Hi, During our bbs survey hike up Stebbins' Run (~ 41deg 36min N, 81deg 16 min W) yesterday we found 9 Louisiana Waterthrushes in 6 distinct territories, over a 1.8 km length of stream bed. The territories are remarkable in the regularity of their spacing of about 300m. We can determine boundaries because the birds will move up stream ahead of us to the edge of their territory and then will fly back past us. The boundaries are also distinct features such as a waterfall or side run. I also mark each location as a point using GPS and can review the location data later. Louisiana Waterthushes are now fully established on nesting territory over most of their range. They are among the earliest and most regular warbler migrants we find, and are found on or about the first of April in northern Ohio. Louisiana Waterthushes are a habitat specialist and make their living in and around running water with a rocky or gravel bed. They are seldom if ever found along still waters which are the realm of the closely related Northern Waterthrush. Also northern Ohio and and southern Ontario are the northern end of the breeding range for Louisiana Waterthrush and the southern end of the breeding range for Northern Waterthrush. As previously stated extreme care is needed to identify a Louisiana Waterthrush found in inappropriate habitat after the 3rd week of April. Due to the similarity and often overlapping morphology of the Waterthrush species this should only be done if you are very familiar with Louisiana Waterthrush after extensive study becoming familiar with all their vocalizations in the appropriate habitat. The probability far and away favors any Waterthrush found along a lake, pond or marshy area being Northern, in spite of what you might find on eBird. Haans ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Please consider joining our Society, at www.ohiobirds.org/site/membership.php. Our thanks to Miami University for hosting this mailing list. You can join or leave the list, or change your options, at: listserv.miamioh.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask]