Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA, USA.
Caretta Research Project, Savannah, GA, USA.
Environ Entomol. 2021 Jun 18;50(3):649-657. doi: 10.1093/ee/nvab021.
Ants have been suggested as one of many population pressures sea turtles face potentially affecting nesting-beach survival of eggs and hatchlings. However, little is known about the extent to which ants act as incidental or primary mortality factors. Most research has focused on New World fire ants (genus Solenopsis), with confirmed records of other ant species interactions with sea turtle nests in situ being rare. Our study documented the ant species associated with loggerhead sea turtle Caretta caretta (Linnaeus) (Testudines: Cheloniidae) nests in Georgia and determined if ant presence was linked to lower hatching or emergence success. Samples (n = 116) collected from sea turtle nests on eight islands contained 14 ant species including Solenopsis invicta Buren (Hymenoptera: Formicidae), the red imported fire ant, which was the most common ant species encountered. Ant presence was not correlated with lower hatching success, but when other known disturbances were removed, correlated with significantly lower nest emergence success (P < 0.0001). Logistic modeling suggests that proximity of sea turtle nests to the primary dune significantly increases risk of ant predation on hatchling sea turtles. Population managers can reduce this risk by maintaining a 1-m buffer shoreward between dune vegetation and relocated sea turtle nests. Our results suggest that ants may exert a density-dependent pressure on nesting sea turtle populations and call for additional investigations to determine if managing native and invasive ants augments other efforts to improve hatchling survival.
蚂蚁被认为是海龟面临的众多种群压力之一，可能会影响到卵和幼海龟在筑巢海滩上的存活率。然而，人们对蚂蚁作为偶然或主要致死因素的程度知之甚少。大多数研究都集中在新大陆火蚁（属 Solenopsis）上，很少有关于其他蚂蚁物种与海龟巢内相互作用的记录。我们的研究记录了与红海龟 Caretta caretta（Linnaeus）（龟鳖目：Cheloniidae）巢相关的蚂蚁物种，并确定了蚂蚁的存在是否与较低的孵化或出壳成功率有关。从八个岛屿上的海龟巢中采集的样本（n = 116）包含 14 种蚂蚁，其中包括 Solenopsis invicta Buren（膜翅目：蚁科），即红火蚁，这是最常见的蚂蚁物种。蚂蚁的存在与孵化成功率较低没有相关性，但当去除其他已知的干扰因素时，与巢出壳成功率显著降低相关（P < 0.0001）。逻辑回归模型表明，海龟巢与主要沙丘的接近程度显著增加了蚂蚁捕食幼海龟的风险。通过在沙丘植被和重新安置的海龟巢之间保持 1 米的缓冲带，种群管理者可以降低这种风险。我们的研究结果表明，蚂蚁可能对筑巢的海龟种群施加了一种密度依赖的压力，并呼吁进一步调查，以确定管理本地和入侵蚂蚁是否会增强其他提高幼体成活率的努力。
