Procedures and materials used in the mounting of two birds which belong to the Natural Sciences National Museum (MNCN-CSIC) and the Complutense University of Madrid (UCM)

Resumen

In this work, the first results obtained in the study of two mounted birds are presented: a golden eagle, made byJosé Maria Benedito in 1914, which belongs to the Complutense University (UCM), and a pink flamingo (MNCN-CSIC reference: 7511) dated in 1891, which came from Cuba to Spain and is property of the National Museum ofNatural Sciences of Spain (MNCN-CSIC).Although both birds were mounted in close dates, differences may be observed in the methodology and thematerials employed in preparing them (preservatives, internal iron armatures, paint and fillings although it hasbeen determined that both birds contain arsenic-based compounds). These can be either due to geographicalreasons (taxidermists could have used different techniques in different places), to historical changes in preparingspecimens, or simply due to the factor that they were not created by the same professional. In order to make thecomparative study of both pieces and to determine the nature of the materials employed, different analyticaltechniques have been used: X-ray computed tomography (CT) to study the internal configuration of the pieces(metallic structure and distribution of fillers), stratigraphic study with optical microscopy (OM) and scanningelectron microscopy/energy dispersive spectroscopy (SEM/EDS) to identify the materials used for coloring parts ofthe animal, preservatives and the nature of the internal armatures, and finally OM for the nature of the internalfiller. The characterization of the coatings has been done by using SEM/EDS, Fourier transform infraredspectroscopy (FTIR), gas chromatography/mass spectrometry (GC/MS) and/or OM with selective staining