Despite extensive ecotoxicological evidence on the adverse effects of oil pollution on rodents, little is known about how rodents make decisions in oil-polluted environments (i.e., outside of lab settings). We investigated the foraging behavior of Allenby gerbils, Gerbillus andersoni allenbyi (GA), that were presented with feeding trays in a semi-natural environment. The trays contained seeds mixed into one of three types of soils – clean soil, and two different soil samples collected from two well-documented terrestrial oil spill sites in Israel. The oil spill disasters occurred in 1975 and 2014 and the spill sites are located within a few hundred meters of each other, in the 'Avrona Nature Reserve in the Arava hyper-arid region in Israel.Gerbils of both sexes avoided foraging in 2014-polluted soil, but surprisingly, they foraged more in 1975-polluted soil. Our results indicate that for the GA, the 1975-polluted soil is an advantageous substrate to forage on, probably because its texture facilitates more efficient foraging, leading to greater energetic gain, and creating a trade-off between energetic gain and perceived foraging cost due to its pollution. We also proceeded to investigate some physiological consequences of chronic exposure to the 2014-polluted soil in the laboratory. Chronic oil exposure did not lead to mortality or weight loss, but female gerbils exhibited heightened cortisol. We conclude that terrestrial oil pollution may have significant sublethal impacts on animal behavior, even when there is no obvious short-term physiological cost to the exposure.

中文翻译：

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沙鼠的觅食行为揭示了原油污染的生态意义


尽管有广泛的生态毒理学证据证明石油污染对啮齿动物的不利影响，但人们对啮齿动物如何在石油污染的环境中（即实验室环境之外）做出决定知之甚少。我们研究了 Allenby 沙鼠 Gerbillus andersoni allenbyi （GA） 的觅食行为，它们在半自然环境中被放置在喂食盘中。托盘里装着混合到三种土壤中的一种的种子——干净的土壤，以及从以色列两个有据可查的陆地漏油地点收集的两种不同的土壤样本。漏油灾难发生在 1975 年和 2014 年，泄漏地点位于以色列阿拉瓦极干旱地区的阿夫罗纳自然保护区，彼此相距不到几百米。我们的结果表明，对于 GA 来说，1975 年污染的土壤是有利的觅食基质，可能是因为它的质地有助于更高效的觅食，从而获得更大的能量增益，并在能量增益和由于其污染而感知的觅食成本之间产生权衡。我们还继续在实验室调查长期暴露于 2014 年污染土壤的一些生理后果。长期接触油脂不会导致死亡或体重减轻，但雌性沙鼠表现出皮质醇升高。我们得出结论，陆地石油污染可能对动物行为产生重大的亚致命影响，即使暴露没有明显的短期生理成本。