C-2 



METHODOLOGY 



Data were assembled by contacting competent persons known 

 to be experts on particular species or groups of species. 

 Contact was made by personal interview, by telephone, and by a 

 three-page questionnaire asking for detailed information on 

 rare, endangered, or threatened species. This material was 

 then compiled on the following data sheets. 



The significant literature was reviewed, with emphasis 

 placed on more recent papers and books (from 1960 to 1973) . 

 Since a time lag often exists between gathering of data and 

 its publication, the most-up-to-date information was obtained 

 through personal communication. 



CLASSIFICATION OF SPECIES 



There are not many rare, endangered, or threatened 

 species of vertebrate animals in the Chesapeake Bay region. 

 Those that occur there are dependent in part on the presence 

 of natural and undisturbed habitats, and also on the broader 

 aspect of uncontaminated environmental conditions. This is 

 particularly important to birds of prey which are dependent on 

 a long food chain, and where they may accumulate high levels 

 of persistent chemicals. Chesapeake Bay is especially important 

 as a nesting area for the endangered southern subspecies of the bald 

 eagles and for ospreys. Both species reach relatively high con- 

 centrations in this area. 



