Latest news with #ClaryanaAraújo-Wan
The Independent
05-02-2025
- Science
- The Independent
The weird way dolphins are peeing in the Amazon River is baffling scientists
Scientists are perplexed by a strange new behaviour shown by the Amazon river dolphin of flipping belly-up to urinate with another male 'actively' seeking the stream with its snout. The quirky dolphin, commonly known as boto, is considerably less shy than its cousin the bottlenose dolphin and often engages in playful activities. Previous studies have shown that boto is less fearful of foreign objects than other dolphin species, holding fishermen's oars and playing with sticks, clay, rocks, logs, and turtles. Now, Canadian biologists have documented dozens of instances of 'strange behaviour' by boto involving urination. 'Our study shows that while aerial urination may be rare, or rarely observed, in cetaceans, it is relatively common in botos.' They are not sure why the dolphins engage in this behaviour but suspect it may have something to do with scent marking to aid mate selection. 'We were really shocked, as it was something we had never seen before,' Claryana Araújo-Wan, co-author of the new study, told New Scientist. The study documents 36 instances of 'aerial urination' by boto between 2014 and 2018 and records the sequence, duration and social context of the behaviour. Two-thirds of the documented cases involve the presence of receiver dolphins. 'Aerial urination starts with a boto slowly positioning itself upside down, exposing its penis above water, and ejecting a stream of urine into the air,' notes the study, published in the journal Behavioural Processes. 'When a 'receiver' male is present, it either approaches the urine stream with its rostrum, sometimes pursuing it, or stays where the stream contacts the water.' Most of these events last about 10 seconds and involve males as urinators and receivers. The study theorises that bristles on the dolphin's snout may be acting as chemical sensors in detecting urine streams. The strange behaviour may be a form of communication. 'Aerial urination, often occurring in the presence of other males, serves social or communicative functions beyond the physiological need for waste elimination,' the study states. While land mammals are well known for using urine to mark territory, assert dominance and advertise their physical condition, such behaviour is far more difficult to observe in the aquatic environment. Body structures to aid in the sense of smell are also absent or greatly reduced in marine mammals like toothed whales, baleen whales and dolphins, so the use of urine for chemical communication is generally not expected. But recent studies have shown that dolphins can detect odorants and secretions in both air and water such as the components of urine and faeces. Researchers suspect the boto is using a 'quasi' smell, combining elements of touch into a 'haptic' sense that is more felt than sniffed to assess the physiological state of other members of the species. They hope for further studies to test this hypothesis. 'Understanding the behavioural context in which signals are exchanged helps contextualise the information conveyed and illuminate its potential function,' they write in the new study.
The Independent
05-02-2025
- Science
- The Independent
Scientists perplexed by strange urination routine of Amazon river dolphin
Scientists are perplexed by a strange new behaviour shown by the Amazon river dolphin of flipping belly-up to urinate with another male 'actively' seeking the stream with its snout. The quirky dolphin, commonly known as boto, is considerably less shy than its cousin the bottlenose dolphin and often engages in playful activities. Previous studies have shown that boto is less fearful of foreign objects than other dolphin species, holding fishermen's oars and playing with sticks, clay, rocks, logs, and turtles. Now, Canadian biologists have documented dozens of instances of 'strange behaviour' by boto involving urination. 'Our study shows that while aerial urination may be rare, or rarely observed, in cetaceans, it is relatively common in botos.' They are not sure why the dolphins engage in this behaviour but suspect it may have something to do with scent marking to aid mate selection. 'We were really shocked, as it was something we had never seen before,' Claryana Araújo-Wan, co-author of the new study, told New Scientist. The study documents 36 instances of 'aerial urination' by boto between 2014 and 2018 and records the sequence, duration and social context of the behaviour. Two-thirds of the documented cases involve the presence of receiver dolphins. 'Aerial urination starts with a boto slowly positioning itself upside down, exposing its penis above water, and ejecting a stream of urine into the air,' notes the study, published in the journal Behavioural Processes. 'When a 'receiver' male is present, it either approaches the urine stream with its rostrum, sometimes pursuing it, or stays where the stream contacts the water.' Most of these events last about 10 seconds and involve males as urinators and receivers. The study theorises that bristles on the dolphin's snout may be acting as chemical sensors in detecting urine streams. The strange behaviour may be a form of communication. 'Aerial urination, often occurring in the presence of other males, serves social or communicative functions beyond the physiological need for waste elimination,' the study states. While land mammals are well known for using urine to mark territory, assert dominance and advertise their physical condition, such behaviour is far more difficult to observe in the aquatic environment. Body structures to aid in the sense of smell are also absent or greatly reduced in marine mammals like toothed whales, baleen whales and dolphins, so the use of urine for chemical communication is generally not expected. But recent studies have shown that dolphins can detect odorants and secretions in both air and water such as the components of urine and faeces. Researchers suspect the boto is using a 'quasi' smell, combining elements of touch into a 'haptic' sense that is more felt than sniffed to assess the physiological state of other members of the species. They hope for further studies to test this hypothesis.
Yahoo
05-02-2025
- Science
- Yahoo
Scientists perplexed by strange urination routine of Amazon river dolphin
Scientists are perplexed by a strange new behaviour shown by the Amazon river dolphin of flipping belly-up to piss with another male 'actively' seeking the urine stream with its snout. The quirky dolphin, commonly known as boto, is considerably less shy than its cousin the bottlenose dolphin and often engages in playful activities. Previous studies have shown that boto is less fearful of foreign objects than other dolphin species, holding fishermen's oars and playing with sticks, clay, rocks, logs, and turtles. Now, Canadian biologists have documented dozens of instances of 'strange behaviour' by boto involving urination. 'Our study shows that while aerial urination may be rare, or rarely observed, in cetaceans, it is relatively common in botos.' They are not sure why the dolphins engage in this behaviour but suspect it may have something to do with scent marking to aid mate selection. 'We were really shocked, as it was something we had never seen before,' Claryana Araújo-Wan, co-author of the new study, told New Scientist. The study documents 36 instances of 'aerial urination' by boto between 2014 and 2018 and records the sequence, duration and social context of the behaviour. Two-thirds of the documented cases involve the presence of receiver dolphins. 'Aerial urination starts with a boto slowly positioning itself upside down, exposing its penis above water, and ejecting a stream of urine into the air,' notes the study, published in the journal Behavioural Processes. 'When a 'receiver' male is present, it either approaches the urine stream with its rostrum, sometimes pursuing it, or stays where the stream contacts the water.' Most of these events last about 10 seconds and involve males as urinators and receivers. The study theorises that bristles on the dolphin's snout may be acting as chemical sensors in detecting urine streams. The strange behaviour may be a form of communication. 'Aerial urination, often occurring in the presence of other males, serves social or communicative functions beyond the physiological need for waste elimination,' the study states. While land mammals are well known for using urine to mark territory, assert dominance and advertise their physical condition, such behaviour is far more difficult to observe in the aquatic environment. Body structures to aid in the sense of smell are also absent or greatly reduced in marine mammals like toothed whales, baleen whales and dolphins, so the use of urine for chemical communication is generally not expected. But recent studies have shown that dolphins can detect odorants and secretions in both air and water such as the components of urine and faeces. Researchers suspect the boto is using a 'quasi' smell, combining elements of touch into a 'haptic' sense that is more felt than sniffed to assess the physiological state of other members of the species. They hope for further studies to test this hypothesis. 'Understanding the behavioural context in which signals are exchanged helps contextualise the information conveyed and illuminate its potential function,' they write in the new study.
Yahoo
31-01-2025
- Science
- Yahoo
Male Amazon river dolphins pee into the air, confusing scientists
Researchers say they have made a startling discovery in the Amazon River. But their evidence wasn't collected from the water—it could be seen from shore. After around 219 hours of observations, they can confirm that male Amazon river dolphins (Inia geoffrensis), also known as botos, often roll onto their backs and urinate over three feet into the air. It isn't random. The male botos appear to be peeing with a purpose. Over four years, a team from Canada's CetAsia Research Group traveled to the Amazon river, where they then closely watched river dolphin social interactions. Researchers documented a total of 36 separate instances of male botos deciding to pee while floating in the unconventional position. The findings, presented in a recent study published in the journal Behavioural Processes, support rare, anecdotal stories of past boto behavior. 'Aerial urination starts with a boto slowly positioning itself upside down, exposing its penis above water, and ejecting a stream of urine into the air,' the team explained in their study. What's more, another male dolphin was swimming nearby about two-thirds of the time, and often approached the urine stream as it landed in the water about three feet away. They sometimes waited in place, but in other instances, they even pursued the pee trajectory using their snout, or rostrum.'We were really shocked, as it was something we had never seen before,' study author Claryana Araújo-Wan recounted to New Scientist on January 31st. Urine is a common communication tool used by many terrestrial animals such as dogs, bears, and cats. It's seen far less frequently in aquatic environments, but Araújo-Wan and their colleagues offered a few examples in their study. Dominant male African cichlid fish (Astatotilapia burtoni) interpret urine pulses for both reproductive and territorial information. The narrow-clawed crayfish (Astacus leptodactylus), meanwhile, urinates as a sign of aggression. In both of these cases, however, it's more about the act of peeing than what is actually in the pee itself. This makes the boto behavior all the more interesting, according to researchers. Dolphins lack a strong sense of both smell and taste, so it's still somewhat unclear how they are interpreting the urine streams. The study's authors hypothesized that the male Amazon river dolphins may rely on their rostrum bristles to interpret their fellow boto's urine composition, such as hormonal content indicating physical health and social position. A previous study from a team at Stephen F. Austin State University in Texas confirmed bottlenose dolphins (Tursiops truncates) use their tongues to identify other cetaceans through the taste of their urine. Knowing this, it's also possible that botos in the Amazon may engage in similar activities. But all that still doesn't explain why the botos are firing pee streams into the air. Researchers conceded that 'aerial urination likely serves a social function beyond waste elimination,' but stopped short of landing on any definitive reason beyond possible 'social or communicative functions.' Given their heightened ability to sense acoustical signals, it may be that the aerial urine alerts dolphins to check it out as it hits the water. Regardless of the actual reason, confirming the unique behavior among Amazon river dolphins now opens up the possibility for future study. With more time—and more pee—researchers may eventually learn much more about the aquatic mammal's complex social dynamics.
