| 摘要 |
<p>PROBLEM TO BE SOLVED: To discover a crow's nest or to determine a possibility of nest building with high accuracy and at low cost or promptly and with low burden or to implement nest building search over a wide range.SOLUTION: A sensor 11 is mounted to a crossarm 53 or the like of a pole 52, and it is detected that a crow touches a detection surface 26 of the sensor 11. On the basis of a result of the detection, how many times the crow touches the detection surface 26 is counted and on the basis of a result of the counting, the presence/absence of crow's nest building or a possibility of nest building is determined. For example, in the case where a day on which the number of times of touch exceeds a reference value is continued for a predetermined number of days or more for each pole, the presence/absence of next building or the possibility is determined, the reference value or the number of days used for this determination is decided on the basis of features in crow's nest building activities.</p> |
