Platt Steven G, Monyrath Vuthy, Sovannara Heng, Kheng Long, Rainwater Thomas R
Wildlife Conservation Society, Phnom Penh, Cambodia.
Zoo Biol. 2012 Sep-Oct;31(5):534-45. doi: 10.1002/zoo.20418. Epub 2011 Aug 24.
The Siamese crocodile (Crocodylus siamensis) is considered one of the least studied and most critically endangered crocodilians in the world. Although few wild populations remain, more than 700,000 C. siamensis are held on commercial crocodile farms in Southeast Asia. Despite conservation concerns, many aspects of C. siamensis life history remain poorly known, particularly with regards to its reproductive biology. We studied nesting phenology, clutch characteristics, and other aspects of C. siamensis reproductive biology on crocodile farms in Cambodia during 2000 and 2001. Oviposition among captive crocodiles began in February and continued into early June. The mean (±1 SD) oviposition date based on pooled data from 2000 and 2001 was 5 April ± 24 days. Mean oviposition date differed significantly between 2000 and 2001, possibly as a result of annual variability among nesting cues. The mean incubation period was 72 ± 3 days and eggs hatched from 5 May to 18 August. Mean clutch size (25.0 ± 8.8 eggs; n = 183) differed significantly between years, possibly resulting from the >2.5-fold increase in sample size during 2001. There was no correlation between clutch size and oviposition date during either 2000 or 2001. A single female produced two clutches during 2001, complimenting previous reports of double-clutching among C. siamensis. The mean length and width of 515 eggs were 78.2 ± 4.9 and 48.1 ± 2.5 mm, respectively; mean egg mass was 90.8 ± 16.5 g (n = 471). One unpipped egg contained a set of twins.
暹罗鳄（Crocodylus siamensis）被认为是世界上研究最少且濒危程度最高的鳄鱼之一。尽管野生种群数量稀少，但东南亚的商业鳄鱼养殖场中仍饲养着超过70万只暹罗鳄。尽管存在保护方面的担忧，但暹罗鳄生活史的许多方面仍然鲜为人知，尤其是其繁殖生物学。我们在2000年和2001年期间对柬埔寨鳄鱼养殖场中暹罗鳄的筑巢物候、窝卵特征及其他繁殖生物学方面进行了研究。圈养鳄鱼的产卵始于2月并持续至6月初。根据2000年和2001年汇总数据得出的平均（±1标准差）产卵日期为4月5日±24天。2000年和2001年的平均产卵日期差异显著，这可能是由于筑巢线索的年度变化所致。平均孵化期为72±3天，卵在5月5日至8月18日孵化。平均窝卵数（25.0±8.8枚卵；n = 183）在不同年份间差异显著，这可能是由于2001年样本量增加了2.5倍以上。在2000年或2001年期间，窝卵数与产卵日期之间均无相关性。2001年有一只雌性鳄鱼产了两窝卵，这补充了之前关于暹罗鳄双窝产卵的报道。515枚卵的平均长度和宽度分别为78.2±4.9毫米和48.1±2.5毫米；平均卵重为90.8±16.5克（n = 471）。一枚未破壳的卵中有一对双胞胎。
