During the Yangtze Freshwater Dolphin Expedition 2012,Yangtze finless porpoises(Neophocaena asiaeorientalis)were acoustically monitored in 9 port areas at night.During 6566 min of nocturnal monitoring,porpoise sonar w...During the Yangtze Freshwater Dolphin Expedition 2012,Yangtze finless porpoises(Neophocaena asiaeorientalis)were acoustically monitored in 9 port areas at night.During 6566 min of nocturnal monitoring,porpoise sonar was detected for 488 min(7.43%of the total time).Of all 81 encounters,the longest echolocation span obtained was 102.9 min,suggesting frequent and prolonged porpoise occupation of the port areas.A combined total of 2091 click trains were recorded,with 129(6.2%)containing minimum inter-click intervals(ICIs)below 10 ms(termed a buzz).Buzzes with a decrease in ICIs and search and approach phases that resembled feeding echolocation signals accounted for 44.2%(N=52)of all buzzes.Buzzes with an increase in ICIs,suggesting a mirrored prey capture phase,accounted for 20.2%(N=26)and could reflect attempts to locate escaped prey because they were followed by approach-phase feeding buzzes.Anecdotal evidence of porpoises fleeing the proximity of vessels was observed.The recordings indicating clusters of porpoises feeding near the port areas suggest a forced choice for feeding due to the relatively higher prey availability in the port areas compared to other areas in the Yangtze River that are probably overfished.展开更多
The behaviour of broiler chickens has been extensively studied as a function of stocking density and environmental conditions,but limited information was reported in the scientific literature about the effect of feede...The behaviour of broiler chickens has been extensively studied as a function of stocking density and environmental conditions,but limited information was reported in the scientific literature about the effect of feeder type on birds’feeding process.The main objective of this study was to assess the effects of three different feeder types in relation to the birds’behaviour in its surroundings.The analysed feeders were:tube-type with partition grid(F1);tube-type without partition grid(F2);and automatic type with partition grid(F3).The considered variables were:occupied area(OA);activity index(AI)(flock movement);total birds presented in the area(TB);and birds effectively eating(EE).OA and AI were calculated by computational image analysis while TB and EE were manually measured.The results indicated that the feeder type could have influenced the birds’behaviour regarding to OA(R2=0.56),TB(R2=0.48),and EE(R2=0.40),but AI(R2=0.01)was not found to be directly influenced by the feeder type.A higher percentage of birds effectively eating were found in F2(86.4%),which was the one with the largest free area to access the feed.Similar average number of total birds was found in F1,but with a lower percentage of individuals effectively eating(63.3%),which means that birds were nearby this feeder performing other behaviours.Since the assessed feeders were in the same house under the same conditions,it can be suggested that not only the free area to access the feed but potentially the design of feeders could have influenced the birds’feeding preference.The real beneficial effect of the adoption of partition grid on feed trays is still uncertain,and it is also unclear whether the financial value of reduced wastage would compensate the possible reduction in feed intake.展开更多
Background:Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features(natural or human-modified)play a crucial role in the avian species composition and p...Background:Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features(natural or human-modified)play a crucial role in the avian species composition and population structure.To examine this,a study was carried out in Bhubaneswar,India,to understand the ecological niche distinction in birds based on habitat heterogeneity.Regular sampling was conducted in 30 sampling sites covering six different habitat types in a predominantly urban landscape of Bhubaneswar for understanding the ecological niche in birds.The birds were classified into 11 types of foraging guilds.Results:The insectivorous guild had the highest bird species richness(181 species)and the omnivorous guild had the lowest(11 species).The piscivorous guild and wetland habitat had the strongest linkage,followed by the insectivorous guild and agricultural land.The frugivorous guild was significantly correlated with forest habitats(r=0.386,p<0.01)and park and garden habitats(r=0.281,p<0.01).This urban area hosted a higher number of bird species in certain habitat types,viz.,agricultural lands(52%,115 species)and forest patches(50%,111 species).Conclusion:The present study highlights the importance of agricultural lands,forest patches,parks and gardens,and wetlands inside the cityscape for supporting avifauna.It is therefore suggested that such habitats should be conserved inside an urban area to protect native avifauna.Thus,the city development plan must invariably include strategies for conserving the forest patches inside the urban area.Measures must be taken to restrain the degradation of agricultural lands and reduce their utilization for non-agricultural purposes,which will help in further reducing the bird population decline in the urban landscape.展开更多
基金suported by grants from the Knowledge Innovation Program of Chinese Academy of Sciences(No.KSCX2-EW-Z-4)the National Natural Science Foundation of China(No.31170501 and 31070347)+1 种基金the Special Fund for Agro-scientific Research in the Public Interest of the Ministry of Agriculture of China(No.201203086)the Ocean Park Conservation Foundation,Hong Kong.Some logistic support was provided by Wuhan Baiji Conservation Foundation and Societe Generale de Surveillance S.A.Special thanks are also extended to the academic editor and anonymous reviewers for their helpful critique of an earlier version of this manuscript.
文摘During the Yangtze Freshwater Dolphin Expedition 2012,Yangtze finless porpoises(Neophocaena asiaeorientalis)were acoustically monitored in 9 port areas at night.During 6566 min of nocturnal monitoring,porpoise sonar was detected for 488 min(7.43%of the total time).Of all 81 encounters,the longest echolocation span obtained was 102.9 min,suggesting frequent and prolonged porpoise occupation of the port areas.A combined total of 2091 click trains were recorded,with 129(6.2%)containing minimum inter-click intervals(ICIs)below 10 ms(termed a buzz).Buzzes with a decrease in ICIs and search and approach phases that resembled feeding echolocation signals accounted for 44.2%(N=52)of all buzzes.Buzzes with an increase in ICIs,suggesting a mirrored prey capture phase,accounted for 20.2%(N=26)and could reflect attempts to locate escaped prey because they were followed by approach-phase feeding buzzes.Anecdotal evidence of porpoises fleeing the proximity of vessels was observed.The recordings indicating clusters of porpoises feeding near the port areas suggest a forced choice for feeding due to the relatively higher prey availability in the port areas compared to other areas in the Yangtze River that are probably overfished.
文摘The behaviour of broiler chickens has been extensively studied as a function of stocking density and environmental conditions,but limited information was reported in the scientific literature about the effect of feeder type on birds’feeding process.The main objective of this study was to assess the effects of three different feeder types in relation to the birds’behaviour in its surroundings.The analysed feeders were:tube-type with partition grid(F1);tube-type without partition grid(F2);and automatic type with partition grid(F3).The considered variables were:occupied area(OA);activity index(AI)(flock movement);total birds presented in the area(TB);and birds effectively eating(EE).OA and AI were calculated by computational image analysis while TB and EE were manually measured.The results indicated that the feeder type could have influenced the birds’behaviour regarding to OA(R2=0.56),TB(R2=0.48),and EE(R2=0.40),but AI(R2=0.01)was not found to be directly influenced by the feeder type.A higher percentage of birds effectively eating were found in F2(86.4%),which was the one with the largest free area to access the feed.Similar average number of total birds was found in F1,but with a lower percentage of individuals effectively eating(63.3%),which means that birds were nearby this feeder performing other behaviours.Since the assessed feeders were in the same house under the same conditions,it can be suggested that not only the free area to access the feed but potentially the design of feeders could have influenced the birds’feeding preference.The real beneficial effect of the adoption of partition grid on feed trays is still uncertain,and it is also unclear whether the financial value of reduced wastage would compensate the possible reduction in feed intake.
文摘Background:Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features(natural or human-modified)play a crucial role in the avian species composition and population structure.To examine this,a study was carried out in Bhubaneswar,India,to understand the ecological niche distinction in birds based on habitat heterogeneity.Regular sampling was conducted in 30 sampling sites covering six different habitat types in a predominantly urban landscape of Bhubaneswar for understanding the ecological niche in birds.The birds were classified into 11 types of foraging guilds.Results:The insectivorous guild had the highest bird species richness(181 species)and the omnivorous guild had the lowest(11 species).The piscivorous guild and wetland habitat had the strongest linkage,followed by the insectivorous guild and agricultural land.The frugivorous guild was significantly correlated with forest habitats(r=0.386,p<0.01)and park and garden habitats(r=0.281,p<0.01).This urban area hosted a higher number of bird species in certain habitat types,viz.,agricultural lands(52%,115 species)and forest patches(50%,111 species).Conclusion:The present study highlights the importance of agricultural lands,forest patches,parks and gardens,and wetlands inside the cityscape for supporting avifauna.It is therefore suggested that such habitats should be conserved inside an urban area to protect native avifauna.Thus,the city development plan must invariably include strategies for conserving the forest patches inside the urban area.Measures must be taken to restrain the degradation of agricultural lands and reduce their utilization for non-agricultural purposes,which will help in further reducing the bird population decline in the urban landscape.
