Izaak Walton Nature Preserve, in partnership with the Thorn Creek chapter of the Audubon Society, will be offering three guided migratory bird walks at the preserve in coming weeks.Members of the Thorn Creek Audubon Society will lead small groups out into the preserve in search of migratory birds. There will be two walks, one at 8 a.m. and another at 10:30 a.m., on Sunday, April 7, Sunday, April 28, and Sunday, May 19. Walkers will meet at Senior Hall.The dates are spread out during the migratory season to enable participants to observe different . . .