翡翠水庫食蛇龜野生動物保護區之食蛇龜(Cuora flavomarginata)族群特性與變動趨勢

Population Characteristics and Dynamics of the Yellow-margined Box Turtle (Cuora flavomarginata) in the Yellow-margined Box Turtle Wildlife Refuge in Northern Taiwan

鍾明璋(Chung Min-Chang)

指導教授 ： 陳添喜

國立屏東科技大學/獸醫學院/野生動物保育研究所/碩士(2023年)

https://doi.org/10.6346/NPUST202300077

摘要

食蛇龜(Cuora flavomarginata)因受非法獵捕與棲地改變的生存威脅，最近20年野生族群快速消失，於國內已被公告為瀕臨絕種保育類野生動物。翡翠水庫集水區內為食蛇龜野生族群重要分布範圍，仍有國內少數穩定的野生族群，已於2013年公告劃設為翡翠水庫食蛇龜野生動物保護區。本研究目的為了解棲地受保護下食蛇龜野生族群的族群特性，以及透過1996開始進行族群監測結果，探討食蛇龜野生族群的變動趨勢，並提供保育上的建議。本研究於2021-2022年以樣區巡視及陷阱誘捕方式進行食蛇龜重複捕捉標放，總共進行53次調查，放置1002次陷阱，累計捕獲100隻食蛇龜，分別有68隻雌龜、30隻雄龜、2隻幼龜，捕獲性別比為2.27:1(雌:雄)，體型結構分佈集中於140.0-159.9mm。利用POPAN模式估算族群個體數結果，於1997-2003年為348-393隻， 2012-2015年下降至252-286隻，於2016-2019年為156-208隻，2020-2021年僅剩112-184隻；利用Cormack-Jolly-Seber (CJS)模式估算食蛇龜族群表存活率(apparent survival)，在1996-2003年維持在0.94-1.00之間變動，2011年的推算值有明顯下降(0.69)，於2012-2014年有回升趨勢(0.87-0.97)，2015年後下降未明顯回升(0.78-0.92)；利用Pradel model估算食蛇龜族群年增長率(λ)，在1997-2002年維持在0.963-1.048之間變動，2011年推算值約0.682，2012-2014年為0.881-1.105，2015年降為0.720，2016年後族群年增長率雖上升為0.902-0.967，但族群量仍持續下降。比較1996-2022年體型組成，2012年以後未判定性別幼龜及體型較小個體所占比例下降，顯示族群自然繁殖補充受到限制。本研究樣區食蛇龜野生族群受棲地自然演替及棲地受保護後捕食者增加影響，繁殖成功率下降。本研究族群雖然受到保護，但在遭受非法獵捕後，個體數、表存活率與族群年增長率估算值仍有下降趨勢，瀕危食蛇龜族群保育仍需適度進行棲地營造與管理，並持續監測非法獵捕對野生族群的影響。

關鍵字

非法獵捕 ； 族群特性 ； 族群變動

並列摘要

In Taiwan, the populations of the yellow-margined box turtle (Cuora flavomarginata) has been threatened by illegal hunting and habitat destruction, and its population has decline in the past two decades. In 2013 year, the Wildlife Refuge was set up in northern Taiwan to protect the yellow-margined box turtle. This study purpose to understand the population characteristic of yellow-margined box turtle in a monitored area of the Yellow-margined Box Turtle Wildlife Refuge, and using long-term data to explore population dynamic in twenty-five years. In 2021-2022 year, mark recapture study with search the study site and trap to yellow-margined box turtle, a total of 53 surveys were conducted, 1002 traps were placed, and a total of 100 yellow-margined box turtles were captured, including 68 females, 30 males, and 2 juveniles, female to male sex ratio is 2.27:1(Female:Male), the distribution of carapace length structure is concentrated in 140.0-159.9mm. Using the POPAN open population model to estimate the number of individuals in the population, it was 348-393 individuals in 1997-2003, 252-286 individuals in 2012-2015, and dropped to 156-208 individuals in 2016-2019; Using the Cormack-Jolly-Seber (CJS) model to estimate the apparent survival of the yellow-margined box turtles, it was at 0.94-1.00 from 1996 to 2003, dropped to 0.69 in 2011, and rose in 2012-2015 to 0.87-0.97, after 2015 dropped to 0.78-0.92; Using the Pradel model to estimate the annual growth rate (λ) of the yellow-margined box turtles, it was at 0.95-1.05 in 1997-2003, dropped to 0.68 in 2011-2012, 0.89-1.12 in 2012-2015, declined in 2015-2016 to 0.71. After 2016 population growth rate rose to 0.90-0.96 but population size still reduce. Comparing the carapace length structure from 1996 to 2022, the proportion of juveniles and smaller individuals decreased after 2012, indicates that the population's recruitment is limited. The population of yellow-margined box turtles in a monitored area was affected by the natural succession and not easy to reproduce because of predators increase after the habitat was protected. Although the monitored area are protected, the population size, apparent survival and population growth rate are still on a downward trend after illegal hunted. The conservation of endangered yellow-margined box turtles need to habitat creation and management, and continuous monitoring of the impact of illegal hunting on yellow-margined box turtles populations.

並列關鍵字

illegal hunt ； population characteristic ； population dynamics

參考文獻

林務局 (2021) 瀕危物種食蛇龜保育行動計畫（初稿）。行政院農委會林務局。33頁。

陳添喜 (1998) 台灣北部地區斑龜(Ocadia sinensis)及食蛇龜(Cuora flavomarginata)生活史之研究。國立臺灣師範大學博士論文。124頁。

張慧 (1986) 黃緣閉殼龜養殖的研究。動物學雜誌，北京 21(1):11-13。

趙平 (1993) 黃緣閉殼龜的泄殖系統。動物學雜誌，北京 28(2):31-34。

蔡承儒 (2019) 翡翠水庫食蛇龜野生動物保護區食蛇龜(Cuora flavomarginata)之活動範圍、棲地利用與微棲地選擇。國立屏東科技大學碩士論文。62頁