Limited information still exists on the movements of bottlenose dolphins in South Australian coastal waters. There is, however, a need to overcome this paucity of information for an effective development and implement...Limited information still exists on the movements of bottlenose dolphins in South Australian coastal waters. There is, however, a need to overcome this paucity of information for an effective development and implementation of conservation and management initiatives in these waters that are increasingly threatened by anthropogenic activities. This study infers potential movements of bottlenose dolphins (Tursiops spp.) between Kangaroo Island that separate and shelter South Australian coastal waters from the Southern Ocean swell, and the South Australian mainland (The Fleurieu Peninsula and The Adelaide Dolphin Sanctuary). Bottlenose dolphins were identified from three separate photo-identification catalogues collated from around the South Australian coastline. Of the 3518, 654 and 181 dolphins sighted in Kangaroo Island, Fleurieu Peninsula and the Adelaide Dolphin Sanctuary, 233, 74 and 40 individuals were recognizable, respectively. Resighting rates were similar in Kangaroo Island (70.4%) and Fleurieu Peninsula (75.7%), but much lower in the Adelaide Dolphin Sanctuary (35%). Ten individuals were resighted between Kangaroo Island and the Fleurieu Peninsula, whilst no matches were made between these two locations and the Adelaide Dolphin Sanctuary catalogue. This suggests a longitudinal connectivity between Kangaroo Island and South Australian mainland waters, but a lack of latitudinal connectivity that may result from the physical stratification processes that separate northern and southern South Australian waters. Our results also demonstrate the highly mobile nature of this species within South Australian waters as well as establish photo-identification as an effective non-invasive tool in which to monitor long-term movement patterns).展开更多
A method based on syntactic pattern recognition was presented to automatically classify whistles of bottlenose dolphin. Dolphin whistles have typically been characterized in terms of their instantaneous frequency as a...A method based on syntactic pattern recognition was presented to automatically classify whistles of bottlenose dolphin. Dolphin whistles have typically been characterized in terms of their instantaneous frequency as a function of time, which is also known as ＂whistle contour＂. The frequency variation features of a whistle were extracted according to its contour. Then, the frequency variation features were used for learning grammatical patterns. A whistle was classified according to grammatical pattern of its frequency variation features. The exper- imental results showed that the classification accuracy of the proposed method was 95%. The method can provide technical support for acoustic study of dolphins＇ biological behavior.展开更多
This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua,Venezuela,over a multi-year period.Using photo-identification,the ...This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua,Venezuela,over a multi-year period.Using photo-identification,the most recent study(2019-2020)identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting.Site Fidelity(SF)and Residence(RES)indices were calculated and Agglomerative Hierarchical Clustering(AHC)modeling was performed,with three patterns of residence obtained:resident(25%),semi-resident(17.86%)and transient(57.14%).These results were contrasted with remodeled data from a previous study(2006-2007),showing similar patterns:resident(24.44%),semi-resident(28.89%)and transient(46.67%).Importantly,two individuals were found to have been resident over the extended period.A breeding female sighted for the first time in 2004 and again in 2020(16 years)and the other from 2005 to 2020(15 years).This region is an important area for marine mammals,known to support a resident reproductive population over many years,as well seabirds,sea turtles,whale sharks and fishermen.We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.展开更多
文摘Limited information still exists on the movements of bottlenose dolphins in South Australian coastal waters. There is, however, a need to overcome this paucity of information for an effective development and implementation of conservation and management initiatives in these waters that are increasingly threatened by anthropogenic activities. This study infers potential movements of bottlenose dolphins (Tursiops spp.) between Kangaroo Island that separate and shelter South Australian coastal waters from the Southern Ocean swell, and the South Australian mainland (The Fleurieu Peninsula and The Adelaide Dolphin Sanctuary). Bottlenose dolphins were identified from three separate photo-identification catalogues collated from around the South Australian coastline. Of the 3518, 654 and 181 dolphins sighted in Kangaroo Island, Fleurieu Peninsula and the Adelaide Dolphin Sanctuary, 233, 74 and 40 individuals were recognizable, respectively. Resighting rates were similar in Kangaroo Island (70.4%) and Fleurieu Peninsula (75.7%), but much lower in the Adelaide Dolphin Sanctuary (35%). Ten individuals were resighted between Kangaroo Island and the Fleurieu Peninsula, whilst no matches were made between these two locations and the Adelaide Dolphin Sanctuary catalogue. This suggests a longitudinal connectivity between Kangaroo Island and South Australian mainland waters, but a lack of latitudinal connectivity that may result from the physical stratification processes that separate northern and southern South Australian waters. Our results also demonstrate the highly mobile nature of this species within South Australian waters as well as establish photo-identification as an effective non-invasive tool in which to monitor long-term movement patterns).
文摘A method based on syntactic pattern recognition was presented to automatically classify whistles of bottlenose dolphin. Dolphin whistles have typically been characterized in terms of their instantaneous frequency as a function of time, which is also known as ＂whistle contour＂. The frequency variation features of a whistle were extracted according to its contour. Then, the frequency variation features were used for learning grammatical patterns. A whistle was classified according to grammatical pattern of its frequency variation features. The exper- imental results showed that the classification accuracy of the proposed method was 95%. The method can provide technical support for acoustic study of dolphins＇ biological behavior.
基金We thank the fisherman José“Cata”,Grisel Velásquez(UNISIG-IVIC),Laboratory of Ecosystems and Global Change,Venezuelan Institute of Scientific Research,PADI Foundation(N°40470)the Cetacean Society International and the Society of Marine Mammalogy for their funding which enabled this study.
文摘This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua,Venezuela,over a multi-year period.Using photo-identification,the most recent study(2019-2020)identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting.Site Fidelity(SF)and Residence(RES)indices were calculated and Agglomerative Hierarchical Clustering(AHC)modeling was performed,with three patterns of residence obtained:resident(25%),semi-resident(17.86%)and transient(57.14%).These results were contrasted with remodeled data from a previous study(2006-2007),showing similar patterns:resident(24.44%),semi-resident(28.89%)and transient(46.67%).Importantly,two individuals were found to have been resident over the extended period.A breeding female sighted for the first time in 2004 and again in 2020(16 years)and the other from 2005 to 2020(15 years).This region is an important area for marine mammals,known to support a resident reproductive population over many years,as well seabirds,sea turtles,whale sharks and fishermen.We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.
