1
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Balseiro A, Herrero-García G, García Marín JF, Balsera R, Monasterio JM, Cubero D, de Pedro G, Oleaga Á, García-Rodríguez A, Espinoza I, Rabanal B, Aduriz G, Tuñón J, Gortázar C, Royo LJ. New threats in the recovery of large carnivores inhabiting human-modified landscapes: the case of the Cantabrian brown bear (Ursus arctos). Vet Res 2024; 55:24. [PMID: 38395920 PMCID: PMC10893660 DOI: 10.1186/s13567-024-01279-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
Understanding mortality causes is important for the conservation of endangered species, especially in small and isolated populations inhabiting anthropized landscapes where both natural and human-caused mortality may hinder the conservation of these species. We investigated the mortality causes of 53 free-ranging brown bears (Ursus arctos) found dead between 1998 and 2023 in the Cantabrian Mountains (northwestern Spain), a highly human-modified region where bears are currently recovering after being critically threatened in the last century. We detected natural traumatic injuries in 52.63% and infectious diseases in 39.47% of the 38 bears for which the mortality causes were registered, with 21.05% of these cases presenting signs of both infectious diseases and traumas. More specifically, almost 30% of the bears died during or after intraspecific fights, including sexually selected infanticide (10.53%). In addition, primary infectious diseases such as infectious canine hepatitis, distemper, clostridiosis and colibacillosis caused the death of 15.79% of the bears. The number of direct human-caused deaths (i.e., shooting, poisoning, snare) decreased over the study period. This study also reveals three new mortality causes triggered by pathogens, two of which-Clostridium novyi and verotoxigenic Escherichia coli-not previously described in ursids, and the other one, canine distemper virus, never reported in brown bears as cause of death. New management strategies for the conservation of Cantabrian bears, which are urgently needed due to the rapid expansion of the population, should consider the mortality causes described in this study and must promote further research to elucidate how the high prevalence of infectious diseases may threaten the current recovery of the population.
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Affiliation(s)
- Ana Balseiro
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24071, León, Spain.
| | - Gloria Herrero-García
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24071, León, Spain
| | | | - Ramón Balsera
- Dirección General de Medio Natural y Planificación Rural del Principado de Asturias, 33007, Oviedo, Asturias, Spain
| | - Juana María Monasterio
- Dirección General de Medio Natural y Planificación Rural del Principado de Asturias, 33007, Oviedo, Asturias, Spain
| | - David Cubero
- Dirección General de Patrimonio Natural y Política Forestal de La Junta de Castilla y León, 47014, Valladolid, Castilla y León, Spain
| | - Gabriel de Pedro
- Dirección General de Patrimonio Natural y Política Forestal de La Junta de Castilla y León, 47014, Valladolid, Castilla y León, Spain
| | - Álvaro Oleaga
- Sociedad de Servicios del Principado de Asturias S.A. (SERPA), La Laboral, 33203, Gijón, Spain
| | - Alberto García-Rodríguez
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24071, León, Spain
| | - Israel Espinoza
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24071, León, Spain
| | - Benjamín Rabanal
- Laboratorio de Técnicas Instrumentales, Facultad de Veterinaria, Universidad de León, 24071, León, Spain
| | - Gorka Aduriz
- Departamento de Sanidad Animal, NEIKER-Instituto Vasco de Investigación y Desarrollo Agrario, 48160, Derio (Bizkaia), Spain
| | - José Tuñón
- Fundación Oso de Asturias, 33114, Proaza, Asturias, Spain
| | | | - Luis José Royo
- Departamento de Biología Funcional, Genética, Universidad de Oviedo, 33006, Oviedo, Spain
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2
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Penteriani V, Hartasánchez A, García JD, Magadan Ruitiña JR, Mar Delgado MD. Brown bear body patches are temporally stable and represent a unique individual visual signature. URSUS 2023. [DOI: 10.2192/ursus-d-22-00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Vincenzo Penteriani
- National Museum of Natural Sciences (MNCN), Department of Evolutionary Ecology, Spanish National Research Council (CSIC), c/José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - Alfonso Hartasánchez
- FAPAS Fondo para la Protección de los Animales Salvajes, Ctra. AS-228, km 8.9 – Tuñón, 33115 Santo Adriano, Asturias, Spain
| | - Juan Díaz García
- Consejería de Ordenación del Territorio, Infraestructuras y Medio Ambiente, Dirección General de Biodiversidad, Principado de Asturias, 33000 Oviedo, Spain
| | - José Ramón Magadan Ruitiña
- FAPAS Fondo para la Protección de los Animales Salvajes, Ctra. AS-228, km 8.9 – Tuñón, 33115 Santo Adriano, Asturias, Spain
| | - María del Mar Delgado
- Biodiversity Research Institute (IMIB, CSIC-UO-PA), Mieres Campus, 33600 Mieres, Spain
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3
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Shimozuru M, Jimbo M, Adachi K, Kawamura K, Shirane Y, Umemura Y, Ishinazaka T, Nakanishi M, Kiyonari M, Yamanaka M, Amagai Y, Ijuin A, Sakiyama T, Kasai S, Nose T, Shirayanagi M, Tsuruga H, Mano T, Tsubota T, Fukasawa K, Uno H. Estimation of breeding population size using DNA-based pedigree reconstruction in brown bears. Ecol Evol 2022; 12:e9246. [PMID: 36091344 PMCID: PMC9448969 DOI: 10.1002/ece3.9246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 07/18/2022] [Accepted: 07/27/2022] [Indexed: 11/11/2022] Open
Abstract
Robust estimates of demographic parameters are critical for effective wildlife conservation and management but are difficult to obtain for elusive species. We estimated the breeding and adult population sizes, as well as the minimum population size, in a high-density brown bear population on the Shiretoko Peninsula, in Hokkaido, Japan, using DNA-based pedigree reconstruction. A total of 1288 individuals, collected in and around the Shiretoko Peninsula between 1998 and 2020, were genotyped at 21 microsatellite loci. Among them, 499 individuals were identified by intensive genetic sampling conducted in two consecutive years (2019 and 2020) mainly by noninvasive methods (e.g., hair and fecal DNA). Among them, both parents were assigned for 330 bears, and either maternity or paternity was assigned to 47 and 76 individuals, respectively. The subsequent pedigree reconstruction indicated a range of breeding and adult (≥4 years old) population sizes: 128-173 for female breeders and 66-91 male breeders, and 155-200 for female adults and 84-109 male adults. The minimum population size was estimated to be 449 (252 females and 197 males) in 2019. Long-term continuous genetic sampling prior to a short-term intensive survey would enable parentage to be identified in a population with a high probability, thus enabling reliable estimates of breeding population size for elusive species.
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Affiliation(s)
- Michito Shimozuru
- Laboratory of Wildlife Biology and Medicine, Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
| | - Mina Jimbo
- Laboratory of Wildlife Biology and Medicine, Faculty of Veterinary Medicine Hokkaido University Sapporo Japan.,Hokkaido Research Organization Sapporo Japan
| | - Keisuke Adachi
- Laboratory of Wildlife Biology and Medicine, Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
| | - Kei Kawamura
- Laboratory of Wildlife Biology and Medicine, Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
| | - Yuri Shirane
- Laboratory of Wildlife Biology and Medicine, Faculty of Veterinary Medicine Hokkaido University Sapporo Japan.,Hokkaido Research Organization Sapporo Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Toshio Tsubota
- Laboratory of Wildlife Biology and Medicine, Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
| | - Keita Fukasawa
- Center for Environmental Biology and Ecosystem Studies National Institute for Environmental Studies Tsukuba Japan
| | - Hiroyuki Uno
- Faculty of Agriculture Tokyo University of Agriculture and Technology Tokyo Japan
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4
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Kawamura K, Jimbo M, Adachi K, Shirane Y, Nakanishi M, Umemura Y, Ishinazaka T, Uno H, Sashika M, Tsubota T, Shimozuru M. Diel and monthly activity pattern of brown bears and sika deer in the Shiretoko Peninsula, Hokkaido, Japan. J Vet Med Sci 2022; 84:1146-1156. [PMID: 35811130 PMCID: PMC9412065 DOI: 10.1292/jvms.21-0665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mammals exhibit several types of diel activity pattern, including nocturnal, diurnal,
crepuscular, and cathemeral. These patterns vary inter- and intra-specifically and are
affected by environmental factors, individual status, and interactions with other
individuals or species. Determining the factors that shape diel activity patterns is
challenging but essential for understanding the behavioral ecology of animal species, and
for wildlife conservation and management. Using camera-trap surveys, we investigated the
species distributions and activity patterns of terrestrial mammals on the Shiretoko
Peninsula, Hokkaido, Japan, with particular focus on brown bears and sika deer. From June
to October 2019, a total of 7,530 observations were recorded by 65 camera-traps for eight
species, including two alien species. The diel activity pattern of brown bears was
diurnal/crepuscular, similar to that of bears in North America, but different from
European populations. Bear observations were more frequent during the autumnal hyperphagia
period, and adult females and sub-adults were more diurnal than adult males. In addition,
bears inside the protected area were more diurnal than those outside it. These findings
suggest that appetite motivation, competitive interactions between conspecifics, and human
activities potentially affect bear activity patterns. Similar to other sika deer
populations and other deer species, the diel activity patterns of sika deer were
crepuscular. Deer showed less variation in activity patterns among months and sex-age
classes, while adult males were observed more frequently during the autumn copulation
period, suggesting that reproductive motivation affects their activity patterns.
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Affiliation(s)
- Kei Kawamura
- Faculty of Veterinary Medicine, Hokkaido University
| | - Mina Jimbo
- Faculty of Veterinary Medicine, Hokkaido University
| | | | - Yuri Shirane
- Faculty of Veterinary Medicine, Hokkaido University.,Hokkaido Research Organization
| | | | | | | | - Hiroyuki Uno
- Institute of Agriculture, Tokyo University of Agriculture and Technology
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5
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Jimbo M, Ishinazaka T, Shirane Y, Umemura Y, Yamanaka M, Uno H, Sashika M, Tsubota T, Shimozuru M. Diet selection and asocial learning: Natal habitat influence on lifelong foraging strategies in solitary large mammals. Ecosphere 2022. [DOI: 10.1002/ecs2.4105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Mina Jimbo
- Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
| | | | - Yuri Shirane
- Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
- Hokkaido Research Organization Sapporo Japan
| | | | | | - Hiroyuki Uno
- Faculty of Agriculture Tokyo University of Agriculture and Technology Tokyo Japan
| | - Mariko Sashika
- Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
| | - Toshio Tsubota
- Faculty of Veterinary Medicine Hokkaido University Sapporo Japan
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6
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Multispecies facial detection for individual identification of wildlife: a case study across ursids. Mamm Biol 2022; 102:921-933. [PMID: 36164481 PMCID: PMC9499902 DOI: 10.1007/s42991-021-00168-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 08/06/2021] [Indexed: 01/31/2023]
Abstract
To address biodiversity decline in the era of big data, replicable methods of data processing are needed. Automated methods of individual identification (ID) via computer vision are valuable in conservation research and wildlife management. Rapid and systematic methods of image processing and analysis are fundamental to an ever-growing need for effective conservation research and practice. Bears (ursids) are an interesting test system for examining computer vision techniques for wildlife, as they have variable facial morphology, variable presence of individual markings, and are challenging to research and monitor. We leveraged existing imagery of bears living under human care to develop a multispecies bear face detector, a critical part of individual ID pipelines. We compared its performance across species and on a pre-existing wild brown bear Ursus arctos dataset (BearID), to examine the robustness of convolutional neural networks trained on animals under human care. Using the multispecies bear face detector and retrained sub-applications of BearID, we prototyped an end-to-end individual ID pipeline for the declining Andean bear Tremarctos ornatus. Our multispecies face detector had an average precision of 0.91-1.00 across all eight bear species, was transferable to images of wild brown bears (AP = 0.93), and correctly identified individual Andean bears in 86% of test images. These preliminary results indicate that a multispecies-trained network can detect faces of a single species sufficiently to achieve high-performance individual classification, which could speed-up the transferability and application of automated individual ID to a wider range of taxa. Supplementary Information The online version contains supplementary material available at 10.1007/s42991-021-00168-5.
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7
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Naganuma T, Tanaka M, Tezuka S, M.J.G. Steyaert S, Tochigi K, Inagaki A, Myojo H, Yamazaki K, Koike S. Animal-borne video systems provide insight into the reproductive behavior of the Asian black bear. Ecol Evol 2021; 11:9182-9190. [PMID: 34306614 PMCID: PMC8293739 DOI: 10.1002/ece3.7722] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 11/18/2022] Open
Abstract
Previous studies on the mating system of the Asian black bear (Ursus thibetanus) have been limited to observations of captive populations and estimations of multiple paternities. Hence, the mating system of wild bears remains poorly understood. Animal-borne camera systems (i.e., cameras mounted on animals) provide novel tools to study the behavior of elusive animals. Here, we used an animal-borne video system to record the activities of wild bears during the mating season. Video camera collars were attached to four adult Asian black bears (male "A" and "B," and female "A" and "B") captured in Tokyo, central Japan, in May and June 2018. The collars were retrieved in July 2018, after which the video data were downloaded and analyzed in terms of bear activity and mating behavior. All the bears were found to interact with other uniquely identifiable bears for some of the time (range 9-22 days) during the deployment period (range 36-45 days), and multiple mating in males was documented. Both males and females exhibited different behaviors on social days (i.e., days when the bear interacted with conspecifics) compared with solitary days (i.e., days with no observed interactions with conspecifics). Compared with solitary days, the bears spent a lower proportion of time on foraging activities and higher proportion of time on resting activities on social days. Our results suggest that Asian black bears have a polygamous mating system, as both sexes consort and potentially mate with multiple partners during a given mating season. Furthermore, bears appeared to reduce their foraging activities on social days and engaged more in social interactions.
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Affiliation(s)
- Tomoko Naganuma
- Institute of Global Innovation ResearchTokyo University of Agriculture and TechnologyFuchuJapan
| | - Mii Tanaka
- Faculty of AgricultureTokyo University of Agriculture and TechnologyFuchuJapan
| | - Shiori Tezuka
- Faculty of AgricultureTokyo University of Agriculture and TechnologyFuchuJapan
| | | | - Kahoko Tochigi
- United Graduate School of Agricultural ScienceTokyo University of Agriculture and TechnologyFuchuJapan
| | - Akino Inagaki
- United Graduate School of Agricultural ScienceTokyo University of Agriculture and TechnologyFuchuJapan
| | - Hiroaki Myojo
- United Graduate School of Agricultural ScienceTokyo University of Agriculture and TechnologyFuchuJapan
| | - Koji Yamazaki
- Department of Forest ScienceFaculty of Regional Environmental ScienceTokyo University of AgricultureSetagayaJapan
| | - Shinsuke Koike
- Institute of Global Innovation ResearchTokyo University of Agriculture and TechnologyFuchuJapan
- Institute of AgricultureTokyo University of Agriculture and TechnologyFuchuJapan
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8
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Shirane Y, Jimbo M, Yamanaka M, Nakanishi M, Mori F, Ishinazaka T, Sashika M, Tsubota T, Shimozuru M. Dining from the coast to the summit: Salmon and pine nuts determine the summer body condition of female brown bears on the Shiretoko Peninsula. Ecol Evol 2021; 11:5204-5219. [PMID: 34026001 PMCID: PMC8131783 DOI: 10.1002/ece3.7410] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/06/2021] [Accepted: 02/18/2021] [Indexed: 11/10/2022] Open
Abstract
Body condition in mammals fluctuates depending on energy intake and expenditure. For brown bears (Ursus arctos), high-protein foods facilitate efficient mass gain, while lipids and carbohydrates play important roles in adjusting dietary protein content to optimal levels to maximize energy intake. On the Shiretoko Peninsula, Hokkaido, Japan, brown bears have seasonal access to high-lipid pine nuts and high-protein salmon. To assess seasonal and annual fluctuation in the body condition of adult female brown bears in relation to diet and reproductive status, we conducted a longitudinal study in a special wildlife protection area on the Shiretoko Peninsula during 2012-2018. First, analyses of 2,079 bear scats revealed that pine nuts accounted for 39.8% of energy intake in August and salmon accounted for 46.1% in September and that their consumption by bears varied annually. Second, we calculated the ratio of torso height to torso length as an index of body condition from 1,226 photographs of 12 adult females. Results indicated that body condition continued to decline until late August and started to increase in September when salmon consumption increased. In addition, body condition began to recover earlier in years when consumption of both pine nuts and salmon was high. Furthermore, females with offspring had poorer body condition than solitary females, in particular in late August in years with low salmon consumption. Our findings suggest that coastal and subalpine foods, which are unique to the Shiretoko Peninsula, determine the summer body condition of female brown bears, as well as their survival and reproductive success.
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Affiliation(s)
- Yuri Shirane
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | - Mina Jimbo
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | | | | | - Fumihiko Mori
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | | | - Mariko Sashika
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | - Toshio Tsubota
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | - Michito Shimozuru
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
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9
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Maternal human habituation enhances sons' risk of human-caused mortality in a large carnivore, brown bears. Sci Rep 2020; 10:16498. [PMID: 33020503 PMCID: PMC7536428 DOI: 10.1038/s41598-020-73057-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/11/2020] [Indexed: 01/06/2023] Open
Abstract
Human habituation of large carnivores is becoming a serious problem that generates human-wildlife conflict, which often results in the removal of animals as nuisances. Although never tested, human habituation potentially reduces the fitness of adult females by reducing their offspring's survival as well as their own, due to an increased likelihood of human-caused mortality. Here, we tested this hypothesis in brown bears inhabiting Shiretoko National Park, Japan. We estimated the frequency of human-caused mortality of independent young (aged 1-4 years) born to mothers living in areas with different maternal levels of human habituation and different proximities to areas of human activity. The overall mortality rate was higher in males than in females, and in females living near a town than those in a remote area of park. Surprisingly, more than 70% of males born to highly habituated mothers living around a remote wildlife protection area were killed by humans; this proportion is greater than that for males born to less-habituated mothers living in almost the same area. The current study clarified that interactions among maternal human habituation, birthplace (proximity to town), age, and sex determine the likelihood of human-caused mortality of brown bears at an early stage of life.
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10
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Shirane Y, Mori F, Yamanaka M, Nakanishi M, Ishinazaka T, Mano T, Jimbo M, Sashika M, Tsubota T, Shimozuru M. Development of a noninvasive photograph-based method for the evaluation of body condition in free-ranging brown bears. PeerJ 2020; 8:e9982. [PMID: 32999770 PMCID: PMC7505064 DOI: 10.7717/peerj.9982] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/27/2020] [Indexed: 11/20/2022] Open
Abstract
Body condition is an important determinant of health, and its evaluation has practical applications for the conservation and management of mammals. We developed a noninvasive method that uses photographs to assess the body condition of free-ranging brown bears (Ursus arctos) in the Shiretoko Peninsula, Hokkaido, Japan. First, we weighed and measured 476 bears captured during 1998–2017 and calculated their body condition index (BCI) based on residuals from the regression of body mass against body length. BCI showed seasonal changes and was lower in spring and summer than in autumn. The torso height:body length ratio was strongly correlated with BCI, which suggests that it can be used as an indicator of body condition. Second, we examined the precision of photograph-based measurements using an identifiable bear in the Rusha area, a special wildlife protection area on the peninsula. A total of 220 lateral photographs of this bear were taken September 24–26, 2017, and classified according to bear posture. The torso height:body/torso length ratio was calculated with four measurement methods and compared among bear postures in the photographs. The results showed torso height:horizontal torso length (TH:HTL) to be the indicator that could be applied to photographs of the most diverse postures, and its coefficient of variation for measurements was <5%. In addition, when analyzing photographs of this bear taken from June to October during 2016–2018, TH:HTL was significantly higher in autumn than in spring/summer, which indicates that this ratio reflects seasonal changes in body condition in wild bears. Third, we calculated BCI from actual measurements of seven females captured in the Rusha area and TH:HTL from photographs of the same individuals. We found a significant positive relationship between TH:HTL and BCI, which suggests that the body condition of brown bears can be estimated with high accuracy based on photographs. Our simple and accurate method is useful for monitoring bear body condition repeatedly over the years and contributes to further investigation of the relationships among body condition, food habits, and reproductive success.
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Affiliation(s)
- Yuri Shirane
- Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Fumihiko Mori
- Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | | | | | | | - Tsutomu Mano
- Hokkaido Research Organization, Sapporo, Hokkaido, Japan
| | - Mina Jimbo
- Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Mariko Sashika
- Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Toshio Tsubota
- Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Michito Shimozuru
- Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
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11
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Shimozuru M, Shirane Y, Tsuruga H, Yamanaka M, Nakanishi M, Ishinazaka T, Kasai S, Nose T, Masuda Y, Fujimoto Y, Mano T, Tsubota T. Incidence of Multiple Paternity and Inbreeding in High-Density Brown Bear Populations on the Shiretoko Peninsula, Hokkaido, Japan. J Hered 2020; 110:321-331. [PMID: 30629255 DOI: 10.1093/jhered/esz002] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/09/2019] [Indexed: 11/15/2022] Open
Abstract
Understanding the breeding ecology of a species is essential for the appropriate conservation and management of wildlife. In brown bears, females occasionally copulate with multiple males in one breeding season, which may lead to multiple paternity in a single litter. In contrast, inbreeding, a potential factor in the reduction of genetic diversity, may occur, particularly in threatened populations. However, few studies have reported the frequency of these phenomena in brown bear populations. Here, we investigated the incidence of multiple paternity and inbreeding in a high-density brown bear population on the Shiretoko Peninsula in Hokkaido, Japan. A total of 837 individuals collected from 1998 to 2017 were genotyped at 21 microsatellite loci, and parentage analysis was performed. Out of 70-82 litters with ≥2 offspring, 14.6-17.1% of litters were sired by multiple males. This was comparable to the rate reported in a Scandinavian population, although population density and litter size, factors that potentially affect the incidence of multiple paternity, differed between the 2 populations. Out of 222 mother-father mating pairs, 6 litters (2.7%) resulted from matings between fathers and daughters. Additionally, 1 (0.5%) and 4 (1.8%) cases of mating between maternal half-siblings and between paternal half-siblings, respectively, were observed; however, no cases of mating between mothers and sons or between full siblings were observed. Our results suggest that male-biased natal dispersal effectively limits mating between closely related individuals (aside from fathers and daughters) in brown bears.
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Affiliation(s)
- Michito Shimozuru
- The Laboratory of Wildlife Biology and Medicine, Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Yuri Shirane
- The Laboratory of Wildlife Biology and Medicine, Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Hifumi Tsuruga
- Hokkaido Research Organization, Sapporo, Hokkaido, Japan
| | | | | | | | | | - Takane Nose
- Shiretoko Nature Foundation, Shari, Hokkaido, Japan
| | | | - Yasushi Fujimoto
- The South Shiretoko Brown Bear Information Center, Shibetsu, Hokkaido, Japan
| | - Tsutomu Mano
- Hokkaido Research Organization, Sapporo, Hokkaido, Japan
| | - Toshio Tsubota
- The Laboratory of Wildlife Biology and Medicine, Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
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12
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Shimozuru M, Shirane Y, Jimbo M, Yamanaka M, Nakanishi M, Ishinazaka T, Kasai S, Nose T, Fujimoto Y, Tsuruga H, Mano T, Tsubota T. Male reproductive input, breeding tenure, and turnover in high-density brown bear (Ursus arctos yesoensis) populations on the Shiretoko Peninsula, Hokkaido, Japan. CAN J ZOOL 2020. [DOI: 10.1139/cjz-2019-0061] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Male reproductive behavior has not been thoroughly investigated in large, non-social mammals. We studied male reproductive input using field observations and microsatellite DNA data for the brown bear (Ursus arctos yesoensis Lydekker, 1897) population in a special wildlife protection area on the Shiretoko Peninsula in Hokkaido, Japan. We identified the father of 82 offspring born between 2006 and 2018 from 54 litters produced by 20 females and revealed that they were sired by a total of 19 males. Overall, paternity was distributed relatively evenly among different males, although litter production tended to be skewed to a few bears in some years. Male breeding tenure varied among individuals, but most tenures were within the range of 1 to 6 years. Human-caused mortality, mostly occurring near human residential areas, induced male turnover, indicating that the special wildlife protection area located in the inner part of the Shiretoko Peninsula is not free from human impact. The frequency of successful reproduction was highest in 10- to 14-year-old bears, which is consistent with the period when males reach physical maturity. These results contribute to an understanding of breeding systems in large solitary mammals and to appropriate conservation and management strategies for brown bear populations.
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Affiliation(s)
- Michito Shimozuru
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Yuri Shirane
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Mina Jimbo
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Masami Yamanaka
- Shiretoko Nature Foundation, 531 Iwaubetsu, Shari, Hokkaido 099-4356, Japan
| | - Masanao Nakanishi
- Shiretoko Nature Foundation, 531 Iwaubetsu, Shari, Hokkaido 099-4356, Japan
| | | | - Shinsuke Kasai
- Shiretoko Nature Foundation, 531 Iwaubetsu, Shari, Hokkaido 099-4356, Japan
| | - Takane Nose
- Shiretoko Nature Foundation, 531 Iwaubetsu, Shari, Hokkaido 099-4356, Japan
| | - Yasushi Fujimoto
- South Shiretoko Brown Bear Information Center, 2-1 Minami 5 Higashi 1, Shibetsu, Hokkaido 086-1655, Japan
| | - Hifumi Tsuruga
- Hokkaido Research Organization, Kita 19 Nishi 11, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Tsutomu Mano
- Hokkaido Research Organization, Kita 19 Nishi 11, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Toshio Tsubota
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
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Shirane Y, Shimozuru M, Yamanaka M, Tsuruga H, Nakanishi M, Ishinazaka T, Nose T, Kasai S, Shirayanagi M, Masuda Y, Fujimoto Y, Mano T, Sashika M, Tsubota T. Sex-biased dispersal and inbreeding avoidance in Hokkaido brown bears. J Mammal 2019. [DOI: 10.1093/jmammal/gyz097] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AbstractNatal dispersal likely plays an important role in avoiding inbreeding among large carnivores. We tested the hypothesis that male-biased dispersal reduces close inbreeding by limiting the spatial overlap of opposite-sex pairs of close relatives in brown bears (Ursus arctos) in the Shiretoko Peninsula, Hokkaido, Japan. We genotyped 837 individuals collected in 1998–2017 at 21 microsatellite loci and performed parentage analysis. To calculate natal dispersal distance, we considered the site where the mother was identified as the birthplace of her offspring, and the site where the offspring were identified as their dispersed place. As predicted, we found that dispersal distances were significantly greater for males (12.4 km ± 1.0) than for females (7.7 km ± 0.9), and those for males increased from 3 years old, indicating that males begin to disperse around the time sexual maturation begins. Relatedness decreased with distance among pairs of females, and the mean relatedness was significantly higher between pairs of females than between pairs of males or between female–male pairs within 3 km. Closely related female–male pairs rarely (5–6%) resided in close proximity (< 3 km), compared with pairs of closely related females. Our study revealed that the potential for close inbreeding was low in Hokkaido brown bears because males are effective dispersers.
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Affiliation(s)
- Yuri Shirane
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido, Japan
| | - Michito Shimozuru
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido, Japan
| | - Masami Yamanaka
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido, Japan
| | - Hifumi Tsuruga
- Hokkaido Research Organization, Kita, Kita-ku, Sapporo, Hokkaido, Japan
| | | | | | | | - Shinsuke Kasai
- Shiretoko Nature Foundation, Iwaubetsu, Shari, Hokkaido, Japan
| | | | - Yasushi Masuda
- Shiretoko Nature Foundation, Iwaubetsu, Shari, Hokkaido, Japan
- Shari Town Office, 12 Hon-machi, Shari, Hokkaido, Japan
| | - Yasushi Fujimoto
- South Shiretoko Brown Bear Information Center, Shibetsu, Hokkaido, Japan
| | - Tsutomu Mano
- Hokkaido Research Organization, Kita, Kita-ku, Sapporo, Hokkaido, Japan
| | | | - Toshio Tsubota
- Department of Environmental Veterinary Science, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido, Japan
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14
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Shirane Y, Shimozuru M, Yamanaka M, Tsuruga H, Hirano S, Nagano N, Moriwaki J, Nakanishi M, Ishinazaka T, Nose T, Kasai S, Shirayanagi M, Masuda Y, Fujimoto Y, Osada M, Akaishi M, Mano T, Masuda R, Sashika M, Tsubota T. Sex-biased natal dispersal in Hokkaido brown bears revealed through mitochondrial DNA analysis. EUR J WILDLIFE RES 2018. [DOI: 10.1007/s10344-018-1222-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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15
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Penteriani V, Zarzo-Arias A, Bombieri G, Cañedo D, Díaz García J, Delgado MM, Peón Torre P, Fernández Otero M, Vázquez García P, Vázquez VM, Sánchez Corominas T. Density and reproductive characteristics of female brown bears in the Cantabrian Mountains, NW Spain. THE EUROPEAN ZOOLOGICAL JOURNAL 2018. [DOI: 10.1080/24750263.2018.1499826] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- V. Penteriani
- Pyrenean Institute of Ecology (IPE), CSIC, Zaragoza, Spain
- Research Unit of Biodiversity (UMIB, UO-CSIC-PA), Oviedo University, Mieres, Spain
| | - A. Zarzo-Arias
- Research Unit of Biodiversity (UMIB, UO-CSIC-PA), Oviedo University, Mieres, Spain
| | - G. Bombieri
- Research Unit of Biodiversity (UMIB, UO-CSIC-PA), Oviedo University, Mieres, Spain
| | - D. Cañedo
- Consejería de Ordenación del Territorio, Infraestructuras y Medio Ambiente, Dirección General de Biodiversidad, Principado de Asturias, Oviedo, Spain
| | - J. Díaz García
- Consejería de Ordenación del Territorio, Infraestructuras y Medio Ambiente, Dirección General de Biodiversidad, Principado de Asturias, Oviedo, Spain
| | - M. M. Delgado
- Research Unit of Biodiversity (UMIB, UO-CSIC-PA), Oviedo University, Mieres, Spain
| | - P. Peón Torre
- Consejería de Ordenación del Territorio, Infraestructuras y Medio Ambiente, Dirección General de Biodiversidad, Principado de Asturias, Oviedo, Spain
| | - M. Fernández Otero
- Consejería de Ordenación del Territorio, Infraestructuras y Medio Ambiente, Dirección General de Biodiversidad, Principado de Asturias, Oviedo, Spain
| | - P. Vázquez García
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universidad de Valencia, Valencia, Spain
| | - V. M. Vázquez
- Consejería de Ordenación del Territorio, Infraestructuras y Medio Ambiente, Dirección General de Biodiversidad, Principado de Asturias, Oviedo, Spain
- Real Instituto de Estudios Asturianos (RIDEA), Oviedo, Spain
| | - T. Sánchez Corominas
- Consejería de Ordenación del Territorio, Infraestructuras y Medio Ambiente, Dirección General de Biodiversidad, Principado de Asturias, Oviedo, Spain
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