Preservation of species diversity and abundances in Pacific island land snail death assemblages

Data from 11 land snail surveys undertaken on the islands of the Pacific (Hawaii, American Samoa, Palau) are analyzed in order to ascertain the proportions of species represented in the death assemblage alone or the live assemblage alone, and whether the abundances of the individual species in the two assemblages are correlated. The percentage of species collected only as dead shells ranged from 13% to 52% (mean = 31.6%), while that found only in the live assemblage was considerably lower (mean 10.2%). At nine of the 11 localities the rank abundances of species in the dead and live assemblages were significantly correlated, although in most cases the correlation was not strong. Taphonomic differences among species and localities as well as sample sizes may weaken the correlations, but real change in abundances of certain species may also be involved.