Growth indicators including weight, body length, wings length, tail length, tarsus, gape, the third toe and head width of 21 nestlings of Great Bustard (Otis tarda) were measured and investigated in Harbin Zoo, Harbin...Growth indicators including weight, body length, wings length, tail length, tarsus, gape, the third toe and head width of 21 nestlings of Great Bustard (Otis tarda) were measured and investigated in Harbin Zoo, Harbin, China during 1999-2002, and methods on successfully fostering nestlings of the bird were also summarized in this article. The results showed: the Great Bustard is a kind of premature bird and its birth weight was 86.31?.56g (N=21); environmental temperature for the neonatal nestlings should be controlled at 36C; the feeding principle having many meals but little food at each for the nestlings should be followed; since six weeks after birth, nestlings of both gender began to show significant difference in body weight, the weight of male was 1.8 times of that of the female after fourteenth week, and by weight and body figure sexual identity could be easily discerned when 3 or 4 months old; There is no significant difference in growth and development of all organs between male and female nestlings and organ growth curves were fit into Logistic equation.展开更多
Twelve indices of blood for great bustard were determined by using JT-TR blood cell analyzer. Theyincluded white cell number, red cell number, hemoglobin density, hematocrit. mean volume of red cell, mean hemoglobin o...Twelve indices of blood for great bustard were determined by using JT-TR blood cell analyzer. Theyincluded white cell number, red cell number, hemoglobin density, hematocrit. mean volume of red cell, mean hemoglobin of red cell, mean hemoglobin density of red cell, distribution width of red cell, platelet number, platelethematocrit, mean platelet volume, and platelet distribution width. The analysis data indicated that the blood ofgreat bustard have strong function of taking oxygen. The current breeding condition is fine and suitable for thephysiological requirements of great bustard.展开更多
Ultra-micro structure of eggshell was observed and compositions of eggshell and feather were analyzed. The results showed that the structure of eggshell has special characters besides common structure. The content of ...Ultra-micro structure of eggshell was observed and compositions of eggshell and feather were analyzed. The results showed that the structure of eggshell has special characters besides common structure. The content of poisonous elements in wild great bustard(Otis talda) eggshell and feather is significant lower than that in eggshell of crested foes(Nipponis nippon) and in feather of red crown crane(Grus japonesis) because of less disturbance by people. The contents of 14 elements of female’s feather all are higher than those of male’s.展开更多
The Great Bustard(Otis tarda) world population is estimated to be 44100–57000 individuals in 2010,of which about 57–70% occur in Spain,15–25% in European Russia,4–10% in China,Mongolia and south-eastern Russia,3–...The Great Bustard(Otis tarda) world population is estimated to be 44100–57000 individuals in 2010,of which about 57–70% occur in Spain,15–25% in European Russia,4–10% in China,Mongolia and south-eastern Russia,3–4% in Portugal,3% in Hungary,1–2% in Turkey,and smaller numbers in ten other countries.The reliability of current censuses and estimates may be described as high for a large fraction of the world population(67–75%),and low for the remain-ing 25–33%(including Russia,Mongolia,China,Turkey,Ukraine,Iran and Kazakhstan).In spite of continued declines reported for some countries(e.g.,Turkey,Iran,China) ,the present survey suggests that total numbers have not significantly decreased worldwide during the last decade,as opposed to the globally declining trend currently assumed.This is due to a large fraction of the world total living in countries whose overall surveys are apparently stable(e.g.,Spain,Portugal),after a noticeable recovery during the last few decades once the hunting ban was established.Only 6–10% of the world total is apparently still decreasing,mostly due to agricultural intensification,other causes of habitat degradation,and locally,also illegal hunting and collision with power lines.A small fraction of the world population(3–4%),is clearly(Germany,Austria) or apparently(Hungary) increasing,due to management and conservation measures.Finally,19–22% of the world total has an uncertain status,due to inaccurate current or past censuses which prevent establishing reliable population trends.We recommend 1)keeping conservation efforts and the species’protection status worldwide,and 2)carrying out urgently nation-wide surveys in countries with low quality estimates,in order to confirm world numbers and trends.展开更多
A trial of artificial incubation to great bustard (Otis tarda ) egg was conducted from 1995 to 1997.Among the 45 collected eggs, 28 eggs were fertilized and 26 hatched, with fertilizing rate 62.2% and incubation rate ...A trial of artificial incubation to great bustard (Otis tarda ) egg was conducted from 1995 to 1997.Among the 45 collected eggs, 28 eggs were fertilized and 26 hatched, with fertilizing rate 62.2% and incubation rate 92.85%. The mean Incubation-days for great bustard egg was confirmed as 24.4(21-28 days) with the formula for caculating fresh egg weight (W=KwLB2) and that for counting the incubated days by parents birds in field (ld=24(w-y)/0.144y). The proper incubation temperature and relative humidity were 36-37.8℃ and 50-65%.respectively. The egg weights and egg size average 130.45 g and 77.411.42 × 55.5 ± 0.65-mm respectively. The total weight loss of egg was 18.38±0.646 g, daily weight loss 0.748±0.071g in the incubation time. with a weight loss rate of 13.6±1 .02%. A linear regression equation to discribe the relationship between the egg weight and incubation days, was built, y=130.73-0.619± (x--incubation day, y--egg weight). r=-0.978. Twenty-eight hours were nassassary for great bustard embryo to complete the fledging when the were put in gas room. The mean weight of fledglings was 86.3±3.29 g(n=26).展开更多
There are two subspecies of Great Bustards in China : Otis tarda tarda, a rare resident of in Kashi region,Tianshan Mountains and Turpan region in xinjiang Uygur Autonomous Region in northwestern China. The other is O...There are two subspecies of Great Bustards in China : Otis tarda tarda, a rare resident of in Kashi region,Tianshan Mountains and Turpan region in xinjiang Uygur Autonomous Region in northwestern China. The other is O. t. dybowskii found in northeastern China. In 840 km2 survey area 150 Great Bustards were found. The average density was 0.81birds/ km2. Reasons for the decline of Great Bustard were analyzed. Conservation measures for the Great Bustards are recommended.展开更多
The distribution and migration of houbara bustard in China was studied by range investigation and tracking through PTT satellite transmitter from 1997 to 2004. The houbara bustard occurs in the Junggar Basin, north pa...The distribution and migration of houbara bustard in China was studied by range investigation and tracking through PTT satellite transmitter from 1997 to 2004. The houbara bustard occurs in the Junggar Basin, north part of Tacheng Basin and valley of Ulungur river in northern Xinjiang, southern part of Turpan Basin and Barkol in eastern Xinjiang. In Inner Mongolia, the houbara bustard occurs in Urathouqi, Alxahouqi and Ejinaqi. In Gansu province, the houbara bustard occurs in Wuwei, Minqin and Shandan. The whole range is not contiguous area. Houbara bastard started migration from Junggar Basin in northern Xinjiang, Turpan Basin and Barkol in eastern Xinjiang, Wuwei in western Gansu Province and Bayan Nur in western Inner Mongolia in the middle of September. Flying to the west and northwest, via Junggar Basin and area between Bole and Habahe in northern Xinjiang, entered Kazakhstan, they turned toward southwest, passed Uzbekistan and Turkmenistan, arrived in Arabia Bay of southern Iran or flied over Afghanistan, arrived in southern Pakistan for wintering. The whole migration usually took 35 +/- 13 days covering a distance of 4 800-7 000 km. In the next year, houbara went back to the breeding grounds in China through the same routes at the beginning of March. However, it took the birds 64 +/- 17 days to finish the spring migration. They arrived in breeding site between middle of April and late May. The sub-adults arrived later and did not breed.展开更多
Great bustard is one of the enelangered species in China. It breeds in China. The breeding area is not complete, but scattered, which is from the northeast of Neimenggu grassland to the sand land of Hulunbeier. This b...Great bustard is one of the enelangered species in China. It breeds in China. The breeding area is not complete, but scattered, which is from the northeast of Neimenggu grassland to the sand land of Hulunbeier. This breeding areas are isolated by Daxing’an Mountain, which are Neimeng, Songnen Plain and Kerqin sand land. The total area is about 7810 km2. The estimated total number of Great Bustands in the Northeast area of China is 377 birds.展开更多
This article presents the distribution and status of bustards,which are listed as first-category protected animals according to the survey results during 1990–2002 in China.The Chinese populations of Otis tarda dybow...This article presents the distribution and status of bustards,which are listed as first-category protected animals according to the survey results during 1990–2002 in China.The Chinese populations of Otis tarda dybowskii are breeding in south-west of Heilongjiang Province,western Jilin Province,east and middle Inner Mongolia,north Ningxia Hui Autonomous Region,and Gansu Province.A few can winter in the south breeding-range.Its winterrange lies from the south to the Yellow River,as far as to Guizhou Province and Jiangxi Province.Its population number is about 200–300 or 500–800.The Chinese populations of O.t.tarda are breeding in the north and west of Xinjiang.It is unclear about its winter-range,which is presumed to be in south Asia.Recently we found individuals wintering in Chabuchaer and west Xinjiang.The population number is about 2000–3000.The habitat in breeding range includes steppe,grassland,desert grassland,and farmland.The habitat in winter range is the beach of rivers and lakes,meadows,meadow-grassland,and wheatland.The Chinese populations of Chlamydotis undulata macqueeni are breeding in the fringe of the Jungar Basin,the banks of the Ulungur River,Balikun and south Turpan Basin in Xinjiang,west Inner Mongolia,and west Gansu.Northeast Mulei in eastern Jungar Basin of Xinjiang is the main breeding-range in the world.The bird uses desert and desert grassland as its habitat.Its winter-range is west Asia and south Asia.Its population number is about 2000.The Chinese populations of Tetrax tetrax are breeding in north Xinjiang,and China is located on the east border of its breeding-range.Its habitat is grassland and semi-desert,and its winter-range lies in south Asia.Its population in China is very scarce.In addition,we analyzed the causes of their endangerment and put forward protection tactics of Chinese Bustards.展开更多
Instantaneous scanning and focal animal sampling methods were used to record the behaviors of nine wild Great Bustards(Otis tarda)and their time budget from November 2004 to January 2005.The results indicated that for...Instantaneous scanning and focal animal sampling methods were used to record the behaviors of nine wild Great Bustards(Otis tarda)and their time budget from November 2004 to January 2005.The results indicated that foraging and resting time accounted for as high as 46.40%and 39.12%,respectively,while the rest of the behaviors,such as walking,alerting,preening and flying,only shared 6.83%,2.03%,2.64%and 1.84%,respectively.There were significant differences in foraging time,alert time and walking time between males and females(P<0.05).The preening and flying were closely related to males(Pearson’s correlation,r=0.932),and it was similar for resting and walking in females(Pearson’s correlation,r=0.716).Resting occurred mainly at dawn and dusk,and foraging appeared mostly from 9:30 to 11:30 and from 14:30 to 16:30.Non-parameter testing demonstrates that time budget among resting,flying and others in two temperature intervals(>−5 and℃≤−5)℃was significantly different.展开更多
The parasitic infection of houbara bustard(Chlamydotis undulate)in north of Iran,Golestan Province was reported in this study.The carcass of a male houbara bustard about 2 years old with 2.5 kg body weight,was forfeit...The parasitic infection of houbara bustard(Chlamydotis undulate)in north of Iran,Golestan Province was reported in this study.The carcass of a male houbara bustard about 2 years old with 2.5 kg body weight,was forfeited from impermissible hunters by the Department of Environment in Gorgan,Golestan Province during January 2015.The gastrointestinal tracts was dissected and examined for helminth infection.Species of Nematoda,Cestoda and Acanthocephala were found which were as following:Hartertia obesa,Idiogenes otidis,Mediorhynchus taeniatus,respectively from small intestine.Based on the results obtained from the present study,it can be concluded that Chlamydotis undulata may play an important role in the transmission of the mentioned parasites.In addition,this is the first report of Hartertia obesa,Idiogenes otidis,Mediorhynchus taeniatus in Iran.展开更多
Great Bustards(Otis tarda dybowskii)are one of the world’s heaviest flying birds,occupying grassland habitats in Eastern Asia.Our study is located at the most eastern Chinese wintering site in Cangzhou,Hebei Province...Great Bustards(Otis tarda dybowskii)are one of the world’s heaviest flying birds,occupying grassland habitats in Eastern Asia.Our study is located at the most eastern Chinese wintering site in Cangzhou,Hebei Province,where approximately 100 individuals are concentrated in a small area(17.53 km2).Solid information is still lacking about the wintering areas for this subspecies in its eastern range and specifically for China.The study area consists of intensely used farmland in proximity to humans and is lacking conservation areas and wild,open fields.Here,we present our results from two years of field data collection on habitat selection.We choose a machine learning model approach based on a rapid assessment methodology for the winter habitat of the Great Bustard.It is based on a spatial analysis of the best available environmental data,which were collected relatively quickly.These relatively new methods in ecology are based on an ensemble of decision trees and include algorithms such as TreeNet,Random Forest and CART used in parallel.In this study,we collected bustard droppings(presence only)from 48 locations between December 2011 and January 2012 and used the sites as training data.Droppings from 23 locations were collected in November 2012,and those sites were used as test data.We used eight environmental variables as predictor layers for the response variable of bustard presence/availability.We employed a Geographic Information System(ArcGIS 10.1and Geospatial Modelling Environment)and Google Earth.Compared with the other three models,we found that predictions from Random Forest obtained a significant difference between presence and absence.According to this model,the three most important factors for wintering Great Bustards are distance to residential area,distance to water pools,and farmland area.Our model shows that wintering Great Bustards prefer locations that are over 400 m away from residential areas,within 900 m of water pools and on areas of farmland smaller than 0.5 km2.We think we can apply our analysis to Great Bustard management in our study area and the adjacent region and that this work sets a baseline for future research.展开更多
文摘Growth indicators including weight, body length, wings length, tail length, tarsus, gape, the third toe and head width of 21 nestlings of Great Bustard (Otis tarda) were measured and investigated in Harbin Zoo, Harbin, China during 1999-2002, and methods on successfully fostering nestlings of the bird were also summarized in this article. The results showed: the Great Bustard is a kind of premature bird and its birth weight was 86.31?.56g (N=21); environmental temperature for the neonatal nestlings should be controlled at 36C; the feeding principle having many meals but little food at each for the nestlings should be followed; since six weeks after birth, nestlings of both gender began to show significant difference in body weight, the weight of male was 1.8 times of that of the female after fourteenth week, and by weight and body figure sexual identity could be easily discerned when 3 or 4 months old; There is no significant difference in growth and development of all organs between male and female nestlings and organ growth curves were fit into Logistic equation.
文摘Twelve indices of blood for great bustard were determined by using JT-TR blood cell analyzer. Theyincluded white cell number, red cell number, hemoglobin density, hematocrit. mean volume of red cell, mean hemoglobin of red cell, mean hemoglobin density of red cell, distribution width of red cell, platelet number, platelethematocrit, mean platelet volume, and platelet distribution width. The analysis data indicated that the blood ofgreat bustard have strong function of taking oxygen. The current breeding condition is fine and suitable for thephysiological requirements of great bustard.
文摘Ultra-micro structure of eggshell was observed and compositions of eggshell and feather were analyzed. The results showed that the structure of eggshell has special characters besides common structure. The content of poisonous elements in wild great bustard(Otis talda) eggshell and feather is significant lower than that in eggshell of crested foes(Nipponis nippon) and in feather of red crown crane(Grus japonesis) because of less disturbance by people. The contents of 14 elements of female’s feather all are higher than those of male’s.
基金provided by project CGL2008-02567 of the Dirección General de Investigación
文摘The Great Bustard(Otis tarda) world population is estimated to be 44100–57000 individuals in 2010,of which about 57–70% occur in Spain,15–25% in European Russia,4–10% in China,Mongolia and south-eastern Russia,3–4% in Portugal,3% in Hungary,1–2% in Turkey,and smaller numbers in ten other countries.The reliability of current censuses and estimates may be described as high for a large fraction of the world population(67–75%),and low for the remain-ing 25–33%(including Russia,Mongolia,China,Turkey,Ukraine,Iran and Kazakhstan).In spite of continued declines reported for some countries(e.g.,Turkey,Iran,China) ,the present survey suggests that total numbers have not significantly decreased worldwide during the last decade,as opposed to the globally declining trend currently assumed.This is due to a large fraction of the world total living in countries whose overall surveys are apparently stable(e.g.,Spain,Portugal),after a noticeable recovery during the last few decades once the hunting ban was established.Only 6–10% of the world total is apparently still decreasing,mostly due to agricultural intensification,other causes of habitat degradation,and locally,also illegal hunting and collision with power lines.A small fraction of the world population(3–4%),is clearly(Germany,Austria) or apparently(Hungary) increasing,due to management and conservation measures.Finally,19–22% of the world total has an uncertain status,due to inaccurate current or past censuses which prevent establishing reliable population trends.We recommend 1)keeping conservation efforts and the species’protection status worldwide,and 2)carrying out urgently nation-wide surveys in countries with low quality estimates,in order to confirm world numbers and trends.
文摘A trial of artificial incubation to great bustard (Otis tarda ) egg was conducted from 1995 to 1997.Among the 45 collected eggs, 28 eggs were fertilized and 26 hatched, with fertilizing rate 62.2% and incubation rate 92.85%. The mean Incubation-days for great bustard egg was confirmed as 24.4(21-28 days) with the formula for caculating fresh egg weight (W=KwLB2) and that for counting the incubated days by parents birds in field (ld=24(w-y)/0.144y). The proper incubation temperature and relative humidity were 36-37.8℃ and 50-65%.respectively. The egg weights and egg size average 130.45 g and 77.411.42 × 55.5 ± 0.65-mm respectively. The total weight loss of egg was 18.38±0.646 g, daily weight loss 0.748±0.071g in the incubation time. with a weight loss rate of 13.6±1 .02%. A linear regression equation to discribe the relationship between the egg weight and incubation days, was built, y=130.73-0.619± (x--incubation day, y--egg weight). r=-0.978. Twenty-eight hours were nassassary for great bustard embryo to complete the fledging when the were put in gas room. The mean weight of fledglings was 86.3±3.29 g(n=26).
文摘There are two subspecies of Great Bustards in China : Otis tarda tarda, a rare resident of in Kashi region,Tianshan Mountains and Turpan region in xinjiang Uygur Autonomous Region in northwestern China. The other is O. t. dybowskii found in northeastern China. In 840 km2 survey area 150 Great Bustards were found. The average density was 0.81birds/ km2. Reasons for the decline of Great Bustard were analyzed. Conservation measures for the Great Bustards are recommended.
基金financed by international cooperation between China and UZE:Project of Houbara Conservation and Ecological Monitoring in China (0866031)The Key Projects of Chinese Academy of Sciences (KZ295-JI-114)
文摘The distribution and migration of houbara bustard in China was studied by range investigation and tracking through PTT satellite transmitter from 1997 to 2004. The houbara bustard occurs in the Junggar Basin, north part of Tacheng Basin and valley of Ulungur river in northern Xinjiang, southern part of Turpan Basin and Barkol in eastern Xinjiang. In Inner Mongolia, the houbara bustard occurs in Urathouqi, Alxahouqi and Ejinaqi. In Gansu province, the houbara bustard occurs in Wuwei, Minqin and Shandan. The whole range is not contiguous area. Houbara bastard started migration from Junggar Basin in northern Xinjiang, Turpan Basin and Barkol in eastern Xinjiang, Wuwei in western Gansu Province and Bayan Nur in western Inner Mongolia in the middle of September. Flying to the west and northwest, via Junggar Basin and area between Bole and Habahe in northern Xinjiang, entered Kazakhstan, they turned toward southwest, passed Uzbekistan and Turkmenistan, arrived in Arabia Bay of southern Iran or flied over Afghanistan, arrived in southern Pakistan for wintering. The whole migration usually took 35 +/- 13 days covering a distance of 4 800-7 000 km. In the next year, houbara went back to the breeding grounds in China through the same routes at the beginning of March. However, it took the birds 64 +/- 17 days to finish the spring migration. They arrived in breeding site between middle of April and late May. The sub-adults arrived later and did not breed.
文摘Great bustard is one of the enelangered species in China. It breeds in China. The breeding area is not complete, but scattered, which is from the northeast of Neimenggu grassland to the sand land of Hulunbeier. This breeding areas are isolated by Daxing’an Mountain, which are Neimeng, Songnen Plain and Kerqin sand land. The total area is about 7810 km2. The estimated total number of Great Bustands in the Northeast area of China is 377 birds.
基金This study was supported by the National Natural Science Foundation of China(Grant No.39370103)Key Projects of Chinese Academy of Sciences(No.K952-JI-114)Wildlife Development Agency of Abu Dhabi,United Arab Emirates.
文摘This article presents the distribution and status of bustards,which are listed as first-category protected animals according to the survey results during 1990–2002 in China.The Chinese populations of Otis tarda dybowskii are breeding in south-west of Heilongjiang Province,western Jilin Province,east and middle Inner Mongolia,north Ningxia Hui Autonomous Region,and Gansu Province.A few can winter in the south breeding-range.Its winterrange lies from the south to the Yellow River,as far as to Guizhou Province and Jiangxi Province.Its population number is about 200–300 or 500–800.The Chinese populations of O.t.tarda are breeding in the north and west of Xinjiang.It is unclear about its winter-range,which is presumed to be in south Asia.Recently we found individuals wintering in Chabuchaer and west Xinjiang.The population number is about 2000–3000.The habitat in breeding range includes steppe,grassland,desert grassland,and farmland.The habitat in winter range is the beach of rivers and lakes,meadows,meadow-grassland,and wheatland.The Chinese populations of Chlamydotis undulata macqueeni are breeding in the fringe of the Jungar Basin,the banks of the Ulungur River,Balikun and south Turpan Basin in Xinjiang,west Inner Mongolia,and west Gansu.Northeast Mulei in eastern Jungar Basin of Xinjiang is the main breeding-range in the world.The bird uses desert and desert grassland as its habitat.Its winter-range is west Asia and south Asia.Its population number is about 2000.The Chinese populations of Tetrax tetrax are breeding in north Xinjiang,and China is located on the east border of its breeding-range.Its habitat is grassland and semi-desert,and its winter-range lies in south Asia.Its population in China is very scarce.In addition,we analyzed the causes of their endangerment and put forward protection tactics of Chinese Bustards.
文摘Instantaneous scanning and focal animal sampling methods were used to record the behaviors of nine wild Great Bustards(Otis tarda)and their time budget from November 2004 to January 2005.The results indicated that foraging and resting time accounted for as high as 46.40%and 39.12%,respectively,while the rest of the behaviors,such as walking,alerting,preening and flying,only shared 6.83%,2.03%,2.64%and 1.84%,respectively.There were significant differences in foraging time,alert time and walking time between males and females(P<0.05).The preening and flying were closely related to males(Pearson’s correlation,r=0.932),and it was similar for resting and walking in females(Pearson’s correlation,r=0.716).Resting occurred mainly at dawn and dusk,and foraging appeared mostly from 9:30 to 11:30 and from 14:30 to 16:30.Non-parameter testing demonstrates that time budget among resting,flying and others in two temperature intervals(>−5 and℃≤−5)℃was significantly different.
文摘The parasitic infection of houbara bustard(Chlamydotis undulate)in north of Iran,Golestan Province was reported in this study.The carcass of a male houbara bustard about 2 years old with 2.5 kg body weight,was forfeited from impermissible hunters by the Department of Environment in Gorgan,Golestan Province during January 2015.The gastrointestinal tracts was dissected and examined for helminth infection.Species of Nematoda,Cestoda and Acanthocephala were found which were as following:Hartertia obesa,Idiogenes otidis,Mediorhynchus taeniatus,respectively from small intestine.Based on the results obtained from the present study,it can be concluded that Chlamydotis undulata may play an important role in the transmission of the mentioned parasites.In addition,this is the first report of Hartertia obesa,Idiogenes otidis,Mediorhynchus taeniatus in Iran.
基金supported by the National Forestry Bureau of China(1105-LYSJWT-113)
文摘Great Bustards(Otis tarda dybowskii)are one of the world’s heaviest flying birds,occupying grassland habitats in Eastern Asia.Our study is located at the most eastern Chinese wintering site in Cangzhou,Hebei Province,where approximately 100 individuals are concentrated in a small area(17.53 km2).Solid information is still lacking about the wintering areas for this subspecies in its eastern range and specifically for China.The study area consists of intensely used farmland in proximity to humans and is lacking conservation areas and wild,open fields.Here,we present our results from two years of field data collection on habitat selection.We choose a machine learning model approach based on a rapid assessment methodology for the winter habitat of the Great Bustard.It is based on a spatial analysis of the best available environmental data,which were collected relatively quickly.These relatively new methods in ecology are based on an ensemble of decision trees and include algorithms such as TreeNet,Random Forest and CART used in parallel.In this study,we collected bustard droppings(presence only)from 48 locations between December 2011 and January 2012 and used the sites as training data.Droppings from 23 locations were collected in November 2012,and those sites were used as test data.We used eight environmental variables as predictor layers for the response variable of bustard presence/availability.We employed a Geographic Information System(ArcGIS 10.1and Geospatial Modelling Environment)and Google Earth.Compared with the other three models,we found that predictions from Random Forest obtained a significant difference between presence and absence.According to this model,the three most important factors for wintering Great Bustards are distance to residential area,distance to water pools,and farmland area.Our model shows that wintering Great Bustards prefer locations that are over 400 m away from residential areas,within 900 m of water pools and on areas of farmland smaller than 0.5 km2.We think we can apply our analysis to Great Bustard management in our study area and the adjacent region and that this work sets a baseline for future research.
