Note – all images and video are credited to Dan Link and Anna Vallery between December 2025 and January 2026.
Each year, more than a million albatross return to Midway Atoll National Wildlife Refuge—the world’s largest albatross colony. Since 1991, an annual census has relied on biologists and volunteers walking the entire 1,500-acre atoll to count every nest, producing one of the most comprehensive seabird species monitoring datasets. However, growing challenges—including shrinking budgets, staff shortages, and an increasingly complex landscape—are putting this critical, long-term monitoring effort at risk.
On November 7, 2025, we launched a 3-to-1 Matching Challenge to help fund the Refuge’s Annual Albatross Census and the 2nd year of an innovative Drone Research Project. By November 25, thanks to our motivated donors, we surpassed our goal. Together, a total of $100,000 was secured for the projects, ensuring that both could proceed as planned! Mahalo for making this milestone possible! Read more about the 3-to-1 Matching Challenge.
After weeks of planning and preparation—detailed in an earlier blog introducing the drones on Midway—the two‑week drone project has officially concluded. This field season was led by volunteers Anna Vallery and Dan Link, both biologists and FAA certified drone pilots who have also completed Department of the Interior training specific to the drone model used in the project. The project is permitted by both the U.S. Fish and Wildlife Service and the Papahānaumokuākea Marine National Monument/Marine National Sanctuary.
Surveying the Atoll: Where the Drone Flew
To ensure the data captured the full ecological diversity of Midway Atoll, the team selected a subset of survey sectors across Eastern Island, Sand Island, and Spit Island.
These sectors were chosen to represent the wide range of vegetative communities found across the atoll, including densely vegetated areas dominated by Beach Heliotrope and Naupaka (as seen in pictures below), mixed‑vegetation habitats, and wide open fields, such as the parade grounds.
In total, 15 sectors were surveyed, covering 255 acres of land. However, the scope of the work goes far beyond a number.
A New Way of Seeing: Temporal Image Differencing
One of the most exciting aspects of this project is the use of a relatively new technique for seabird monitoring called Temporal Image Differencing. Each sector was surveyed three separate times. The underlying assumption is that:
- Breeding birds will remain stationary on their nests
- Non‑breeding birds will move between surveys
By comparing imagery collected over time, researchers can begin to distinguish between breeding and non‑breeding albatross—an essential step toward improving population estimates. Because each acre was surveyed three times, the 255 acres of land represent 765 acres of total survey coverage.
Life in the Field: Two Weeks on Midway
Anna and Dan spent two full weeks on Midway, working every day except for a well‑earned pause on Christmas Day.
Drone operations depend heavily on weather conditions. Flights cannot occur in rain and are limited to winds below ~30 mph. Fortunately, only a handful of days were lost to rain during this field season.
Flying the drone is only one part of the job. Before each flight, the team:
- Used an Eos Arrow Gold RTK Receiver (high-accuracy GPS) and set-up Ground Control Points across the survey area to help precisely georeference the imagery
- Conducted one 50‑meter ground transect per 5 acres, counting breeding birds and walking (“walker”) birds
These ground surveys are critical for validating the breeder‑to‑non‑breeder ratios that will later be estimated from the drone imagery. When not in the field, the work continued with entering field data and flight logs, charging batteries, and recording detailed notes on any observed wildlife disturbance.
Do Drones Disturb the Birds?
This is one of the most common—and most important—questions received.
Across multiple field seasons, including this one, the results have been remarkably consistent: virtually no observable disturbance to albatross. Birds closest to launch and landing sites may briefly look toward the drone. Once airborne, albatross show no visible response and have not been observed reacting to the drone during surveys.
Some other species, however, are far more curious.
White Terns are known to enthusiastically mob the drone—along with anything else novel that enters their airspace. Occasional mobbing behavior was also observed from:
- Pacific Golden‑Plover
- White‑tailed Tropicbird
- Bristle‑thighed Curlew
Fortunately, the drone’s built-in obstacle‑avoidance system allows it to pause surveys or maneuver away from birds when needed. Eventually, even the most persistent mobbers lose interest and return to their normal activities.
Why This Work Matters
The drone project represents a powerful step forward in how we monitor one of the world’s largest albatross colonies. By combining high‑resolution aerial imagery, ground‑based validation, and emerging analytical techniques, FOMA and its partners are building tools that can support critical monitoring efforts for years to come.
None of this would be possible without the commitment of our donors, grant partners, and dedicated field teams. Your support—especially during the 3‑to‑1 Matching Challenge—directly fuels innovation, science, and long‑term conservation at Midway Atoll. There's never been a better time to join as a FOMA member – or simply donate to support future projects!
As we move into the next phase of data processing and analysis, we look forward to sharing what these images reveal—and how they will help guide seabird conservation into the future.
Mahalo for standing with us, and for helping Midway’s albatross continue to soar.
Article by Anna Vallery, Wayne Sentman, Krystal Winn & Bill Levin