The Study of Population Ecology and Genetics for Formosan Black Bears in Yushan National Park(2/4)
中文摘要
有鑑於保育瀕危物種的迫切性以及長期生態研究對於野生
動物經營管理之重要性,本計畫延續前期於玉山國家公園進行之台灣黑熊(Ursus thibetanus formosanus)生態研究,持續長期的資料收集及累積,增加我們對於此物種於野外的生態習性、族群遺傳特性的瞭解,並提供具體的經營管理建議,以作為成功保育該物種的依據。園區東側的大分地區為瀕危台灣黑熊重要的棲息地,該地殼斗科植物-青剛櫟(Cyclobalanopsis glauca)的物候週期及結果變動,影響台灣黑熊時空上的活動模式和族群變動。藉由第6年的長期生態資料的收集和分析,持續監測大分地區殼斗科森林青剛櫟的結果量變動,以及利用該地櫟實的潛在種子掠食者及其時空分布。同時藉由遺傳樣本,並進一步釐清玉山國家公園大分地區台灣黑熊的族群量、遺傳多樣性、近親交配指數、族群結構等資訊,以探討此物種的族群永續力。另外,藉由青剛櫟種子命運的監測,探討
動物活動和豐富度與重要食物資源(櫟實)變動之關係,以及彼此間可能的交互作用。大分青剛櫟盛產時,會吸引高密度的黑熊聚集,故在經營管理上需注意或限制遊客於此區的承載量和活動狀況,以確保人員安全,並降低可能造成的干擾。由於熊科
動物的季節性移動,會受到不斷變化的食物資源條件(包括豐富度及分布)影響。因此,為更確切估算園區台灣黑熊的族群數量,以及加強族群的存續力,本研究建議應該進一步瞭解活動於大分地區的黑熊個體的實際活動範圍所含括的地理區域,也就是收集這些個體在時間上和空間上相對於國家公園範圍和位置的分布情況,或活動源自國家公園外圍的哪些區域之資料,以期充分瞭解大分地區或整個國家公園的黑熊族群數量,以及之於全島黑熊族群的生態角色及可能的保育效能。此可透過增加黑熊遺傳樣本採樣的範圍,從玉山國家公園較外圍及附近的區域擴展至更遠的區域達成。
英文摘要
Dafen of the Yushan National Park (YNP) is a critical habitat for locally endangered Formosan black bears (Ursus thibetanus formosanus). The phenology and acorn production of Cyclobalanopsis glauca potentially influence the temporal and spatial movement, activity and relative abundance of bears and other wildlife. The objective aimed to continue the 6th-year acorn and bear monitoring project, and to understand the corn predators and seed fate. The 2011 acorn production estimated by the Graves’ modified scale and the 30 second counting method revealed an index of 1.9±0.98 (±SD) and 49.2±42.5 acorn/per tree, respectively. The production of intact and damaged acorns collected and estimated by 195 seed traps were 34.8 and 16.5 acorns/m2. The yearly changes of the relative abundance of bears based on sign surveys and hair traps coincided with the acorn production dynamicsAmong the 100 individuals identified from the DNA samples collected in 2008, 46 females and 44 males were further define d, except for 10 unknowns. The sex ratio did not bias from 1:1 (χ2 = 0.044, P = 0.833). We applied digital cameras to identify acorn predators, using acorns placed on the ground surface. The removal frequency was highest for small rodents (73%), and then sambar deer (Cervus unicolor swinhoei, 15.3%). However, the acorn were mainly used in amount by sambar deer (73%), and followed by rodents (20%). Other 4 recorded acorn predators, ranked by feeding frequency, included black bears (3.5%), wild boars (Sus scrofa taivanus, 0.7%), and macaques (Macaca cyclopis, 0.7%), and Eurasian jays (Garrulus glandarius, 0.5%). Four types of enclosures were used to evaluate the effects of rodents and large acorn predators. When large predators were excluded from a plot, rodents consumed 29% of the acorns. When rodents were excluded from a plot, large mammals consumed 32% of theacorns. We also found that the acorn consumption levels of predators were likely influenced by the fallen acorn amounts in the neighboring areas. During the 19-month monitoring, the oak seedlings within fences showed a higher survival rate and lifespan than those without fences (survival rate: 67% vs. 34%; lifespan: 13±7 vs. 8 ±5). The result indicated animal activity will effect seeding disturbance.