In a former note (published in ‘The Condor,’ 1913, pp. 120-121) I have called attention to a similar occurrence in eastern Kansas, where other species of birds in addition to Carolina Wrens were concerned. These observations and others of a similar nature seem to show that the Carolina Wren is a bird that may be considered resident in the strictest sense of the word in regions where it is found. In many so-called resident species, though the species as a whole is represented at all seasons individuals are migratory and perform regular journeys each year. With the Carolina Wren however, this does not seem to be true, as adult individuals (in pairs) frequent certain restricted areas throughout the year without reference to season. The immature birds that have not yet become settled, wander somewhat during spring and fall, and individuals may occur at this time in cities or elsewhere outside of their normal haunts. These movements however, are irregular, and seem at most to be restricted to short distances when compared with the regular spring and fall movement found among other birds of recognized migratory habits. It is by these restricted movements that these Wrens extend their local range.
At Plummer’s Island one of these wanderers visited the island and adjacent parts of the mainland on April 7 and worked restlessly about, singing loudly. No others were observed during the spring and summer months and the species did not occur again until December 8 when one was observed skulking in a brush pile below the cabin. One bird (presumably the same one) is still present on the island at present writing (January 12, 1919).
The instances given here are indications of the conditions limiting the range of the Carolina Wren, in one direction at least and show, too, how readily a species apparently common may be reduced or even exterminated in a given region in a very short period of time. In the case of the Carolina Wren the heavy blanket of snow covering the food supply would seem to be the direct cause of extermination rather than prolonged cold, as here at Washington these birds were able to survive a low temperature for a considerable period but were killed when deep snow covered the greater part of their normal feeding ground. It is to the comparatively few that are able to survive that we must look for the perpetuation of the species. The increase in numbers however, seems to be a slow process, as following their decrease in 1912, I found the species still comparatively rare near Lawrence, Kansas, in 1914, 1916 and as late as November, 1918.—ALEXANDER WETMORE, _Biological Survey, Washington, D. C._