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":"48 1","pages":"181 - 190"},"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":"48 1","pages":"145 - 157"},"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":"48 1","pages":"215 - 217"},"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":"48 1","pages":"131 - 135"},"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}
Abstract. The Ryukyu long-furred rat Diplothrix legata is endemic to the central Ryukyus and is the largest arboreal murid in Japan. This species is listed as ‘Endangered’ in the IUCN Red List. Invasive mammalian carnivores have been recorded as predators of this species; however, information on native predators is limited. We observed a juvenile Ryukyu long-furred rat caught by a jungle crow Corvus macrorhynchos connectens in a nesting tree cavity. Our observations suggest that jungle crows may be among the top predators in this area. On the same night on which the predation was observed, adult Ryukyu long-furred rats carried juveniles away from the tree cavity. It is possible that the adult individual left their nest and moved to other sites to avoid further predation. Abstract in Japanese（要旨）． リュウキュウハシブトガラスによるケナガネズミの幼獣の捕食と巣の移動事例． ケナガネズミは中琉球の固有種で，日本で最大の樹上性ネズミ類であり，IUCN Red List で Endangered（EN） に指定されている．本種の捕食者としては，外来食肉目が記録されているが，在来捕食者の情報は少ない．我々 はケナガネズミの営巣樹洞において，リュウキュウハシブトガラスによるケナガネズミの幼獣の捕獲を記録 した．ハシブトガラスが本地域の生態系の中で，上位捕食者として位置する可能性が示唆された．また，同 日夜，ケナガネズミの成獣が残った幼獣を 1 頭ずつくわえて樹洞から出ていった．幼獣の捕食回避のために 巣の移動をした可能性がある
Abstract. The Ryukyu long-furred rat Diplothrix legata is endemic to The central Ryukyus and is Thelargest arboreal murid in Japan. This species is listed as“Endangered”in the IUCN Red List.Invasive mammalian carnivores have been recorded as predators of this species;however,information on native predators is limited. We observed a juvenile Ryukyu long-furred rat caught byjungle crow Corvus macrorhynchos connectens in a nesting tree cavity. Our observations suggestthat jungle crows may be among the top predators in this area. On the same night On which the提前was observedadult Ryukyu long-furred rats carried juveniles away from the tree cavity. It is possible that theadult individual left their nest and moved to other sites to avoid further predation. Abstract inJapanese(摘要).流羽玻璃对幼兽毛鼠的捕食和巢穴移动的事例。毛长鼠是中琉球的特有种，是日本最大的树上性鼠类，被IUCN Red List指定为Endangered (EN)。外来食肉目被记录为本物种的捕食者，而本地捕食者的信息很少。我们在毛鼠的营巢树洞里，记录了九龙飞檐玻璃对毛鼠幼兽的捕获。这表明，飞毛腿玻璃在该地区的生态系统中，可能处于高级捕食者的位置。另外，当天晚上，一头成年毛鼠叼着一头幼兽离开了树洞。有可能是为了躲避幼兽的捕食而移动巢穴。
{"title":"A Record of Predation of a Juvenile Ryukyu Long-Furred Rat Diplothrix legata (Muridae: Rodentia) by a Jungle Crow Corvus macrorhynchos (Corvidae: Passeriformes) and Related Nest Movement","authors":"Teppei Higashi, S. Kobayashi","doi":"10.3106/ms2022-0055","DOIUrl":"https://doi.org/10.3106/ms2022-0055","url":null,"abstract":"Abstract. The Ryukyu long-furred rat Diplothrix legata is endemic to the central Ryukyus and is the largest arboreal murid in Japan. This species is listed as ‘Endangered’ in the IUCN Red List. Invasive mammalian carnivores have been recorded as predators of this species; however, information on native predators is limited. We observed a juvenile Ryukyu long-furred rat caught by a jungle crow Corvus macrorhynchos connectens in a nesting tree cavity. Our observations suggest that jungle crows may be among the top predators in this area. On the same night on which the predation was observed, adult Ryukyu long-furred rats carried juveniles away from the tree cavity. It is possible that the adult individual left their nest and moved to other sites to avoid further predation. Abstract in Japanese（要旨）． リュウキュウハシブトガラスによるケナガネズミの幼獣の捕食と巣の移動事例． ケナガネズミは中琉球の固有種で，日本で最大の樹上性ネズミ類であり，IUCN Red List で Endangered（EN） に指定されている．本種の捕食者としては，外来食肉目が記録されているが，在来捕食者の情報は少ない．我々 はケナガネズミの営巣樹洞において，リュウキュウハシブトガラスによるケナガネズミの幼獣の捕獲を記録 した．ハシブトガラスが本地域の生態系の中で，上位捕食者として位置する可能性が示唆された．また，同 日夜，ケナガネズミの成獣が残った幼獣を 1 頭ずつくわえて樹洞から出ていった．幼獣の捕食回避のために 巣の移動をした可能性がある","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":"48 1","pages":"137 - 141"},"PeriodicalIF":1.0,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44202002","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. Large carnivores utilize human areas, resulting in frequent conflict with humans. We aimed to identify the factors affecting the habitat use of leopards and sloth bears in human-dominated areas of the proposed Jawai Leopard Community Conservation Reserve, Rajasthan, western India. Within the 1 km2 grid framework, the presence of species was recorded (84 events - leopards and 71- sloth bears) and modeled using the maximum entropy algorithm concerning terrain and land-use pattern-related covariates. Also, we modeled the potential movement areas using the least-cost pathway approach. Outcomes informed that suitable habitats for leopards (126.1 km2; 40.8% of study area) were more widely distributed than sloth bears (103.7 km2; 33.5%). Models suggested that elevated-rugged hillocks were positively related to both species' habitat use, followed by scrub and water resources. Leopards showed more adaptability towards human settlements than sloth bears. Thirty potential movement pathways (between 15 core habitats) for leopards and 19 for sloth bears (between 11 core habitat nodes) were identified; out of these, 45% and 48% of pathways for leopards and sloth bears, respectively, are facing threats by the movement barriers such as railway tracks and human settlements. Conserving highly and moderately centralized pathways can be a better approach for sustainable landscape conservation in parallel.
{"title":"Roads to the Hills: Potential Space Use Patterns of Sloth Bears and Leopards in Semiarid Landscape of Western India","authors":"A. Jangid, Ravi Kumar Sharma, K. Ramesh","doi":"10.3106/ms2022-0046","DOIUrl":"https://doi.org/10.3106/ms2022-0046","url":null,"abstract":"Abstract. Large carnivores utilize human areas, resulting in frequent conflict with humans. We aimed to identify the factors affecting the habitat use of leopards and sloth bears in human-dominated areas of the proposed Jawai Leopard Community Conservation Reserve, Rajasthan, western India. Within the 1 km2 grid framework, the presence of species was recorded (84 events - leopards and 71- sloth bears) and modeled using the maximum entropy algorithm concerning terrain and land-use pattern-related covariates. Also, we modeled the potential movement areas using the least-cost pathway approach. Outcomes informed that suitable habitats for leopards (126.1 km2; 40.8% of study area) were more widely distributed than sloth bears (103.7 km2; 33.5%). Models suggested that elevated-rugged hillocks were positively related to both species' habitat use, followed by scrub and water resources. Leopards showed more adaptability towards human settlements than sloth bears. Thirty potential movement pathways (between 15 core habitats) for leopards and 19 for sloth bears (between 11 core habitat nodes) were identified; out of these, 45% and 48% of pathways for leopards and sloth bears, respectively, are facing threats by the movement barriers such as railway tracks and human settlements. Conserving highly and moderately centralized pathways can be a better approach for sustainable landscape conservation in parallel.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":"48 1","pages":"117 - 129"},"PeriodicalIF":1.0,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48757916","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. Crop damage caused by mammals is not uniformly distributed and is more localized near the forest; this damage distribution differs from that of insect pests. Species that cause damage are often forest inhabitants and hence the damage sites are also biased toward the forest edge. However, these species do not necessarily use forests as their home ranges for cover or shelter, but may be entirely urban (e.g., urban bears). Forest vegetation cannot be considered essential for these species, as this contradicts the behavior of animals that use urbanized areas only. Our review illustrates why crop damage is uneven, localized at forest edges, and less likely to occur on farmlands away from forests in terms of population density, food availability, personality, habituation, and human behavior. This review reveals the role and risk perception of human disturbances. If risk of farmland is perceived to be greater than the true risk, mammals prefer farmlands near forests with low degrees of human disturbances (perceptual trap). The current damage distribution is a result of this perceptual trap because hunting pressures are not always higher in farmlands than in forests.
{"title":"Why Mammals do Not Damage Entire Farmlands Like Insect Pests Do? A Review from a Behavioral Perspective","authors":"T. Honda, Hironori Ueda","doi":"10.3106/ms2022-0054","DOIUrl":"https://doi.org/10.3106/ms2022-0054","url":null,"abstract":"Abstract. Crop damage caused by mammals is not uniformly distributed and is more localized near the forest; this damage distribution differs from that of insect pests. Species that cause damage are often forest inhabitants and hence the damage sites are also biased toward the forest edge. However, these species do not necessarily use forests as their home ranges for cover or shelter, but may be entirely urban (e.g., urban bears). Forest vegetation cannot be considered essential for these species, as this contradicts the behavior of animals that use urbanized areas only. Our review illustrates why crop damage is uneven, localized at forest edges, and less likely to occur on farmlands away from forests in terms of population density, food availability, personality, habituation, and human behavior. This review reveals the role and risk perception of human disturbances. If risk of farmland is perceived to be greater than the true risk, mammals prefer farmlands near forests with low degrees of human disturbances (perceptual trap). The current damage distribution is a result of this perceptual trap because hunting pressures are not always higher in farmlands than in forests.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":"48 1","pages":"75 - 89"},"PeriodicalIF":1.0,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44498006","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. Agricultural damage caused by wild Japanese monkeys (Macaca fuscata) has become a serious problem in Japan. Residents have tried to protect their crop fields from monkey invasions, but the excellent physical and learning abilities of the monkeys have made the protection difficult. At present, many local governments are attempting to reduce the damage mainly through culling, but unplanned population management often results in over-culling, which consequently leads to local extinction. Here, I introduce a case study in Kami Town, Hyogo Prefecture, western Japan, in which the local government simultaneously implemented three countermeasures: 1) organizing a monkey patrol group, 2) expanding inexpensive and easy-to-use electric fences, and 3) selective capturing of problem animals. After the implementation of these countermeasures, frequency of chasing away the monkeys around crop field (a total of 319 times in 2010 compared to less than 100 times in 2017) and amount of agricultural damage (2011: 2 925 000 JPY, 2017: 876 000 JPY) decreased. These results showed that in order to decrease agricultural damage while maintaining a stable monkey population, a combination of multiple countermeasures is a good solution, and methods applied in Kami Town should also be implemented in other areas where monkeys regularly damage crops.
{"title":"Monkey Damage Management in Japan: A Case Study in Hyogo Prefecture, Western Japan","authors":"Y. Morimitsu","doi":"10.3106/ms2020-0068","DOIUrl":"https://doi.org/10.3106/ms2020-0068","url":null,"abstract":"Abstract. Agricultural damage caused by wild Japanese monkeys (Macaca fuscata) has become a serious problem in Japan. Residents have tried to protect their crop fields from monkey invasions, but the excellent physical and learning abilities of the monkeys have made the protection difficult. At present, many local governments are attempting to reduce the damage mainly through culling, but unplanned population management often results in over-culling, which consequently leads to local extinction. Here, I introduce a case study in Kami Town, Hyogo Prefecture, western Japan, in which the local government simultaneously implemented three countermeasures: 1) organizing a monkey patrol group, 2) expanding inexpensive and easy-to-use electric fences, and 3) selective capturing of problem animals. After the implementation of these countermeasures, frequency of chasing away the monkeys around crop field (a total of 319 times in 2010 compared to less than 100 times in 2017) and amount of agricultural damage (2011: 2 925 000 JPY, 2017: 876 000 JPY) decreased. These results showed that in order to decrease agricultural damage while maintaining a stable monkey population, a combination of multiple countermeasures is a good solution, and methods applied in Kami Town should also be implemented in other areas where monkeys regularly damage crops.","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":"48 1","pages":"109 - 115"},"PeriodicalIF":1.0,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49300752","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. To obtain proper estimates of wildlife abundance by harvest-based models (HBMs), an understanding of the model structure and data properties is required. Otherwise, there may be a risk of failure to obtaining adequate estimates. In this study, we estimated the abundance of sika deer using several spatially fine-scale HBMs with different structures and aimed to clarify the effects of the model structure and data quality on estimates. We used monitoring data collected by the Gifu Prefectural Government and other data collected by the authors. Four HBMs were constructed according to the combinations of the model structure (considering overdispersion in the observation models) and data (with or without additional observation data), and their parameters were estimated. The results showed that among the four HBMs, reasonable deer abundance was estimated by two HBMs in which overdispersion was considered in the observation models of the less precision data only. As the parameters failed to converge in the other two HBMs in which overdispersion was considered in all observation models, the abundance would be overestimated. Thus, our results confirmed that understanding the model structure and data properties was essential for obtaining proper estimates of wildlife abundance from currently available data with HBM. Abstract in Japanese （要旨）．ニホンジカ個体数推定のためのHarvest-based modelsにおける適切なモデル設計の検討．Harvest-based models（HBMs）を用いて野生動物の適切な個体数推定値を得るためには，モデルの構造とデータの特性を理解することが必要である．これらに対する理解が不十分な場合，適切な推定値を得られないリスクが大きくなる．本研究では，狩猟メッシュを単位とした空間解像度の高いHBMsを複数構築してニホンジカ個体数の推定を試み，モデル構造とデータの質が個体数推定値に及ぼす影響を明らかにすることを目指した．データとして，岐阜県が収集したモニタリングデータと，筆者らが収集した観測データを用いた．モデル構造（観測モデルにおける過分散の考慮の有無）とデータ（追加観測データの有無）の組み合わせにより，4つのHBMsを構築し個体数推定を試みた．その結果，4つのモデルのうち，精度の低いデータに対する観測モデルのみに過分散を設定した2つのモデルでは妥当なニホンジカ個体数が推定された．一方，すべての観測モデルで過分散を考慮した他の2つのモデルではパラメータは収束せず，また個体数推定値は過大であった．本研究の結果から，ある時点で利用可能なデータからHBMsを用いて野生動物の個体数を適切に推定するためには，モデル構造とデータの特性に対する理解が不可欠であることが確認された．
Abstract。To obtain proper estimates of wildlife abundance by harvest-based models（HBMs），an understanding of the model structure and data properties is required。Otherwise，there may be a risk of failure to obtaining adequate estimates。In this study，we estimated the abundance of sika deer using several spatially fine-scale HBMs with different structures and aimed to clarify the effets of the model structure and data quality on estimates。We used monitoring data collected by the Gifu Prefcural Government and other data collected by the authors。Four HBMs were constructed according to the combinations of the model structure（considering overdispersion in the observation models）and data（with or without additional observation data），and their parameters were estimated。The results showed that among the four HBMs，reasonable deer abundance was estimated by two HBMs in which overdispersion was considered in the observation models of the less precision data only。As the parameters failed to converge in the other two HBMs in which overdispersion was considered in all observation models，the abundance would be overestimated。Thus，our results confirmed that understanding the model structure and data properties was essential for obtaining proper estimates of wildlife abundance from currently available data with HBM。Abstract in Japan ese，在本研究中，通过构建多个以狩猎网格为单位的空间分辨率高的HBMs来尝试估计梅花鹿个体数，模型结构和数据质量对个体数估计值的影响，利用岐阜县收集的监测数据和笔者收集的观测数据。通过模型结构（观测模型中有无考虑过分散）和数据（有无追加观测数据）的组合，构建了4个HBMs，在仅对精度低的数据的观测模型设定过分散的两个模型中，估计了合理的梅花鹿个体数。另一方面，在所有观测模型中考虑过分散的其他两个模型中，参数不收敛，为了从某一时刻可用的数据中使用HBMs恰当地推定野生动物的个体数，确认了对模型结构和数据特性的理解是不可缺少的。
{"title":"Examination of the Appropriate Inference Procedure in a Model Structure for Harvest-Based Estimation of Sika Deer Abundance","authors":"M. Ando, Takashi Ikeda, H. Iijima","doi":"10.3106/ms2021-0049","DOIUrl":"https://doi.org/10.3106/ms2021-0049","url":null,"abstract":"Abstract. To obtain proper estimates of wildlife abundance by harvest-based models (HBMs), an understanding of the model structure and data properties is required. Otherwise, there may be a risk of failure to obtaining adequate estimates. In this study, we estimated the abundance of sika deer using several spatially fine-scale HBMs with different structures and aimed to clarify the effects of the model structure and data quality on estimates. We used monitoring data collected by the Gifu Prefectural Government and other data collected by the authors. Four HBMs were constructed according to the combinations of the model structure (considering overdispersion in the observation models) and data (with or without additional observation data), and their parameters were estimated. The results showed that among the four HBMs, reasonable deer abundance was estimated by two HBMs in which overdispersion was considered in the observation models of the less precision data only. As the parameters failed to converge in the other two HBMs in which overdispersion was considered in all observation models, the abundance would be overestimated. Thus, our results confirmed that understanding the model structure and data properties was essential for obtaining proper estimates of wildlife abundance from currently available data with HBM. Abstract in Japanese （要旨）．ニホンジカ個体数推定のためのHarvest-based modelsにおける適切なモデル設計の検討．Harvest-based models（HBMs）を用いて野生動物の適切な個体数推定値を得るためには，モデルの構造とデータの特性を理解することが必要である．これらに対する理解が不十分な場合，適切な推定値を得られないリスクが大きくなる．本研究では，狩猟メッシュを単位とした空間解像度の高いHBMsを複数構築してニホンジカ個体数の推定を試み，モデル構造とデータの質が個体数推定値に及ぼす影響を明らかにすることを目指した．データとして，岐阜県が収集したモニタリングデータと，筆者らが収集した観測データを用いた．モデル構造（観測モデルにおける過分散の考慮の有無）とデータ（追加観測データの有無）の組み合わせにより，4つのHBMsを構築し個体数推定を試みた．その結果，4つのモデルのうち，精度の低いデータに対する観測モデルのみに過分散を設定した2つのモデルでは妥当なニホンジカ個体数が推定された．一方，すべての観測モデルで過分散を考慮した他の2つのモデルではパラメータは収束せず，また個体数推定値は過大であった．本研究の結果から，ある時点で利用可能なデータからHBMsを用いて野生動物の個体数を適切に推定するためには，モデル構造とデータの特性に対する理解が不可欠であることが確認された．","PeriodicalId":49891,"journal":{"name":"Mammal Study","volume":"48 1","pages":"91 - 108"},"PeriodicalIF":1.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47706560","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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