4. Results
4.1. Density estimation
In Cat Tien National Park birds were detected both in the grassland and around Crocodile Lake. In Yok Don birds were detected in two of the three sections (north and south) and were absent from the central section.
Density estimates from distance sampling were obtained for 12 line transects, 10 from Yok Don National Park and two from Cat Tien National Park, and for three point transects around Crocodile Lake in Cat Tien National Park. We excluded five line transects from the center of Yok Don National Park from the analysis because there were no green peafowl detections there. The minimum number of detections for distance sampling analysis followed the recommended minimum number of 60–80 detections (Buckland et al., 2001). As the number of detection for Yok Don National Park was 54, after eliminating double counted records of same calling bird, we combined the detections from both Yok Don and Cat Tien National Parks into one data set and stratified the analysis by site.
The density of green peafowl was 0.25 calling males/km2 for Yok Don National Park, while in the southeast of Cat Tien National Park the density was 3.03 calling males/km2 and in the center, around Crocodile Lake, it was 4.69 calling males/km2 (Table 1).