KOREASCHOLAR

2004년 2월부터 2005년 6월까지 제주특별자치도 애월읍 신엄리에서 흑로의 번식과정을 조사하였다. 한배 산란수는 3.24±0.75개(N=17, 범위 2~4개)였으며, 알은 새벽이나 밤에 1~3일 간격으로 산란하였다. 알(N=39)의 크기는 장경 46.73±l.91mm, 단경 34.06±0.83mm, 무게 27.67±3.12g, 두께 0.26±0.03mm였다. 흑로의 둥지 보수나 짓기는 매년 2월부터 시작해서 늦게는 4월말까지, 산란기는3월초부터 늦게는 5월 초순까지였고, 부화기는4월 초순에서 5월 중순까지, 이소기는 5월 중순부터 7월말까지였다. 보충 산란은 1차 번식과정 중 포란과 육추에 실패한 5~6월에 바로 시도하는 것으로 추정된다. 포란 기간은 28.17±4.12일(N=6)이었으며, 알은 비동시성으로 부화되었다. 육추 기간은 40.00±6.84일(N=5)이었으며, 새끼의 부리, 날개, 부척, 체중의 성장속도는 부화가 빠른 개체일수록 빠른 경향을 보였다. 우리나라에서 번식하는 백로과 조류의 산란시기를 비교해보면, 흑로는 왜가리보다는 느렸으나, 해오라기, 쇠백로, 중대백로는 보다는 빨랐다.

This study was based on the breeding process of the Pacific Reef Herons (Egretta sacra) bred in Aewol-eup, Jeju Island, for two years from February 2004 to June 2005. The clutch size of the pacific reef herons was 3.24±0.75(N=17, range: 2~4), and the egg-laying was at dawn or night intervals of one to three days. The major diameter of the egg(N=39) was 46.73±1.91mm, the minor diameter thereof 34.06±0.83mm, the weight thereof 27.67±3.12g, and the thickness of the egg shell thereof 0.26±0.03mm. In relation to the breeding cycles of the Pacific Reef Herons, the nesting or nest repairing was made from February to the end of April each year, the egg laying from the beginning of March to the beginning of May, the hatching from the beginning of April to the middle of May, and the nest departure from the middle of May to the end of July. The supplement brood was started immediately from May to June when the first brood had failed. The incubation period was 28.17±4.12(N=6) days, and hatched asynchronously. The fledgling period was 40.00±6.84(N=5) days, and bill, wing, tarsus and weight developments of early hatched nestlings were the fastest among the same brood. Compared with other egret species, the egg laying period of the Pacific Reef Heron was faster than that of the Black-crowned Night Heron, Little Egret and Great Egret, but later than that of Grey Heron, in Korea.

• 오홍식 | Oh, Hong-Shik
• 김원택 | Kim, Won-Tack
• 김완병 | Kim, Wan-Byung