CZS Sarasota Dolphin Program: 5/18/08

Friday, May 23, 2008

Franciscana Dolphins - Tracking Day #81

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

Thursday, May 22, 2008

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.

Tuesday, May 20, 2008

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.

Monday, May 19, 2008

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.

Science as it Happens!

Ranging Patterns and Habitat Use of Franciscana Dolphins off Argentina: 2008

In March 2008, Chicago Zoological Society conservation scientists Randall Wells, Jason Allen, and Aaron Barleycorn returned to Bahia San Blas, Argentina, to work with Pablo Bordino and his dedicated team of students, colleagues, and fishermen, and a veterinary team from Disney’s Animal Programs, to conduct additional satellite-linked tagging of franciscana dolphins. Building on the tagging and tracking work during 2007 that indicated a high degree of residency to Bahia San Blas over periods as long as six months, the next phase of the project was designed to address specific questions about:

1) what part of the water column the dolphins use – if the dolphins show preference for water of particular depths, then fishermen might be able to set their nets at different depths in order to avoid the dolphins. Up to three satellite-linked transmitters with time-depth recorders (TDRs) will provide information on the depths of dives as well as locations.

2) developing correction factors for aerial and boat surveys for dolphin abundance that take into account the dive patterns of the animals – the TDRs provide information on dive durations and time spent at specific depths where the animals might be visible to scientists.

3) social patterns – deploying tags with identical duty cycles, it is possible to determine if the animals exhibit a stable or fluid pattern of social associations, through examination of their location data to see if they remain together or separate. In addition to the location data from the TDR tags, as many as 5 location-only tags may be deployed. Genetic samples collected during the tagging process will allow determination of relatedness of dolphins caught together.

The first two transmitters, both TDRs, were deployed on a juvenile male (#42483) and an adult female (#42485) on March 4, 2008. As data are received from these and subsequent transmitters, they will be displayed on this site, as maps showing dolphin locations.

The radio transmitter ("tag") was specially designed for dolphins and weighs only 15 grams. The expected battery life is approximately four weeks, and the tag naturally falls off some time later.

Major support for this project was provided by the Chicago Zoological Society and Disney’s Animal Programs, with tags and tag data processing assistance provided by Dolphin Quest.

CZS Sarasota Dolphin Program