短嘴金丝燕繁殖生物学特征与保护对策

Breeding biology and conservation strategy of the Himalayan swiftlet (Aerodramus brevirostris innominata) in southern China

1994年4月至2007年11月,在湖南壶瓶山国家级自然保护区内,通过定点监测与环志标记等方法,对短嘴金丝燕(Aerodramus brevirostris innominata)的繁殖生物学进行了研究。结果表明,短嘴金丝燕在本地区为夏候鸟,每年4月初迁来,11月初迁走,居留期约210天。所研究的神景洞洞穴内居住了大约2,000只个体,种群性比为1:1,不同年份种群数量基本稳定。环志标记结果发现,短嘴金丝燕出生1年后即可达到性成熟;其婚配形式为典型的单配制。短嘴金丝燕在黑暗洞穴内营巢,巢材主要为唾液和苔藓,筑巢期长达60天左右,且有利用旧巢的习性。产卵集中在6月,大部分每巢产卵2枚,少数产1枚。第1枚卵产出后开始孵卵,由雌雄鸟共同承担,但以雌鸟为主。孵卵温度为37.3±1.0℃;孵卵期为27.9±3.4天;繁殖成功率为71.4%。雏鸟晚成性,育雏主要由雄鸟承担;雏鸟食物成分与亲鸟基本相同,全为昆虫,育雏期27天左右;雏鸟离巢后首先在洞穴内练习飞行,3–4天后出洞活动。刚离巢时雏鸟体重甚至超过成鸟,离巢后体重有减轻现象。目前,威胁我国短嘴金丝燕生存的主要因素是其分布区的旅游开发和非法采集燕窝对其繁殖活动的干扰。因此,我们建议有关部门停止对短嘴金丝燕栖息的洞穴及其周边活动区域的旅游开发,并禁止非法采集燕窝。

From April 1994 to November 2007, we studied the breeding biology of the Himalayan swiftlet （Aerodramus brevirostris innominata） based on field investigations, behavior observations, and bird bandings in the Shenjing Cave of Hupingshan National Nature Reserve, Hunan Province. Overall, we found a total breeding population of 2,000 swiftlets in the cave. The Himilayan swiftlet is a summer migrant in the area which arrives in early April and departs in early November. This species is monogamous with a sex ratio of about 1：1, and reaches sexual maturity at one year of age. Birds nested in dark caves, with nests primarily composed of saliva and mosses. Birds took 60 days to finish nest construction, and old nests from previous years were fully reused. We found that egg laying began after nest construction and peaked in June. In most cases, two eggs were found in each nest, while occasionally one egg. Both males and females were involved in incubation, but females invested relatively more time. The incubating temperature, duration, and hatching success were 37.3±1.0 ℃, 27.9±3.4 days, and 71.4%, respectively. Nestlings were altricial, and were fed mainly by males for about 27 days with insects, which were the same as adults’ diet. They spent another 3or4 days to learn to fly in the cave before fledgling the nest. Fledglings gained substantial weight, which tended to be greater total weight than the parents, before leaving the nest. We observed a concordant decrease in weight upon reaching sexual maturity. Primary threats to Himalayan swiftlets in China include disturbance to breeding activities resulting from tourism development and illegal nest-collection. We suggest that authorities halt development of caves and surrounding areas and ban the illegal nests collection.