Boyce Mark S, Baxter Peter W J, Possingham Hugh P
Department of Biological Sciences, University of Alberta, Edmonton T6G 2E9, Canada.
Theor Popul Biol. 2012 Dec;82(4):340-7. doi: 10.1016/j.tpb.2012.03.002.
Moose populations are managed for sustainable yield balanced against costs caused by damage to forestry or agriculture and collisions with vehicles. Optimal harvests can be calculated based on a structured population model driven by data on abundance and the composition of bulls, cows, and calves obtained by aerial-survey monitoring during winter. Quotas are established by the respective government agency and licenses are issued to hunters to harvest an animal of specified age or sex during the following autumn. Because the cost of aerial monitoring is high, we use a Management Strategy Evaluation to evaluate the costs and benefits of periodic aerial surveys in the context of moose management. Our on-the-fly "seat of your pants" alternative to independent monitoring is management based solely on the kill of moose by hunters, which is usually sufficient to alert the manager to declines in moose abundance that warrant adjustments to harvest strategies. Harvests are relatively cheap to monitor; therefore, data can be obtained each year facilitating annual adjustments to quotas. Other sources of "cheap" monitoring data such as records of the number of moose seen by hunters while hunting also might be obtained, and may provide further useful insight into population abundance, structure and health. Because conservation dollars are usually limited, the high cost of aerial surveys is difficult to justify when alternative methods exist.
驼鹿种群的管理目标是实现可持续产量，同时平衡因对林业或农业造成损害以及与车辆碰撞而产生的成本。可以根据一个结构化的种群模型来计算最佳捕获量，该模型由冬季通过空中调查监测获得的有关驼鹿数量以及成年雄鹿、成年雌鹿和幼鹿组成的数据驱动。各自的政府机构会设定配额，并向猎人发放许可证，以便他们在接下来的秋季捕获特定年龄或性别的驼鹿。由于空中监测成本高昂，我们采用管理策略评估方法，在驼鹿管理的背景下评估定期空中调查的成本和效益。我们临时采用的、不依赖独立监测的替代方法是仅基于猎人捕杀驼鹿的情况进行管理，这通常足以提醒管理人员注意到驼鹿数量的下降，从而有必要调整捕获策略。监测捕获情况相对成本较低；因此，每年都能获取数据，便于每年调整配额。还可能获取其他“低成本”监测数据来源，例如猎人在狩猎时看到的驼鹿数量记录，这些数据可能会提供有关种群数量、结构和健康状况的进一步有用见解。由于保护资金通常有限，当存在替代方法时，空中调查的高成本就难以说得通了。
