Drone photogrammetry offers rangewide body‑condition comparisons; researchers push for standard metrics

Casey Beerick, an assistant professor at the Marine Mammal Institute, presented a rangewide drone photogrammetry workflow and a software tool (Excerty) that incorporates photogrammetric uncertainty so measurements from different drones can be compared. "We're quantifying and incorporating photogrammetric uncertainty associated with different drones," she said, noting collaborators use drones ranging from consumer models to high‑end systems.

Beerick described an assembled dataset of just over 2,200 individuals from multiple foraging areas and compared body‑area‑index (BAI) and other metrics across sites. Using central California as a long‑term anchor (mean BAI ≈ 27), she reported that Oregon's Pacific Coast Feeding Group (PCFG) whales were generally below that baseline, Sitka and West Vancouver Island populations were often higher, and Kodiak and San Francisco Bay whales appeared lower. Beerick urged adoption of a shared, documented metric and recommended publishing multiple standardized metrics (single width, BAI, body volume) so future syntheses can use comparable values.

Speakers and audience members discussed tradeoffs among metrics: single‑width measures are fast and widely used, BAI can capture more body‑area variation, and body volume is useful for energetics. Beerick said her workflow and package output all major metrics to facilitate cross‑study comparisons and encouraged making data and methods open access so smaller groups with lower‑cost equipment can contribute comparable measurements.

The presentation and discussion stressed pairing live‑animal condition metrics with necropsy and biomarker data to better interpret what external condition indices mean for survival and reproduction.