Betty - January 12 (Final Update)

After 105 days of tracking, we have not received any signals from Betty for the past 2 days. Several lines of evidence suggest that this is likely due to the tag coming off the fin, rather than any problem with Betty herself, or with the tag electronics. The sequence in which different kinds of data stopped being transmitted (longer messages stopped first) suggests a repositioning of the tag on the fin, as would happen if one or more of the 3 attachment pins were no longer functional. The battery strength was still adequate as of the most recent status message. Betty was still making a few dives to 600-800 m and staying down on occasion for 8-9 min within the past week or so.

This pattern of events leading up to cessation of signals is comparable to what happened with the rehabbed Risso's dolphin "Clyde" after a little more than 3 weeks of tracking. In Betty's case, the performance was greatly improved, with the tag remaining attached and functional for 45 days more than our expected 60 days.

As of earlier this week, Betty was still in the same area where she had spent the past 6 weeks or so, west of Key West. Unless we receive more signals from Betty, this will be the final update.