Abstract:
The conservation and recovery of increasingly threatened tropical freshwater turtle populations depends on effective management plans and actions. Here we show that community-based actions saved Yellow-spotted river turtle (Podocnemis unifilis) eggs submerged by unseasonal flooding and ensured the release of hatchlings. We recovered 926 eggs and 65 premature hatchlings from 74 submerged nests at 16 flooded nesting areas along 75 km of waterways. The rescued eggs were transferred to a rearing center and incubated. Hatchlings emerged from eggs that had remained underwater for up to two days. Hatchlings were maintained in 250-500 L nursery tanks until yolk sac scars had closed. Healthy hatchlings were then immediately released around the original nesting areas. We released 599 hatchlings (60.4%) from 991 submerged eggs and hatchlings. Egg survival (61.7% (571/926)) was substantially less than hatchling survival (94.2% (599/636)) but within the expected range of values reported for this species. These findings suggest that Yellow-spotted river turtle eggs and embryos are resistant to short-term submersion, which could help explain the widespread distribution of this species across highly seasonal Amazonian rivers. Management plans should take the possible survival of submerged eggs into consideration as part of species conservation and recovery actions.
摘要:
日益受到威胁的热带淡水龟种群的保护和恢复取决于有效的管理计划和行动。在这里,我们表明,基于社区的行动挽救了被非季节性洪水淹没的黄斑河龟(Podocnemisunifilis)卵,并确保了幼体的释放。我们从沿75公里水道的16个洪水泛滥的筑巢区的74个淹没巢中回收了926个卵和65个过早孵化的卵。将获救的卵转移到饲养中心并孵育。幼鸟从在水下停留了两天的卵中出现。将幼体保持在250-500升的育苗罐中,直到卵黄囊疤痕闭合为止。然后,健康的幼体立即在原始筑巢区域周围释放。我们从991个淹没的卵和幼体中释放了599个幼体(60.4%)。卵存活率(61.7%(571/926))大大低于孵化存活率(94.2%(599/636)),但在该物种报告的预期值范围内。这些发现表明,黄色斑点的河龟卵和胚胎对短期浸没具有抵抗力,这可能有助于解释该物种在高季节性亚马逊河流中的广泛分布。作为物种保护和恢复行动的一部分,管理计划应考虑淹没卵的可能存活。