scale studies. Continue reading →
Technological advancements in the past 20 years or so have spurred rapid growth in the study of migratory connectivity (the linkage of individuals and populations between seasons of the annual cycle). A new article in Methods in Ecology and Evolution provides methods to help make quantitative comparisons of migratory connectivity across studies, data types, and taxa to better understand the causes and consequences of the seasonal distributions of populations.
The seasonal long-distance migration of all kinds of animals – from whales to dragonflies to amphibians to birds – is as astonishing a feat as it is mysterious and this is an especially exciting time to study migratory animals. In the past 20 years, rapidly advancing technologies – from tracking devices, to stable isotopes in tissues, to genomics and analytical techniques for the analysis of ring re-encounter databases – mean that it’s now possible to follow many animals throughout the year and solve many of the mysteries of migration.
What is Migratory Connectivity?
One of the many important things we’re now able to measure is migratory connectivity, the connections of migratory individuals and populations between seasons. There are really two components of migratory connectivity:
Linking the geography of where individuals and populations occur between seasons.
The extent, or strength, of co-occurrence of individuals and populations between seasons.