A network of towers that track small migratory animals provides researchers with information that can help conserve populations of insect, bat and bird species that are declining at an alarming rate.
Currently, only a small number of automated radio tracking towers linked to the Motus Wildlife Tracking System exist in North Carolina.
But researchers and conservationists hope that will change as part of a collaborative multistate, nonprofit effort to secure a $1 million federal grant to put more Motus towers on the ground in southeast and maintain hundreds of towers in the northeast.
North Carolina, along with Pennsylvania, Vermont and Alabama, led the charge by applying for a competitive wildlife grant, a grant that would bolster the presence of a tracking system that gives researchers insight into the finer details of small animal migration patterns. .
Motus towers track receivers designed to tag smaller migrating animals like dragonflies, microbats and small bird species like warblers and sparrows.
Tracking the movements of these animals helps researchers understand the timing of migration — where and for how long animals stop to rest, feed and breed — and which areas are important to different species, a said Marae West, a doctoral student at the University of North Carolina. Wilmington and board member of the Cape Fear Audubon Society.
“All of that is super important to keep them,” she said. “If we don’t know where they are or where they’re going, it’s really hard to conserve a species. So I think all of this is really helpful in understanding how birds migrate, why they move, how they move, and then how we can better conserve the areas they use.
For example, West, who studies the biology of overwintering populations of salt marshes, seashores, and Nelson’s sparrows, was able to see that one of the birds tagged for his study stayed in Delaware for 15 days.
Earlier this year, West completed an effort initiated by his academic adviser, UNCW assistant professor Raymond Danner, who in 2018 wanted to install Motus towers in the area.
Thanks to his efforts, the newest Motus Tower in North Carolina stands 20 feet tall on Lea Island, an uninhabited barrier island that stretches between Topsail Island and Figure Eight Island.
Motus towers are not built from kits. They are assembled from parts that can be purchased from any number of vendors. They can be built as stand-alone towers, as is the case on Lea Island, or attached to existing towers, such as the one funded by a private donor on Bald Head Island.
Construction costs vary between $3,000 and $7,000.
When a tower picks up a signal from a tagged animal – up to 9 miles away – information about that individual animal is sent to the global Motus network and uploaded to Motus.org.
Motus beacons initially read at a frequency of 166 megahertz, but with ever-changing technological advancements, updated towers can read beacons at a frequency of 434 megahertz.
Kendrick Weeks, supervisor of the North Carolina Wildlife Resources Commission’s Western Wildlife Diversity Program, explained that the Motus system gives researchers a picture of a species’ full life cycle, which is missing information. on migratory landbirds that breed in North America, then winter in the Caribbean, South America and Central America.
“Because they can face threats anywhere in this life cycle, on spring grounds, during migration, on wintering grounds and, of course, during fall migration,” said weeks. “Because of this wide range of birds, it takes something like that, a collaborative effort, to do monitoring.”
It points to the results of an extensive survey conducted in 2019 by American and Canadian researchers who found that North America had lost 3 billion birds since the 1970s.
“A lot of them are these neotropical migrants,” such as shorebirds and grassland birds, Weeks said. “Interestingly, in this analysis, waterfowl were not reduced. It really shows that effort, that conservation that has been made over the last 50 years for waterfowl. All of this work to conserve habitat and regulate hunting has really helped waterfowl populations. We don’t necessarily have this pattern for many other birds.
To do this, researchers and conservationists have embarked on a broader collaborative effort to expand the information collected through Motus.
There is currently a Motus tower in western North Carolina. Two more are in preparation. There are none in Piedmont, a popular region for thrushes.
The grant would be split 50-50 between the northeastern states and the southeastern states. Grant recipients are expected to be announced later this year.
The grant would help fund a “fence” of towers about 18.5 miles apart along the mountains of southern North Carolina, Weeks said. It would be about half a dozen rounds.
“That’s our main goal at this point, but we would like to expand it more and more to the whole mountain region as well as the state,” he said.
The diversity of Neotropical migratory landbirds is much higher in the mountain region of the state, where there is a wide assortment of warblers, including the golden-winged warbler, Cerulean warbler, Canada warbler, and prairie warbler.
Weeks also points out that the potential for monitoring goes beyond birds, from bats to butterflies to dragonflies.
“We’re really working with partners to try to get this network in place,” Weeks said. “We cannot do it alone. As a state agency, we are involved in research a bit, but a lot of that is done with academic institutions. There are many bird conservation organizations that can be helpful.
Adam Smith, a quantitative ecologist with the U.S. Fish and Wildlife Service’s Wildlife Refuge System Inventory and Monitoring Branch in the South Atlantic-Gulf and Mississippi River Basin region, said collaborative efforts to expand Motus are one of his favorite aspects of the system.
“But it’s also one of the most difficult,” he said. “Conservation dollars and staff are low or dwindling and really this kind of collaborative effort is increasingly becoming one of our best chances of actually doing meaningful conservation work. With something like Motus, individuals can still carry out their projects of interest, but at the same time they can benefit from a whole host of other projects that are unrelated apart from using the same technology.
Smith installed the first tower in North Carolina in 2015 on Cedar Island. He placed a few more on the coast of South Carolina.
The initial goal then was to build a coastal network of towers to track the salt meadow sparrow.
There are about a dozen Motus stations, most of which read at 166 megahertz, on shelters in Florida. Smith said in an April 15 phone interview with Coastal Review that he would be heading to Florida soon to upgrade those towers so they can also read 434 megahertz.
It updated all five stations on shelters in North Carolina with this dual-mode capability last year.
“The advancement of Motus or the use of Motus that really drives us is that many migratory birds are in decline for a variety of reasons, some of which we partially understand and some of which we don’t,” Smith said.
“But they have these really complex annual life cycles that only last part of the time on the breeding grounds and part of the time somewhere in Central or South America or the southeastern United States and then they spend a very large part of their year moving from these. places and return. There is enough evidence to suggest that active migration is the hardest part of the life cycle to survive,” Smith continued. “I think Motus has the potential to really inform the genre of this first step to try to identify these large-scale patterns and look for things that stand out as areas that are constantly used and worthy of further exploration. how birds use that site and what particular areas of that general area are worth acquiring or protecting or doing something for conservation work.