Wood Storks are a critical indicator species for Western Everglades ecosystem health. Long-term monitoring of their nesting effort helps gauge the effects of regional conservation and restoration efforts, as well as the impacts of a changing climate and development. Audubon has monitored Wood Storks nesting annually at Corkscrew Swamp Sanctuary since 1958, amassing the longest continuous data for this species. In recent years, Audubon has also begun monitoring new colonies in the region and Wood Storks have just kicked off the 2025 nesting season. How do we monitor nests at the top of 75-foot-tall bald cypress trees or other trees in remote locations? Eyes in the skies with both planes and drones!

Nesting Wood Storks

Wood Storks typically build nests and fledge their young in treetop colonies surrounded by water, where the presence of American alligators is their best defense against marauding raccoons and other terrestrial predators. However, this survival strategy can make it difficult to reach the nest sites for monitoring.

For decades, Audubon has relied on binoculars and photographing the nests from a small plane. While this method is effective in assessing the number of nests and documenting chicks in nests, it is expensive, and scheduling can be restrictive and weather-dependent. Taking still photos of small objects from the window of a moving airplane is no small feat, and it is also quite difficult to get clear images that give biologists high confidence in their counts. It is also difficult to follow the progress of individual nests over time.

Utilizing Drone Technology

Unmanned aerial vehicles (also called drones) have become a valuable tool for scientists studying a variety of topics. In recent years, Audubon has found ways to use them at the Sanctuary to expand our work, such as for measuring changes in plant communities. In 2023, Audubon biologist Jacob Zetzer started using a drone to record the numbers and species of wading birds using restored marshes as an indicator of restoration success. As Zetzer demonstrated the benefits of using drones to reach and collect visual data from remote locations, the team realized the tool could do much more.

This past June, Zetzer began some trials to see if drones could improve Audubon’s long-term Wood Stork nest monitoring. In his first attempts, he found the drone provided clear images and videos and cautiously determined how close he could get to the colony without seeming to disturb or stress the birds. While drones haven’t replaced planes entirely (we still need them at certain times of the season), bringing drone imagery into ArcGIS allows Zetzer to precisely map individual nests in the space (reducing the chance of over- or under-counting) and follow the success of each nest over time, resulting in more accurate assessments.

(Note: Audubon staff at Corkscrew Swamp Sanctuary are FAA-certified remote pilots and use drones for critical scientific research. Drone use is not permitted in the Sanctuary by visitors).

Establishing New Partnerships

Drones make it easier to access hard-to-reach areas, but pilots must still be close enough for the pilot to maintain a visual line of sight with the drone. To monitor a Wood Stork colony located on a small island in the middle of the Caloosahatchee River, the team was grateful to find support from John and Kathy Cookman of Manatee and Eco River Tours of Fort Myers. The Cookmans donated their boat and their time to ferry Zetzer to the perfect location to launch and fly the drone. That trial was a big success and Audubon is deeply grateful to the Cookmans for offering to continue to donate their services for the 2025 nesting season!

FIrst Flights of the 2025 Nesting Season

Audubon conducted two Wood Stork monitoring flights of the 2025 nesting season by small plane. While the team saw promising signs of nesting at two of five prior colony locations, including at Lenore Island in the Caloosahatchee River, the historic Corkscrew colony remains inactive.

More data on Wood Stork nesting efforts and success provide insights into how they, and other species, are adapting to a changing climate and wetland loss from rampant development across the Sunshine State—data Audubon uses to help preserve and protect the habitats that birds and people need.