. The Canadian field-naturalist. 1974 Notes 215 during the 127 seconds of totality. These levels are about equivalent to those measured under a clear sky 30 minutes after sunset or at night with a half moon. Observations and Conclusions The songs heard during an observation period were tallied as total songs for each species per minute of listen- ing time. A total of 17 different species, consisting mainly of warblers and sparrows, were identified by song. The most vociferous species are listed in Table 1 by common name, the reference being Godfrey (1966). Each column lists the total number of
. The Canadian field-naturalist. 1974 Notes 215 during the 127 seconds of totality. These levels are about equivalent to those measured under a clear sky 30 minutes after sunset or at night with a half moon. Observations and Conclusions The songs heard during an observation period were tallied as total songs for each species per minute of listen- ing time. A total of 17 different species, consisting mainly of warblers and sparrows, were identified by song. The most vociferous species are listed in Table 1 by common name, the reference being Godfrey (1966). Each column lists the total number of songs heard in a given period. The time interval is approximately 60 seconds in all cases except one, the exception being of 82-seconds duration just before totality. Totality, which actually lasted for about 127 seconds, was arbitrarily taken to be two 1-minute intervals. Normal Singing Rate versus Eclipse Singing Rate Four species. Yellow Warbler, Common Yellow- throat, Red-winged Blackbird, and Song Sparrow, were the only persistent singers during our observation periods, and together they account for almost three-quarters of the songs heard. The total number of songs per minute of observation is given in the last row of Table 1. We had an overall average of about 14 songs per minute with a minimum of four and a maximum of 22. This minimum of four songs per minute occurred during the first minute of totality! A one-tailed level of significance test for the four songs-per-minute rate is ; that is, there is a probabil- ity of one in 100 that the observed rate could have occur- red by chance. To perform this test it is assumed that all observations other than during totality represent a normal background; that is, without other influences such as the diurnal cycle, a reasonable assumption, except perhaps for the last observation period. Thus the song rate during the first half of totality was reduced 'significantly'; the same cannot be said for the latter half. A closer ex
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