SOUNDS AND BEHAVIOR CHANGES IN Sotalia fluviatilis (GERVAIS, 1853), IN NORTH BAY OF SANTA CATARINA ISLAND (BRASIL), CAUSED BY TOUR BOATS.
(1) SANTOS-LOPES,
A. R. ; (2) MANNA-CESAR, G. (1) Núcleo de
Estudos Bioacústicos e Biológicos – NEBB (2) Lab. de Mamíferos Aquáticos –
Lamaq, ECZ, CCB, UFSC – Brasil.
Sounds studies and behavior observations were carried out
in dolphins Sotalia fluviatilis at North Bay of Santa Catarina Island. The task goal was
to observe possible behavior and sound alterations caused by the presence of tour boats in
these animals. The dolphins sounds emissions weren’t decreased by the entry and
permanence of the boats in the bay. Basic moving behavior is changed and the dolphins
start to follow the boats. The dolphins take advantage of the caused reflux that dispels
and disorients the shoals, to make their fishing maneuvers. It was observed that the
animals are used to these vessels, but the remaining trash path, fireworks and loud music
are harmful. The studies on the environmental impact is contributing for a secure Dolphin
Watching to the animals, instructive for the tourist, satisfying fisherman and ship
owners.
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SOUND RECORDING METHODS AND CHARACTERIZATION OF COMMUNICATION AND ECHOLOCATION SOUNS IN Sotalia fluviatilis DOLPHINS (GERVAIS, 1853) (MAMMALIA, CETACEA, DELPHINIDAE).
SANTOS-LOPES, A.R.¹
& MONTEIRO-FILHO, E.L.A²
(1) Lab. de Mamíferos Aquáticos – Lamaq, ECZ, CCB,
UFSC; (2) Depto de Zoologia, Centro Politécnico, UFPR – Brasil.
Sounding recording methods were tested in dolphins
Sotalia fluviatilis either in Cananéia (SP), as in Florianópolis (SC), the south part of
the dolphins distribution. An already existing methodology was adapted to the present
reality, allowing to characterize the communication and echolocation sounds of this
species. Depth differences were tested according to the place in order to avoid to maximum
outer interference, apart from the usual that occur in marine recordings.
As a result to the observations: screams (? 5,5 kHz with
harmonics, duration of 0,064 – 1,029 seconds); echolocation clicks (4 – 4,5 kHz,
duration of 8,01 – 15,27 seconds). Whistles and gargling that weren’t counted
due to the low intensity that were emitted. Some pattern behavior were observed during the
recording and associated to the fishing maneuvers such as: moving, feeding, blow in the
surface and jumping.
INDIVIDUAL SOUNDINGS REGISTERS OF BOTTLENOSE DOLPHIN IN THE CHANNEL OF LAGUNA (SC) - BRASIL.
MANNA-CESAR, G.¹ ; SANTOS-LOPES, A.R.² (1) Lab. de Mamíferos Aquáticos – Lamaq, ECZ, CCB, UFSC; (2) Núcleo de Estudos Bioacústicos e Biológicos - NEBB - Brasil.
This report presents preliminary results of individual sonar emissions registrated in Bottlenose dolphins in freedom (Laguna (SC) - 28°30’ S and 48°45’ W). There are registers of a male and a female in cooperative fishery strategic situation whit local fishermen. The registers were made in different days, where just one animal was recorded by day. This registers were possible because there was a low (decrease) fishery productivity in these days (the quantity of fishes inside the channel was small). As a result to the female recorders: screams (20% - 2 different types), and echolocation clicks (80%). Male results: Screams (10%) and echolocation clicks (90%). Like the animals were isolated of the others members of the group (band), and were just concentrated in the capture of food, there was a great range of echolocation clicks. The probability to recorder isolated dolphins (individuals) in freedom is very small. Generally, they are in small groups, what made this marines individual recorders of a great value.
SOUDINGS AND BEHAVIOR PATTERN OF BOTTLENOSE DOLPHINS IN THE CHANNEL OF LAGUNA (SC) - BRASIL.
MANNA-CESAR, G.¹; SANTOS-LOPES, A.R.²
(1)Lab. de Mamíferos Aquáticos – Lamq, ECZ, CCB,
UFSC; (2) Nuclei de Estudos Bioacústicos e Biológicos - NEBB.
Between 1996 and 1998, sounding and behavior observation
in Bottlenose dolphins (Laguna (SC) - 28°30’ S and 48°45’ W), was realized
with the objective to analyze these patterns in freedom animals. There wasn’t
necessary to use boats, because the animals were always next the sea-wall (pier), where
the fishermen were with casting-nets. The registers were: screams (15% - ? 7 kHz with
harmonics); echolocation clicks (55% - ? 8 kHz) and whistles. The whistles 30% have no
sonograms, because they were registered in low intensity what prejudiced the
analyses. The behavior patterns observed were: moving in group, kidding, periscope and
dives. Some patterns were associated with the fishery shifting(manobras=manoeuvre) such
as: following and capture and cooperative fishery with the fishermen. This behavior
patterns were normally observed for fishermen and tourists during all the year.