Habitat Selection Of Mrs. Hume's Pheasant (Syrmaticus Humiae) And Interspecific Comparisons Of Habitat Use In Dazhongshan, Yunnan

The study of habitat selection and use in birds has a long tradition. Habitat-selection studies have recently assumed a new urgency, as a result of the importance of habitat in conservation planning of endangered species. The contents of our study are seasonal habitat selection of Mrs. Hume's Pheasant (Syrmaticus humiae) which is a first grade national protected animals and comparative analysis of habitat use among sympatric endangered pheasants (S. humiae, Lophura nycthemera and Arborophila rufogularis) in Nanhua part of Ailaoshan Nature Reserve (originally called Dazhongshan Nature Reserve of Yunnan). The object of the former is to realize different requirements of habitat in different phases of life cycle of Mrs. Hume Pheasant, and furthermore probe into the influences of habitat selection on survival and breeding of pheasant, and that of the latter is to realize differential patterns of resourses use and interspecific competions of the sympatric pheasants, and what's more, to ravel approaches of differentiation in resources among the sympatric pheasants and their significances. The results will be helpful for the habitat protection of endangered species and for the developments of relative theories in habitat selection in birds and community ecology.From Feb. to Apr. in 2004, we assessed 21 habitat and environmental characteristics of roost sites of sympatric populations of between Mrs. Hume's Pheasant and Silver Pheasant in Nanhua part of Ailaoshan National Nature Reserve. Roost sites of the two pheasants had significant differences in the features of altitude, distance to water, perch height, height of roost tree, canopy tree density and diameter at breast height of root tree, and distance to water and canopy tree density were the discriminators of the two pheasants'roost sites. Our principal components analysis identified that the pheasants tended to roost on high perches of tall trees with large crown and cover in flourishing canopy trees with understroy of dense and tall shrub, and differentiated in the distance of roost sites to roads (i.e. Silver Pheasant roosted far away from roads). Similar location of their roost sites in windproof terrains with east and south aspect suggested that warm microhabitats were beneficial against coolness at night. Choice of tall roost trees implied they might benefit from landmarks or camouflages offered. Separation of foraging and roosting sites for Silver Pheasant indicated that human activities (i.e. hunting, goat grazing) perhaps greatly modified roost-site exploration of pheasants with long hunting history, but Mrs. Hume's Pheasant did not.From Mar. to Apr. in 2005, we conducted the comparative analysis of symparic Mrs. Hume Pheasant, Silver Pheasant and Rufous-throated Partridge in the study area. Comparing trophic niche breadth and overlapping index for 18 ecological factors of spring foraging site among the three pheasants, the results showed that S. humiae held the least eurytopic factors (value of trophic niche breadth bigger than 0.8) (one factor) and the most stenotopic factors (its value less than 0.8) (four factors) of the three pheasants. L. nycthemera held three eurytopic and two stenopic factors, while A. rufogularis showed the reverse of S. humiae with six eurytopic and no stenotopic factors respectively. There were five factors with a high degree overlap in the niche overlapping index between S. humiae and L. nycthemera, while there were only four factors between S. humiae and A. rufogularis and two between L. nycthemera and A. rufogularis. Of the overlapping factors, shrub coverage, leaf litter coverage and seed density were common with a high degree overlap in the niche overlapping index among the three pheasants. The results of a one-way ANOVA indicated that live factors (aspect, tall tree density, herb coverage, seed density and density of edaphic animal) were not significant, while distance to open fields, distance to road and shrub coverage were significant for the three pheasants. Other factors were significant between any two species. The results of a principal component analysis showed that the cumulative percentage is 85.6% in the first 7 principal components for S. humiae, is 86.0% in the first 6 principal components for L. nycthemera and is 79.0% in the first 5 principal components for A. rufogularis. Factors affecting the selection of foraging sites in the three pheasants concentrate in the first 3 principal components. The factors difference of foraging sites among the three pheasants showed a state of mosaic, which meant that there was a separation of niches among the three species. The factor combination of each species prior selection was different as well the importance of each factor was also different.From Nov. to Dec. in 2005, Mar. to Apr. and Jul. to Aug. in 2006, we respectively investgated habitat selection of Mrs. Hume Pheasant in fall and winter, spring and summer in the study area via the method of usage and availabiligy. The pheasant selected broadleaf evergreen forest as habitat category through out the year. In spring, the pheasant tended to prefer to tree species Daphnipnyllum oldhami, herb species Athyrium dissitifolium, and avoid tree species Lindera nacusua, herb species Rubus pectinaris and Vernonia aspera, and show no selection to the shrub species; the canopy tree cover of used plots was significantly higher than that of available plots; the optimal habitat in spring was characterized as developed canopy tree and shrub, less herb cover, abundant liane, sunny exposure, being far from water and openings. In summer, the pheasant favored the tree species Camellia taliensis and Lithocarpus variolosum, shrub species Ternstroemia gymnanthera, herb species Polypodium amoenum, and avoided tree species Pinus armandii and Alnus nepalensis, shrub species Populus bonatii, Lithocarpus variolosum and Mahonia flavida, herb species Pilea martini, Duchesnea indica and Vernonia aspera; the used plots were further from water resource than the available plots; the optimal habitat in summer were characterized as flourishing secondary forest, developed shrub, dense liane, less herb, dense leaf litter cover, shady exposure, adjoining to water resource, being far from roads. In fall and winter, the pheasant tend to select shrub species Ternstroemia gymnanthera, and avoid tree species Castanopsis orthacantha, shrub species Populus bonatii, and herb species Allantodia sp.; the used plots had denser canopy tree, less herb, and denser liane relative to available plots; the optimal of habitat in fall and winter were characterized as flourishing secondary forest, sparse tall shrub, less herb, dense leaf litter, high altitude, being far from water resource and openings.Habitat features of Mrs. Hume's Pheasant differed along seasons, with the exception of aspect, slope, leaf litter cover and density of liane. The discriminant factors of habitat plots among seasons were orderly listed as canpony tree cover, shrub density, average height of canopy trees, distance to road, distance to water, shrub cover and average height of shrub according to their importance. Multiple comparisons and the scatter plot of discrimination both indicated that habitat of Mrs. Hume's Pheasant was similar between spring, fall and winter, and evidently different from that in summer.