Abstract. Understanding the behavior and ecology of non-native species is important to assess their impact on food webs and ecosystem functions and to facilitate the management of non-native species. The present study reports a case of scavenging on a deer carcass by mammals, especially introduced raccoon dogs and native Japanese weasels, in the World Heritage Site of Yakushima, Japan. A sensor camera was placed near the carcass from March to May 2022 to record scavenging behavior of mammals. Out of at least six species of mammals filmed, raccoon dogs and weasels fed on the carcass. Raccoon dogs almost monopolized the carcass, i.e., raccoon dogs were filmed around carrion more frequently and spent more time scavenging than weasels. Raccoon dogs and weasels were filmed around the carcass at similar times in a day, and no overt aggression was observed between the two species, but weasels were displaced by raccoon dogs. Japanese macaques and sika deer avoided and never fed on carrion. The present study suggests that raccoon dogs contribute to carrion decomposition in the World Heritage Site of Yakushima and that comprehensive studies of carrion availability and the scavenger community could help promote the management of introduced raccoon dogs in Yakushima.
{"title":"Scavenging on a Carcass of Sika Deer by Introduced Raccoon Dogs (Nyctereutes procyonoides) in Spring: A Case Report in the World Heritage Site of Yakushima Island, Japan","authors":"Yosuke Kurihara","doi":"10.3106/ms2023-0004","DOIUrl":"https://doi.org/10.3106/ms2023-0004","url":null,"abstract":"Abstract. Understanding the behavior and ecology of non-native species is important to assess their impact on food webs and ecosystem functions and to facilitate the management of non-native species. The present study reports a case of scavenging on a deer carcass by mammals, especially introduced raccoon dogs and native Japanese weasels, in the World Heritage Site of Yakushima, Japan. A sensor camera was placed near the carcass from March to May 2022 to record scavenging behavior of mammals. Out of at least six species of mammals filmed, raccoon dogs and weasels fed on the carcass. Raccoon dogs almost monopolized the carcass, i.e., raccoon dogs were filmed around carrion more frequently and spent more time scavenging than weasels. Raccoon dogs and weasels were filmed around the carcass at similar times in a day, and no overt aggression was observed between the two species, but weasels were displaced by raccoon dogs. Japanese macaques and sika deer avoided and never fed on carrion. The present study suggests that raccoon dogs contribute to carrion decomposition in the World Heritage Site of Yakushima and that comprehensive studies of carrion availability and the scavenger community could help promote the management of introduced raccoon dogs in Yakushima.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44210833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Persistent use of the Mayurjharna forest by elephants led to its declaration as “Mayurjharna Elephant Reserve (ER)” in 2002; however, the usage changed over time. We describe the elephant movement pattern and the quality forage availability in the Mayurjharna ER. We collected past and current sightings of elephants from people and records of the Forest Department and constructed the range used from 1950 to 2018. Initially, the range of elephants in the reserve was ∼80 km2 in 1950–1959 that increased to ∼572 km2 by 1990–1999 but later decreased to ∼152 km2 in 2010–2018. The high human settlements, alteration, and overexploitation of the forest might lead the elephants to the rich agricultural lands outside the reserve, making the reserve just a gateway for elephants to move to other parts of the South Bengal landscape.
{"title":"Mayurjharna Elephant Reserve is Just a Gateway for Elephants: Changes in the Range Use Pattern by Asian Elephants Over Seven Decades","authors":"Aakriti Singh, H. N. Kumara, Santanu Mahato","doi":"10.3106/ms2023-0026","DOIUrl":"https://doi.org/10.3106/ms2023-0026","url":null,"abstract":"Abstract. Persistent use of the Mayurjharna forest by elephants led to its declaration as “Mayurjharna Elephant Reserve (ER)” in 2002; however, the usage changed over time. We describe the elephant movement pattern and the quality forage availability in the Mayurjharna ER. We collected past and current sightings of elephants from people and records of the Forest Department and constructed the range used from 1950 to 2018. Initially, the range of elephants in the reserve was ∼80 km2 in 1950–1959 that increased to ∼572 km2 by 1990–1999 but later decreased to ∼152 km2 in 2010–2018. The high human settlements, alteration, and overexploitation of the forest might lead the elephants to the rich agricultural lands outside the reserve, making the reserve just a gateway for elephants to move to other parts of the South Bengal landscape.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48821935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. We examined the food habits of raccoon dogs (Nyctereutes procyonoides) at an urban high school in Saitama, Japan. The study place is surrounded by residential areas but is adjacent to a pond. Fecal samples (n = 126) were collected from January to December 2022 and analyzed using the point frame method. Fecal composition was diverse in winter, including leaves, fruits, seeds, and artificial materials. In spring, the proportion of Japanese toads (Bufo japonicus formosus) and insects increased, whereas in summer, proportion of hackberry (Celtis sinensis) fruits, insects, and red swamp crayfish (Procambarus clarkii) increased. In autumn, fruits of hackberry and muku tree (Aphananthe aspera) were predominant. Consumption of toads and swamp crayfish suggests that the raccoon dogs are opportunistic feeders. We recovered seeds from only ten species, including fruits from five wild plants; these numbers were lower than those reported previously in rural areas of the same district, where raspberries (Rubus spp.), mulberries (Morus spp.), and Eurya japonica have often been recovered at great proportions. A wide range of artificial materials were recovered but in low quantities. These results reflect the characteristics of the study area, which is an urbanized environment with limited trees and adjacent to a pond.
{"title":"Seasonal Changes in the Diet of Urban Raccoon Dogs in Saitama, Eastern Japan","authors":"S. Takatsuki, Kunio Kobayashi","doi":"10.3106/ms2023-0001","DOIUrl":"https://doi.org/10.3106/ms2023-0001","url":null,"abstract":"Abstract. We examined the food habits of raccoon dogs (Nyctereutes procyonoides) at an urban high school in Saitama, Japan. The study place is surrounded by residential areas but is adjacent to a pond. Fecal samples (n = 126) were collected from January to December 2022 and analyzed using the point frame method. Fecal composition was diverse in winter, including leaves, fruits, seeds, and artificial materials. In spring, the proportion of Japanese toads (Bufo japonicus formosus) and insects increased, whereas in summer, proportion of hackberry (Celtis sinensis) fruits, insects, and red swamp crayfish (Procambarus clarkii) increased. In autumn, fruits of hackberry and muku tree (Aphananthe aspera) were predominant. Consumption of toads and swamp crayfish suggests that the raccoon dogs are opportunistic feeders. We recovered seeds from only ten species, including fruits from five wild plants; these numbers were lower than those reported previously in rural areas of the same district, where raspberries (Rubus spp.), mulberries (Morus spp.), and Eurya japonica have often been recovered at great proportions. A wide range of artificial materials were recovered but in low quantities. These results reflect the characteristics of the study area, which is an urbanized environment with limited trees and adjacent to a pond.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41253702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takashi Ikeda, D. Higashide, Takaaki Suzuki, M. Asano
Abstract. Wild boars can cause crop damage and are vectors causing infectious diseases. Thus, population management is essential to mitigate the damage. Because home range and habitat selection is important for the management of target species, accurate spatial data would provide valuable information to establish population management scheme. In this study, we investigated the home range and habitat selection of wild boars and aimed to help implement effective population management. We captured seven wild boars in central Gifu Prefecture, Japan, and monitored each individual from October 2020 to June 2022. We calculated the home range size and investigated environmental characteristics during daytime and nighttime. The home range sizes estimated from the minimum convex polygon method ranged from 0.32 to 28.51 km2. Moreover, wild boars avoided anthropogenic environments during the daytime and selectively used areas in the cropland category during the nighttime. Therefore, wild boars had narrow home ranges depending on the anthropogenic environments. Consequently, wildlife managers could reduce agricultural damage caused by wild boars by managing bamboo forests and abandoned cultivated lands in the rural landscape. For infectious diseases, moreover, they should implement countermeasures against wild boars around areas where infectious diseases are endemic.
{"title":"Home Range and Habitat Selection of Wild Boar (Sus scrofa) in Rural Landscape","authors":"Takashi Ikeda, D. Higashide, Takaaki Suzuki, M. Asano","doi":"10.3106/ms2022-0057","DOIUrl":"https://doi.org/10.3106/ms2022-0057","url":null,"abstract":"Abstract. Wild boars can cause crop damage and are vectors causing infectious diseases. Thus, population management is essential to mitigate the damage. Because home range and habitat selection is important for the management of target species, accurate spatial data would provide valuable information to establish population management scheme. In this study, we investigated the home range and habitat selection of wild boars and aimed to help implement effective population management. We captured seven wild boars in central Gifu Prefecture, Japan, and monitored each individual from October 2020 to June 2022. We calculated the home range size and investigated environmental characteristics during daytime and nighttime. The home range sizes estimated from the minimum convex polygon method ranged from 0.32 to 28.51 km2. Moreover, wild boars avoided anthropogenic environments during the daytime and selectively used areas in the cropland category during the nighttime. Therefore, wild boars had narrow home ranges depending on the anthropogenic environments. Consequently, wildlife managers could reduce agricultural damage caused by wild boars by managing bamboo forests and abandoned cultivated lands in the rural landscape. For infectious diseases, moreover, they should implement countermeasures against wild boars around areas where infectious diseases are endemic.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46115588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Sociosexual behavior is not directly related to reproduction. It is observed between mature and immature individuals of both sexes and interactions can be between mixed- or same-sex individuals. This behavior may have important social functions. We observed and recorded the sociosexual behavior of wild Indo-Pacific bottlenose dolphins (Tursiops aduncus), underwater off Mikura Island, Japan, with regards to erection and mounting. This behavior was observed mainly between mothers and sons and in groups of subadult males (age 1–13 years). In subadult males, mounting behavior toward one passive individual from two or more individuals playing an active role, occurred in most cases. This behavior involving three or more participants has rarely been observed in other animal species, except for bowhead whales (Balaena mysticetus), common bottlenose dolphins (T. truncatus), and beluga whales (Delphinapterus leucas). Sociosexual behavior in the Mikura Island dolphins may not be agonistic because individuals in the passive role did not try to escape from the individuals playing the active role. Further studies on sociosexual behavior T. aduncus could reveal the social functions of this behavior, such as younger animals practicing mating behaviors required as adults and developing their relationships for when they are adults.
{"title":"Observations and Detailed Descriptions of Sociosexual Behavior in Wild Indo-Pacific Bottlenose Dolphins (Tursiops aduncus)","authors":"Aoi Miyanishi, Mai Sakai, Kazunobu Kogi","doi":"10.3106/ms2022-0006","DOIUrl":"https://doi.org/10.3106/ms2022-0006","url":null,"abstract":"Abstract. Sociosexual behavior is not directly related to reproduction. It is observed between mature and immature individuals of both sexes and interactions can be between mixed- or same-sex individuals. This behavior may have important social functions. We observed and recorded the sociosexual behavior of wild Indo-Pacific bottlenose dolphins (Tursiops aduncus), underwater off Mikura Island, Japan, with regards to erection and mounting. This behavior was observed mainly between mothers and sons and in groups of subadult males (age 1–13 years). In subadult males, mounting behavior toward one passive individual from two or more individuals playing an active role, occurred in most cases. This behavior involving three or more participants has rarely been observed in other animal species, except for bowhead whales (Balaena mysticetus), common bottlenose dolphins (T. truncatus), and beluga whales (Delphinapterus leucas). Sociosexual behavior in the Mikura Island dolphins may not be agonistic because individuals in the passive role did not try to escape from the individuals playing the active role. Further studies on sociosexual behavior T. aduncus could reveal the social functions of this behavior, such as younger animals practicing mating behaviors required as adults and developing their relationships for when they are adults.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44873066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Lim, So Hyeon Han, Ki Yoon Kim, Sungwon Hong, Y. Park
Abstract. In Jangsudae of Seoraksan National Park, South Korea, 14 mammal species have been listed, including ten medium- and large-sized species; additionally, this region is an important habitat for the endangered long-tailed goral (Naemorhedus caudatus). In this study, a camera trap survey was conducted over 103 monitoring days at 18 sites in Jangsudae to evaluate the minimum trapping effort (MTE) needed to detect the ten listed mammal species. The most photographed species were the long-tailed goral, wild boar (Sus scrofa), and Asian badger (Meles leucurus), accounting for 77.1% (n = 366) of the total independent photographs. Long-tailed goral, the most frequently captured mammal species (44.8%), was captured at 17 camera sites (relative abundance index = 206.8). According to the rarefaction analysis, 1840 camera days (102.2 monitoring days at 18 camera sites) were required to photograph all ten resident species. Moreover, at least 1010 and 664 camera days were required to detect 95% and 90% of the ten residential species, respectively. MTE was evaluated in summer when wild species were highly detectable owing to their high activity. Future studies should evaluate MTE through one-year long-term monitoring that includes all four seasons, and compare the results with those of this study.
{"title":"Relative Abundance of Mammals and Estimation of Minimum Trapping Effort Using Camera Traps in Jangsudae, Seoraksan National Park","authors":"S. Lim, So Hyeon Han, Ki Yoon Kim, Sungwon Hong, Y. Park","doi":"10.3106/ms2022-0035","DOIUrl":"https://doi.org/10.3106/ms2022-0035","url":null,"abstract":"Abstract. In Jangsudae of Seoraksan National Park, South Korea, 14 mammal species have been listed, including ten medium- and large-sized species; additionally, this region is an important habitat for the endangered long-tailed goral (Naemorhedus caudatus). In this study, a camera trap survey was conducted over 103 monitoring days at 18 sites in Jangsudae to evaluate the minimum trapping effort (MTE) needed to detect the ten listed mammal species. The most photographed species were the long-tailed goral, wild boar (Sus scrofa), and Asian badger (Meles leucurus), accounting for 77.1% (n = 366) of the total independent photographs. Long-tailed goral, the most frequently captured mammal species (44.8%), was captured at 17 camera sites (relative abundance index = 206.8). According to the rarefaction analysis, 1840 camera days (102.2 monitoring days at 18 camera sites) were required to photograph all ten resident species. Moreover, at least 1010 and 664 camera days were required to detect 95% and 90% of the ten residential species, respectively. MTE was evaluated in summer when wild species were highly detectable owing to their high activity. Future studies should evaluate MTE through one-year long-term monitoring that includes all four seasons, and compare the results with those of this study.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45881146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shun Ishikawa, Shuhma Kohno, Yoshitaka Mizuno, Ryo Masuyama, K. Kitayama, T. Hino
Abstract. The purpose of this study was to examine the influences of seasonal and annual changes in weather conditions, natural food abundance (pine seeds), and the spacing of feeders on the use of walnuts on feeding tables by Japanese squirrels (Sciurus lis) in a suburban forest in Nagoya City, in summer (Jul–Aug) and autumn (Sep–Oct) from 2019 to 2021. Feeder-use increased in severe weather conditions, i.e., low temperature and heavy rain in both seasons, and decreased in summer of the year when pine-seeds were abundant. Feeders were used more in autumn for hoarding before the winter. The intervals among eight feeding tables were widened during the study from c. 100 m in 2019–2020 to c. 300 m in 2021. In the years when the feeders were placed at short intervals, we found two behavioral modifications due to the supplemental feeding: a concentrated distribution of many individuals in 2019 and exclusive occupation by a particular female in 2020. In contrast, in 2021 with the feeding tables placed at wider intervals, the distribution of individuals expanded over the entire study area, and the use of supplementary feeding decreased, while seed consumption increased.
{"title":"Influences of Weather Conditions, Natural Food Abundance, and the Spacing of Feeders on the Feeding-Table Use by Japanese Squirrels Sciurus lis in a Suburban Forest","authors":"Shun Ishikawa, Shuhma Kohno, Yoshitaka Mizuno, Ryo Masuyama, K. Kitayama, T. Hino","doi":"10.3106/ms2022-0028","DOIUrl":"https://doi.org/10.3106/ms2022-0028","url":null,"abstract":"Abstract. The purpose of this study was to examine the influences of seasonal and annual changes in weather conditions, natural food abundance (pine seeds), and the spacing of feeders on the use of walnuts on feeding tables by Japanese squirrels (Sciurus lis) in a suburban forest in Nagoya City, in summer (Jul–Aug) and autumn (Sep–Oct) from 2019 to 2021. Feeder-use increased in severe weather conditions, i.e., low temperature and heavy rain in both seasons, and decreased in summer of the year when pine-seeds were abundant. Feeders were used more in autumn for hoarding before the winter. The intervals among eight feeding tables were widened during the study from c. 100 m in 2019–2020 to c. 300 m in 2021. In the years when the feeders were placed at short intervals, we found two behavioral modifications due to the supplemental feeding: a concentrated distribution of many individuals in 2019 and exclusive occupation by a particular female in 2020. In contrast, in 2021 with the feeding tables placed at wider intervals, the distribution of individuals expanded over the entire study area, and the use of supplementary feeding decreased, while seed consumption increased.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45853661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seisuke Takeda, T. Oshida, M. Motokawa, S. Kawada, H. Endo
Abstract. Bovid morphologies differ depending on body size and habitat. We hypothesized that bovids also vary their mobility of fingers and toes depending on body size and habitat. In this study, we compared the shape of the distal ends of the metapodial bones and the proximal facet of the proximal phalanges to examine the metapodiophalangeal joint gaps and simulated the three-dimensional motion of the bovid metapodiophalangeal joints during the opening and closing states through CT scans to investigate whether the mobility of the finger and toe is affected by body size and habitat. The results showed that species with gaps in the metapodiophalangeal joints had higher mobility and that species living in mountains had larger gaps. This suggests that bovids living in unstable terrains can move better on unstable substrates due to their increased mobility of digit. Similarly, our results indicate that smaller bovids are more likely to display variations in the mobility of digits than larger-sized bovids since greater body size reduces the range of mobility to avoid dislocation risk. Our results show that bovids have been able to be flexible to a range of body sizes and habitats by varying the size of their metapodiophalangeal joint gaps.
{"title":"Morphology of Metapodiophalangeal Joints and Mobility of Finger and Toe in Bovids","authors":"Seisuke Takeda, T. Oshida, M. Motokawa, S. Kawada, H. Endo","doi":"10.3106/ms2022-0049","DOIUrl":"https://doi.org/10.3106/ms2022-0049","url":null,"abstract":"Abstract. Bovid morphologies differ depending on body size and habitat. We hypothesized that bovids also vary their mobility of fingers and toes depending on body size and habitat. In this study, we compared the shape of the distal ends of the metapodial bones and the proximal facet of the proximal phalanges to examine the metapodiophalangeal joint gaps and simulated the three-dimensional motion of the bovid metapodiophalangeal joints during the opening and closing states through CT scans to investigate whether the mobility of the finger and toe is affected by body size and habitat. The results showed that species with gaps in the metapodiophalangeal joints had higher mobility and that species living in mountains had larger gaps. This suggests that bovids living in unstable terrains can move better on unstable substrates due to their increased mobility of digit. Similarly, our results indicate that smaller bovids are more likely to display variations in the mobility of digits than larger-sized bovids since greater body size reduces the range of mobility to avoid dislocation risk. Our results show that bovids have been able to be flexible to a range of body sizes and habitats by varying the size of their metapodiophalangeal joint gaps.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47152119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akiko Enokizu, Tadamichi Morisaka, Kazunobu Kogi, M. Yoshioka
Abstract. Yawning is defined as an involuntary behavior with breathing, characterized by a slow opening of the mouth with inhalation, followed by a maximum gaping phase, and ending with a short exhalation and closing of the mouth. Recent reports on yawning in marine mammals (common bottlenose dolphins and a dugong) have challenged this definition because these marine mammals yawn underwater without breathing. However, yawning in marine mammals has only been studied in captive conditions, which indicates the possibility that yawning is an abnormal behavior in captive animals. Here, we report yawning in free-ranging wild Indo-Pacific bottlenose dolphins off Mikura Island, Japan. Five yawnings that occurred between 8:00 am and 10:30 am were identified from 1816 hours of video data. The dolphins in this population may exhibit more resting behaviors in the morning, which implies that yawning in this population occurred in resting states that required arousal. This is the first reported observation of yawning in Indo-Pacific bottlenose dolphins. The occurrence of yawning in a wild population suggests that it is an innate behavior, rather than abnormal behavior, in dolphins.
{"title":"Yawning in Wild Indo-Pacific Bottlenose Dolphins (Tursiops aduncus)","authors":"Akiko Enokizu, Tadamichi Morisaka, Kazunobu Kogi, M. Yoshioka","doi":"10.3106/ms2022-0060","DOIUrl":"https://doi.org/10.3106/ms2022-0060","url":null,"abstract":"Abstract. Yawning is defined as an involuntary behavior with breathing, characterized by a slow opening of the mouth with inhalation, followed by a maximum gaping phase, and ending with a short exhalation and closing of the mouth. Recent reports on yawning in marine mammals (common bottlenose dolphins and a dugong) have challenged this definition because these marine mammals yawn underwater without breathing. However, yawning in marine mammals has only been studied in captive conditions, which indicates the possibility that yawning is an abnormal behavior in captive animals. Here, we report yawning in free-ranging wild Indo-Pacific bottlenose dolphins off Mikura Island, Japan. Five yawnings that occurred between 8:00 am and 10:30 am were identified from 1816 hours of video data. The dolphins in this population may exhibit more resting behaviors in the morning, which implies that yawning in this population occurred in resting states that required arousal. This is the first reported observation of yawning in Indo-Pacific bottlenose dolphins. The occurrence of yawning in a wild population suggests that it is an innate behavior, rather than abnormal behavior, in dolphins.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41704913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. The small Japanese field mouse Apodemus argenteus is known to disperse the highly toxic seeds of the Japanese star anise Illicium anisatum (Schisandraceae); however, whether the large Japanese field mouse A. speciosus does so remains unexplored. Seeds of I. anisatum were placed in mesh cages with openings sized only for small rodents and monitored at two forest sites in Tsukuba, Ibaraki Prefecture, Japan, in autumn 2018. Any animals approaching or entering the cages were recorded by automated cameras with infrared motion sensors. Only A. speciosus was recorded entering the cages. At both sites, some seeds were consumed inside the cages or transported outside them. These results show that A. speciosus interacts with seeds of I. anisatum and is a potential agent of seed dispersal. Further study is needed to determine whether it can tolerate anisatin, the main neurotoxin in I. anisatum, and the possible tolerance mechanism.
{"title":"The Large Japanese Field Mouse (Apodemus speciosus) as a Consumer and Potential Disperser of Seeds of the Neurotoxic Japanese Star Anise (Illicium anisatum)","authors":"Tetsuro Yoshikawa","doi":"10.3106/ms2022-0042","DOIUrl":"https://doi.org/10.3106/ms2022-0042","url":null,"abstract":"Abstract. The small Japanese field mouse Apodemus argenteus is known to disperse the highly toxic seeds of the Japanese star anise Illicium anisatum (Schisandraceae); however, whether the large Japanese field mouse A. speciosus does so remains unexplored. Seeds of I. anisatum were placed in mesh cages with openings sized only for small rodents and monitored at two forest sites in Tsukuba, Ibaraki Prefecture, Japan, in autumn 2018. Any animals approaching or entering the cages were recorded by automated cameras with infrared motion sensors. Only A. speciosus was recorded entering the cages. At both sites, some seeds were consumed inside the cages or transported outside them. These results show that A. speciosus interacts with seeds of I. anisatum and is a potential agent of seed dispersal. Further study is needed to determine whether it can tolerate anisatin, the main neurotoxin in I. anisatum, and the possible tolerance mechanism.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46794543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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