“This review identified and defined an important area of ecology and evolution—migratory connectivity.”

This review identified and defined an important area of ecology and evolution—migratory connectivity. Though this phenomenon had been recognized in previous work, nobody had thoroughly explained its implications for the ecology and evolution of migratory animals. Moreover, migratory connectivity is by definition a large-scale problem, and we point out that only now are the tools being developed to address this issue.

It describes an important ecological phenomenon that had not received much attention.

Migratory connectivity is simply the idea that summer and winter populations of migratory organisms are connected to each other by the movement of individuals. Because of this, things that happen to populations on the wintering grounds can affect populations on the breeding grounds and vice versa. This concept is simple but has important implications for phenomena as diverse as conservation, evolution, and disease transmission.

I became involved in this research as a side-line to my regular research, which focuses more on the breeding ecology of birds. We recognized that much of what we see on the breeding grounds may be the result of what happens to the birds during the winter when they are in the far south.

We were frustrated by the fact that we knew little about where these birds spent their winters, and began to discuss possible ways to study these migratory connections. From these discussions, we developed more specific theories about the possible patterns of migratory connectivity and their implications.

The concept of migratory connectivity has very important social and political implications. For example, birds do not recognize international boundaries, so populations of birds in one country can be affected by activities in another country. Similarly, the movement patterns of migratory animals have important implications for disease transmission, as illustrated by recent interest in bird flu.