Table 2. Effective areas surveyed (EAS) for Ivory-billed Woodpeckers by visual means during 2 years for tracts along White River (WR) and Bayou de View (BDV), Arkansas (Fig. 2), assuming effective detection distances of 25 m for line transect (LT) surveys and 50 m for variable circular plot (VCP) surveys.

2004–2005 2005–2006
Survey Site Area (ha) LT (km) VCP (#) EAS (ha) LT (km) VCP (#) EAS (ha)
BDV 9500 900 300 4592 1000 613 5168
WR 19 700 2 280 518 11 559 1660 1552 8725