Franciscana Dolphins - Tracking Day #180-Final

Final Update
Six months into tracking, the battery strength of Kona's transmitter has dropped below the level where we should expect further signals. She provided more than 44,500 transmissions, nearly 20,000 more than expected. Her last transmission was within several km of where she was originally tagged almost 6 months ago.

Franciscana Dolphins - Tracking Day #179

Kona is at the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #178

Kona is south of the mouth of Bahia San Blas. CLS/Argos is having some
technical difficulties this morning.

Franciscana Dolphins - Tracking Day #177

Kona continues to move through the waters at the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #176

Kona remains on the sandbanks south of the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #173-174

Kona has spent the past two days outside the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #172

Kona is outside the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #171

Kona remains near the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #170

Kona is using the entrance channel and mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #169

Kona is back inside the bay.

Franciscana Dolphins - Tracking Day #168

Kona is back inside the bay.

Franciscana Dolphins - Tracking Day #167

Kona has moved out of the bay, a bit offshore.

Franciscana Dolphins - Tracking Day #166

Kona has moved deep inside Bahia San Blas, near her capture site.

Franciscana Dolphins - Tracking Day #165

Kona is just off the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #164

Kona is inside the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #163

Kona is back inside Bahia San Blas, not far from her original capture site.

Franciscana Dolphins - Tracking Day #162

Kona is at the sandbanks south of the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #161

Kona is a bit to the south of the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #160

Kona has moved a bit farther offshore of the mouth of Bahia San Blas, into waters 20 m deep.

Franciscana Dolphins - Tracking Day #159

Kona is over the sandbanks just to the south of the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #158

Kona remains offshore of Bahia San Blas.

Franciscana Dolphins - Tracking Day #157

Kona remains just offshore of the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #156

Kona continues to spend time outside the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #155

Kona remains off the mouth of the bay.

Franciscana Dolphins - Tracking Day #154

Kona has moved to the sandbanks to the north of the mouth of Bahia San Blas.

Franciscana Dolphins - Tracknig Day #153

Kona is outside of the mouth to Bahia San Blas.

Franciscana Dolphins - Tracknig Day #152

Kona remains in or near the mouth of Bahia San Blas.

Franciscana Dolphins - Tracknig Day #150

Five months into the tracking, Kona is back inside the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #149

Kona moved into the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #148

Kona has returned to the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #147

Kona is near Punta Rasa.

Franciscana Dolphins - Tracking Day #146

Kona remain to the south of Bahia San Blas.

Franciscana Dolphins - Tracking Day #145

Kona remains between the Rio Negro and Punta Rasa.

Franciscana Dolphins - Tracking Day #144

Kona has moved well to the south, toward the Rio Negro. The pattern that is emerging from tracking this year is somewhat different from that from last year. The animals are anchored in Bahia San Blas, returning to it and spending time there, but they have ranged much farther along the coast to the north or south than what we saw last year, moving as far as the next major river in either direction.

Franciscana Dolphins - Tracking Day #143

Kona remains to the south of Bahia San Blas.

Franciscana Dolphins - Tracking Day #142

Kona is south of Punta Rasa. Intern Nacho Bruno returns to Argentina today after participating in training for the past three months in Sarasota.

Franciscana Dolphins - Tracking Day #141

Kona remains near Punta Rasa.

Franciscana Dolphins - Tracking Day #140

Kona is near Punta Rasa.

Franciscana Dolphins - Tracking Day #139

Kona has moved back south to the area off Punta Rasa.

Franciscana Dolphins - Tracking Day #138

Kona has moved back to the south a bit. The battery strength of her tag continues to be good.

Franciscan Dolphins - Tracking Day #136

Kona is moving back inside Bahia San Blas.

Franciscana Dolphins Tracking Day #135

Kona remains at the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #134

Kona has moved into shallower water near the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #133

Kona remains near the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #132

Kona is in the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #131

Kona is at the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #130

Kona is off the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #129

Kona has returned to the area off the mouth of Bahia San Blas, but she remains in deeper waters than she was earlier in the tracking.

Franciscana Dolphins Tracking Day #128

Kona has moved back toward Bahia San Blas. Although the sample size is small, Pablo suggests that her movements might exemplify one reason why abundance estimates have been consistently lower in Bahia San Blas in winter.

Franciscana Dolphins Tracking Day #127

Kona has moved to the south, farther from Bahia San Blas than previously recorded. As Pablo suggests, perhaps she has found a new boyfriend...

Franciscana Dolphins Tracking Day #125

Kona remains in the vicinity of the lighthouse and Punta Rasa.

Franciscana Dolphins Tracking Day #126

Kona has moved a bit south of the lighthouse this morning.

Franciscana Dolphins Tracking Day #124

Kona remains in the vicinity of the lighthouse.

Franciscana Dolphins - Tracking Day #123

Kona has moved a bit to the north, back inside the Protected Area.

Franciscana Dolphins - Tracking Day #122

Kona remains near Punta Rasa.

Franciscana Dolphins - Tracking Day #121

Kona remains south of Bahia San Blas, moving between Punta Rasa and Punta Rubia, near the 20 m contour.

Franciscana Dolphins - Tracking Day #120

Four months into the tracking, Kona is heading back toward Bahia San Blas, moving along the 20 m contour.

Franciscana Dolphins - Tracking Day #119

Kona remains south of Bahia San Blas. Relaxing the location quality criteria, we can see that Tunken was near the mouth of Bahia San Blas yesterday, but no more recent data are available.

Franciscana Dolphins - Tracking Day #118

Signal Fading After 45,000 Transmissions
Tunken is still transmitting, but after 45,000 transmissions (only 25,000 were expected for this transmitter), battery strength has declined to the point where the signals are not sufficiently strong to provide good locations (hence, no updated location on today's map) or dive data, and we expect to lose contact with him soon. Kona has made 30,000 transmissions, and is beginning to show some decline in battery strength. She remains to the south of Bahia San Blas.

Franciscana Dolphins - Tracking Day #117

Kona remains to the south of the bay, while Tunken remains in the vicinity of Bahia San Blas.

Franciscana Dolphins - Tracking Day #116

Kona continues to the south, farther than she has been tracked previously, while Tunken remains near Bahia San Blas.

Franciscana Dolphins - Tracking Day #115

Genetic Analyses: New Hypothesis About Franciscana Mating Associations
Kona has continued moving to the south, while Tunken remains at the mouth of the bay. Martin Mendez has performed genetic analyses on the dolphins captured and tagged this year, and determined that the two males (Tunken and Nahuel) are not related to the females (Kure and Kona, respectively) with whom they were caught and subsequently interacted repeatedly, or for an extended period of time. The hypothesis that they were mothers with their older male calves can now be rejected, leaving in place the even-more-interesting alternative hypothesis that the adult females were spending extensive periods of time with young adult males (based on length), probably for mating purposes.

Extended associations between an adult female and a single, unrelated adult male are quite unusual among the odontocete cetaceans. If extended mating associations are the norm for Franciscana reproduction, then it raises new questions about the impacts of losses of a pair member from fishing nets.

Franciscana Dolphins - Tracking Day #114

Kona has moved to the south, while Tunken remains in the bay.

Franciscana Dolphins - Tracking Day #113

Kona remains outside the mouth of the bay while Tunken is inside,

Franciscana Dolphins - Tracking Day #112

Tunken has moved deep into Bahia San Blas while Kona remains outside the mouth.

Franciscana Dolphins - Tracking Days #110-111

Kona remains offshore while Tunken is using the main, deep channel off San Blas.

Fanciscana Dolphins - Tracking Day #109

Tunken is deep inside Bahia San Blas, while Kona remains outside the mouth of the bay.

Franciscana Dolphins - Tracking Day #108

CLS-Argos is having technical difficulties this morning, so maps are not available, but both dolphins have been transmitting over the past day.

Franciscana Dolphins - Tracking Day #107

Tunken is inside Bahia San Blas, while Kona remains outside the mouth.

Franciscana Dolphins - Tracking Day #106

Both dolphins remain near the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #105

Both dolphins are near the sandbanks south of the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #104

Kona has returned from the south of Bahia San Blas, while Tunken remains in the bay.

Franciscana Dolphins - Tracking Day #103

Tunken remains at the entrance to Bahia San Blas while Kona is to the south.

Franciscana Dolphins - Tracking Day #102

Kona has moved a bit farther to the south, while Tunken remains in the vicinity of Bahia San Blas.

Franciscana Dolphins - Tracking Day #101

Tunken is to the north of the mouth of the bay, while Kona is relatively far offshore to the south.

Franciscana Dolphins - Tracking Day #100

Similar to yesterday, Tunken is in the channel near San Blas, and Kona is just outside the bay.

Franciscana Dolphins - Tracking Day #99

Tunken is near the mouth of Bahia San Blas, while Kona has moved a bit to the south.

Franciscana Dolphins - Tracking Day #98

Tunken remains inside the bay while Kona is in fairly deep water outside the mouth.

Franciscana Dolphins - Tracking Day #97

Argos is having difficulties this morning - no maps are available, but data indicate that both animals have transmitted over the past day.

Franciscana Dolphins - Tracking Day #96

Tunken remains inside the bay while Kona remains just outside.

Franciscana Dolphins - Tracking Day #95

Tunken is inside the bay, while Kona is near the mouth of the bay.

Franciscana Dolphins - Tracking Day #94

Tunken is deep inside Bahia San Blas, while Kona remains near the mouth.

Franciscana Dolphins - Tracking Day #93

Kona remains outside the mouth of Bahia San Blas, while Tunken has moved inside.

Franciscana Dolphins - Tracking Day #92

Both dolphins are outside the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #91

Tunken has moved to the mouth of Bahia San Blas, where Kona remains.

Franciscana Dolphins - Tracking Day #90

At the three-month point in tracking, Tunken has moved inside Bahia San Blas, while Kona remains at the mouth.

Franciscana Dolphins - Tracking Day #89

Tunken and Kona are both at the mouth of Bahia San Blas. Nahuel's battery level dropped below the threshold for transmission after more than 30,000 transmissions, so we do not expect to hear from him again.

Franciscana Dolphins - Tracking Day #88

Tunken and Nahuel are at the mouth of Canal de Culebra, while Kona remains just outside Bahia San Blas.

Franciscana Dolphins - Tracking Day #87

Tunken is to the north, near Banco Culebra, Nahuel in between, and Kona off the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #86

Tunken is headed toward Canal de Culebra, while Nahuel remains there and Kona remains at the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #85

Pattern remains comparable to previous days over the past week: Tunken in Bahia San Blas, Kona just outside, and Nahuel near Canal de Culebra.

Franciscana Dolphins - Tracking Day #84

The pattern of the past few days remains unchanged: Kure/Tunken in Bahia San Blas, Kona near the mouth, and Nahuel near Canal de Culebra.

Franciscana Dolphins - Tracking Day #82

The pattern is unchanged from the past few days. Nahuel is to the north, and the others remain in Bahia San Blas.

Franciscana Dolphins - Tracking Day #81

Kure/Tunken remain in Bahia San Blas, with Kona at the mouth, and Nahuel apparently returning from the north.

Franciscana Dolphins - Tracking Day #80

The pattern of the past few days continues, with Kure/Tunken deep inside Bahia San Blas, Kona outside the mouth,and Nahuel to the north.

Franciscana Dolphins - Tracking Day #79

A similar pattern to the past few days. Kure/Tunken are deep inside Bahia San Blas, Kona is near the mouth, and Nahuel remains in the vicinity of Canal de Culebra. If all goes as planned, Leo Berninsone and Carpi Echezaretta will go to Bahia San Blas for much-needed photo-ID work next week, and hopefully document the condition of the tags.

Franciscana Dolphins - Tracking Day #78

Nahuel remains north of Banco Culebra, while Kona is inside Bahia San Blas and Kure/Tunken are near the mouth of Bahia San Blas. Pablo is summarizing the results of the three years of satellite tracking in a paper to be presented at the International Whaling Commission's annual scientific meeting in Chile later this month.

Franciscana Dolphins - Tracking Day #77

Yesterday's pattern continues, with Nahuel still to the north of the others.

Franciscana Dolphins - Tracking Day #76

Nahuel is now north of Banco Culebra, farther north than we have tracked him to date, but still south the the northernmost extent of the track of Kure/Tunken. Kure and Tunken remain inside Bahia San Blas, while Kona is at the mouth.

Franciscana Dolphins - Tracking Day #75

Three of the dolphins are in Bahia San Blas, while Nahuel remains in the vicinity of Canal de Culebra.

Franciscana Dolphins - Tracking Day #74

All of the banks are outside the mouths of the bays, with Kona to the south, Kure/Tunken in the middle, and Nahuel having returned to the vicinity of Canal de Culebra.

Franciscana Dolphins - Tracking Day #72

Kure/Tunken have moved north to Canal de Culebra, while Nahuel has begun to return to Bahia San Blas. Kona remains in Bahia San Blas. Based on data from April 26 - May 7 , the following patterns were observed for the three dolphins with TDRs:

Dive Duration (44,111 dives):
0-30 seconds = 37% to 51% of dives
30-60 sec = 25% to 29% of dives
60-90 sec = 21% to 28% of dives
Max duration = >300 sec for all 3 dolphins (a few dives)

Dive Depth (44,884 dives):
0-5 meters = 40% to 53% of dives
5-10 m = 27% to 38% of dives
10-15 m = 12% to 23% of dives
Max depth = 25-35 m

Franciscana Dolphins - Tracking Day #71

Nahuel continues his movements to the north of the others, while they remain in Bahia San Blas.

Franciscana Dolphins - Tracking Day #70

Kure/Tunken remain together in Bahia San Blas, as does Kona. Nahuel is moving to the north, near Canal de Culebra.

Franciscana Dolphins - Tracking Day #69

Kure/Tunken are making typical movements through Bahia San Blas. Kona is at the mouth of the bay, and Nahuel continues his new movement pattern offshore of the sandbanks.

Franciscana Dolphins - Tracking Day #68

Kure/Tunken have moved well inside the bay, while Kona and Nahuel remain outside, apparently separated. Nahuel is in fairly deep water, farther offshore. Pablo Bordino and Agustina Caride have returned to Argentina after participating in the CZS bottlenose dolphin health assessment program in Saraasota Bay.

Franciscana Dolphins - Tracking Day #67

All four dolphins are in the mouth of Bahia San Blas. Kure/Tunken remain together, but the others are separate. All three of the TDR tags are nearing the expected total number of transmissions, but their batteries still indicate good strength.

Franciscana Dolphins - Tracking Day #65

Kure/Tunken have returned to Bahia San Blas. Kona/Nahuel do not appear to be together.

Franciscana Dolphins - Tracking Day #64

Kure/Tunken have returned southward to Canal de Culebra, while Kona and Nahuel appear to be spending less time together in Bahia San Blas.

Franciscana Dolphins - Tracking Day #63

Kure/Tunken have turned back toward the south from the Rio Colorado. Kona and Nahuel are in Bahia San Blas, but they may have separated again.

Franciscana Dolphins - Tracking Day #62

Kure/Tunken remain just south of the Rio Colorado, at the north end of Bahia Anegada, in about 10-15 meters of water, while Kona/Nahuel have moved back into Bahia San Blas.

Franciscana Dolphins - Tracking Day #61

Kure/Tunken have moved northward to a point off the mouth of the Rio Colorado, farther north than any of our previous tracking in this area. Kona/Nahuel remain together at the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #60

Two Month Tracking Goal Achieved
Today we achieved our goal of two months of tracking for all four tags. Kure/Tunken have moved a bit farther to the north, while Kona/Nahuel are together in in the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #59

The pairs continue yesterday's patterns.

Franciscana Dolphins - Tracking Day #58

Both pairs remain outside the bay, with Kure/Tunken to the north of Banco Culebra, and Kona/Nahuel together and outside the mouth of Bahia San Blas. According to the tide tables, they have just experienced a set of somewhat extreme tides, that are now moderating.

Franciscana Dolphins - Tracking Day #57

Kure/Tunken remain together near the Canal Culebra to the northeast of Banco Nordeste, while Kona and Nahuel are together at the mouth of Bahia San Blas. Argentinean research assistants of AquaMarina Agustina Caride and Ignacio "Nacho" Bruno arrive in Sarasota tomorrow as part of an internship training program. Agustina will be here for about 10 days, and Nacho will remain through July.

Franciscana Dolphins Tracking Day #56

Kure/Tunken are together and northeast of Banco Nordeste, and Kona/Nahuel are together and in the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #55

Kure/Tunken are together and headed north again, to the east of Banco Nordeste. Kona and Nahuel were together in the channel in Bahia San Blas yesterday, but do not appear to be together now.

Franciscana Dolphins Tracking Day #53

The four dolphins are inside the bay. Early this morning it appeared that all four were in the same general area of the bay, but it is unclear if this continued as they moved farther into the bay.

Franciscana Dolphins Tracking Day #52

Kure/Tunken are inside the bay, while Kona/Nahuel are together to the north of the mouth of the bay.

Franciscana Dolphins Tracking Day #51

The pairs continue their patterns of the last few days in Bahia San Blas.

Franciscana Dolphins Tracking Day #50

The pair of Kure/Tunken is farther inside the bay than is the pair of Kona/Nahuel this morning.

Franciscana Dolphins Tracking Day #49

Seven Weeks and Counting
Seven weeks into the tracking, Kure/Tunken have returned to Bahia San Blas, and Kona/Nahuel appear to be together at the mouth of the bay. Pablo has indicated that researchers Leo and Carpi will return to San Blas within the next few weeks to try to find and photograph the tagged dolphins and other distinctive fins.

Franciscana Dolphins Tracking Day #48

The dolphins remain mostly at the mouths of the bays. Kona and Nahuel have come back together again, while Kure/Tunken remain together N of Banco Nordeste.

Franciscana Dolphins Tracking Day #47

The animals continue their patterns of recent days. Nahuel and Kure/Tunken are mostly outside the bay mouth, with the pair to the north.

Franciscana Dolphins Tracking Day #46

Yesterday's pattern holds. All of the animals are spending a fair amount of time outside the bay, with Kure/Tunken still to the north, following last month's pattern.

Franciscana Dolphins Tracking Day #45

The animals are again emphasizing the mouth of the bay in their daily movements. It was precisely a month ago that Kure/Tunken moved northeast of Banco Nordeste, where they are today, suggesting the possibility of a lunar (tidal?) cycle to their movements. Nahuel and Kona remain apart, while the pair of Kure/Tunken remains tight.

Franciscana Dolphins Tracking Day #44

All four of the dolphins are outside of the mouth of the bay. Kure/Tunken are still together and northeast of Banco Nordeste, while Kona and Nahuel are separated outside Bahia San Blas.

Franciscana Dolphins Tracking Day #43

All of the animals are outside the mouth of the bay. Kure and Tunken remain together. Kona and Nahuel are closer than they were yesterday, but not a tight pair.

Franciscana Dolphins Tracking Day #42

All of the dolphins are outside the mouth of Bahia San Blas. Kure/Tunken remain together, while the others are apart.

Franciscana Dolphins Tracking Day #41

Kure and Tunken are moving as a tight pair between Nahuel (deep inside the
bay) and Kona (just outside the mouth of the bay).

Franciscana Dolphins Tracking Day #40

Kure and Tunken are at the mouth of the bay, as is Kona, but not with them.
Kona and Nahuel remain separated.

Franciscana Dolphins - Tracking Day #39

Kona remains near the mouth of the bay, while the other three dolphins have moved deeper inside the bay. Nahuel's movements have been paralleling those of the Kure/Tunken pair recently, rather than remaining with Kona.

Franciscana Dolphins Tracking Day #38

Kure and Tunken remain as a tight pair, while Nahuel seems to be ranging widely, not spending much time with Kona. It will be very interesting to determine from genetics if these males are older sons of the females, and if we might be documenting the period of separation.

Franciscana Dolphins Tracking Day #37

The dolphins remain in Bahia San Blas. Pairings were a bit more difficult to discern over the past 24 hours. Nahuel followed a very similar pattern to the day before, moving deep into the bay at about the same time of day.

Franciscana Dolphins Tracking Day #36

The four dolphins continue their previous patterns, with Kure and Tunken moving together through the main channel in Bahia San Blas, and Kona and Nahuel covering much of the same area, but apparently not always together.

Franciscana Dolphins Tracking Day #35

The dolphins remain in the bay, with Kure and Tunken remaining together.

Franciscana Dolphins Tracking Day #34

To date, the tags have provided more than 750 positions. The dolphins remain in the bay. Kona and Nahuel moved into the northern reaches, and were together at least some of the time. Kure and Tunken remain as a tight pair, and were in the northwestern portion of the bay.

Franciscana Dolphins Tracking Day #33

Kona and Nahuel are together deep inside the bay, while Kure and Tunken are together near the mouth.

Franciscana Dolphins Tracking Day #32

The animals remain in Bahia San Blas, with Kure and Tunken remaining in a very tight pair, and the other two seemingly less tight. Dive patterns among the three dolphins with TDRs (Kure, Tunken, Nahuel) are very consistent. Based on preliminary analyses of more than 80,000 dive records, common dives are to 5-15 meters, and last 60-90 seconds. Rarely, dives appear to have lasted 4-5 minutes or more. Maximum dive depths reach the bottom in the deepest waters of the area, 30-35 meters.

Franciscana Dolphins Tracking Day #31

The dolphins continue their patterns in Bahia San Blas. Kure and Tunken moved outside the mouth, and remain together. Earlier, they were in very close proximity to Nahuel deep inside the bay.

Franciscana Dolphins Tracking Day #30

The patterns continue. Both pairs of animals continue to move through Bahia San Blas.

Franciscana Dolphins Tracking Day #29

The dolphins remain in or just outside of Bahia San Blas. Although the pairs seem pretty tight, there was at least one occasion when Kona and Nahuel moved through the channel separately.

Franciscan Dolphins Tracking Day #28

Both sets of animals remain in Bahia San Blas, and although their final locations for the day could not indicate they were together (because they were at different times), they were together for much if not all of the period prior to the end of the day's transmission session.

Franciscana Dolphins Tracking Day #27

The four dolphins continue to engage in typical patterns in Bahia San Blas, with the pairs apparently remaining intact.

Franciscana Dolphins Tracking Day #26

Kona and Nahuel are returning from their little sojourn to the south of the bay, and have been together much if not all of the time on this trip. Kure and Tunken remain inside the bay.

Franciscana Dolphins Tracking Day #25

Kure and Tunken remain together and in Bahia San Blas, while Kona and Nahuel have moved to the south outside of the bay. Much as the movements of Kure and Tunken to the north last week were somewhat beyond anything we saw in tracking last year, the movements of Kona and Nahuel to the south now extends by a bit the range we documented last year.

Franciscana Dolphins - Tracking Day #24

The animals continue typical patterns for franciscana dolphins in Bahia San Blas. Each pair was intact through much if not all of the tracking window.

Franciscana Dolphins Tracking Day #23

Both pairs of animals appear to be following a similar pattern of movements in the bay, and each pair continues to be intact for at least part of each tracking window. Today's map is similar to yesterday's, with Kure and Tunken to the north of Nahuel, and Kona at the mouth of the bay for their most recent positions.

Franciscana Dolphins - Tracking Day #22

Kure and Tunken are together as the red dots in the upper left portion of the map. Kona and Nahuel were together earlier, but Kona wasn't picked up on the final satellite pass of the period, so we can't say they were together at the end of the period.

Franciscana Dolphins - Tracking Day #21

Tunken and Kure were togther inside the bay at the end of the transmission window. Other movements were more difficult to interpret as it appeared that signal quality was generally not very good yesterday (a number of positions on land).

Franciscana Dolphins - Tracking Day #20 (March 22)

All four dolphins are in Bahia San Blas today, and appear to have been in close proximity to one another early this morning.

Franciscana Dolphins - Tracking Day #19 (March 21)

All four dolphins are in Bahia San Blas, moving through the main channel. At some point during the tracking window, each pair was intact, but it is unclear who was together most recently because the times of most recent positions (red dots) are different for each animal.

Franciscana Dolphins - Tracking Day #17 (March 20)

Dolphins Near Mouth of Bay
Tunken and Kure have returned to Bahia San Blas, and as of early this morning they were off the mouth of the bay, with Nahuel not too far away. It is likely that Kona was also there, but we did not get a signal from her during the same satellite pass as the others. David Douglas, the USGS scientist who developed the filtering program to determine which satellite fixes are reasonable to use for analyses, has also developed a program to evaluate social associations between our dolphins based on separation distance. When considering only those signals from different animals received within 10 minutes of each other, a clear pattern of consistent, close association is apparent for each pair of dolphins caught and tagged together. Evaluation of photos obtained by the Argentinean photo-ID team confirmed that the orcas they observed earlier this week were in fact the same two whales seen in the same areea a year ago, and different from the pair seen last week. The team will remain in the field through Sunday.

Franciscana Dolphins - Tracking Day #16 (March 19)

Kona and Nahuel are together to the northeast of the banks north of San Blas, but they may be returning to Bahia San Blas. Kure and Tunken were together earlier in the tracking window inside the bay, but it is unclear if they are still together as Nahuel moved to the mouth of the bay (his most recent positions are several hours more recent than Kona's). Martin Mendez will have all of the genetic samples from the tagging efforts over the past four years in-hand by May, and will be proceeding with analyses to determine relationships of the tagged animals as well as those caught in fishing nets. The photo-ID team found orcas yesterday, and it is believed that they were the same ones seen by our team in 2007 in Bahia San Blas.

Franciscana Dolphins - Tracking Day #15 (March 18)

Dolphins Remain Inside Protected Area

Nahuel and Kona remain to the northeast of San Blas, and appear to continue to move together. Kure and Tunken remain in Bahia San Blas. Early this morning they appeared to be together, but Kure does not have a position from the same time as Tunken's most recent position at the mouth of the bay, so I can't say if they remain together. According to Pablo, the movements of both sets of animals remain inside the marine protected area. The photo-ID team photographed dolphins yesterday, including a resighting of one seen earlier in this session, but did not find any of the tagged dolphins. They will remain in San Blas for several more days.

Franciscana Dolphins - Tracking Day #14 (March 17)

Dolphins Remain Outside of Bay
The two pairs of dolphins are near banks outside of the bay, with Kure and Tunken NE off Banco Nordeste for the third day, and Kona and Nahuel off the mouth of Bahia San Blas. Both sets of animals were together during the tracking window. The photo-ID team saw many dolphins yesterday, but it was too rough to take photos.

Franciscana Dolphins - Tracking Day #13 (March 16)

Dolphin Pairs Remain Together
For a second day, Tunken and Kure have remained to the northeast of the range described for the dolphins tracked during 2007, and they appeared to be together for much of the overnight tracking period. Kona and
Nahuel remained within the previously-described range. They appeared to be together through much of the period, but the red dots for their most recent positions, outside the mouth of the bay, were separated in time
by several hours.

These positions, near sandbanks outside of the bay, will make it difficult or the photo-ID team to work with the animals today unless it is unusually calm. Rough seas over the banks create difficulties for safe boat operations, and the tiny dorsal fins of the dolphins (less than 6 inches tall) are obscured by waves. Note that the banks where Kona and Nahuel were located are called "Hellcat Banks."

Franciscana Dolphins - Tracking Day #12 (March 15)

Tunken and Kure Ranging Farther
Tunken and Kure have moved to the northeast of the banks to the north of San Blas, ranging a bit farther than any of the dolphins we tracked last year. They appeared to be together much of the time, but were not together at the end of the daily tracking period. Kona and Nahuel were paralleling each other's movements inside the bay, if they were not indeed together, through much of the period.

Franciscana Dolphins - Tracking Day #11 (March 14)

Dolphins Diving Deep
The dolphins continue their expected patterns of movement in the bay. Although the first pair appeared to be together yesterday, they all appeared to be moving independently this morning. It wil be great when, in several months, the genetics data should be available to allow us to determine if animals caught together are related. Dive data from the three dolphins with TDRs indicate some dives to 30-35 meters (the deepest water available in the bay), and for more than three minutes in some cases.

Franciscana Dolphins - March 11

Rough Seas
The winds were too high and the seas too rough to conduct any field work today, so we cleaned up the field station and prepared for our return trip. Two of the Argentinean students who have worked in our Sarasota lab over the past two years (Leo and Carpì) will remain in San Blas for another week to conduct photographic identification surveys, using the methodology they learned in Sarasota. They plan to return at intervals through the year to document identifiable dolphins and monitor our tagged dolphins.

Dolphins Remain Inside Bay
All four of the dolphins were again inside the bay this morning, with the first two we tagged, Tunken and Kure, moving together (the 2 red dots farthest to the left). The other two dolphins, the female, Kona (warrior in Mapuche) and the male, Nahuel (jaguar in Mapuche) were in the same general area, but did not appear to be together.

Franciscana Dolphins - March 10

Final Day of Tagging

Today was the final day to attempt tagging. We did not catch any franciscanas today, but we added several to our photo-identification catalog. In total, we have tagged four dolphins with satellite-linked transmitters. Their positions as of this morning are shown in the attached map, with the red dots being the most recent, and all occurring within the same minute or so. This shows that they are following similar movement patterns, but they are not together in the same group at this time, suggesting perhaps a fluid social structure. More data will be required to document how often individuals join and separate.

The three transmitters with time-depth recoding capability appear to be collecting data appropriately, but limitations of the internet site in San Blas preclude our being able to fully review the data in the field. If they are indeed functioning properly, then we will have accomplished our primary goal for this year´s tagging session.

Killer Whales Spotted

Today we had an added treat - two killer whales entered the bay and passed by our boats. They both had distinctive fins, and we will try to compare them to the existing identification catalog for Argentina. They appeared to be different from the pair we saw here last year - last year's orcas were not in the existing catalog for Patagonia.

Tomorrow will be our last day in the field. We will work with our colleagues from Argentina to refine the photo-ID abilities they have learned working with our Sarasota lab over the past two years, and we will search for distinctive dolphins, our current tags, and individuals tagged last year who should have shed their tags.

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.

Betty - January 9

Signals were received from Betty today, but no location data were provided.

Betty - January 8

No word from Betty today - too early to speculate about reasons.

Betty - January 7

Betty has returned north to the general area where she has spent the past six weeks.

Betty - January 6

Betty is a bit south of her 10-day cluster of positions, but still over the edge of the shelf. We'll have to wait to see if she is moving on or returning to the area of the cluster.

Betty - January 5

We have begun receiving location data from Betty once again, as seas in the Gulf of Mexico subside. She remains in the same area where she has been since 27 November--west of Key West, over the edge of the continental shelf.

Betty - January 4

Betty is still transmitting, but we are not getting location data from the transmissions. My first guess is still that the rough seas are interfering with transmission. Seas are subsiding today, so we should be able to test this over time.

Betty - January 3

So far today, no news from Betty. There were only two transmissions received yesterday (an unusually small number). Given that the battery and dive data from January 1 appeared reasonable, I would speculate that the high waves and steep seas associated with the continuing strong winds of the major cold front that passed through are interfering with the signal transmission.

Betty - January 2

Betty remains in the same area. Here is today's map---she is currently in the middle of the 11-day cluster of positions.