Bird Migration Explorer

Curtis Smalling: Five Highlights from the Bird Migration Explorer

We asked our conservation director to give us his favorite insights and bird stories from the new interactive platform.

Tracking birds is hard work. Field ornithologists spend long days under the sun on the open beach or knee-deep in the marsh, all to figure out ways to safely catch and track birds using tiny GPS devices and other cutting-edge technology. In my own career, this has meant countless mornings chasing Golden-winged Warblers and Yellow-bellied Sapsuckers through the North Carolina mountains. 

The data we gain from this kind of work is hard won. It often ends up in academic journals, contributing important information to our understanding of birds and their movements. But it’s less often that the amazing bird journeys we’re uncovering reach the public eye. 

The Bird Migration Explorer—launched this fall by Audubon and our partners—gives the public an unprecedented look at this tracking data, combining it with other “big bird data” like eBird models to give us a more complete picture of where and when birds migrate, and the threats they face along the way. 

In many ways, we are in a golden age of migration science. When I banded my first Golden-winged Warblers 20 years ago, I never imagined we would eventually have tracking devices small enough to stick on the back of a bird that weighs less than two nickels. The Bird Migration Explorer puts this information in one accessible and interactive location.  

I spent a while playing around with the Explorer to see what it shows about our birds in North Carolina, and I encourage you to do the same. Here are a few of fun and/or interesting highlights: 

Tundra Swan 

Eastern North Carolina is well known for the huge flocks of Tundra Swans that descend on our sounds and wetlands every winter. The Explorer shows just how compact their wintering range is on the East Coast—you can see all the yellow dots, which represent the movement of individual birds, converge on northeastern North Carolina in November—compared to the swans on the West Coast, which have a much broader wintering range. The two populations breed in remote stretches of the Artic and appear to jumble together during early fall migration, and then go their separate ways. 

Wood Thrush 

The Wood Thrush is a beloved songbird of North Carolina’s forests and backyards. It’s also a classic example of bird that has a tight breeding and wintering range and migration pattern. Six years ago, a project by Forsyth Audubon, the National Audubon Society, and the Smithsonian Migratory Bird Center found that at least some of our Wood Thrushes travel to spend the winter in Belize.  

The Explorer allows you to see the journey of birds we tracked from Forsyth County and the threats they face along their migration journeys, as well as the similar routes taken by other Wood Thrush on the East Coast. 

Broad-winged Hawks 

North Carolina birdwatchers wait with bated breath for Broad-winged Hawks to appear at hawk watch location across the state. The journey is epic and transcontinental, and the Explorer shows just how tight the bird’s passage is as they funnel through Veracruz, Mexico down to Central America (a phenomenon known as the River of Raptors). It also shows how threats like wind energy development become more pronounced in these locations. 

Kirtland’s Warbler 

The Kirtland’s Warbler is a rare bird that breeds in Michigan and winters in the Bahamas. A sighting of this species in North Carolina is always special. The Explorer shows at least four recorded tracks of Kirtland’s Warblers migrating to North Carolina’s upper coastal plain to fly out over the ocean to their island wintering grounds.  

The map also shows the importance of the southern Appalachian region for Kirtland’s Warblers during spring migration, which is somewhat surprising given how relatively few records we have on the ground. (One of those is at the Meat Camp Environmental Study Area in Watauga County, a habitat near my home that I own and manage, and the only place a Kirtland’s has been recorded singing in the state.) 

Yellow-billed Cuckoo 

The Yellow-billed Cuckoo is a great example of the anecdotal nature of many species data: there is only one tracked bird in the Explorer. Which underscores just how much we still don't know. Do our eastern cuckoos do that same thing as the lone tracked bird in the Explorer, which is a western bird? Are our eastern cuckoos the cluster that seems to winter in more northern South America? Do they migrate across the Gulf of Mexico or do they go south through Hispaniola and Florida? So many questions left to be answered. 

Just the Beginning 

The Explorer is an evolving platform, and will only ramp up as we get more data. For example, Audubon North Carolina worked with partners this summer to attach small transmitters to breeding Golden-winged Warblers in the Appalachian Mountains so we can track their movements locally as well as across their range, via Motus towers. This is the first project of its kind for this species, undertaken in partnership with the University of Maine and others. We’re just beginning to get data back on the journeys of these individual birds, and all of it will feed into the Explorer.  

As time passes and more data is added to the Explorer, it will only become more dynamic, helpful, and just plain fun. 

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