US Navy
Marine Species Monitoring
A Macrocephalus Mother's Day Tradition
For the second year in a row on Mother’s Day, the HDR-led marine science team encountered a group of female sperm whales with calves offshore of Virginia Beach in a warm patch of 72-degree water. On Sunday, May 10, 2026, approximately nine sperm whales, including 3 calves, were acoustically detected 77 miles from shore in 1,600m of water. The group was tracked through their dive and visually detected upon surfacing.
After collecting ID photos, the Freefly Astro drone was launched, equipped with a CATS tag in tow. After following the group through multiple dive cycles, the tag was successfully deployed on a presumed adult female. The tag was programmed to detach after 2 hours (based on the time of day it was deployed and poor weather forecast for next day) and was successfully recovered. To our knowledge, this is the first CATS tag deployed on a sperm whale via drone tag drop system.
Of the nine sperm whales present, at least two individuals in the group were also present during the encounter a year prior, HDRVAPm116 and HDRVAPm023. Individual HDRVAPm116 was first seen in April 2022, resighted in July 2022 when she was tagged with a DTAG, then re-sighted last Mother’s Day when she was satellite tagged and biopsied. HDRVAPm023 was first seen in August 2017 and also satellite tagged and biopsied last Mother’s Day. Both females have now been seen on five occasions, with each re-sight providing valuable information on how sperm whales utilize these offshore waters. Also in with these females was a male sperm whale, HDRVAPm035, who has been tagged in the past. It is very interesting to see such site fidelity in this species as our team continues this study.
Check out this amazing video from the CATS tag:
