Study Area. We conducted surveys for nesting GHFE at Companiganj sub-district (hereafter Companiganj) of Noakhali district, Chittagong Division in south-central Bangladesh. We chose Companiganj for our surveys because we discovered four GHFE nests during an opportunistic visit to the area in January 2015. We initiated the study during the following breeding season to understand factors for such a high density of GHFE in an area of 305km2with between 183,000 and 183,500 people (Karim et al. 2013). Our study area covered 104km2, located approximately 100 km north of the Bay of Bengal were approximately 3700 km2of water-bodies, agricultural cropland, homestead patches, and human settlements, and approximately 70,500ponds (Karim et al. 2013) dotted the landscape. The average annual precipitation in the study arearangedfrom6.6mmduringthedryseason(January) to 723.4 mm during the monsoon season(July) in 1999–2010, and the mean annual temperature ranged from 21 to 310C (1981–2010; Khatun et al.2016). Breeding Density. We used distance sampling to estimate GHFE breeding-pair density within the study area, as distance sampling is a simple and widely used approach to estimate densities of biological populations in defined areas (Buckland et al. 2001, Thomas et al. 2010, Cornils et al. 2015, Buckland et al. 2016). We searched for nests between 15 November 2015 and 31 January 2016 along eight transect lines that we established following relatively straight roads through home-stead forest and village landscapes with no natural or artificial barriers. We conducted the surveys in winter (November and December), the primary breeding season of the GHFE (Naoroji 2006, Siddiqui et al. 2008). Transects were placed 1 km apart and transect length varied from 9.2–15.5 km. We surveyed each transect by walking slowly (3 km/hr) in a two-person team, while each person searched for GHFE nests on one side of the transect. We used a Garmin e-Trex (Garmin, KS, USA)handheld global positioning system unit to follow transects and to record nest locations. We recorded a nested structure as occupied when at least one GHFE was present, or if the size, structure, and height of a nest we observed were consistent with a GHFE nest but no GHFE was present. In the latter cases, we visited the nest location later for further verification. In all cases, we used 10342 binoculars to examine nests. We measured the perpendicular distance between the transect lines and each GHFE nest we found, and we calculated the total area surveyed for GHFE as a polygon with a 1-km buffer around our transect survey area.