Central Thailand was historically an extensive area of freshwater swamp with areas of raised wooded land. These days most of the area is either farmland or urbanized, but there are still many areas where water birds can be seen particularly as freshwater species are able to use rice fields and fish ponds for nesting and feeding. Much of the less-intensively farmed land contains marshland species and the mudflats of the Gulf of Thailand support internationally important numbers of wintering waders including Asian Dowitcher, Nordmann's Greenshank and the critically endangered Spoon-billed Sandpiper. Parks and orchards within urban areas provide a home to many common species and are a magnet to passage migrants in spring and autumn.
Northern Thailand is characterized by forested mountain peaks between 1500 to 2500 metres in altitude and lowland wetlands, a variety of habitats that provide birders with a wide variety of potential species. Forest types represented in this region include moist evergreen forest, dry dipterocarp woodland, pine forest and broadleaved deciduous forest, all with their own avifaunas and it is these forests, with a high level of affinity to Himalayan ecosystems, that attract most birders with the possibility of a wide range of species that do not occur in other parts of the country, including a large number of migrants escaping the winters further north. Wetlands in this region, although highly disturbed and farmed, remain important to migrant species including wildfowl which are extremely scarce in the rest of the country.