A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence ...A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.展开更多
As ecologically fragile areas,coastal zones are affected by both anthropogenic activities and climate change.However,the impacts of these factors on large nearshore mammals,such as Indo-Pacific humpback dolphins(IPHDs...As ecologically fragile areas,coastal zones are affected by both anthropogenic activities and climate change.However,the impacts of these factors on large nearshore mammals,such as Indo-Pacific humpback dolphins(IPHDs,Sousa chinensis),are poorly understood.Here,modeling revealed that the suitable habitats of IPHDs are affected mainly by the sea surface temperature(SST),and the habitat suitability decreases as the distance to the nearest coastline increases.In addition,anthropogenic activities involving demersal fishing,contamination and shipping have narrowed IPHD habitats and reduced the habitat suitability.We found that climate change will further narrow suitable habitats located farther than 7 km from coastlines and trigger habitat losses in the eastern Taiwan Strait by 2090-2100 under the Representative Concentration Pathway(RCP)8.5 scenario.The projected decreases in habitat suitability and area emphasize the urgency of establishing connected marine protected areas(MPAs)while considering climate change,intergovernmental cooperation,and public involvement.展开更多
Dolphins produce various types of sounds in a wide range of frequencies. Characteristics of some sounds till now have not been correctly registered, that influenced on interpretation of their functions. Studying of th...Dolphins produce various types of sounds in a wide range of frequencies. Characteristics of some sounds till now have not been correctly registered, that influenced on interpretation of their functions. Studying of the characteristics and functions of dolphins’ acoustical signals is the purpose of the present work. In this work the acoustical signals of two dolphins (Tursiops truncatus) were registered by two-channel system in the frequencies band up to 200 kHz at quasi-stationary position of the dolphins. The dolphins along with whistles are producing the packs of coherent and non-coherent broadband pulses. The waveform and spectrum of coherent pulses was invariable within a pack, but considerably varies from a pack to a pack. The waveform of each non-coherent pulse vary from a pulse to a pulse in each pack, therefore their spectrum also vary from a pulse to a pulse and have many extremums in the band of 6 - 200 kHz. It is very likely that the non-coherent pulses play a part of phonemes of a dolphin spoken language and the probing signals of dolphin’s non- coherent sonar. The use possibility of the signals by dolphins for communication and orientation was considered, as the signals apparently are bimodal. Results of the work have significance for further studying of the dolphin’s sonar and spoken language.展开更多
Dolphins are very interesting animals. They look like fish but theyare not fish. Fish have cold blood but dolphins have warm bloodlike other animals. Fish can live under water but dolphins cannot.They can stay under w...Dolphins are very interesting animals. They look like fish but theyare not fish. Fish have cold blood but dolphins have warm bloodlike other animals. Fish can live under water but dolphins cannot.They can stay under water for a long time but then they have tocome up because they breathe air. Fish lay eggs but dolphinshave living babies. These drink their mother’s milk like展开更多
Since 1988, the Japan Enoshima Aquarium (JEA) and the Institute of Hydrobiology of Chinese Academy of Sciences(IHCAS) have carried out long-term joint research on the conservation of Baiji dolphins (Lipotes vexillifer...Since 1988, the Japan Enoshima Aquarium (JEA) and the Institute of Hydrobiology of Chinese Academy of Sciences(IHCAS) have carried out long-term joint research on the conservation of Baiji dolphins (Lipotes vexillifer). According to the research, the population of Baiji dolphins has been decreasing rapidly from 300 in 1986 to less than 100 at present due to environmental deterioration of the Yangtze River. Since it is impossible to conserve the species in the river, as many as possible of the dolphins should be collected and transferred展开更多
An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least ...An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least number of piles is achieved by the multiplier penalty function method. Several engineering cases have been calculated and compared with the result of the conventional design method. It is shown that the number of piles can be reduced at least by 10%～20% and the piles' bearing state is improved greatly.展开更多
In this study, echolocation signals were recorded from a wild Irrawaddy dolphin(Orcaella brevirostris) in shallow water in the Bay of Brunei. During sound recording, a small fishing boat engine startled a nearby Irraw...In this study, echolocation signals were recorded from a wild Irrawaddy dolphin(Orcaella brevirostris) in shallow water in the Bay of Brunei. During sound recording, a small fishing boat engine startled a nearby Irrawaddy dolphin and began chasing it on two occasions. Variations in the acoustic parameters were detected. When the Irrawaddy dolphin was startled and chased, the sound pressure level, number of click trains per minute, pulse number, and average inter-pulse interval(PI) per click train were all affected. The PI increased and exhibited a slight downward trend during the chase. The increase in PI indicated an increase in the inspection distance as the dolphin escaped. Thus, Irrawaddy dolphins may adapt their echolocation signals to stand out from ambient noise in the wild and to improve their search efforts in potentially risky situations. Appropriate management of the burst noise around the dolphins is important.展开更多
On October 1, 2009, sixteen dolphins were obtained from fishermen by incidental catching in the Yellow Sea, China. As the dolphins＇ skin color was ambiguous, morphological parameters were measured, and mitochondrial ...On October 1, 2009, sixteen dolphins were obtained from fishermen by incidental catching in the Yellow Sea, China. As the dolphins＇ skin color was ambiguous, morphological parameters were measured, and mitochondrial DNA cytochrome b （Cyt b） gene sequence was studied to identify the species. Morphological characteristics were consistent with Pantropical spotted dolphins, Stenella attenuata. Furthermore, a partial mitochondrial DNA eytoehrome b （Cyt b） gene sequence as long as 328-bp was studied by extracting genomic DNA from the skins, and six haplotypes were detected in the sixteen dolphins. By comparing homologous sequences available in GenBank （www.ncbi.nlm.nih.gov）, all the six haplotypes had maximal genetic similarity with Pantropical spotted dolphin. Eight species of cetacean （whales and dolphins） are now recognised in the Yellow Sea. To the best of our knowledge, this is the first record of Pantropical spotted dolphins from this region. Despite this species being listed as a Grade II National Key Protected Animal since 1988, little is known of its biology in Chinese waters. We recommend remedial research be undertaken to ensure appropriate management.展开更多
The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied.The primary aim of this study was to identify ...The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied.The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond,individually and as groups,to the relative abundance of prey around a fish farm.Detailed views of dolphins' behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data.A total of 2150 dive intervals were analyzed,corresponding to 342 focal samples,lasting over 34 hours.Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds.This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area.This study's results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding,dolphins did not modify dive duration.Additionally,underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities.Thus,bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey.When top predators display behavioral responses to activities not directed at them,the task of studying all possible effects of human activities can become even more challenging.展开更多
A photo-identification study on Risso’s dolphins was carried out off BardseyIslandinWales(July to September, 1997-2007). Their local abundance was estimated using two different analytical techniques: (1) mark-recaptu...A photo-identification study on Risso’s dolphins was carried out off BardseyIslandinWales(July to September, 1997-2007). Their local abundance was estimated using two different analytical techniques: (1) mark-recapture of well-marked dolphins using a ‘closed-population’ model;and (2) a census technique based on the total number of identified individual dolphins sighted over the study period. The mark-recapture estimates of 121 (left sides;64 - 178 95% CI;CV 0.24) and 145 dolphins (right sides;78 - 213 95% CI;CV 0.24) closely matched the census technique estimates (population size of 90 - 151). It was found that the dolphins showed a degree of long-term and seasonal site-fidelity. A first long-distance match was made for Risso’s dolphins (319 km) betweenBardseyIslandandCornwall, confirming they can be wide-ranging animals. This study demonstrates that the combination of systematic and opportunistic photo-ID studies has complementary value as a population assessment tool in generating the first local abundance estimate for Risso’s dolphins inUKwaters. From the conservation perspective, these studies confirm the regular presence of Risso’s dolphins in these waters and the presence of calves shows breeding.BardseyIslandmay be part of a network of localities that are important habitats to this species where it may take advantage of prey abundance in shallow waters. As such, results of this study may provide assistance to include the Risso’s dolphin in future regional conservation strategies including the envisaged marine protected areas.展开更多
Despite the growing awareness on the importance of gut microbiomes,understanding marine mammal gut microbiomes remains limited due to difficulties in sampling.Spotted dolphins(Stenella attenuata)are widely spread ocea...Despite the growing awareness on the importance of gut microbiomes,understanding marine mammal gut microbiomes remains limited due to difficulties in sampling.Spotted dolphins(Stenella attenuata)are widely spread oceanic cetaceans,and there is a gap in knowledge regarding their gut microbiology.In this study,we opportunistically collected samples from both wild and human-cared spotted dolphins in the southern waters of Hainan Island,China.This provided the opportunity to examine the composition and diversity of the gut microbial communities of this cetacean species.Since these dolphins inhabit a similar water environment,different food sources might be the primary factor distinguishing the gut microbiomes of wild and human-cared populations,offering valuable experimental material to investigate potential differences in gut microbial community structure among marine mammals in similar environments but with varying food sources.We found that the gastrointestinal microbial community structure of wild and human-cared dolphins demonstrated significant differences,both overall and at specific locations.However,no significant difference was observed in the microbial diversity of their gastrointestinal tracts,indicating that the disparities primarily lie in microbiota composition.Additionally,we detected numerous potentially pathogenic bacteria,suggesting a comprehensive future study of marine mammal gut microbiology.Such a study might involve determining health indicator factors associated with these microbiomes.Our study not only supplements information on the gut microbiology of spotted dolphins but also delves into the similarities and differences in gastrointestinal microbial communities within the same marine mammal species when food source variations play a significant role in their lives.展开更多
Humpback dolphins(Sousa spp.)are obligate shallow-water and resident species,and they typically live in fission–fusion societies composed of small-sized groups with changeable membership.However,we have scant knowled...Humpback dolphins(Sousa spp.)are obligate shallow-water and resident species,and they typically live in fission–fusion societies composed of small-sized groups with changeable membership.However,we have scant knowledge of their behavioral ecology,starting with potential factors influencing inter-population variability of their group sizes.Here,we compiled a new global dataset of humpback dolphin group sizes based on 150 published records.Our data indicated an inter-specific consistency of group-living strategy among the 4 species in the Sousa genus,as these species preferred living in small-sized groups with a mean size of mostly no more than 10,a minimum size of single individual or small pairs,and a maximum size of several tens or≈100.In addition,we clearly showed the geographic variations in group sizes of humpback dolphins at a global scale.We found that the geographic variations in humpback dolphin group sizes were primarily associated with the latitude,sea surface temperature,and abundance.To conclude,our findings provide insights into social dynamics and socioecological trade-offs of humpback dolphins,and help better understand how these resident animals adapted to their shallow-water habitats from the perspectives of biogeography and socioecology.展开更多
The Heaviside’s(or Benguela)dolphin(Cephalorhynchus heavisidii)is endemic to the west coast of southern Africa.The present study investigated the population genetic structure across a large portion of the species dis...The Heaviside’s(or Benguela)dolphin(Cephalorhynchus heavisidii)is endemic to the west coast of southern Africa.The present study investigated the population genetic structure across a large portion of the species distribution using mitochondrial control region and nuclear(microsatellite)markers.A total of 395 biopsy skin samples were analyzed;they were collected from free-ranging Heaviside’s dolphins in 7 locations along 1650 km of coast between Table Bay,South Africa and Walvis Bay,Namibia.Both genetic markers rejected the hypothesis of 1 homogenous population but revealed contrasting results in the genetic structuring of putative populations.Mitochondrial DNA suggested either 2 populations or a fine-scale division with 6(sub)populations,while microsatellite markers were indicative of 2 widespread populations with measurable gene flow between them.Neutrality tests and mismatch distribution of the mitochondrial sequences indicated a departure from mutation-drift equilibrium due to a population expansion at the 2 extremes of the geographic range,but not towards the middle of the distribution.These results highlight the importance of evaluating multiple genetic markers to gain reliable insights into population processes and structure.展开更多
Knowledge of an animal＇s home range is a crucial component in making informed management decisions. However, many home range studies are limited by study area size, and therefore may underestimate the size of the hom...Knowledge of an animal＇s home range is a crucial component in making informed management decisions. However, many home range studies are limited by study area size, and therefore may underestimate the size of the home range. In many cases, individuals have been shown to travel outside of the study area and utilize a larger area than estimated by the study design. In this study, data collected by multiple research groups studying bottlenose dolphins on the east coast of Florida were combined to determine how home range estimates increased with increasing study area size. Home range analyses utilized photo-identification data collected from 6 study areas throughout the St Johns River （S JR; Jacksonville, FL, USA） and adjacent waterways, extending a total of 253km to the southern end of Mosquito Lagoon in the Indian River Lagoon Estuarine System. Univariate kernel density estimates （KDEs） were computed for individuals with 10 or more sightings （n= 20）. Kernels were calculated for the primary study area （S JR） first, then additional kernels were calculated by combining the S JR and the next adjacent waterway; this continued in an additive fashion until all study areas were included. The 95% and 50% KDEs calculated for the S JR alone ranged from 21 to 35 km and 4 to 19 kin, respectively. The 95% and 50% KDEs calculated for all combined study areas ranged from 116 to 217 km and 9 to 70 km, respectively. This study illustrates the degree to which home range may be underestimated by the use of limited study areas and demonstrates the benefits of conducting collaborative science.展开更多
INTRODUCTION This special issue of Integrative Zoology(the official journal of the International Society of Zoological Sciences and the Institute of Zoology,Chinese Academy of Sciences)presents recent research progres...INTRODUCTION This special issue of Integrative Zoology(the official journal of the International Society of Zoological Sciences and the Institute of Zoology,Chinese Academy of Sciences)presents recent research progress on whales,dolphins,and porpoises,with focus on those in relatively less investigated waters,such as waters off China,Sri Lanka,and Chile.In this issue,we showed the use of diverse research methods,analytical technologies,and multi-disciplinary tools,with involvement of both large whales,such as the blue whale(Balaenoptera musculus).展开更多
Accurate diet identification of top predators is crucial to fully understand their ecological roles.Compared to terrestrial animals,gathering dietary information from cetaceans is notoriously difficult.Here,we applied a...Accurate diet identification of top predators is crucial to fully understand their ecological roles.Compared to terrestrial animals,gathering dietary information from cetaceans is notoriously difficult.Here,we applied a multilocus metabarcoding approach to investigate the diet of vulnerable Indo-Pacific humpback dolphins and Indo-Pacificfinless porpoises from the Pearl River Estuary(PRE),China.Our analyses identified 21 preyfish species from the 42 humpback dolphin stomachs,as well as 10 species offish and 1 species of cephalopod from the 13finless porpoise stomachs.All of the taxa were assigned to the species level,highlighting that the multimarker approach could facilitate species identification.Most of the prey species were small-and medium-sizedfishes that primarily fed on zooplankton.The calculated similarity index revealed a moderated dietary overlap between the 2 cetaceans,presumably due to the feeding of the 2 predators in association withfishing vessels in the PRE.A more diverse diet was observed in humpback dolphins in the closedfishing season compared to thefishing season,implying the influence on the dolphin diet due to the availability of commercialfishery resources.However,according to the results of species rarefaction curves,ourfindings on the feeding habits of the 2 cetaceans are still limited by insufficient sample size and therefore should be interpreted with caution.This study represents afirst attempt to apply the multilocus DNA metabarcoding technique in the diet analysis of small cetaceans,although more efforts are needed to improve this type of analysis.展开更多
Globally,the threat of endangerment and extinction of small cetaceans was highlighted after the recent extinction of the Chinese River dolphin or Baiji(Lipotes vexillifer).Species with a small population size and a li...Globally,the threat of endangerment and extinction of small cetaceans was highlighted after the recent extinction of the Chinese River dolphin or Baiji(Lipotes vexillifer).Species with a small population size and a limited geographic range,such as Ganges River dolphins(GRD),are more vulnerable to extinction.The social and behavioral needs of cetaceans have been identified as potential factors increasing their vulnerability to human disturbance.However,little is known about how GRD adapt their behaviors and diel activity patterns to spatiotemporal variation.In this paper,we examined the underwater behavior of GRDs in Nepal by collecting echolocation clicks from three spatially stratified habitats in the Sapta Koshi River system over a six-month period.Our research found that GRDs behave differently in response to spatial heterogeneity,indicating diverse environmental requirements for GRD persistence.Behavioral activity and duration varied across habitats but not across time of day,suggesting that GRD behaviors are likely to be regulated by habitat structure regardless of the time of day.However,GRD consistently exhibited nocturnal activity peaks even when diurnal activity varied substantially.This indicates that river dolphins may favor nocturnal refuges as a reaction to human disturbance in highly regulated rivers.Managing human disturbances in conjunction with habitat heterogeneity can improve the persistence of riverine cetaceans.Here,we document behavioral and ecological information pertaining to GRD,which is essential to the formation of river dolphin recovery plans that link ecological perspectives to planning and management.展开更多
Based on historic sightings,Chinese white dolphins have inhabited the waters around the mainland since the 1600s and could once be spotted from Macao to the coast of Shanghai.Despite their name,the dolphins are recogn...Based on historic sightings,Chinese white dolphins have inhabited the waters around the mainland since the 1600s and could once be spotted from Macao to the coast of Shanghai.Despite their name,the dolphins are recognized for their pink color,which develops as they age These days there are four major populations in China's Mainland,including the Pearl River Estuary,Xiamen,Beibu Bay and Leizhou Samantha Lee.展开更多
Based on historic sightings,Chinese white dolphins have inhabited the waters around the Mainland since the 1600s,and could once be spotted from Macao to the coast of Shanghai.Despite their name,the dolphins are recogn...Based on historic sightings,Chinese white dolphins have inhabited the waters around the Mainland since the 1600s,and could once be spotted from Macao to the coast of Shanghai.Despite their name,the dolphins are recognized by their pink color;which develops as they age.These days there are four major populations in China's Mainland,including the Pearl River Estuary;Xiamen,Beibu Bay and Leizhou.展开更多
文摘A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.
基金This work was supported by the National Natural Science Founda-tion of China(NSFC)(Grant No.41901349)Marine Economy Develop-ment Foundation of Guangdong Province(Grant No.GDNRC[2022]21)+1 种基金Basic Scientific Research Program of National Nonprofit Research Insti-tutes(Grant No.ZX2022QT025)the Startup Foundation for Tal-ented Scholars in South China Normal University(Grant No.8S0472).
文摘As ecologically fragile areas,coastal zones are affected by both anthropogenic activities and climate change.However,the impacts of these factors on large nearshore mammals,such as Indo-Pacific humpback dolphins(IPHDs,Sousa chinensis),are poorly understood.Here,modeling revealed that the suitable habitats of IPHDs are affected mainly by the sea surface temperature(SST),and the habitat suitability decreases as the distance to the nearest coastline increases.In addition,anthropogenic activities involving demersal fishing,contamination and shipping have narrowed IPHD habitats and reduced the habitat suitability.We found that climate change will further narrow suitable habitats located farther than 7 km from coastlines and trigger habitat losses in the eastern Taiwan Strait by 2090-2100 under the Representative Concentration Pathway(RCP)8.5 scenario.The projected decreases in habitat suitability and area emphasize the urgency of establishing connected marine protected areas(MPAs)while considering climate change,intergovernmental cooperation,and public involvement.
文摘Dolphins produce various types of sounds in a wide range of frequencies. Characteristics of some sounds till now have not been correctly registered, that influenced on interpretation of their functions. Studying of the characteristics and functions of dolphins’ acoustical signals is the purpose of the present work. In this work the acoustical signals of two dolphins (Tursiops truncatus) were registered by two-channel system in the frequencies band up to 200 kHz at quasi-stationary position of the dolphins. The dolphins along with whistles are producing the packs of coherent and non-coherent broadband pulses. The waveform and spectrum of coherent pulses was invariable within a pack, but considerably varies from a pack to a pack. The waveform of each non-coherent pulse vary from a pulse to a pulse in each pack, therefore their spectrum also vary from a pulse to a pulse and have many extremums in the band of 6 - 200 kHz. It is very likely that the non-coherent pulses play a part of phonemes of a dolphin spoken language and the probing signals of dolphin’s non- coherent sonar. The use possibility of the signals by dolphins for communication and orientation was considered, as the signals apparently are bimodal. Results of the work have significance for further studying of the dolphin’s sonar and spoken language.
文摘Dolphins are very interesting animals. They look like fish but theyare not fish. Fish have cold blood but dolphins have warm bloodlike other animals. Fish can live under water but dolphins cannot.They can stay under water for a long time but then they have tocome up because they breathe air. Fish lay eggs but dolphinshave living babies. These drink their mother’s milk like
文摘Since 1988, the Japan Enoshima Aquarium (JEA) and the Institute of Hydrobiology of Chinese Academy of Sciences(IHCAS) have carried out long-term joint research on the conservation of Baiji dolphins (Lipotes vexillifer). According to the research, the population of Baiji dolphins has been decreasing rapidly from 300 in 1986 to less than 100 at present due to environmental deterioration of the Yangtze River. Since it is impossible to conserve the species in the river, as many as possible of the dolphins should be collected and transferred
基金TheworkwassupportedbytheNationalFoundationofHighPerformanceComputation (No .9810 0 5 )
文摘An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least number of piles is achieved by the multiplier penalty function method. Several engineering cases have been calculated and compared with the result of the conventional design method. It is shown that the number of piles can be reduced at least by 10%～20% and the piles' bearing state is improved greatly.
基金The National Key R&D Program of China under contract No.2017YFC1405100the Key Laboratory of Marine Ecology and Environmental Science and Engineering,Ministry of Natural Resources under contract No.MESE-2016-05+1 种基金the National Natural Science Foundation of China-Shandong Joint Fund for Marine Ecology and Environmental Sciences under contract No.U1406403the China-ASEAN Maritime Cooperation Fund
文摘In this study, echolocation signals were recorded from a wild Irrawaddy dolphin(Orcaella brevirostris) in shallow water in the Bay of Brunei. During sound recording, a small fishing boat engine startled a nearby Irrawaddy dolphin and began chasing it on two occasions. Variations in the acoustic parameters were detected. When the Irrawaddy dolphin was startled and chased, the sound pressure level, number of click trains per minute, pulse number, and average inter-pulse interval(PI) per click train were all affected. The PI increased and exhibited a slight downward trend during the chase. The increase in PI indicated an increase in the inspection distance as the dolphin escaped. Thus, Irrawaddy dolphins may adapt their echolocation signals to stand out from ambient noise in the wild and to improve their search efforts in potentially risky situations. Appropriate management of the burst noise around the dolphins is important.
基金Supported by the International Cooperation Department,State Oceanic Administration(No.HC10701-10(1))the National Special Research Fund for Non-Profit Marine Sector(No.201105011)+1 种基金the National Natural Science Foundation of China(No.41206159)the Natural Science Foundation of Shandong Province,China(No.Y2007D75)
文摘On October 1, 2009, sixteen dolphins were obtained from fishermen by incidental catching in the Yellow Sea, China. As the dolphins＇ skin color was ambiguous, morphological parameters were measured, and mitochondrial DNA cytochrome b （Cyt b） gene sequence was studied to identify the species. Morphological characteristics were consistent with Pantropical spotted dolphins, Stenella attenuata. Furthermore, a partial mitochondrial DNA eytoehrome b （Cyt b） gene sequence as long as 328-bp was studied by extracting genomic DNA from the skins, and six haplotypes were detected in the sixteen dolphins. By comparing homologous sequences available in GenBank （www.ncbi.nlm.nih.gov）, all the six haplotypes had maximal genetic similarity with Pantropical spotted dolphin. Eight species of cetacean （whales and dolphins） are now recognised in the Yellow Sea. To the best of our knowledge, this is the first record of Pantropical spotted dolphins from this region. Despite this species being listed as a Grade II National Key Protected Animal since 1988, little is known of its biology in Chinese waters. We recommend remedial research be undertaken to ensure appropriate management.
基金Funding for this research came from the Bottlenose Dolphin Research Institute-BDRI and private donations
文摘The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied.The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond,individually and as groups,to the relative abundance of prey around a fish farm.Detailed views of dolphins' behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data.A total of 2150 dive intervals were analyzed,corresponding to 342 focal samples,lasting over 34 hours.Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds.This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area.This study's results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding,dolphins did not modify dive duration.Additionally,underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities.Thus,bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey.When top predators display behavioral responses to activities not directed at them,the task of studying all possible effects of human activities can become even more challenging.
文摘A photo-identification study on Risso’s dolphins was carried out off BardseyIslandinWales(July to September, 1997-2007). Their local abundance was estimated using two different analytical techniques: (1) mark-recapture of well-marked dolphins using a ‘closed-population’ model;and (2) a census technique based on the total number of identified individual dolphins sighted over the study period. The mark-recapture estimates of 121 (left sides;64 - 178 95% CI;CV 0.24) and 145 dolphins (right sides;78 - 213 95% CI;CV 0.24) closely matched the census technique estimates (population size of 90 - 151). It was found that the dolphins showed a degree of long-term and seasonal site-fidelity. A first long-distance match was made for Risso’s dolphins (319 km) betweenBardseyIslandandCornwall, confirming they can be wide-ranging animals. This study demonstrates that the combination of systematic and opportunistic photo-ID studies has complementary value as a population assessment tool in generating the first local abundance estimate for Risso’s dolphins inUKwaters. From the conservation perspective, these studies confirm the regular presence of Risso’s dolphins in these waters and the presence of calves shows breeding.BardseyIslandmay be part of a network of localities that are important habitats to this species where it may take advantage of prey abundance in shallow waters. As such, results of this study may provide assistance to include the Risso’s dolphin in future regional conservation strategies including the envisaged marine protected areas.
基金funded by the Hainan Provincial Natural Science Foundation of China(422RC744)Youth Innovation Promotion Association of Chinese Academy of Sciences(2020363)the“One Belt and One Road”Science and Technology Cooperation Special Program of the International Partnership Program of the Chinese Academy of Sciences(Grant No.183446KYSB20200016).
文摘Despite the growing awareness on the importance of gut microbiomes,understanding marine mammal gut microbiomes remains limited due to difficulties in sampling.Spotted dolphins(Stenella attenuata)are widely spread oceanic cetaceans,and there is a gap in knowledge regarding their gut microbiology.In this study,we opportunistically collected samples from both wild and human-cared spotted dolphins in the southern waters of Hainan Island,China.This provided the opportunity to examine the composition and diversity of the gut microbial communities of this cetacean species.Since these dolphins inhabit a similar water environment,different food sources might be the primary factor distinguishing the gut microbiomes of wild and human-cared populations,offering valuable experimental material to investigate potential differences in gut microbial community structure among marine mammals in similar environments but with varying food sources.We found that the gastrointestinal microbial community structure of wild and human-cared dolphins demonstrated significant differences,both overall and at specific locations.However,no significant difference was observed in the microbial diversity of their gastrointestinal tracts,indicating that the disparities primarily lie in microbiota composition.Additionally,we detected numerous potentially pathogenic bacteria,suggesting a comprehensive future study of marine mammal gut microbiology.Such a study might involve determining health indicator factors associated with these microbiomes.Our study not only supplements information on the gut microbiology of spotted dolphins but also delves into the similarities and differences in gastrointestinal microbial communities within the same marine mammal species when food source variations play a significant role in their lives.
基金This study was financially supported by the Major Science and Technology Project in Hainan province(ZDKJ2016009-1-1)the National Natural Science Foundation of China(41306169,41406182,and 41422604)+2 种基金the Ocean Park Conservation Foundation of Hong Kong(AW02-1920)the Chinese White Dolphin Conservation Action Project of Ministry of Agriculture and Rural of People’s Republic of China(Y760091HT1)the Biodiversity Investigation,Observation and Assessment Program of Ministry of Ecology and Environment of China(2019-2023).
文摘Humpback dolphins(Sousa spp.)are obligate shallow-water and resident species,and they typically live in fission–fusion societies composed of small-sized groups with changeable membership.However,we have scant knowledge of their behavioral ecology,starting with potential factors influencing inter-population variability of their group sizes.Here,we compiled a new global dataset of humpback dolphin group sizes based on 150 published records.Our data indicated an inter-specific consistency of group-living strategy among the 4 species in the Sousa genus,as these species preferred living in small-sized groups with a mean size of mostly no more than 10,a minimum size of single individual or small pairs,and a maximum size of several tens or≈100.In addition,we clearly showed the geographic variations in group sizes of humpback dolphins at a global scale.We found that the geographic variations in humpback dolphin group sizes were primarily associated with the latitude,sea surface temperature,and abundance.To conclude,our findings provide insights into social dynamics and socioecological trade-offs of humpback dolphins,and help better understand how these resident animals adapted to their shallow-water habitats from the perspectives of biogeography and socioecology.
基金SANBI to conduct research on Heaviside’s dolphins(001/2011)the work was conducted under permits from the Department of Environmental Affairs(RES2009/06,RES2010/24,RES2011/70 and RES2012/67)Samples from Namibia were exported under permit from the Ministry of Environment and Tourism(78438,120586 and 138004)。
文摘The Heaviside’s(or Benguela)dolphin(Cephalorhynchus heavisidii)is endemic to the west coast of southern Africa.The present study investigated the population genetic structure across a large portion of the species distribution using mitochondrial control region and nuclear(microsatellite)markers.A total of 395 biopsy skin samples were analyzed;they were collected from free-ranging Heaviside’s dolphins in 7 locations along 1650 km of coast between Table Bay,South Africa and Walvis Bay,Namibia.Both genetic markers rejected the hypothesis of 1 homogenous population but revealed contrasting results in the genetic structuring of putative populations.Mitochondrial DNA suggested either 2 populations or a fine-scale division with 6(sub)populations,while microsatellite markers were indicative of 2 widespread populations with measurable gene flow between them.Neutrality tests and mismatch distribution of the mitochondrial sequences indicated a departure from mutation-drift equilibrium due to a population expansion at the 2 extremes of the geographic range,but not towards the middle of the distribution.These results highlight the importance of evaluating multiple genetic markers to gain reliable insights into population processes and structure.
文摘Knowledge of an animal＇s home range is a crucial component in making informed management decisions. However, many home range studies are limited by study area size, and therefore may underestimate the size of the home range. In many cases, individuals have been shown to travel outside of the study area and utilize a larger area than estimated by the study design. In this study, data collected by multiple research groups studying bottlenose dolphins on the east coast of Florida were combined to determine how home range estimates increased with increasing study area size. Home range analyses utilized photo-identification data collected from 6 study areas throughout the St Johns River （S JR; Jacksonville, FL, USA） and adjacent waterways, extending a total of 253km to the southern end of Mosquito Lagoon in the Indian River Lagoon Estuarine System. Univariate kernel density estimates （KDEs） were computed for individuals with 10 or more sightings （n= 20）. Kernels were calculated for the primary study area （S JR） first, then additional kernels were calculated by combining the S JR and the next adjacent waterway; this continued in an additive fashion until all study areas were included. The 95% and 50% KDEs calculated for the S JR alone ranged from 21 to 35 km and 4 to 19 kin, respectively. The 95% and 50% KDEs calculated for all combined study areas ranged from 116 to 217 km and 9 to 70 km, respectively. This study illustrates the degree to which home range may be underestimated by the use of limited study areas and demonstrates the benefits of conducting collaborative science.
文摘INTRODUCTION This special issue of Integrative Zoology(the official journal of the International Society of Zoological Sciences and the Institute of Zoology,Chinese Academy of Sciences)presents recent research progress on whales,dolphins,and porpoises,with focus on those in relatively less investigated waters,such as waters off China,Sri Lanka,and Chile.In this issue,we showed the use of diverse research methods,analytical technologies,and multi-disciplinary tools,with involvement of both large whales,such as the blue whale(Balaenoptera musculus).
基金supported by the Natural Science Foundation of Guangdong Province(2017A030308005)in Chinathe National Natural Science Foundation of China(41576128,42007225)+4 种基金Guangdong Basic and Applied Basic Research Foundation(2020A1515010910)in ChinaChina Postdoctoral Science Foundation(2019M653153)Fundamental Research Funds for the Central Universities(19lgpy95)Ocean Park Conservation Foundation of Hong Kong(MM01.1718)Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021004,311020003).
文摘Accurate diet identification of top predators is crucial to fully understand their ecological roles.Compared to terrestrial animals,gathering dietary information from cetaceans is notoriously difficult.Here,we applied a multilocus metabarcoding approach to investigate the diet of vulnerable Indo-Pacific humpback dolphins and Indo-Pacificfinless porpoises from the Pearl River Estuary(PRE),China.Our analyses identified 21 preyfish species from the 42 humpback dolphin stomachs,as well as 10 species offish and 1 species of cephalopod from the 13finless porpoise stomachs.All of the taxa were assigned to the species level,highlighting that the multimarker approach could facilitate species identification.Most of the prey species were small-and medium-sizedfishes that primarily fed on zooplankton.The calculated similarity index revealed a moderated dietary overlap between the 2 cetaceans,presumably due to the feeding of the 2 predators in association withfishing vessels in the PRE.A more diverse diet was observed in humpback dolphins in the closedfishing season compared to thefishing season,implying the influence on the dolphin diet due to the availability of commercialfishery resources.However,according to the results of species rarefaction curves,ourfindings on the feeding habits of the 2 cetaceans are still limited by insufficient sample size and therefore should be interpreted with caution.This study represents afirst attempt to apply the multilocus DNA metabarcoding technique in the diet analysis of small cetaceans,although more efforts are needed to improve this type of analysis.
文摘Globally,the threat of endangerment and extinction of small cetaceans was highlighted after the recent extinction of the Chinese River dolphin or Baiji(Lipotes vexillifer).Species with a small population size and a limited geographic range,such as Ganges River dolphins(GRD),are more vulnerable to extinction.The social and behavioral needs of cetaceans have been identified as potential factors increasing their vulnerability to human disturbance.However,little is known about how GRD adapt their behaviors and diel activity patterns to spatiotemporal variation.In this paper,we examined the underwater behavior of GRDs in Nepal by collecting echolocation clicks from three spatially stratified habitats in the Sapta Koshi River system over a six-month period.Our research found that GRDs behave differently in response to spatial heterogeneity,indicating diverse environmental requirements for GRD persistence.Behavioral activity and duration varied across habitats but not across time of day,suggesting that GRD behaviors are likely to be regulated by habitat structure regardless of the time of day.However,GRD consistently exhibited nocturnal activity peaks even when diurnal activity varied substantially.This indicates that river dolphins may favor nocturnal refuges as a reaction to human disturbance in highly regulated rivers.Managing human disturbances in conjunction with habitat heterogeneity can improve the persistence of riverine cetaceans.Here,we document behavioral and ecological information pertaining to GRD,which is essential to the formation of river dolphin recovery plans that link ecological perspectives to planning and management.
文摘Based on historic sightings,Chinese white dolphins have inhabited the waters around the mainland since the 1600s and could once be spotted from Macao to the coast of Shanghai.Despite their name,the dolphins are recognized for their pink color,which develops as they age These days there are four major populations in China's Mainland,including the Pearl River Estuary,Xiamen,Beibu Bay and Leizhou Samantha Lee.
文摘Based on historic sightings,Chinese white dolphins have inhabited the waters around the Mainland since the 1600s,and could once be spotted from Macao to the coast of Shanghai.Despite their name,the dolphins are recognized by their pink color;which develops as they age.These days there are four major populations in China's Mainland,including the Pearl River Estuary;Xiamen,Beibu Bay and Leizhou.
