孵化期遗鸥卵质量变化及卵参数测定

Eggs Mass Variation and Parameters Measurement of Larus relictus in Incubation Period

本研究在红碱淖湿地共收集遗鸥Larus relictus卵111枚,采用实测和公式计算的方法进行卵参数测定。结果表明,同窝卵各参数随产卵顺序依次减少(卵质量:1=59.31 g±3.86 g,2=56.59 g±3.67 g,3=54.99 g±3.96 g),其中第1枚卵质量与第2、3枚卵质量差异有统计学意义(P<0.05)。这可能与自身能量储备有关,通过减轻卵质量和缩小卵大小,但又不影响卵孵化率,以达到亲鸟最大繁殖适合度的策略。遗鸥在孵化阶段卵质量损失9.50 g±1.45 g,损失率为15.82%±1.94%。孵化后3~5 d和雏鸟出壳前2 d卵质量损失出现明显峰值,整体上卵质量损失速度与胚胎发育速度一致。野外调查中,当能获得卵鲜质量时,用Paganelli公式计算;反之,用Narhshin公式计算。但2种方法计算结果与实测结果差异无统计学意义(P>0.05)。总体上,在遗鸥卵参数测定中,Paganelli公式比Narushin公式更简便、快捷。

In this study,a total of 111 eggs of relict gull（ Larus relictus） were collected in Hongjiannao wetland,and eggs parameters were determined by formula method and manual measure. The results showed that eggs parameters were reduced along with egg laying sequence in the same clutch（ egg mass： 1 = 59. 31 g ± 3. 86 g,2 = 56. 59 g ± 3. 67 g,and3 = 54. 99 g ± 3. 96 g）,and the first egg had significant differences with the second and the third egg（ P〈0. 05）. This might be due to the management of energy storage which could achieve the maximum breeding fitness of parental birds by reducing egg mass and egg size but without influencing the hatching rate of eggs. The mean mass loss of eggs was 9. 50 g ±1. 45 g,and the loss rate was 15. 82% ± 1. 94%. Additionally,egg loss peaked in 3-5 d of post-hatching and 2 d of prenestling,on the whole,egg mass loss rate was consistent with the embryonic development. Paganelli formula was used to determine the raw mass of eggs in field investigation,where others were calculated by Narhshin formula. However,the results of both formula methods had not significant differences with that of manual measure（ P〉0. 05）. Overall,Paganelli formula is simple and quick than Narushin formula in parameters measurement of L. relictus.