四川梅花鹿的繁殖行为

Abstract

2006年4-12月和2007年3-11月在四川省铁布自然保护区观察和统计了野生梅花鹿的繁殖行为,包括发情交配、产仔、发情吼叫、爬跨及其昼夜节律行为等.结果表明,四川梅花鹿为季节性发情动物,发情交配行为发生在9月上旬至12月中旬,集中在10-11月(占(86.99±3.24)%).四川梅花鹿发情交配日期最早见于9月8日,最晚为12月16日,跨度约90-100 d(±6 d,<em>n</em>=90).雌鹿交配日期与其繁殖经历具有低度正相关性(Kendall's tau-b和Spearman's rho,0.3 < <em>r</em> < 0.5,<em>P</em> < 0.05),成体雌鹿交配日期稍微早于初次配种雌鹿.雄鹿发情吼叫和爬跨行为具有明显的昼夜节律性,各有2个高峰期(05:00-08:00和18:00-21:00),夜间有小节律的发情吼叫和爬跨时期.U-test检验表明发情吼叫频次和爬跨频率在昼夜间有极显著差异(<em>P</em> < 0.01).雄鹿吼叫行为与其交配行为具有高度正相关性(Kendall's tau-b和Spearman's rho,0.8<<em>r</em> < 1.0,<em>P</em> < 0.05),主雄、次雄和群外单身雄鹿的昼夜吼叫次数有极显著差异(<em>P</em> < 0.01).雌鹿产仔期从4月下旬开始到7月下旬结束,集中在5-6月(占(91.51±4.96)%),产仔日期最早见于4月29日,最晚为7月28日,跨度约80-90 d(±5 d,<em>n</em>=130).梅花鹿产仔日期与其分娩经历具有低度正相关性(Kendall's tau-b和Spearman's rho,0.3 < <em>r</em> < 0.5,<em>P</em> < 0.05),成体雌鹿产仔日期早于初次繁殖雌鹿.雌鹿每胎产1-2个幼仔,单双胎率分别为98.86%(± 6.96%,<em>n</em>=129)和1.01%(± 0.07%,<em>n</em>=1).妊娠期和哺乳期梅花鹿采食行为分配占较大比率,其次是卧息和移动,哺乳期采食行为分配低于妊娠期,这与妊娠期正逢冬季,食物资源相对匮乏有关,而哺乳期恰逢夏季,植物生长旺盛,食物资源相对丰富.;Sika deer (<em>Cervus nippon</em>) is an endangered species, which has been listed on the IUCN Red List of Threatened Species and the Appendices of the CITES. In addition, Sika deer is also classified as a Category I key species under the Wild Animal Protection Law in China. Reproductive behaviors of Sichuan sika deer (<em>C.n.sichuanicus</em>), including rutting and copulating, fawning season, circadian rhythms of estrous roar and mounting behavior, etc., were observed and recorded from April to December 2006 and from March to November 2007 in Tiebu Natural Reserve, Zoige County, Sichuan Province, China. The results indicated that Sichuan sika deer was seasonal estrus animal. The behaviors of estrus and copulation were observed from early September to the middle of December, with a higher frequency ((86.99±3.24)%) occurring between October and November. The earliest rutting and mating behaviors occurred at 8 September and the latest in 16 December, covering a period of 90 -100 d (± 6 d, <em>n</em>=90). There was a low positive correlation between the mating date of female deer and their mating experience (Kendall's tau-b and Spearman's rho, 0.3 < <em>r</em> < 0.5, <em>P</em> < 0.05), and the mating date for the adult females were slightly earlier than that for the first breeding ones. The behaviors of estrous roar and mounting in males have noticeable circadian rhythms, in which each have two peak periods (05:00-08:00, 18:00 -21:00) and several low rhythm at night. U-test showed that the roar frequency and mounting rate were significantly different between daytime and night (<em>P</em> < 0.01). The roar behaviors in males were high positive related to their mating behaviors (Kendall's tau-b and Spearman's rho, 0.8 < <em>r</em> < 1.0, <em>P</em> < 0.05), and there were statistically significant differences in the frequency of circadian roar among dominant males, subordinate males and single males (<em>P</em> < 0.01). Hinds fawning took place from the end of April to the end of July, and most frequently ((91.51± 4.96)%) between May and June (<em>P</em> < 0.01). The earliest calving happened on 29 April and the latest on 28 July, covering a period of 80 -90 days d (± 5 d, <em>n</em>=130). There was a low positive correlation between the fawning date of females and their parturition experience (Kendall's tau-b and Spearman's rho, 0.3 < <em>r</em> < 0.5, <em>P</em> < 0.05), and the fawning date in adult females was slightly earlier than the first breeding females. Its litter sizes ranged from one to two fawns once, and single and twinning rate were 98.86% (± 6.96%, <em>n</em>=129) and 1.01% (± 0.07%, <em>n</em>=1), respectively. Among all behaviors, feeding behavior has a largest proportion, followed by the resting and moving behaviors during pregnancy and lactation. The proportion of feeding behavior during lactation lower than it would be during pregnancy, which is related to the different situation of food resources in the two periods. Food resources were relatively scarce in winter (pregnancy period), and rich in summer (suckling period).