A strain of (bird flu) may circulate in migratory birds.Logical formLearned from2 sentences. An oasis can be for hundreds of species of migratory birds.Logical formLearned from2 sentences. Some fish can be migratory.Logical formLearned from2 sentences. A (wintering ground) can be for migratory birds.Logical formLearned from2 sentences. Treaties can be migratory.Logical formLearned from2 sentences. Passerines can be migratory.Logical formLearned from2 sentences. Migratory birds may carry avian flu.Logical formLearned from2 sentences. Elk can be migratory.Logical formLearned from2 sentences. Thousands can be upon thousands of migratory birds.Logical formLearned from2 sentences. (Stopping grounds) can be for migratory birds.Logical formLearned from2 sentences. Call can be for thousands of migratory birds.Logical formLearned from2 sentences. A diversity can be constituted-of-or-filled-with migratory birds.Logical formLearned from2 sentences. Studies of migratory birds may show that something-is-the-case.Logical formLearned from2 sentences. Connection can be with migratory birds.Logical formLearned from2 sentences. Egrets can be migratory.Logical formLearned from2 sentences.