title: Assessment of mercury exposure and maternal-foetal transfer in Miniopterus schreibersii (Chiroptera: Miniopteridae) from southeastern Iberian Peninsula.
abstract: Mercury (Hg) is a highly toxic and widely distributed metal that is bioaccumulated in insectivorous mammals and may cause adverse effects on the reproductive system. Bats are considered excellent Hg bioindicators due to their wide distribution, life span, trophic position, metabolic rate and food intake. However, few studies have analysed Hg residues in bats, and to the best of our knowledge, no studies have been made in the Iberian Peninsula. The main aim of this study was to undertake the first ever assessment of Hg exposure in Schreiber's bent-winged bats inhabiting a natural cave in the southeast of Spain. The findings suggest that Schreiber's bent-winged bats in the sampling area are chronically exposed to low levels of Hg. The Hg concentrations found in different tissues (fur, kidney, liver, muscle and brain) were below the threshold levels associated with toxic effects in mammals. Non-gestating females showed Hg concentrations in the brain and muscle that doubled those found in gestating females. This could be due to Hg mobilization from the mother to the foetus in gestating females, although other factors could contribute to explain this result such as variations in hunting areas and the insect-prey consumed and/or different energetic needs and average food consumption during the breeding season. Hg levels were 1.7 times higher, although not significant, in foetus' brains than in the maternal brains, and Hg concentration in foetus' brain was significantly correlated with levels in the corresponding mothers' kidney. These results suggest that there could be an active mother-to-foetus transfer of Hg in bats, which would be of special relevance in a scenario of higher Hg exposure than that found in this study. However, further research is needed to support this view due to the limited number of samples analysed. Given the scarce ecotoxicological data available for bats and their protected status, we encourage further opportunistic studies using carcasses found in the field, the validation of non-destructive samples such as fur and guano for Hg monitoring, and new modelling approaches that will increase the data needed for proper ecological risk assessment in bat populations.
authors.affiliation: Department of Ecology and Hydrology, Faculty of Biology, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain.|Laboratorio de Ecología del Paisaje Forestal, Departamento de Ciencias Forestales, Universidad de La Frontera, P.O. Box-54-D, Temuco, Chile.
authors.forename: Fulgencio
authors.initials: F
authors.lastname: Lisón
authors.affiliation: Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain. silvia.espin@um.es.|Section of Ecology, Department of Biology, University of Turku, 20014, Turku, Finland. silvia.espin@um.es.
authors.forename: Silvia
authors.initials: S
authors.lastname: Espín
authors.affiliation: Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Aroca
authors.affiliation: Department of Ecology and Hydrology, Faculty of Biology, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain.
authors.forename: José F
authors.initials: JF
authors.lastname: Calvo
authors.affiliation: Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain.
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: García-Fernández
mesh_terms: D000818:Animals; D002685:Chiroptera; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D008099:Liver; D008431:Maternal-Fetal Exchange; D008628:Mercury / Q000633:toxicity*; D009132:Muscles; D011247:Pregnancy; D012621:Seasons; D013030:Spain
chemical_list: D004785:Environmental Pollutants; D008628:Mercury
keywords: Brain; Foetus; Fur; Kidney; Liver; Maternal transfer; Muscle; Total mercury; Wildlife toxicology