The biggest current drawback to the Motus array has been its coastal nature and limited geographic extent. Originally designed to track seabirds, shorebirds and coastally migrating songbirds, its roughly 325 towers are largely along the Great Lakes, Atlantic or Gulf of Mexico shorelines, although some towers have been erected in the Arctic, Alaska, South America and northern Europe.
Except for a few towers along the Connecticut River valley, and a small cluster in southwestern Pennsylvania, there was essentially no coverage across an enormous area in the interior Northeast, including New England and the central Appalachians — despite the fact that this mountainous region is one of the most significant migratory corridors for all species in North America. Nor did it cover the critical Piedmont and coastal plain inland of the shore itself, although banding studies suggest these are important migratory routes for many species.
We’ve already begun to plug that geographic gap by creating a Northeastern interior Motus array—beginning with an extensive cross-state line in Pennsylvania in 2017 and filling a gap in western PA in 2018.