Background:As the major load-bearing structures,bones exhibit various properties related to mechanical perfor-mance to adapt to different locomotor intensities.The habits and ontogenetic changes of locomotion in anima...Background:As the major load-bearing structures,bones exhibit various properties related to mechanical perfor-mance to adapt to different locomotor intensities.The habits and ontogenetic changes of locomotion in animals can,thus,be explored by assessing skeletal mechanical performance.Methods:In this study,we investigated the growing femoral mechanical performance in an ontogenetic series of Cabot’s Tragopans(Tragopan caboti)and Pigeons(Columba livia domestica).Micro-computed tomography-based finite element analysis was conducted to evaluate the stress,strain,and strain energy density(SED)of femora under axial and radial loading.Results:Femora deflected medio-laterally and dorso-ventrally under axial and radial loading,respectively.Femora deformed and tensed more severely under radial loading than axial loading.In adult individuals,Cabot’s Tragopans had lower strain and SED than pigeons.During ontogeny,the strain and SED of pigeons decreased sharply,while Cabot’s Tragopans showed moderately change.The structural properties of hatchling pigeons are more robust than those of hatchling Cabot’s Tragopans.Conclusions:Limb postures have dominant effect on skeletal deformation.The erect posture is preferred by large mammals and birds to achieve a high safety factor of bones during locomotion.Adult Cabot’s Tragopans have stronger femora than pigeons,reflecting a better bone adaption to the terrestrial locomotion of the studied pheas-ant species.Changes in strain and SED during growth reflect the marked difference in locomotor ability between precocial and altricial hatchlings.The femora of hatchling Cabot’s Tragopans were built with better energy efficiency than deformation resistance,enabling optimized mechanical performance.In contrast,although weak in mechani-cal function at the time of hatching,pigeon femora were suggested to be established with a more mature structural design as a prerequisite for rapid growth.These results will be helpful for studies regarding developmental patterns of fossil avian spec展开更多
Reintroduction of captive-bred animals into suitable habitats is an important technique for the long-term conservation and recovery of populations of endangered species in fragmented landscapes.Inbreeding depression i...Reintroduction of captive-bred animals into suitable habitats is an important technique for the long-term conservation and recovery of populations of endangered species in fragmented landscapes.Inbreeding depression is an inherent risk when using captive populations for reintroduction programs and needs to be carefully assessed prior to reintroduction.In this study,we evaluated inbreeding levels within a captive breeding program and one remnant wild population of Cabot's Tragopan (Tragopan caboti),an endangered pheasant species endemic to China,for which reintroduction is now an essential conservation strategy for long-term population persistence.Fifteen highly polymorphic microsatellite loci were developed to genotype individuals.Inbreeding coefficients (FIS) reveal that there is no evidence of inbreeding within the Tragopan Breeding Center of Beijing Normal University (TBCBNU) captive population and the remnant population from the Wuyi-Yandang Mountains.Diversity of origin,large founder population size and a rational breeding strategy are the most critical factors preventing inbreeding depression within the TBCBNU captive population.We suggest that the TBCBNU population is a suitable candidate stock for T.caboti reintroduction programs and that there is an urgent need to better coordinate and strengthen reproduction management of captive T.caboti populations to sustain the long-term ex situ conservation of the species.展开更多
The hindlimbs play a crucial role in bird locomotion,making the biomechanical properties of the musculoskeletal system in these limbs a focal point for researchers studying avian behaviour.However,a comprehensive anal...The hindlimbs play a crucial role in bird locomotion,making the biomechanical properties of the musculoskeletal system in these limbs a focal point for researchers studying avian behaviour.However,a comprehensive analysis of the mechanical performance within the long bones of hindlimbs during locomotion remains lacking.In the present study,the strain and deformation of the femur of Cabot’s Tragopans(Tragopan caboti)were estimated.We employed inverse simulation to calculate the force and moment of femoral muscles during mid-stance terrestrial locomotion and conducted finite element analysis to calculate femoral strain.Results showed that during mid-stance,the femur experiences combined deformation primarily characterized by torsion,bending,and compression.It emphasises the importance of considering the influence of varying loads on bone adaptation when investigating bone form-function relationships.Muscles were found to play a significant role in offsetting joint loads on the femur,subsequently reducing the deformation and overall strain on the bone.This reduction enhances femoral safety during locomotion,allowing birds to meet mechanical demands while maintaining a lightweight bone structure.Notably,the M.iliotrochantericus caudalis significantly reduces torsional deformation of the proximal femur,protecting the vulnerable femoral neck from high fracture risk induced by rotation load.Given that the femur torsion during terrestrial locomotion in birds is associated with changes in hindlimb posture due to their adaptation to flight,the characteristics of M.iliotrochantericus caudalis may provide insight into the locomotor evolution of theropods and the origin of avian flight.展开更多
The Western tragopan(Tragopan melanocephalus)is recorded in the IUCN Red List of 2017 as a vulnerable bird species in Pakistan.This study provides valuable information for the conservation of Western tragopan,which is...The Western tragopan(Tragopan melanocephalus)is recorded in the IUCN Red List of 2017 as a vulnerable bird species in Pakistan.This study provides valuable information for the conservation of Western tragopan,which is a globally threatened avian flagship species in Pakistan.This study was conducted to investigate and resolve the conservation challenges surrounding the species in two major habitat zones-Salkhala Game Reserve and Machiara National Park.The study was implemented in May-June 2020 for population density using call count data.Also,questionnaire was used for local residents’perceptions and habitat suitability modeling map was generated using the MaxEnt model based on previously recorded occurrence points as well as recorded in the survey.A total of 26 western Tragopans were identified by call count during the sampling period.Moreover,about 77.3%cited Western Tragopan they more likely to hunt while the remaining 22.6%locals recorded other pheasant.About 45.3%of this hunting for fun but only 22%for economic values and only 3%of people consider hunting as a part of their culture.Results of modeling habitat suitability of the Western tragopan showed that the species suitable habitats are small and patchy in Pakistan.We found that the Normalized Difference Vegetation Index(NDVI)with 40.6 percent contribution was the most important variable in shaping the species distribution.Our model identified some new suitable patches which can be the target of future field monitoring for finding new populations of the species and future conservation planning.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.31471951).
文摘Background:As the major load-bearing structures,bones exhibit various properties related to mechanical perfor-mance to adapt to different locomotor intensities.The habits and ontogenetic changes of locomotion in animals can,thus,be explored by assessing skeletal mechanical performance.Methods:In this study,we investigated the growing femoral mechanical performance in an ontogenetic series of Cabot’s Tragopans(Tragopan caboti)and Pigeons(Columba livia domestica).Micro-computed tomography-based finite element analysis was conducted to evaluate the stress,strain,and strain energy density(SED)of femora under axial and radial loading.Results:Femora deflected medio-laterally and dorso-ventrally under axial and radial loading,respectively.Femora deformed and tensed more severely under radial loading than axial loading.In adult individuals,Cabot’s Tragopans had lower strain and SED than pigeons.During ontogeny,the strain and SED of pigeons decreased sharply,while Cabot’s Tragopans showed moderately change.The structural properties of hatchling pigeons are more robust than those of hatchling Cabot’s Tragopans.Conclusions:Limb postures have dominant effect on skeletal deformation.The erect posture is preferred by large mammals and birds to achieve a high safety factor of bones during locomotion.Adult Cabot’s Tragopans have stronger femora than pigeons,reflecting a better bone adaption to the terrestrial locomotion of the studied pheas-ant species.Changes in strain and SED during growth reflect the marked difference in locomotor ability between precocial and altricial hatchlings.The femora of hatchling Cabot’s Tragopans were built with better energy efficiency than deformation resistance,enabling optimized mechanical performance.In contrast,although weak in mechani-cal function at the time of hatching,pigeon femora were suggested to be established with a more mature structural design as a prerequisite for rapid growth.These results will be helpful for studies regarding developmental patterns of fossil avian spec
文摘Cabot’s Tragopan (Tragopan caboti) (Galliformes: Phasianidae) is one of the endemic pheasant species in China. It is categorized as Vulnerable in the
基金supported by the National Key Technology R & D Program of China (No. 2008BAC39B05)the National Natural Science Foundation of China (No. 30670289)
文摘Reintroduction of captive-bred animals into suitable habitats is an important technique for the long-term conservation and recovery of populations of endangered species in fragmented landscapes.Inbreeding depression is an inherent risk when using captive populations for reintroduction programs and needs to be carefully assessed prior to reintroduction.In this study,we evaluated inbreeding levels within a captive breeding program and one remnant wild population of Cabot's Tragopan (Tragopan caboti),an endangered pheasant species endemic to China,for which reintroduction is now an essential conservation strategy for long-term population persistence.Fifteen highly polymorphic microsatellite loci were developed to genotype individuals.Inbreeding coefficients (FIS) reveal that there is no evidence of inbreeding within the Tragopan Breeding Center of Beijing Normal University (TBCBNU) captive population and the remnant population from the Wuyi-Yandang Mountains.Diversity of origin,large founder population size and a rational breeding strategy are the most critical factors preventing inbreeding depression within the TBCBNU captive population.We suggest that the TBCBNU population is a suitable candidate stock for T.caboti reintroduction programs and that there is an urgent need to better coordinate and strengthen reproduction management of captive T.caboti populations to sustain the long-term ex situ conservation of the species.
基金supported by the National Natural Science Foundation of China(No.31471951,No.31970411).
文摘The hindlimbs play a crucial role in bird locomotion,making the biomechanical properties of the musculoskeletal system in these limbs a focal point for researchers studying avian behaviour.However,a comprehensive analysis of the mechanical performance within the long bones of hindlimbs during locomotion remains lacking.In the present study,the strain and deformation of the femur of Cabot’s Tragopans(Tragopan caboti)were estimated.We employed inverse simulation to calculate the force and moment of femoral muscles during mid-stance terrestrial locomotion and conducted finite element analysis to calculate femoral strain.Results showed that during mid-stance,the femur experiences combined deformation primarily characterized by torsion,bending,and compression.It emphasises the importance of considering the influence of varying loads on bone adaptation when investigating bone form-function relationships.Muscles were found to play a significant role in offsetting joint loads on the femur,subsequently reducing the deformation and overall strain on the bone.This reduction enhances femoral safety during locomotion,allowing birds to meet mechanical demands while maintaining a lightweight bone structure.Notably,the M.iliotrochantericus caudalis significantly reduces torsional deformation of the proximal femur,protecting the vulnerable femoral neck from high fracture risk induced by rotation load.Given that the femur torsion during terrestrial locomotion in birds is associated with changes in hindlimb posture due to their adaptation to flight,the characteristics of M.iliotrochantericus caudalis may provide insight into the locomotor evolution of theropods and the origin of avian flight.
文摘The Western tragopan(Tragopan melanocephalus)is recorded in the IUCN Red List of 2017 as a vulnerable bird species in Pakistan.This study provides valuable information for the conservation of Western tragopan,which is a globally threatened avian flagship species in Pakistan.This study was conducted to investigate and resolve the conservation challenges surrounding the species in two major habitat zones-Salkhala Game Reserve and Machiara National Park.The study was implemented in May-June 2020 for population density using call count data.Also,questionnaire was used for local residents’perceptions and habitat suitability modeling map was generated using the MaxEnt model based on previously recorded occurrence points as well as recorded in the survey.A total of 26 western Tragopans were identified by call count during the sampling period.Moreover,about 77.3%cited Western Tragopan they more likely to hunt while the remaining 22.6%locals recorded other pheasant.About 45.3%of this hunting for fun but only 22%for economic values and only 3%of people consider hunting as a part of their culture.Results of modeling habitat suitability of the Western tragopan showed that the species suitable habitats are small and patchy in Pakistan.We found that the Normalized Difference Vegetation Index(NDVI)with 40.6 percent contribution was the most important variable in shaping the species distribution.Our model identified some new suitable patches which can be the target of future field monitoring for finding new populations of the species and future conservation planning.
