white-fronted goose and bean goose on stop-overs

whitefronted goose bean stopovers abundance birds agriculture animal anser albifrons fabalis bird congestion cultivation wheat dry eaten grain economy fat depot feeding field flight flock geese gatherings getting growing grey harmful farming hordes landfall landing laughing migrating migration stop migrations migratory myriad nature nutrition plowed rookery rural sky spring stopover stubble thousands wildlife autumn make long stops process replenish energy resources agricultural as place