12万余只候鸟是怎么数出来的

Core Insights - The total number of migratory birds arriving at the Cangzhou Nandagang Wetland has exceeded 120,000 this autumn, raising questions about the counting methods used [1][2]. Group 1: Counting Methods - The primary counting methods employed are direct counting and group counting, chosen based on the situation [1]. - For small, stationary groups of a single bird species, direct counting is used, while group counting is applied for larger flocks [1][3]. - Experienced patrollers conduct mobile surveys along five designated observation lines, maintaining a speed of 8 to 10 km/h by vehicle and 2 to 3 km/h on foot to cover all bird habitats [2]. Group 2: Observation Techniques - In areas with dense bird populations, patrollers stop for fixed observations, using direct counting for smaller numbers and group counting for larger flocks [3]. - Group counting involves dividing the visible area into sections and multiplying the number of birds in one section by the total number of sections [3]. - To enhance monitoring, 11 AI cameras and 3 sound monitoring devices have been installed, collecting over 250,000 valid data points since their implementation [3]. Group 3: Future Plans - The wetland's status as a bird sanctuary necessitates improved monitoring accuracy and comprehensiveness, prompting plans to refine patrol routes and observation points [3].