The area comprises approximately 2000 grid cells divided among 11 regions. Historical data gleaned from literature sources, museum collections and the data bases of conservation departments and private individuals will be incorporated, but distribution maps will distinguish between current and historical data.
Aural records form the bulk of the new data.
Inexperienced observers submit tape recordings which are processed by RO's. Detailed report forms are completed for all records, and audio tapes are archived. Tadpole specimens, photographs, and sight records provide additional distribution data. Data collection during 1996-1998 was relatively slow as considerable time and effort was invested in advertising the atlas in the media and in the recruitment and training of volunteer atlasers by means of workshops, public lectures, etc. These data already represent a substantial increase over existing distribution data for the region.