The eastern sarus crane (Antigone antigone sharpii; ESC) is a species related to wetland ecosystems in Southeast Asia. The habitat suitability of the eastern sarus crane in Ayeyarwady Delta was surveyed between March 2018 and February 2019. Eastern sarus cranes were found at 73 locations and Maximum Entropy (MaxEnt) was used to classify the habitat suitability among different seasons. MaxEnt showed the largest total area of highly suitable habitat was in the winter season (2450 km2, AUC = 0.968), while the least amount of available suitable habitat was evident during the rainy season (1028.7 km2, AUC = 0.979). A difference in the assessment of home range areas using the Minimum Convex Polygon (95% MPC) and the Kernel Density Estimate (95% KDE) was found. The total area in the winter season was highest at 95% KDE (13,839.5 km2) and lowest in the rainy season (1238.1 km2), while 95% MCP was highest in the rainy season (7892.9 km2) and lowest in the summer season (7014.6 km2). Analysis of the environmental parameters indicated that low temperature in the summer season and high precipitation in the rainy season and winter season are important for ESC habitat suitability. These climatic parameters were important for ESC in all seasons (AUC > 0.9). Important parameters influencing ESC habitat suitability were elevation, slope, distance to road in the summer season, elevation, distance to road and village and slope in the rainy season, and elevation and slope in the winter season. Annual precipitation was the main parameter influencing ESC habitat suitability in both summer and winter, while in the rainy season it was mean diurnal range (>90%).

Subspecies are often less well-defined than species but have become one of the basic units for legal protection. Evidence for the erection or synonymy of subspecies therefore needs to be founded on the best science available. Here we show that there is clear genetic disjunction in the Sarus Crane Antigone antigone, where previously the variation had appeared to be clinal. Based on a total sample of 76 individuals, analysis of 10 microsatellite loci from 67 samples and 49 sequences from the mitochondrial control region, this research establishes that the Australian Sarus Crane A. a. gillae differs significantly from both A. a. antigone (South Asia) and A. a. sharpii (Myanmar and Indochina). A single sample from the extinct Philippine subspecies A. a luzonica clustered with A. a. gillae, hinting at the potential for a more recent separation between them than from A. a. antigone and A. a. sharpii, even though A. a. sharpii is closer geographically. The results demonstrate that failure to detect subspecies through initial genetic profiling does not mean discontinuities are absent and has significance for other cases where subspecies are dismissed based on partial genetic evidence. It could also be potentially important for sourcing birds for reintroduction to the Philippines.