Franciscana Dolphins - March 9

Four Dolphins Near Sandbanks
Rain and high winds have kept us on shore today, but the satellite-linked transmitters show us that all four (4) tagged dolphins are moving through the bay as expected. This morning, all four were in the vicinity of the sandbanks where they were caught and tagged several days ago. The large red dots indicate the most recent position, and smaller white dots indicate older positions within the past 24 hours. As with any remote tracking, there is some imprecision, as demonstrated by the one white dot in a small cove to the south. Given the position of the animal immediately before and after this one, we can be pretty sure that it is anomalous.

Once the final data are obtained from Argos, we will run them through a filter program that will eliminate the biologically-impossible positions.

Franciscana Dolphins - March 7

Two Additional Dolphins Tagged
Today we tagged two more franciscana dolphins, an adult male and an adult female. They are now transmitting, along with juvenile male Tunken and adult female Kure, tagged on Tuesday. The large red dots on the map are the most recent daily locations of each dolphin.

They are following patterns similar to those observed last year.

Tumken and Kure - March 6

Strong winds and rain squalls kept the team off the water today, but tracking of the first 2 tagged dolphins, Tumken, the young male (42483), and adult female Kure (42485) continues via satellite. Their movements so far are closely following those of the four dolphins tagged in the same area last year. We have begun to receive our first dive data for this species. Tumken has made dives as deep as 20-25 meters and remained down for as long as 2-2.5 minutes, although most dives have been for 1-1.5 minutes, and to about 5-10 meters.

Yesterday, Chicago Zoological Society (CZS) research assistant Aaron Barleycorn obtained a dorsal fin photograph that was matched by CZS Dolphin Conservation Program Lab Manager Jason Allen to a fin photographed last year near the same location. This marks the first documentation of residency by a franciscana dolphin across more than one year at a site. Field work will continue through March 11 , with tracking via satellite continuing for as long as the tags transmit.

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.

Betty - January 10

Betty remains in the same general area as she has for the past 6 weeks.