Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central...Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central Asia, exerts a substantial influence on avian migration patterns. Species traversing such ecological barriers may adopt multiple optimal routes, which can contribute to the formation of migratory divides. From 2018 to 2021, the migration routes of 13 adult Common Cuckoos (Cuculus canorus) breeding in the north of the Qinghai-Tibet Plateau were tracked using satellite transmitters. We found Common Cuckoos have two primary migration routes: western and eastern, respectively following western and eastern edges of the Qinghai-Tibet plateau. The eastern and western routes are likely the optimal routes for the Central Asian Common Cuckoos population to navigate the Qinghai-Tibet Plateau. Furthermore, two individuals exhibited intermediate migration routes, suggesting attempted traverses of the Qinghai-Tibet Plateau, although neither completed the migration. These intermediate routes may indicate migratory behavior influenced by hybridization between eastern and western populations or migratory flexibility. Common Cuckoos exhibit significantly faster migration speed, flight speed, and shorter stopover durations during spring compared to autumn. The observed seasonal differences in migration behavior support birds following time-minimization strategies during spring migration. These results revealed the diverse migration routes of Common Cuckoos shaped by the Qinghai-Tibet Plateau and seasonal variation in migration patterns.展开更多
China’s continuous and rapid economic growth has led to the reclamation of large sections of the intertidal mud coast in combination with port construction,such as that of the proposed Tongzhou Bay port on the Jiangs...China’s continuous and rapid economic growth has led to the reclamation of large sections of the intertidal mud coast in combination with port construction,such as that of the proposed Tongzhou Bay port on the Jiangsu coast.These reclamations threaten the local ecosystem services.An ecotope distribution map was created and a hydrodynamic numerical model of Tongzhou Bay was set up to quantify the impacts of reclamation on the ecosystem.Based on the field data and model results,several abiotic features were classified into 11 ecotopes and visualized in an ecotope map of the Tongzhou Bay ecosystem.Validation with spatial distributions of two threatened shorebird species(bar-tailed godwit and great knot) showed confirmation with the mid-range and low-range littoral zones(inundated from 40% to 100% of a tidal cycle),indicating the importance of the areas with these conditions to these populations.Overlaying the ecotope map with recent and proposed land reclamation schemes revealed a loss of ecotopes,composed of the high-range(42%),mid-range(48%),and low-range(38%) littoral habitats,corresponding to a 44%-45% loss of the most important ecotopes for bar-tailed godwit and great knot(mid-range and low-range littoral zones).These results confirm the applicability of the novel ecotope assessment approach in practice.展开更多
China’s coastal wetlands provide breeding,migration stopover,and wintering habitats for about 230 waterbird species,which is more than a quarter of all waterbirds in the world.Large-scale and high intensity human act...China’s coastal wetlands provide breeding,migration stopover,and wintering habitats for about 230 waterbird species,which is more than a quarter of all waterbirds in the world.Large-scale and high intensity human activities have resulted in serious loss and degradation of coastal wetlands over the past half century,causing population declines in many waterbirds.Through a literature review and expert surveys,this article reviews conservation measures taken in recent decades to protect waterbirds in China’s coastal wetlands and provides recommendations for future conservation action from three aspects:policy and administration,habitat conservation and management,and multiparty participation.Over the past decades,many conservation legislation,regulations and action plans at the national level and more site-specific measures and interventions have been implemented,with notable improvement in the effectiveness in policy making and multi-stakeholder participation.Accordingly,some threats to waterbirds have been mitigated and many key sites for waterbirds have been designated as strictly protected nature reserves.However,some critical issues still remain,mostly related to habitat conservation and management,such as coastal wetland restoration,control of invasive Spartina alterniflora,control of environmental pollution,and improvement of artificial habitat quality.We highlight that protecting natural tidal wetlands and improving habitat quality are critical for the conservation of coastal waterbirds,especially those highly dependent on the intertidal wetlands.China has demonstrated strong commitment to ecological conservation and restoration for the future,in terms of both funding and policies for biodiversity and wetland ecosystems.It is important that this commitment to conserve coastal waterbirds is supported continuously by science-and evidence-based decisions and actions.展开更多
Tanzania’s Ruaha landscape is prominent for its potential wildlife resources, which play a key role in sustaining the economy and livelihoods of the people. However, most of these resources are illegally obtained and...Tanzania’s Ruaha landscape is prominent for its potential wildlife resources, which play a key role in sustaining the economy and livelihoods of the people. However, most of these resources are illegally obtained and traded in different places within and outside the Ruaha landscape. Due to its illegal nature, most of the important information regarding the trade is poorly documented. Therefore, the current study aimed first, to explore the origin and destination of wildlife products;second, to assess the relationship between hunters and buyers or customers;third, to assess the means used to transport wildlife products;and lastly, to assess who influences people to engage in illegal hunting and trade activities. In addition, we assess the materials used in the exchange of wildlife products. Semi-structured questionnaires and face-to-face interviews were used to collect information from 123 respondents. Social network analysis was used to indicate the origin and destination of wildlife products. The findings show that 70% of wildlife products originate from the Ruaha National Park and MBOMIPA wildlife management areas, with the remaining 30% originating from villages. The majority of respondents (65%) reported transporting wildlife products by foot and bicycle as the primary modes of transportation. Suppliers of wildlife products are reported to have close and long-term relationships with their customers and traders, with most of whom being friends and relatives. We found most poachers to be influenced by their friends and relatives in terms making decision to engage in illegal wildlife trade. In addition, crops like maize and rice were the most popular products used to exchange with wildlife products in the Ruaha landscape. Therefore, in order to combat illegal trade in wildlife products at the local level, alternative income-generating activities need to be promoted accompanied by not only well-funded anti-poaching programmes but also more effective surveillance plans. These should entail the use of advanced techniques and skills, such as wildlife forensics.展开更多
Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion ...Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston’s (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km<sup>2 </sup>revealed 286 lions (95% CI, 236 - 335) during the wet season, and 196 lions (95% CI, 192 - 200) during the dry season. The density of lions was 9.1/100 km<sup>2 </sup>during the wet season, and 6.3/100 km<sup>2</sup> during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on the distribution of the observed lions to call-back stations. We suggest that the proximity to water sources is important in study design. Further, we suggest that density and population size are useful indices in identifying conservation area priorities and lion coexistence strategies.展开更多
Pied Avocets(Recurvirostra avosetta)are common migratory shorebirds in the East Asian–Australasian Flyway.From 2019 to 2021,GPS/GSM transmitters were used to track 40 Pied Avocets nesting in northern Bohai Bay to ide...Pied Avocets(Recurvirostra avosetta)are common migratory shorebirds in the East Asian–Australasian Flyway.From 2019 to 2021,GPS/GSM transmitters were used to track 40 Pied Avocets nesting in northern Bohai Bay to identify annual routines and key stopover sites.On average,southward migration of Pied Avocets started on 23 October and arrived at wintering sites(mainly in the middle and lower reaches of the Yangtze River and coastal wetlands)in southern China on 22 November;northward migration started on 22 March with arrival at breeding sites on 7 April.Most avocets used the same breeding sites and wintering sites between years,with an average migration distance of 1124 km.There was no significant difference between sexes on the migration timing or distance in both northward and southward migration,except for the departure time from the wintering sites and winter distribution.The coastal wetland of Lianyungang in Jiangsu Province is a critical stopover site.Most individuals rely on Lianyungang during both northward and southward migration,indicating that species with short migration distances also heavily rely on a few stopover sites.However,Lianyungang lacks adequate protection and is facing many threats,including tidal flat loss.We strongly recommend that the coastal wetland of Lianyungang be designated as a protected area to effectively conserve the critical stopover site.展开更多
Background: Departure decisions and behaviors of migratory birds at stopover sites are expected to maximize fit?ness by trade?offs among avoiding predators, optimizing refueling(energy) capacity, and matching other li...Background: Departure decisions and behaviors of migratory birds at stopover sites are expected to maximize fit?ness by trade?offs among avoiding predators, optimizing refueling(energy) capacity, and matching other life?history events. We predict that species with different body sizes and migratory destinations will exhibit different behaviors when departing from the same stopover site. We also predict that with strong time constraint at the final pre?breed?ing stopover site, departure decisions may be less sensitive to exogenous factors, such as wind condition, compared to other stopover or nonbreeding sites.Methods: We recorded migratory departures of four shorebird species, i.e. Eurasian Curlew(Numenius arquata), Bar?tailed Godwit(Limosa lapponica), Great Knot(Calidris tenuirostris), and Grey Plover(Pluvialis squatarola), at Yaluji?ang Estuary Wetlands in China, a final pre?breeding stopover site in the northern Yellow Sea, from 2011 to 2014. We compared flock sizes, departure time and departure directions between species, and investigated the effects of tide and weather conditions(rain and ground wind speed and direction) on the departure decision of shorebirds.Results: We found that larger species departed in smaller flocks and were more variable in daily departure time. Departure trajectory of all four species appeared to be influenced by coastal topography. With the east–west coast?line and intertidal mudflat on the south, birds exhibited westward or eastward deflection from the shortest migra?tory routes. Bar?tailed Godwit was the only species that deviated to the southeast and did not climb over the land. Birds avoided departure during precipitation, while their departure was not related to ground wind benefit or tidal condition.Conclusions: Body size among species, which influences their vulnerability to predators, might be important in shaping shorebird departure strategies. Diverse departure directions could be the result of different wind use tac?tics in climbing stage. Narrow optimal time window of breeding might lead to reduced flexibility in departure date at a final pre?breeding site. Both endogenous and exogenous are important in shaping departure behaviors and decisions.展开更多
Lion populations are declining globally, including in Tanzania, and Africa. However, Katavi National Park is a landscape with potential for a sustainable and healthy population of African lions (Panthera leo), but the...Lion populations are declining globally, including in Tanzania, and Africa. However, Katavi National Park is a landscape with potential for a sustainable and healthy population of African lions (Panthera leo), but there is currently limited reliable data indicating density and population size. This hinders the development of conservation action plans, including population monitoring, for this species. To address this data gap, we assessed lions’ demography and population estimates (population size and density) in the Katavi National Park using a call-back survey method. In addition, we assessed ecological factors that influenced distribution of lions to the call-back stations. Our estimated population size revealed 84 lions (95% CI 53 - 116), with a density of 5/100 km<sup>2</sup> (95% CI 3.14 - 6.86) in the sampled area, representing 38% of the total park. This resulted in an estimated 214 individuals when extrapolated to the whole park. Sixty-seven percent of lions that responded to the stations were female, and ecological factors that significantly influenced their distribution included elevation, land cover, precipitation, temperature, wind speed, and prey abundance. Our results suggest that female lions are more abundant than males in Katavi National Park and that population size and density estimates, as well as understanding prey-lion relations, are important indices for lion monitoring and identifying conservation priorities. Further, our study suggests that the call-back survey method is an effective, rapid, and less costly population assessment method for lions, may be useful for assessing other social species in the Katavi ecosystem and can be a useful tool for community engagement and contributing to scientific monitoring.展开更多
Establishing knowledge of local communities regarding the potential health risks of illegal bushmeat hunting and its related practices is among the essential means to developing effective conservation and public healt...Establishing knowledge of local communities regarding the potential health risks of illegal bushmeat hunting and its related practices is among the essential means to developing effective conservation and public health programs. To reveal the understanding of the local people regarding the potential health risks of bushmeat consumption and handling of wildlife products, we used a semi-structured questionnaire to survey 261 households in eight villages located adjacent to the western part of Nyerere National Park. Also, we interviewed eight key informants, including conservation personnel and veterinary officers, in the study area. The proportion of local people who were unaware that handling of wildlife products and bushmeat consumption were risky behaviours towards acquiring zoonotic diseases was slightly higher (57%) than the proportion of respondents who were aware of the likely risks of zoonotic diseases from the practices. After all, the majority (83%) of local people admitted having come into contact with wildlife products, while over 70% reported having consumed bushmeat. We found that local communities living closer to the park boundaries (<15 km) have a higher likelihood of contacting wildlife products, and that community members who have lived in the area for more than ten years have experienced more contact with wildlife products than immigrants. Moreover, the age of inhabitants and length of stay were found to be the most significant factors in determining the likelihood of bushmeat consumption. Most people seemed to prefer bushmeat to domestic meat, arguing that bushmeat is far more flavorful, tender, not tainted with chemicals, and has less fat, making it safer. Our study demonstrated that local communities participate in risky practices without contemplating the health consequences that could emerge should a zoonotic disease outbreak occur. Among other strategies, we recommended conservation and public health institutions to increase awareness campaigns on the possible health risks of zoonotic diseases associated with wildlife.展开更多
The trophy hunting industry in Tanzania plays a significant role in wildlife conservation as well as economic and community development. Trophy hunting has been conducted in Rungwa Game Reserve (RGR) for several decad...The trophy hunting industry in Tanzania plays a significant role in wildlife conservation as well as economic and community development. Trophy hunting has been conducted in Rungwa Game Reserve (RGR) for several decades;however, the trophy hunting opinions from the local communities living adjacent to the reserve are not well documented. This study aimed to assess the awareness and attitudes of local communities living adjacent to Rungwa Game Reserves toward trophy hunting. Furthermore, the study assessed factors that influenced the opinions of participants by using structural equation modeling. We used semi-structured interviews and key informant interviews in the three villages adjacent to RGR. The local communities are aware of existing hunting operations around the game reserves. The study found positive attitudes among local communities toward trophy hunting, only if local people accrue benefits from hunting operations. The community’s attitudes towards trophy hunting varied across household size and occupation. Education and household position had an indirect influence on the community’s attitude. Our findings suggest that socio-demographic variables are important to consider when assessing awareness and attitudes toward trophy hunting. Local communities are willing to support trophy hunting operations if the benefits obtained from hunting are significant and it can improve wildlife conservation and their livelihood. In conclusion, trophy hunting is important to local communities living adjacent to protected areas, and banning them may have a significant impact on their livelihood and wildlife conservation. Therefore, it is recommended that conservation policies and interventions consider the dual significance of trophy hunting, fostering strategies that balance socio-economic benefits for communities and wildlife conservation.展开更多
Trophy hunting has severe consequences on wild animals’ behaviors, which in return has implications for affecting wildlife populations. The Selous Game Reserve is a protected area in Tanzania that has been subjected ...Trophy hunting has severe consequences on wild animals’ behaviors, which in return has implications for affecting wildlife populations. The Selous Game Reserve is a protected area in Tanzania that has been subjected to commercial trophy hunting for decades, and information about the effects of trophy hunting on animals’ welfare is still scarce. The Flight Initiating Distance (FID) can be a good measure to evaluate the welfare of animals and the level of risk perception towards anthropogenic disturbances, including trophy hunting. The study used linear mixed models to assess the flight responses of twelve commonly hunted species in the Selous game reserve (S.G.R.). The study compared animal vigilance between species, vegetation types, and group size. The FID varied between species, with which more vigilance was observed in zebras, elands, wildebeests, and sable antelopes. The study found a significant influence of vegetation cover on individual species’ FID. Further, the study found a significant influence of group size on animals’ vigilance (L. M. M., 95% CI = 0.590 - 4.762), in which there was a decrease in FID with an increase in group size for wildebeests. At the same time, other species, such as buffaloes, eland, hartebeests, and zebras, had their FIDs increasing with the increase in group size. We conclude that the impact of trophy hunting on savannah ungulates varies between species, vegetation covers, and group size of individual species. Regulatory authorities should consider minimum approach distances by trophy hunters in different vegetation cover to reduce animal biological disturbances.展开更多
Organic fertilization may influence soil carbon−iron(C-Fe)cycling and enhance phosphorus(P)availability,yet the direct connection between soil organic matter molecules and iron-reducing processes in long-term fertiliz...Organic fertilization may influence soil carbon−iron(C-Fe)cycling and enhance phosphorus(P)availability,yet the direct connection between soil organic matter molecules and iron-reducing processes in long-term fertilized paddy soils remains underexplored.In this study,we conducted a microcosm experiment using paddy soils treated with six distinct fertilization regimes involving varying P and organic matter inputs up to five years.We assessed P activation under reflooding conditions,evaluated Fe reduction,and characterized dissolved organic matter(DOM)at the molecular level using Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS),alongside profiling soil microbial community composition via high-throughput sequencing.Our findings revealed that after 25 days of reflooding,soil Olsen-P content increased by an average of 73%compared to its initial state,showing a strong correlation with the Fe reduction process.Specifically,treatments involving pig manure application exhibited higher Fe reduction rates and enhanced P activation,highlighting the role of organic matter in facilitating Fe reduction.Examination of Fe-reducing microorganisms revealed that their relative abundance was decoupled from Fe reduction and P release rates,potentially due to limitations of lower soil organic matter content.Further analysis of DOM composition and network structures suggested that high-molecular-weight DOM,particularly lignin,acted as key resources for Fe-reducing microbes,thereby driving Fe reduction and promoting P release.Overall,our study highlights the crucial role of soil DOM in enabling microbial-driven Fe reduction and enhancing P availability,providing insights valuable for sustainable agricultural practices.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31672296).
文摘Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central Asia, exerts a substantial influence on avian migration patterns. Species traversing such ecological barriers may adopt multiple optimal routes, which can contribute to the formation of migratory divides. From 2018 to 2021, the migration routes of 13 adult Common Cuckoos (Cuculus canorus) breeding in the north of the Qinghai-Tibet Plateau were tracked using satellite transmitters. We found Common Cuckoos have two primary migration routes: western and eastern, respectively following western and eastern edges of the Qinghai-Tibet plateau. The eastern and western routes are likely the optimal routes for the Central Asian Common Cuckoos population to navigate the Qinghai-Tibet Plateau. Furthermore, two individuals exhibited intermediate migration routes, suggesting attempted traverses of the Qinghai-Tibet Plateau, although neither completed the migration. These intermediate routes may indicate migratory behavior influenced by hybridization between eastern and western populations or migratory flexibility. Common Cuckoos exhibit significantly faster migration speed, flight speed, and shorter stopover durations during spring compared to autumn. The observed seasonal differences in migration behavior support birds following time-minimization strategies during spring migration. These results revealed the diverse migration routes of Common Cuckoos shaped by the Qinghai-Tibet Plateau and seasonal variation in migration patterns.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFC0405401)the Science and Technology Project of Traffic and Transportation in Jiangsu Province(Grant No.2017ZX01).
文摘China’s continuous and rapid economic growth has led to the reclamation of large sections of the intertidal mud coast in combination with port construction,such as that of the proposed Tongzhou Bay port on the Jiangsu coast.These reclamations threaten the local ecosystem services.An ecotope distribution map was created and a hydrodynamic numerical model of Tongzhou Bay was set up to quantify the impacts of reclamation on the ecosystem.Based on the field data and model results,several abiotic features were classified into 11 ecotopes and visualized in an ecotope map of the Tongzhou Bay ecosystem.Validation with spatial distributions of two threatened shorebird species(bar-tailed godwit and great knot) showed confirmation with the mid-range and low-range littoral zones(inundated from 40% to 100% of a tidal cycle),indicating the importance of the areas with these conditions to these populations.Overlaying the ecotope map with recent and proposed land reclamation schemes revealed a loss of ecotopes,composed of the high-range(42%),mid-range(48%),and low-range(38%) littoral habitats,corresponding to a 44%-45% loss of the most important ecotopes for bar-tailed godwit and great knot(mid-range and low-range littoral zones).These results confirm the applicability of the novel ecotope assessment approach in practice.
基金financially supported by National Key Research and Development Program of China (2022YFF1301004)the National Natural Science Foundation of China (31830089 and 32170518)TP’s work in the East Asian-Australasian Flyway through Global Flyway Network was supported by WWF-Netherlands,the MAVA Foundation and many other benefactors
文摘China’s coastal wetlands provide breeding,migration stopover,and wintering habitats for about 230 waterbird species,which is more than a quarter of all waterbirds in the world.Large-scale and high intensity human activities have resulted in serious loss and degradation of coastal wetlands over the past half century,causing population declines in many waterbirds.Through a literature review and expert surveys,this article reviews conservation measures taken in recent decades to protect waterbirds in China’s coastal wetlands and provides recommendations for future conservation action from three aspects:policy and administration,habitat conservation and management,and multiparty participation.Over the past decades,many conservation legislation,regulations and action plans at the national level and more site-specific measures and interventions have been implemented,with notable improvement in the effectiveness in policy making and multi-stakeholder participation.Accordingly,some threats to waterbirds have been mitigated and many key sites for waterbirds have been designated as strictly protected nature reserves.However,some critical issues still remain,mostly related to habitat conservation and management,such as coastal wetland restoration,control of invasive Spartina alterniflora,control of environmental pollution,and improvement of artificial habitat quality.We highlight that protecting natural tidal wetlands and improving habitat quality are critical for the conservation of coastal waterbirds,especially those highly dependent on the intertidal wetlands.China has demonstrated strong commitment to ecological conservation and restoration for the future,in terms of both funding and policies for biodiversity and wetland ecosystems.It is important that this commitment to conserve coastal waterbirds is supported continuously by science-and evidence-based decisions and actions.
文摘Tanzania’s Ruaha landscape is prominent for its potential wildlife resources, which play a key role in sustaining the economy and livelihoods of the people. However, most of these resources are illegally obtained and traded in different places within and outside the Ruaha landscape. Due to its illegal nature, most of the important information regarding the trade is poorly documented. Therefore, the current study aimed first, to explore the origin and destination of wildlife products;second, to assess the relationship between hunters and buyers or customers;third, to assess the means used to transport wildlife products;and lastly, to assess who influences people to engage in illegal hunting and trade activities. In addition, we assess the materials used in the exchange of wildlife products. Semi-structured questionnaires and face-to-face interviews were used to collect information from 123 respondents. Social network analysis was used to indicate the origin and destination of wildlife products. The findings show that 70% of wildlife products originate from the Ruaha National Park and MBOMIPA wildlife management areas, with the remaining 30% originating from villages. The majority of respondents (65%) reported transporting wildlife products by foot and bicycle as the primary modes of transportation. Suppliers of wildlife products are reported to have close and long-term relationships with their customers and traders, with most of whom being friends and relatives. We found most poachers to be influenced by their friends and relatives in terms making decision to engage in illegal wildlife trade. In addition, crops like maize and rice were the most popular products used to exchange with wildlife products in the Ruaha landscape. Therefore, in order to combat illegal trade in wildlife products at the local level, alternative income-generating activities need to be promoted accompanied by not only well-funded anti-poaching programmes but also more effective surveillance plans. These should entail the use of advanced techniques and skills, such as wildlife forensics.
文摘Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston’s (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km<sup>2 </sup>revealed 286 lions (95% CI, 236 - 335) during the wet season, and 196 lions (95% CI, 192 - 200) during the dry season. The density of lions was 9.1/100 km<sup>2 </sup>during the wet season, and 6.3/100 km<sup>2</sup> during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on the distribution of the observed lions to call-back stations. We suggest that the proximity to water sources is important in study design. Further, we suggest that density and population size are useful indices in identifying conservation area priorities and lion coexistence strategies.
基金the National Natural Science Foundation of China(grant number 31830089,32270518,31801985)the Non-profit Foundation of Marine Environment and Ecological Conservation of CNOOC(grant number CF-MEEC/TR/2020-20).
文摘Pied Avocets(Recurvirostra avosetta)are common migratory shorebirds in the East Asian–Australasian Flyway.From 2019 to 2021,GPS/GSM transmitters were used to track 40 Pied Avocets nesting in northern Bohai Bay to identify annual routines and key stopover sites.On average,southward migration of Pied Avocets started on 23 October and arrived at wintering sites(mainly in the middle and lower reaches of the Yangtze River and coastal wetlands)in southern China on 22 November;northward migration started on 22 March with arrival at breeding sites on 7 April.Most avocets used the same breeding sites and wintering sites between years,with an average migration distance of 1124 km.There was no significant difference between sexes on the migration timing or distance in both northward and southward migration,except for the departure time from the wintering sites and winter distribution.The coastal wetland of Lianyungang in Jiangsu Province is a critical stopover site.Most individuals rely on Lianyungang during both northward and southward migration,indicating that species with short migration distances also heavily rely on a few stopover sites.However,Lianyungang lacks adequate protection and is facing many threats,including tidal flat loss.We strongly recommend that the coastal wetland of Lianyungang be designated as a protected area to effectively conserve the critical stopover site.
基金financially supported by the National Natural Science Foundation of China(31071939,31572280,and 31772467)
文摘Background: Departure decisions and behaviors of migratory birds at stopover sites are expected to maximize fit?ness by trade?offs among avoiding predators, optimizing refueling(energy) capacity, and matching other life?history events. We predict that species with different body sizes and migratory destinations will exhibit different behaviors when departing from the same stopover site. We also predict that with strong time constraint at the final pre?breed?ing stopover site, departure decisions may be less sensitive to exogenous factors, such as wind condition, compared to other stopover or nonbreeding sites.Methods: We recorded migratory departures of four shorebird species, i.e. Eurasian Curlew(Numenius arquata), Bar?tailed Godwit(Limosa lapponica), Great Knot(Calidris tenuirostris), and Grey Plover(Pluvialis squatarola), at Yaluji?ang Estuary Wetlands in China, a final pre?breeding stopover site in the northern Yellow Sea, from 2011 to 2014. We compared flock sizes, departure time and departure directions between species, and investigated the effects of tide and weather conditions(rain and ground wind speed and direction) on the departure decision of shorebirds.Results: We found that larger species departed in smaller flocks and were more variable in daily departure time. Departure trajectory of all four species appeared to be influenced by coastal topography. With the east–west coast?line and intertidal mudflat on the south, birds exhibited westward or eastward deflection from the shortest migra?tory routes. Bar?tailed Godwit was the only species that deviated to the southeast and did not climb over the land. Birds avoided departure during precipitation, while their departure was not related to ground wind benefit or tidal condition.Conclusions: Body size among species, which influences their vulnerability to predators, might be important in shaping shorebird departure strategies. Diverse departure directions could be the result of different wind use tac?tics in climbing stage. Narrow optimal time window of breeding might lead to reduced flexibility in departure date at a final pre?breeding site. Both endogenous and exogenous are important in shaping departure behaviors and decisions.
文摘Lion populations are declining globally, including in Tanzania, and Africa. However, Katavi National Park is a landscape with potential for a sustainable and healthy population of African lions (Panthera leo), but there is currently limited reliable data indicating density and population size. This hinders the development of conservation action plans, including population monitoring, for this species. To address this data gap, we assessed lions’ demography and population estimates (population size and density) in the Katavi National Park using a call-back survey method. In addition, we assessed ecological factors that influenced distribution of lions to the call-back stations. Our estimated population size revealed 84 lions (95% CI 53 - 116), with a density of 5/100 km<sup>2</sup> (95% CI 3.14 - 6.86) in the sampled area, representing 38% of the total park. This resulted in an estimated 214 individuals when extrapolated to the whole park. Sixty-seven percent of lions that responded to the stations were female, and ecological factors that significantly influenced their distribution included elevation, land cover, precipitation, temperature, wind speed, and prey abundance. Our results suggest that female lions are more abundant than males in Katavi National Park and that population size and density estimates, as well as understanding prey-lion relations, are important indices for lion monitoring and identifying conservation priorities. Further, our study suggests that the call-back survey method is an effective, rapid, and less costly population assessment method for lions, may be useful for assessing other social species in the Katavi ecosystem and can be a useful tool for community engagement and contributing to scientific monitoring.
文摘Establishing knowledge of local communities regarding the potential health risks of illegal bushmeat hunting and its related practices is among the essential means to developing effective conservation and public health programs. To reveal the understanding of the local people regarding the potential health risks of bushmeat consumption and handling of wildlife products, we used a semi-structured questionnaire to survey 261 households in eight villages located adjacent to the western part of Nyerere National Park. Also, we interviewed eight key informants, including conservation personnel and veterinary officers, in the study area. The proportion of local people who were unaware that handling of wildlife products and bushmeat consumption were risky behaviours towards acquiring zoonotic diseases was slightly higher (57%) than the proportion of respondents who were aware of the likely risks of zoonotic diseases from the practices. After all, the majority (83%) of local people admitted having come into contact with wildlife products, while over 70% reported having consumed bushmeat. We found that local communities living closer to the park boundaries (<15 km) have a higher likelihood of contacting wildlife products, and that community members who have lived in the area for more than ten years have experienced more contact with wildlife products than immigrants. Moreover, the age of inhabitants and length of stay were found to be the most significant factors in determining the likelihood of bushmeat consumption. Most people seemed to prefer bushmeat to domestic meat, arguing that bushmeat is far more flavorful, tender, not tainted with chemicals, and has less fat, making it safer. Our study demonstrated that local communities participate in risky practices without contemplating the health consequences that could emerge should a zoonotic disease outbreak occur. Among other strategies, we recommended conservation and public health institutions to increase awareness campaigns on the possible health risks of zoonotic diseases associated with wildlife.
文摘The trophy hunting industry in Tanzania plays a significant role in wildlife conservation as well as economic and community development. Trophy hunting has been conducted in Rungwa Game Reserve (RGR) for several decades;however, the trophy hunting opinions from the local communities living adjacent to the reserve are not well documented. This study aimed to assess the awareness and attitudes of local communities living adjacent to Rungwa Game Reserves toward trophy hunting. Furthermore, the study assessed factors that influenced the opinions of participants by using structural equation modeling. We used semi-structured interviews and key informant interviews in the three villages adjacent to RGR. The local communities are aware of existing hunting operations around the game reserves. The study found positive attitudes among local communities toward trophy hunting, only if local people accrue benefits from hunting operations. The community’s attitudes towards trophy hunting varied across household size and occupation. Education and household position had an indirect influence on the community’s attitude. Our findings suggest that socio-demographic variables are important to consider when assessing awareness and attitudes toward trophy hunting. Local communities are willing to support trophy hunting operations if the benefits obtained from hunting are significant and it can improve wildlife conservation and their livelihood. In conclusion, trophy hunting is important to local communities living adjacent to protected areas, and banning them may have a significant impact on their livelihood and wildlife conservation. Therefore, it is recommended that conservation policies and interventions consider the dual significance of trophy hunting, fostering strategies that balance socio-economic benefits for communities and wildlife conservation.
文摘Trophy hunting has severe consequences on wild animals’ behaviors, which in return has implications for affecting wildlife populations. The Selous Game Reserve is a protected area in Tanzania that has been subjected to commercial trophy hunting for decades, and information about the effects of trophy hunting on animals’ welfare is still scarce. The Flight Initiating Distance (FID) can be a good measure to evaluate the welfare of animals and the level of risk perception towards anthropogenic disturbances, including trophy hunting. The study used linear mixed models to assess the flight responses of twelve commonly hunted species in the Selous game reserve (S.G.R.). The study compared animal vigilance between species, vegetation types, and group size. The FID varied between species, with which more vigilance was observed in zebras, elands, wildebeests, and sable antelopes. The study found a significant influence of vegetation cover on individual species’ FID. Further, the study found a significant influence of group size on animals’ vigilance (L. M. M., 95% CI = 0.590 - 4.762), in which there was a decrease in FID with an increase in group size for wildebeests. At the same time, other species, such as buffaloes, eland, hartebeests, and zebras, had their FIDs increasing with the increase in group size. We conclude that the impact of trophy hunting on savannah ungulates varies between species, vegetation covers, and group size of individual species. Regulatory authorities should consider minimum approach distances by trophy hunters in different vegetation cover to reduce animal biological disturbances.
基金supported by the National Natural Science Foundation of China(Grant Nos.42477335,42077088)the Zhejiang Province“Agriculture,Rural Areas,Rural People and Nine Institutions”Science and Technology Collaboration Program(Grant No.2023SNJF039)X.P.L.was supported by a scholarship from the China Scholarship Council.
文摘Organic fertilization may influence soil carbon−iron(C-Fe)cycling and enhance phosphorus(P)availability,yet the direct connection between soil organic matter molecules and iron-reducing processes in long-term fertilized paddy soils remains underexplored.In this study,we conducted a microcosm experiment using paddy soils treated with six distinct fertilization regimes involving varying P and organic matter inputs up to five years.We assessed P activation under reflooding conditions,evaluated Fe reduction,and characterized dissolved organic matter(DOM)at the molecular level using Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS),alongside profiling soil microbial community composition via high-throughput sequencing.Our findings revealed that after 25 days of reflooding,soil Olsen-P content increased by an average of 73%compared to its initial state,showing a strong correlation with the Fe reduction process.Specifically,treatments involving pig manure application exhibited higher Fe reduction rates and enhanced P activation,highlighting the role of organic matter in facilitating Fe reduction.Examination of Fe-reducing microorganisms revealed that their relative abundance was decoupled from Fe reduction and P release rates,potentially due to limitations of lower soil organic matter content.Further analysis of DOM composition and network structures suggested that high-molecular-weight DOM,particularly lignin,acted as key resources for Fe-reducing microbes,thereby driving Fe reduction and promoting P release.Overall,our study highlights the crucial role of soil DOM in enabling microbial-driven Fe reduction and enhancing P availability,providing insights valuable for sustainable agricultural practices.
