山麻雀物種分布模式

Species distribution models of Russet Sparrow (Passer cinnamomeus)

謝承恩(Cheng-En Hsieh)

指導教授 ： 李培芬

國立臺灣大學/生命科學院/生態學與演化生物學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201903853

摘要

瞭解限制物種分布的環境因子是物種保育重要的基礎，但受限於物種特性或調查限制，物種的分布範圍、棲息地等相關知識無法全面瞭解。物種分布模式 (Species Distribution Models) 運用物種出現的紀錄和相關的環境因子來預測物種的潛在棲地，於提供生態與保育管理的資訊，評估生物多樣性與保護區設定的策略等有廣泛的應用價值。在臺灣，山麻雀 (Passer cinnamomeus) 面臨數量減少與分布範圍縮減的威脅，目前估計全臺灣島族群量在1,000隻以下。山麻雀主要分布海拔介於600至2000公尺，早期文獻稱山麻雀的數量普遍，常可見於空曠或已開墾之地區。過去一些可見到山麻雀蹤跡的地區，現已不再有山麻雀的紀錄，山麻雀面臨的威脅尚未確定。過去山麻雀的研究多針對臺灣特定地區進行，其族群狀態與趨勢為綜合不同空間尺度，各項環境與生物因子共同作用的結果。本研究嘗試由東亞尺度分析山麻雀完整分布範圍的環境特性，並與臺灣分布現況比較，以探討其分布受壓縮的程度與可能原因。藉由山麻雀在東亞分布的資料與環境資料，以三種模式(MaxEnt, GARP和Bioclim)分別建立東亞尺度(約10×10公里)及臺灣尺度(約1×1公里)的物種分布模式，並分析合適棲地的棲地特性。結果顯示，將山麻雀在東亞尺度預測的合適棲地範圍投射於臺灣島，和臺灣尺度的合適棲地範圍比較時，東亞尺度在臺灣的合適棲地範圍大於臺灣尺度 (60.6% > 13.8%)。不同尺度預測模式的重要環境因子亦不相同，東亞尺度的重要環境因子皆與自然的植被類型有關，而臺灣尺度則和海拔高度、溫度與降水量有關。由模式之合適棲地特性分析得知，山麻雀的合適棲地分布較靠近山區 (1100m) 且年降水量豐沛 (1400mm) 的區域，從植被類型來看，合適棲地位於農業和自然環境的交界帶。透過不同尺度的物種分布模式結果，山麻雀在臺灣的合適棲地範圍應大於現有的分布範圍，推測棲地量應不是山麻雀分布限制的因子。建議未來可針對非繁殖季的棲息環境、不同海拔的繁殖成功率與行為及築巢地點的選擇來探討山麻雀在臺灣分布受限的因子，並可以參考本研究臺灣尺度的合適棲地範圍，規劃系統性調查和長期監測，為山麻雀的保育提供更完整的資訊。

關鍵字

山麻雀 ； 物種分布模式 ； 合適棲地 ； eBird賞鳥資料庫

並列摘要

Understanding the environmental factors that influence the distribution of species is an important basis for species conservation, but restricted by species characteristics or survey constraints, the knowledge of species distribution and habitats cannot be fully understood. Species Distribution Models use species occurrences data and related environmental data to predict potential habitats, providing information on ecological and conservation management, and evaluate strategies for biodiversity and protected areas.
In Taiwan, the Russet Sparrow (Passer cinnamomeus) faces the threat of abundance declining and distribution range decreasing. It is estimated that the population in Taiwan is below 1,000. The Russet Sparrow mainly distribute on the altitude range from 600 to 2000 meters. The earlier literature recorded that the number of Russet Sparrow was common and could be found around agricultural land, but now Russet Sparrow cannot be observed in some areas where Russet Sparrow was abundant before. However, the threat has not been determined.
The researches about Russet Sparrow were mostly studied in specific areas of Taiwan. The population status and trends were the results of combining different spatial scales and various environmental and biological factors. This study attempts to analyze the environmental characteristics of the complete distribution of Russet Sparrow from the East Asian scale, and compare it with the current situation in Taiwan to explore the distribution extent and possible reasons. Using eBird open data and environmental data to establish East Asia scale (about 10×10 km) and Taiwan scale (about 1×1 km) of species distribution models by three models (MaxEnt, GARP and Bioclim) respectively. And then analyze the habitat characteristics of suitable habitats.
The results show that when comparing different scale of suitable habitats in Taiwan, the suitable habitats range from East Asian scale are larger than the Taiwan scale (60.6% > 13.8%). The important environmental factors of different scales are also different, the factors of East Asian scale are related to natural vegetation types, while the Taiwan scale is related to the altitude, temperature seasonality and precipitation seasonality. The suitable habitats of Russet Sparrow is close to mountainous area (1100m) and the annual precipitation is abundant (1400mm). From the vegetation type, the suitable habitats is located in the agricultural and natural environment. Through the results of species distribution patterns of different scales, the suitable habitat of the mountain sparrow in Taiwan should be larger than the existing distribution range. It is assumed that the habitat amount should not be a factor limiting the distribution of Russet Sparrow.
It is suggested that in the future, we can explore the factors that restrict the distribution of Russet Sparrow in Taiwan, like habitats of non-breeding seasons, the reproductive success rate and behavior at different altitudes, and the choice of nesting sites. We can use the suitable habitat range of Taiwan scale in this study to plan systematic investigations and long-term monitoring, providing more complete information for the conservation of Russet Sparrow.

並列關鍵字

Russet Sparrow ； Species distribution model ； suitable habitat ； eBird

參考文獻

Araujo, M. B., and M. New. 2007. Ensemble forecasting of species distributions. Trends in Ecology and Evolution 22:42-47.

Booth, T. H., H. A. Nix, J. R. Busby, M. F. Hutchinson, and J. Franklin. 2014. Bioclim: the first species distribution modelling package, its early applications and relevance to most current MaxEnt studies. Diversity and Distributions 20:1-9.

Bourke, J., K. Busse, and W. Böhme. 2012. Searching for a lost frog (Rhinoderma rufum): identification of the most promising areas for future surveys and possible reasons of its enigmatic decline. North-Western Journal of Zoology 8:99-106.

Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2018. The eBird/Clements checklist of birds of the world: v2018.

Boyce, M. S., P. R. Vernier, S. E. Nielsen, and F. K. Schmiegelow. 2002. Evaluating resource selection functions. Ecological Modelling 157:281-300.