Home Range, Activity Rhythm And Foraging Strategy Of Bharal (Pseudois Nayaur) In Helan Mountain, China

Blue sheep (Pseudois nayaur) was studied between August 2005 and September 2006 in Helan Mountain National Nature Reserve. Home range, activity rhythm and food habits were the aspects investigated for this species. Tracking 10 radio-collared individuals monitored activity home range and rhythm. Meanwhile, combined with direct observation, feeding tracks analysis and fixed transect line methods, data on food habits were obtained. The results are as follows.1. The changes of home range and core area of blue sheep were greatly by different sexes and ages in Helan Mountain. The average home range size of adult males was 3.74±0.52km~2 , and the average size of adult males' core area was 1.42±0.15 km~2. The size of adult female's home range and core area were 2.95±0.4km~2 and 1.1±0.22km~2. And the size of subadults' home range and core area were 1.6±0.9km~2 and 0.7±0.2km~2. The adult male's size of home range and core area were bigger than adult female's, and the subadult's size of home range and core area were both the least. Blue sheep showed a certain degree of overlaps in home range and core area. The size of overlaps was different by individual. The females' degree of overlap in home range was more greatly than the males'. The overlap in core area was showed a certain degree.2. Daily active rhythm of ten radio-collared blue sheep had been studied by monitoring each individual at 20 minute interval for more than 3continuous days in each month at Helan Mountain Nature Reserve, Ningxia Muslem Municipality from August 2005 to September 2006. The activities of feeding, standing and walking were accounted to 50.29% for each 24 hours, and 52.08, 48.50 for each diurnal and nocturnal hours. The active frequency between females and males were not very different as 51.37% to females and 49.50% to males. The females' active frequency was a little more higher than the males'. Two active peaks were found in 6:00～9:00, 17:00～20:00, during witch blue sheep were observed feeding in the field. A little peak between the two big peak was in 11:00～12:00, and another little peak was in the midnight of 22:00~24:00. The daily active rhythm of blue sheep could be affected by climate factors such as the intensity of sunshine, temperature and raining etc. Blue sheep were engaged in busily feeding in the morning from 06:00 to 07:00 and in the evening of 17:00 to 18:00. At those time period more than 70% of the active signals were recorded for the ten radio-collared blue sheep. The activity rate of radio-collared animals were lower in the hard raining, snowing and windy days. There were difference in active rhythm and time budget between individuals in different ages and sexes among the ten radio-collared blue sheep.3. Winter diet composition, selectivity and foraging strategy of blue sheep was studied with the microhistological analysis technique of feces and food in stomach in combination with field browse surveys from November 2003 to February 2004 and November 2005 to February 2006 in Helan Mountains between Ningxia Muslem Municipality and Inner Mongolia Municipality. We collected 230 pellets of feces of blue sheep, and composed 14 composite sample. Results showed that Graminoids (Stipa spp., Poa spp.), Ulmus pumila, Dasiphora spp., Caragana spp., Rosa xanthina, Prunus monglica were staples. The percentages of these items in diet were 27.55%, 24.46%, 6.867%, 6.55%, 5.36% and 4.14%. Blue sheep had positive selectivities for Ulmus pumila, Lespedeza spp., Prunus monglica, Dasiphora spp., Caragana spp., Rosa xanthina, and Juniperus rigida, and negative selectivities for Graminoids (Stipa spp., Poa spp.), Pinus tabulaeformis and Pinus crassifolia. They were arranged in order of preference as follows: Lespedeza spp.>Juniperus rigida>Rosa xanthina> Caragana spp.>Dasiphora spp.>Ulmus pumila>Prunus monglica>Graminoids> Pinus tabulaeformis > Pinus crassifolia. The Crude protein maintained high percentage in nutrient composition of browsed plants, so protein was sufficient for blue sheep, but energy might be a more critical factor to wintering blue sheep. To obtain maximum energy income with minimum energy paying is the foraging strategy of blue sheep in winter.