Baronia brevicornis Salvin (Lepidoptera), is known as probably the oldest extant butterfly linage and is listed as a conservation priority by the IUCN. We have carried out intensive population surveys during 2000-2004 at El Sumidero (South Mexico) area. Historic and current distribution maps for B. brevicornis have been produced to show currently empty Acacia patches that were previously occupied by the butterfly, and currently occupied patches that were previously empty. Detected extinction and colonization processes can be the result of age conditions and host-plant population structure (Acacia pennatula) and the patch vegetation successional stage. This information represents the baseline to relate the potential effect of habitat succession on butterfly incidence as well as resulting population trends as a result of natural and human-induced variations. A comprehensive framework for the use of surrogates for biodiversity assessments and monitoring schemes in general within protected areas is discussed.