$5,000. The skins arrived at the museum in very poor condition. The lions were reconstructed and are now on permanent display along with their skulls. Modern research In 2001, a review about causes for man-eating behaviour among lions revealed that the proposed human toll of 100 or more was most likely an exaggeration and that the more likely death toll was 28–31 victims. This reduced total was based on their review of Colonel Patterson's original journal, courtesy of Alan Patterson. However, the same study also noted that the journal refers only to Indian workers, and that Patterson stated that the casualties were much higher in the African worker population, but that those numbers were not documented. The two lion specimens in Chicago's Field Museum are known as FMNH 23970, the 'standing' mount, killed on 9 December 1898, and FMNH 23969, the 'crouching' mount, killed on 29 December 1898. Recent studies on the isotopic signature analysis of Δ13C and Nitrogen-15 in their bone collagen and hair keratin were published in 2009. Using realistic assumptions on the consumable tissue per victim, lion energetic needs, and their assimilation efficiencies, researchers compared the man-eaters' Δ13C signatures to various reference standards: Tsavo lions with normal (wildlife) diets, grazers and browsers from Tsavo East and Tsavo West, and the skeletal remains of Taita people from the early 20th century. Interpolation of their estimates across the 9 months of recorded man-eating behavior suggested that FMNH 23969 ate the equivalent of 10.5 humans and that FMNH 23970 ate 24.2 humans. The scientific analysis does not differentiate between entire human corpses consumed, compared to parts of individual prey, since the attacks often raised alarm forcing the lions to slink back into the surrounding area. Many workers over the long construction period went missing, died in accidents, or simply left out of fear; so it is likely almost all of the builders, who stayed on, knew someone missing or supposedly eaten. It appears that Colonel Patterson may have exaggerated his claims as have subsequent investigators (e.g. "135 armed men", Neiburger and Patterson, 2000) though none of these modern studies have taken into account the people who were killed but not eaten by the animals. The diet of the victims would also affect their isotopic signature. A low meat diet would produce a signature more typical of herbivores in the victims, affecting the outcome of the test. That fact is important