I noticed that the mudflats appeared at Pocahontas last summer, and posted the question to the listserv. Someone from the park responded as you did, that it was from disturbance in outlying areas, and also that we had a huge amount of rain last summer. It probably appeared "all of a sudden" after accumulating gradually until it finally broke the surface. To answer your catbird question, none of my field guides mention young birds as lacking the chestnut undertail coverts, although both Stokes and Peterson indicate that it can be inconspicuous. Wendy Ealding You are subscribed to VA-Richmond-General. To unsubscribe, send email to va-richmond-general-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field. To adjust other settings (vacation, digest, etc.) please visit, //www.freelists.org/list/va-richmond-general.