In total, collagen was extracted from six samples of Ibis bone (Table 1). The bone was physically cleaned with a scalpel, subjected to a series of solvent washes to remove possible fats and resins before acid–base-acid washes to demineralise and remove secondary carbonates and to remove humics, gelatinisation and filtration to extract gelatin, and ultrafiltration to collect the largest fragments of protein following a protocol similar to Brock et al. (2010). Details of pre-treatment
protocols are given in (Supplementary Material).