Boone John D, Miller Philip S, Briggs Joyce R, Benka Valerie A W, Lawler Dennis F, Slater Margaret, Levy Julie K, Zawistowski Stephen
Great Basin Bird Observatory, Reno, NV, United States.
Conservation Planning Specialist Group, Species Survival Commission, International Union for Conservation of Nature, Apple Valley, MN, United States.
Front Vet Sci. 2019 Jul 26;6:238. doi: 10.3389/fvets.2019.00238. eCollection 2019.
This study used a previously developed stochastic simulation model (1) to estimate the impact of different management actions on free-roaming kitten and cat mortality over a 10-year period. These longer-term cumulative impacts have not been systematically examined to date. We examined seven management scenarios, including: (1) taking no action, (2) low-intensity removal, (3) high-intensity removal, (4) low-intensity episodic culling, (5) high-intensity episodic culling, (6) low-intensity trap-neuter-return (TNR), and (7) high-intensity TNR. For each scenario we tracked within the model the number of kittens born, the number of kittens surviving to adulthood, and the number of adults removed using lethal control over the entire 10-year simulation. We further defined all kitten deaths and lethal removal of adults as "preventable" deaths because they could potentially be reduced by certain management actions. Our simulation results suggested that the cumulative number of preventable deaths over 10 years for an initial population of 50 cats is highest for a "no-action" scenario, estimated at 1,000 deaths. It is lowest for a high-intensity TNR scenario, estimated at 32 deaths, a 31-fold difference. For all management scenarios tested, including removal and culling, the model predicted fewer preventable deaths than for a no-action scenario. For all management scenarios, the model predicted that the higher-intensity option (defined in terms of the proportion of animals sterilized or removed within a given time period) would result in fewer preventable deaths over time than the lower-intensity option. Based on these findings, we conclude that management intensity is important not only to reduce populations more quickly, but also to minimize the number of preventable deaths that occur over time. Accordingly, the lessons for the animal welfare community are both encouraging and cautionary. With sufficient intensity, management by TNR offers significant advantages in terms of combined lifesaving and population size reduction. At lower intensity levels, these advantages are greatly reduced or eliminated. We recommend that those who seek to minimize suffering and maximize lifesaving for free-roaming cats attempt to balance prospective goals (i.e., saving lives tomorrow) with proximate goals (i.e., saving lives today), and recognize that thoughtful choice of management strategies can ensure that both of these complementary goals are achieved.
本研究使用了先前开发的随机模拟模型（1）来估计不同管理措施对10年内自由放养的小猫和猫死亡率的影响。迄今为止，尚未对这些长期累积影响进行系统研究。我们研究了七种管理方案，包括：（1）不采取行动；（2）低强度捕杀；（3）高强度捕杀；（4）低强度定期扑杀；（5）高强度定期扑杀；（6）低强度诱捕-绝育-放归（TNR）；（7）高强度TNR。对于每种方案，我们在模型中跟踪了10年模拟期内出生的小猫数量、存活至成年的小猫数量以及通过致死控制移除的成年猫数量。我们进一步将所有小猫死亡和成年猫的致死移除定义为“可预防”死亡，因为它们有可能通过某些管理措施减少。我们的模拟结果表明，对于初始数量为50只猫的群体，“不采取行动”方案在10年内可预防死亡的累积数量最高，估计为1000只死亡。高强度TNR方案的可预防死亡数量最低，估计为32只死亡，相差31倍。对于所有测试的管理方案，包括捕杀和扑杀，模型预测的可预防死亡数量均少于“不采取行动”方案。对于所有管理方案，模型预测随着时间推移，高强度方案（根据给定时间段内绝育或移除动物的比例定义）导致的可预防死亡数量将少于低强度方案。基于这些发现，我们得出结论，管理强度不仅对于更快减少种群数量很重要，而且对于随着时间推移尽量减少可预防死亡的数量也很重要。因此，对动物福利界来说，这些经验教训既令人鼓舞又具有警示意义。如果强度足够，TNR管理在拯救生命和减少种群数量方面具有显著优势。在较低强度水平下，这些优势会大大降低或消除。我们建议，那些希望尽量减少自由放养猫咪的痛苦并最大化拯救生命的人，尝试在远期目标（即明天拯救生命）和近期目标（即今天拯救生命）之间取得平衡，并认识到深思熟虑地选择管理策略可以确保实现这两个相辅相成的目标。
