scholarly journals Report of the Working Group on Habitat Use of Tursiops truncatus in the Southwest Atlantic Ocean

10.5597/00215 ◽  
2017 ◽  
Vol 11 (1-2) ◽  
pp. 47-61 ◽  
Author(s):  
Paula Laporta ◽  
Cristiane C.A. Martins ◽  
Liliane Lodi ◽  
Camila Domit ◽  
Els Vermeulen ◽  
...  
Keyword(s):  
Spatial Analysis ◽  
Habitat Use ◽  
Bottlenose Dolphins ◽  
Temporal Analysis ◽  
Southwest Atlantic ◽  
Effort Allocation ◽  
Use Patterns ◽  
Resident Populations ◽  
Available Information ◽  
Survey Effort

The review compiles available information about the habitat use patterns of bottlenose dolphins within the SWAO, including temporal analysis of survey effort allocation, and spatial analysis indicating areas of resident or seasonally resident populations. 

scholarly journals A review on the distribution, abundance, residency, survival and population structure of coastal bottlenose dolphins in Argentina

10.5597/00233 ◽  
2018 ◽  
Vol 12 (1-2) ◽  
pp. 2-16 ◽  
Author(s):  
Els Vermeulen ◽  
Ricardo Bastida ◽  
Leonardo G. Berninsone ◽  
Pablo Bordino ◽  
Mauricio Failla ◽  
...  
Keyword(s):  
Population Structure ◽  
Bottlenose Dolphins ◽  
Grey Literature ◽  
Southwest Atlantic ◽  
Sympatric Distribution ◽  
Present Information ◽  
Species Population ◽  
Region Data ◽  
Survival And Reproduction ◽  
Available Information

Although bottlenose dolphins Tursiops truncatus are among the most common delphinid species, global population trends remain poorly understood. To improve the knowledge of the species in the Southwest Atlantic Ocean, thispaper reviews all available data related to the distribution and occurrence, abundance, residency and ranging patterns, group size and composition, survival and reproduction and population structure of the coastal bottlenose dolphin in Argentina. Most information proved to be scattered in time and space. Based on the available data, total abundance of coastal bottlenose dolphins in Argentina appears to be low. Data show sightings decreased notably since the 1990s in the northern province of Buenos Aires and the province of Chubut, with the species having disappeared completely from the former region. Data also indicated that two genetically and morphologically distinct coastal populations occur in Argentinean coastal waters, with a sympatric distribution in the provinces of Río Negro and Chubut. One is an isolated ‘Evolutionary Signifcant Unit’ within the larger Southwest Atlantic, whereas the other population appears to be genetically related to the Southwest Atlantic offshore ecotype. In the absence of more substantial data, the present information is pertinent to our scientifc knowledge of the species in the country, collating all published information as well as information from grey literature and previously unpublished data. However, the available information appears to remain insufcient to explain the apparent decline in sightings and to assess the remaining abundance nationwide accurately. Therefore, we strongly recommend increased research efforts for an in-depth assessment of the species’ population status in Argentina.

Individuals as information sources: Could followers benefit from leaders’ knowledge?

Behaviour ◽  
2013 ◽  
Vol 150 (6) ◽  
pp. 635-657 ◽  
Author(s):  
J.S. Lewis ◽  
D. Wartzok ◽  
M.R. Heithaus
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Information Sources ◽  
Bottlenose Dolphins ◽  
Florida Keys ◽  
Home Range Size ◽  
Home Ranges ◽  
Fish Biomass ◽  
Use Patterns ◽  
Residential Population

In dynamic fission–fusion societies, following specific individuals consistently would not be expected in the absence of benefits to followers. Followers in groups may benefit if leaders have greater knowledge about habitats that are available for foraging and how to access these areas efficiently. A small residential population of bottlenose dolphins (Tursiops truncatus) in the Lower Florida Keys (LFK) demonstrates such specific individual leadership, but why others choose to follow is unknown. To determine whether consistent leaders demonstrated greater knowledge of resources and habitat we (1) compared habitat use patterns across areas that varied in prey abundance for groups led by consistent leaders and groups led by individuals that did not consistently lead, (2) compared directness of travel along with number of lead animal switches when traveling for these same two group types and (3) compared home range size and home range complexity between animals that consistently led and those that did not. Foraging groups led by consistent leaders were sighted more frequently over habitat with higher fish biomass, while those led by non-consistent leaders were sighted most often over habitat with lower fish biomass. Groups with consistent leaders had less frequent lead animal switches and took more direct paths when traveling than groups led by those that did not consistently lead. Home ranges of consistent leaders did not differ in size from other individuals, but were more complex. Our results indicate that followers in LFK dolphin groups could potentially benefit from those that consistently lead due to use of profitable habitat, ability to navigate efficiently and potentially the number of areas consistent leaders are familiar with.

scholarly journals Report of the Working Group on the Behavioral Ecology of bottlenose dolphins in the Southwest Atlantic Ocean

2017 ◽  
Vol 11 (1-2) ◽  
pp. 106-120
Author(s):  
Camila Domit ◽  
Paula Laporta ◽  
Camilah A. Zappes ◽  
Liliane Lodi ◽  
Lilian S. Hoffmann ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Behavioral Ecology ◽  
Bottlenose Dolphin ◽  
Interspecific Interactions ◽  
Bottlenose Dolphins ◽  
Population Variation ◽  
Acoustic Parameters ◽  
Southwest Atlantic ◽  
Situational Contexts ◽  
Available Information

In this report, we present a compilation of the behavioral patterns of bottlenose dolphins and social structure throughout the Southwest Atlantic Ocean. We have compiled and summarized available data concerning: (i) behavioral activities (states and events), (ii) social structures (group size and composition), (iii) acoustic behavior and (iv) intra and interspecific interactions of bottlenose dolphin populations throughout the SWAO, from northern Brazil to southern Argentina. Lack of systematic and standardized methodologies for data collection precludes robust data analyses in respect of bottlenose dolphin behavior. Available information suggests that the studied populations presented weak intra-population associations and that coastal individuals tend to form smaller groups than their oceanic counterparts. Bottlenose dolphins from SWAO produce stylized whistles in which the acoustic parameters are similar to published ranges around the world and some results indicate significant local inter-population variation in the acoustic parameters of the whistles. Data of intra and interspecific interactions of bottlenose dolphins in the SWAO are scarce and therefore do not fully allow a comprehensive analysis of the situational contexts.

Can animal habitat use patterns influence their vulnerability to extreme climate events? An estuarine sportfish case study

2017 ◽  
Vol 23 (10) ◽  
pp. 4045-4057 ◽  
Author(s):  
Ross E. Boucek ◽  
Michael R. Heithaus ◽  
Rolando Santos ◽  
Philip Stevens ◽  
Jennifer S. Rehage
Keyword(s):  
Habitat Use ◽  
Extreme Climate Events ◽  
Use Patterns ◽  
Extreme Climate ◽  
Climate Events ◽  
Animal Habitat

scholarly journals Habitat use patterns of franciscana dolphins (Pontoporia blainvillei) off southern Brazil in relation to water depth

2009 ◽  
Vol 89 (5) ◽  
pp. 943-949 ◽  
Author(s):  
Daniel Danilewicz ◽  
Eduardo R. Secchi ◽  
Paulo H. Ott ◽  
Ignacio B. Moreno ◽  
Manuela Bassoi ◽  
...  
Keyword(s):  
Habitat Use ◽  
Rio Grande ◽  
Limiting Factors ◽  
Small Scale ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Use Patterns ◽  
Management Procedures ◽  
By Catch ◽  
Pontoporia Blainvillei

The patterns of habitat use by the franciscana dolphins (Pontoporia blainvillei) along its distribution are poorly known. This study investigates the patterns of habitat use with respect to depth for 181 individuals of different age, size, gender and reproductive condition off Rio Grande do Sul, southern Brazil. The results reveal that franciscanas are very homogeneously distributed according to depth. Individuals from all lengths utilize nearly the entire range of depths of the surveyed area. Larger or older animals do not use deeper waters than younger animals, indicating that body size and age are not limiting factors for franciscanas that occupy deeper or offshore waters. Gestation seems to not cause a change in the distribution of females. Although the sex-ratio of the overall data did not vary from 1:1 in different depth intervals, a small-scale comparison between the northern and southern coast demonstrated the existence of some kind of sexual segregation. Franciscana by-catch in Rio Grande do Sul is not sustainable and it is agreed that management procedures are needed. Nevertheless, the available data on species distribution do not allow the designing of a protected area in order to minimize the by-catches of a particular sex/reproductive class.

scholarly journals Intertidal habitat use of bottlenose dolphins (Tursiops truncatus) in Bahía San Antonio, Argentina

2017 ◽  
Vol 98 (5) ◽  
pp. 1109-1118
Author(s):  
Els Vermeulen
Keyword(s):  
Habitat Use ◽  
Intertidal Zone ◽  
Tursiops Truncatus ◽  
San Antonio ◽  
Bottlenose Dolphins ◽  
High Tide ◽  
Marine Conservation ◽  
Shallow Waters ◽  
Encounter Rate ◽  
Western Atlantic

Very little information is available on bottlenose dolphin (Tursiops truncatus) habitat use in the South-western Atlantic. It is, however, essential in understanding their ecology and to improve conservation management. In this study, habitat use of bottlenose dolphins was examined in Bahía San Antonio, an area frequented by the species. Given the large tidal amplitude and extended intertidal zone in this bay, special focus was given to the intertidal vs subtidal habitat use patterns. Bottlenose dolphins were observed in only half of the surveyed area, with on average 1 dolphin group encountered per 100 km surveyed. All dolphin groups were seen in shallow waters <10 m deep. GLM analyses showed that especially during high tide, depth had an important effect on the dolphin encounter rate, with most dolphin groups encountered in the intertidal zone. While in the intertidal zone, most dolphin groups were observed to be engaged in surface feeding activities. The presented data indicate dolphins remained in shallow waters, and moved to the intertidal zone during high tide where they appear to find feeding opportunities. This information is believed to be of high value in understanding this population's ecological needs, and essential when aiming to improve marine conservation efforts at times of increased anthropogenic pressures in the area.

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