COMPARISON BETWEEN PLANT-SPECIES IN BUSHY-TAILED WOODRAT MIDDENS AND IN THE HABITAT

Bushy-tailed woodrats (Neotoma cinerea) collect vegetation and store i t in middens. We asked to what extent plant species collected by woodr ats reflect the array of species growing in the habitat. Species compo sition of plant clippings at 20 bushy-tailed woodrat middens in centra l Colorado was compared to vegetation growing within 30 m of the dens. Amount of overlap between midden and habitat species was low (28-49%) when all taxa were included; however, if only woody taxa were conside red, overlap was 71-89%. Sorensen's Index of Similarity exhibited a li ke pattern; the index increased markedly if only woody tara were inclu ded. Only one plant species not found within 30 m of a den occurred in significant amounts in the middens. Bushy-tailed woodrats collected a wide array of species but were more selective the greater the habitat plant diversity. Results of this and ether studies indicate that the concordance between midden contents and habitat vegetation decreases w ith increasing habitat plant diversity. Ancient woodrat middens are no netheless useful to paleontologists seeking to reconstruct past vegeta tion associations since woody vegetation is well represented in midden s.