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Estimating the Distribution and Abundance of a Cryptic Species, Dipodomys stephensi (Rodentia: Heteromyidae), and Implications for Management
Author(s) -
PRICE M. V.,
ENDO P. R.
Publication year - 1989
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1111/j.1523-1739.1989.tb00089.x
Subject(s) - threatened species , endangered species , ecology , habitat , abundance (ecology) , extinction (optical mineralogy) , population , fragmentation (computing) , habitat fragmentation , habitat destruction , conservation biology , critically endangered , conservation status , biology , umbrella species , geography , paleontology , demography , sociology
A common hurdle in developing conservation plans for endangered species threatened by habitat loss is lack of basic information on distribution and factors affecting population densities. Such information is time‐consuming and expensive to obtain for cryptic species, such as nocturnal small mamma whose presence at a site can only be determined through intensive sampling. We illustrate how readily‐available soils maps can be used to estimate the potential distribution of such a species, Stephens' kangaroo rat. In this case, the distribution map accurately predicts presence or absence of this species at 70% of sites. Our maps reveal extensive habitat loss and fragmentation. Data from repeated censuses at several sites indicate that population densities of this species can vary more than 10‐fold in response to rainfall patterns, and that temporal fluctuations in geographically separated populations are correlated. These results suggest that habitat subdivision is unlikely to substantially increase expected time to extinction for the species as a whole; habitat conservation efforts for Stephens’kangaroo rat should therefore be directed at establishing a few large, widely separated reserves, rather than many smaller reserves.