Articles tagged with Cetaceans
Research on British Risso's dolphins reveals they form a single genetic entity, separate from those in the Azores and Mediterranean. The study suggests these dolphins have been isolated for some time, but further research is needed to determine their boundaries.
Bottlenose dolphins spend much of their time following trawlers to scavenge for food, with up to 76% of bottom trawlers being followed. The high frequency suggests that they may be struggling to hunt normally due to the depletion of prey in the Adriatic Sea.
Researchers found that Bigg's killer whales are increasingly present in Puget Sound, while southern resident killer whales are spending less time in inland waters. The data suggests that social cues may play a role in the changing distribution of southern residents.
Transient killer whales, humpback whales, and grey whales are spotted in the Salish Sea due to seasonal feeding and conservation efforts. Researchers attribute this increase to improved fisheries management, reduced whaling, and increased seal populations, allowing whales to thrive in their ancestral habitats.
Researchers at the University of Washington decoded over 1,700 beluga whale calls in Cook Inlet, revealing insights into their social behavior, communication patterns, and vulnerability to human noise. The study suggests that shipping noise may be disrupting critical calf-mother communication, threatening the population's recovery.
Researchers analyzed centuries-old Swedish newspapers to reconstruct past porpoise distribution patterns in the Baltic Sea. The study found that harbour porpoises once occupied a wider area than they do today, with a loss of about one third of their historic range. Historical records provide valuable insights for conservation efforts.
A new acoustic device, PAL Wideband pinger, has been found to reduce harbour porpoise bycatch in the Black Sea by approximately 74%. The device's wider frequency band (10-150 kHz) is believed to contribute to its effectiveness. Effective strategies to reduce bycatch are urgently needed for the critically endangered species.
Almost 20% of gray whales that enter San Francisco Bay die there, with the majority dying from boat strikes or malnutrition. The area's busy waters and low visibility make it a hazardous location for these animals.
Parties to the Convention on Migratory Species agree to list 40 additional species on Appendices I and II, including iconic species like cheetahs, hyenas, and great hammerhead sharks. The agreement also includes multi-species conservation plans for key regions like the Amazon.
Scientists captured rare view of beaked whales by listening to their natural sounds, revealing deep-diving behavior. The study provides the first detailed description of Gervais' beaked whale dives anywhere in the world.
Researchers at University of Queensland conducted hearing tests across ocean off Australian coast, finding humpbacks react to higher frequency sounds than expected. The study provides direct evidence humpbacks are highly sensitive to higher frequencies at the upper end of human hearing range.
A team of scientists analyzed DNA samples from 623 beluga whales in Bristol Bay, Alaska, revealing a polygynous mating system where males secure few matings per year, but females switch partners frequently across breeding seasons. This unique strategy may help maintain genetic diversity and resilience in the small population.
New research reveals that Indigenous communities in southern Brazil hunted large whales 5,000 years ago, long before previously thought. The study provides strong evidence of active hunting and sheds light on the economies, technologies, and lifeways of postglacial societies along the Atlantic coast of South America.
Researchers used drones to collect respiratory droplets from wild whales in northern Norway, detecting cetacean morbillivirus, a potentially deadly virus that causes severe damage. The study highlights the importance of long-term surveillance to understand how emerging stressors shape whale health.
A Harvard-designed bio-logger captures high-fidelity audio of sperm whale codas, which are later analyzed by machine learning models to uncover structured communication. Recent results show that sperm whales have their own alphabet and use vowels and diphthongs in their language.
Researchers found that killer whales and Pacific white-sided dolphins cooperate while hunting salmon in British Columbia waters. The orcas use dolphin echolocation to locate Chinook salmon, which the dolphins then scavenge for food scraps after the orcas eat their share.
Researchers observed orcas in the Gulf of California targeting juvenile great white sharks, flipping them to induce tonic immobility and extract nutrient-rich livers. The orca pod's hunting technique suggests advanced intelligence and social learning, allowing them to adapt to changing shark nursery areas.
Researchers tested a popular evolutionary theory by comparing maternal length and fetal sex in over 100,000 whales. They found that the fetal sex ratio skews female for longer body size, suggesting that female calves benefit more from heritable fitness than males do. The findings contradict the Trivers-Willard hypothesis.
Beaked whales are recorded in the Foz do Amazonas Basin using passive acoustic monitoring, demonstrating their first documentation in Brazilian waters. The study contributes to understanding cetacean biodiversity and showcases the effectiveness of acoustic monitoring for categorizing elusive sea creatures.
A recent study found that the 2014-2016 Northeast Pacific marine heatwave caused unprecedented ecological disturbance, resulting in widespread kelp and seagrass declines and mass mortality events. The research highlights cascading impacts on species interactions, plankton communities, and offshore ocean productivity.
A new Flinders University study has mapped the distribution of killer whales in Australian waters, identifying three key regions with high habitat suitability. The research highlights the need for stronger conservation measures to protect these unique populations as apex predators in the marine ecosystem.
Researchers found whales and dolphins, including an endangered sperm whale, in the Clarion Clipperton Zone, a vast area of deep ocean and seamounts. Chronic exposure to mining noise could disrupt key behaviors, leading to cascading ecological consequences.
A team of whale experts discovered that southern resident killer whales regularly use lengths of bull kelp as tools to groom each other during social interactions. The whales fashion the tools by breaking off the ends of kelp stalks and then press them against a partner, rolling them between their bodies for long periods.
Killer whales have been observed detaching kelp stalks and using them to massage each other's backs, a behavior dubbed "allokelping". This social bonding behavior may promote skin health and strengthen relationships among the whales.
A team of scientists from the SETI Institute and UC Davis documented humpback whales producing large bubble rings during friendly interactions with humans. This behavior may offer insights into nonhuman intelligence and aid in the search for extraterrestrial life.
Researchers have uncovered evidence of humans using whale bones as tools from 20,000 years ago, shedding light on the marine ecology of the time and the role whales played in past ecosystems. The study identifies five species of large whales used by early humans.
Researchers analyzed 724 ancient Chinese poems to track the decline of the Yangtze finless porpoise's habitat range. The study found that the porpoise's range decreased by at least 65% over 1,400 years, with most of this decline occurring in the past century. This ancient art form provides a unique window into biodiversity conservation.
Researchers propose that timing hypothesis explains the mystery of missing blue whale calves, where births occur in fall and winter, and calves are weaned before returning to feeding areas. This explanation offers alternative insight into high pregnancy rates vs. low sightings of mother-calf pairs.
Baleen whale species that flee from killer whales produce calls at deep frequencies undetectable to their predators, while others sing higher-frequency songs that are easily heard. This 'flight' vs 'fight' difference influences all aspects of baleen whale behavior, from migration patterns and communication to mating and feeding habits.
Juvenile dolphins possess specialized receptors for detecting fatty acids in their mother's milk, which plays a crucial role in energy and brain development. This 'fat taste' system may provide an evolutionary advantage in selecting high-quality milk from mothers.
A new study led by the University of Washington found that only about 7% of areas at highest risk for whale-ship collisions have any measures in place. The team identified high-risk regions, including coastal areas along the Mediterranean, Americas, southern Africa, and parts of Asia, where whales and ships are most likely to meet.
Researchers detected microplastic particles in the breath of wild bottlenose dolphins, suggesting inhalation may be a key route of exposure. The study supports the idea that dolphins could be exposed to potentially harmful microplastics through this pathway.
Researchers analyzed DNA in fecal samples to determine the diet of Alaska and southern resident killer whales. They found that both populations prefer salmon, but differ in when they switch to hunting other fish species. The study provides key insights into the delicate balance between regional abundance of different fish species.
Underwater noise pollution from human activities significantly impacts the ability of orcas to hunt successfully in the Salish Sea. The study found that increased ambient noise levels, particularly around vessel propellers, interfere with echolocation behavior and hunting efforts. This hindrance affects females more than males, potenti...
A new study has confirmed that killer whales take only one breath between dives, providing insights into their unique physiological habits. The researchers used drone footage and biological data from tags to gather information on the animals' habits, revealing that residents spend most of their time making shallow dives.
Researchers have identified heavily used shipping lanes that pass through crucial whale shark feeding grounds, posing a threat to this endangered species. Targeted measures, such as reducing ship speed, could help minimize the impact on the shipping industry while protecting whale sharks.
A recent study found humpback whale entanglements in BC fish farms are extremely rare, with only eight instances over 13 years. Young whales' curiosity may be a contributing factor, according to researchers.
A new species of freshwater dolphin, Pebanista yacuruna, was found in the Peruvian Amazon region and is dated to be 16 million years old. The discovery sheds light on the evolutionary history of freshwater dolphins, revealing a deep connection with South Asian river dolphins.
Researchers at the University of British Columbia have discovered a new population of killer whales in the Northeastern Pacific, with distinct physical characteristics and a diet that includes marine mammals and sea turtles. The orcas were identified through shark-bitten scars and observations by fishermen and birding enthusiasts.
A study found polycyclic aromatic hydrocarbons (PAHs) in Southern Resident killer whales and Bigg's killer whales off the coast of B.C., with contaminants from oil spills and wildfire smoke. The presence of PAHs suggests recent exposures to toxic chemicals, emphasizing the need for improved pollution management.
Researchers found that commercial ship noise completely masks Cook Inlet beluga whales' most commonly used calls, compromising their critical communication. The study documents the complex vocal repertoire of the population and provides a quantified measure of masking by ship noise on their communication.
New research reveals that endangered whales and dolphins inhabit the Hellenic Trench off Greece year-round, challenging seismic surveys and oil and gas exploration. The study confirms the presence of four species, including sperm whales, in both summer and winter, highlighting the need for conservation measures.
A study by Newcastle University reveals that gillnets in Thailand's small-scale fisheries catch an estimated 5.6 million rays, 457 thousand sharks, and other threatened species each year. The researchers urge regulation of these fishing methods to protect megafauna from extinction.
A new study reveals that northern and southern resident orcas differ in their hunting behaviors, with males catching more salmon per hour than females. Southern resident males outperform females by 152%, highlighting a distinct pattern of foraging that may contribute to the population decline.
Scientists discovered high levels of toxic chemicals, including 4-nonylphenol from toilet paper, in the bodies of orcas in B.C., which may contribute to their population decline. Forever chemicals like 7:3-fluorotelomer carboxylic acid were also found, highlighting the need for pollution management and regulation.
Scientists from BGI Genomics successfully generated a gapless genome assembly for the East Asian finless porpoise, which is approximately 2.5 Gb in size and has 22,814 protein-coding genes. The study provides new resources for comparative genomics of cetaceans and conservation biology of threatened species.
A team of researchers has observed orcas killing white sharks in South Africa using drone and helicopter footage. The study provides the first direct evidence of this behavior, showing that orcas are capable of pursuing, capturing, and incapacitating white sharks.
Researchers suggest special blood vessels called 'retia mirabilia' reduce brain pressure pulses, preventing damage. Computer modeling supports theory, which could be applied to other animals and humans.
A study published in Current Biology reveals that ancient dolphins, including the false killer whale and orca, ate fish instead of other marine mammals. The findings suggest that these species evolved similar cranial anatomy and feeding behaviors within the last five million years.
A recent study reveals that narwhals are highly affected by noise pollution from ships and seismic airgun pulses, triggering stress and altering their behavior. Researchers hope that better management of noise pollution will protect these unique Arctic animals.
A study explores how human activities on land can affect aquatic animals, specifically the fungal pathogen Cryptococcus gattii. The research found that terrestrial hotspots were likely where spores settled before infecting marine mammals in the Salish Sea.
Researchers discovered three phases of growth that explain how cetaceans shift their nasal passage from a parallel to an angled orientation. This finding provides insight into the developmental process and could inform our understanding of cetacean evolution.
Researchers analyzed 18 extinct reptile species and 14 modern relatives, finding similarities in the vestibular system of open-ocean swimmers, including cetaceans. The study suggests that distinct evolutionary routes resulted in similar adaptations for different types of terrestrial animals transitioning to marine environments.
A study found that highly specialized coronulid barnacles exclusively attach to the fins of dolphins, particularly along the trailing edge facing away from water flow. The barnacles select suitable areas on the fins to filter nutrients and protect developing larvae.
A new genetic analysis published in PLoS One found that Franciscana dolphins entangled in fishing nets are more likely to be mother-offspring pairs, leading to reduced genetic diversity and reproductive potential. The study's findings have significant implications for the conservation of small marine mammals.