Comprehending　the　alterations　in　wintering　grounds　of　migratory　birds　amid　global　change　and　anthropogenic　influences　is　pivotal　for　advancing　wetland　sustainability　and　ensuring　avian　conservation.　Frequent　extreme　droughts　in　the　middle　and　lower　Yangtze　River　region　of　China　have　posed　severe　ecological　and　socio-economic　dilemmas.　The　integration　of　internet-derived,　crowdsourced　geographic　data　with　remote-sensing　imagery　now　facilitates　assessments　of　these　avian　habitats.　Poyang　Lake,　China’s　largest　freshwater　body,　suffered　an　unprecedented　drought　in　2022,　offering　a　unique　case　study　on　avian　habitat　responses　to　climate　extremes.　By　harnessing　social　and　online　platforms’　media　reports,　we　analyzed　the　types,　attributes　and　proportions　of　migratory　bird　habitats.　This　crowdsourced　geographic　information,　corroborated　by　Sentinel-2　optical　remote-sensing　imagery,　elucidated　the　suitability　and　transformations　of　these　habitats　under　drought　stress.　Our　findings　revealed　marked　variations　in　habitat　preferences　among　bird　species,　largely　attributable　to　divergent　feeding　ecologies　and　behavioral　patterns.　Dominantly,　shallow　waters　emerged　as　the　most　favored　habitat,　succeeded　by　mudflats　and　grasslands.　Remote-sensing　analyses　disclosed　a　stark　60%　reduction　in　optimal　habitat　area　during　the　drought　phase,　paralleled　by　a　1.5-fold　increase　in　unsuitable　habitat　areas　compared　to　baseline　periods.　These　prime　habitats　were　chiefly　localized　in　Poyang　Lake’s　western　sub-lakes.　The　extreme　drought　precipitated　a　drastic　contraction　in　suitable　habitat　extent　and　heightened　fragmentation.　Our　study　underscores　the　value　of　crowdsourced　geographic　information　in　assessing　habitat　suitability　for　migratory　birds.　Retaining　sub-lake　water　surfaces　within　large　river　or　lake　floodplains　during　extreme　droughts　emerges　as　a　key　strategy　to　buffer　the　impacts　of　hydrological　extremes　on　avian　habitats.　This　research　contributes　to　refining　conservation　strategies　and　promoting　adaptive　management　practices　of　wetlands　in　the　face　of　climate　change.　©　2025　by　the　authors.