繁殖季节同域分布的红腹角雉和血雉的觅食生境选择

Foraging habitat selection by sympatric Temminck’s tragopan and blood pheasant during breeding season in southwestern China

红腹角雉(Tragopan temminckii)和血雉(Ithaginis cruentus)是主要分布在中国的受胁雉类,到目前为止,对这两种雉类的生态学特征的了解并不多。作者于2006年5-8月,在四川省栗子坪自然保护区公益海,运用样线法和样方取样法对红腹角雉和血雉在繁殖季节的觅食生境选择进行了对比研究。研究结果表明,两种雉在海拔分布和觅食生境上都存在重叠,红腹角雉主要分布在较低海拔(1,950?3,450m),血雉分布在相对较高海拔(2,760?3,800m)。它们对针叶林和针阔混交林都表现出正选择性,而对箭竹林表现出负选择性。微生境尺度上,两种雉觅食生境的乔木和草本盖度均较大,草本高度高;两种雉的活动区内针叶林面积较大,距林区公路较近;红腹角雉对坡向没有选择性,血雉偏好西南坡向的生境。与对照样方相比,红腹角雉的觅食生境的箭竹高度和盖度小,血雉觅食生境的箭竹高度和盖度与对照样方无显著差异。红腹角雉活动区内的箭竹林面积比例显著小于血雉活动区,针阔混交林面积比例显著大于血雉活动区。表明两种雉类在需要某些共同资源的情况下,对觅食生境的利用产生了分异,这是两种雉类能够同域分布的基础条件之一。

Temminck＇s tragopan （Tragopan temminckii） and blood pheasant （Ithaginis cruentus） are two threatened species mainly distributed in China. However, we know little about the ecology of these two pheasants. Between May and August in 2006, we investigated foraging habitat selection by the two sympatric species in Liziping Nature Reserve in Sichuan Province, China, using line transect and systematic sampling methods. Temminck＇s tragopans occurred at relatively low altitudes （1,950-3,450 m）, while blood pheasants occurred at higher altitudes （2,760-3,800 m）. No differences were found between the two species in terms of use of forest types. Both species preferred coniferous and mixed coniferous-broadleaved forest and they seldom occurred in forest areas with dense arrow bamboo （Fargesia spathacea）. At the microhabitat scale, both species were consistently associated with dense tree coverage, and dense coverage of tall herbaceous plants. Home ranges of the two species contained more coniferous trees than random, and foraging sites were close to forest roads. We did detect some habitat use differences between the two species. Blood pheasant foraging habitats were associated with southwest-facing slopes, while Temminck＇s tragopans did not select sites based on aspect. The habitats of Temminck＇s tragopans were associated with lower arrow bamboo and sparse bam- boo coverage compared to the control sites. There were more mixed coniferous-broadleaved forests and less forest-bamboo mixed forests in Temminck＇s tragopans＇ home ranges than in blood pheasants＇ home ranges. We suggest that basic differences in habitat use can explain how the two species are able to maintain sympatric distributions.