NOAA/WDS Paleoclimatology - Magurici Cave, Romania 1,130 Year Bat Guano d13C and d15N Data

A 285-cm core of bat guano was recovered from Magurici Cave in north-west Romania and analyzed for d13C, d15N and pollen. Guano deposition occurred from AD 881 until 1240 and from AD 1651 to 2013, allowing for the interpretation of summer variations in precipitation and temperature during the Medieval Warm Period (MWP) and the Little Ice Age (LIA). A 2 per mil increase in d13C, 1.5 per mil decrease in d15N, and the presence of Ulmus, Quercus and Carpinus betulus indicate a warm and dry MWP occurred in the region. The lack of deposition during the beginning of the LIA suggests a possible climate-induced change in prey availability resulting in bats vacating the cave. Variation of d13C values between -25 and -23 per mil at AD 1650 (LIA) indicates similar drier conditions as at the end of MWP. However, a 2 per mil decrease in d13C values that occurred between AD 1790 and 1900 suggests climate was trending towards wetter conditions at the end of the LIA. From AD 1938 to 2013, d13C values appear to be more influenced by temperature, indicating that this parameter had a more significant effect on carbon discrimination than water availability.