SeaDoc study finds that rehabilitated seal pups range twice as far

Published 12:28 pm Wednesday, August 24, 2011

SeaDoc Society recently released some preliminary findings from an ongoing seal study it has been conducting since last summer. The study has been using satellites to track the movements of 10 rehabilitated and 10 wild-reared seal pups.

“Earlier this month SeaDoc post-doctoral fellow Dr. Nacho Vilchis built a preliminary mathematical model to analyze the tracking data collected by satellite,” wrote SeaDoc director Joe Gaydos in the update. “After creating data integrity thresholds to remove unreliable position data and comparing daily movement, overall distance travelled and direction of movement, the results show that the rehabilitated seals not only swim twice as far on a daily basis, but they also end up traveling twice as far from their release locations as do the wild-weaned pups. Learned behavior during the brief 3-4 week nursing period when a pup is with its mother likely enables wild harbor seal pups to move less daily and remain closer to their weaning site than rehabilitated pups.”

Gaydos said to his knowledge, the study has also documented one of the longest distances recorded for a weaned harbor seal pup: one rehabilitated pup traveled from San Juan Island to the Oregon coast. It costs about $3,000 to rehabilitate a stranded harbor seal pup, and current seal populations are healthy.

Gaydos will be presenting these findings at the upcoming International Conference of the Wildlife Disease Association in Quebec, Canada.The seal study is being coordinated in conjunction with Washington’s Department of Fish and Wildlife and Wolf Hollow Rehabilitation Center.

For Seattle Times coverage of the story, see “Baby seals saved, returned to the wild – then what? Scientists now track them” and “Born to be wild: rehabbed and wild seal pups behave differently.”