Cárdenas Max, Grijalva C Jaime, de la Torre Stella
Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador.
Escuela de Veterinaria, Universidad San Francisco de Quito, Quito, Ecuador.
Front Vet Sci. 2021 Oct 28;8:766348. doi: 10.3389/fvets.2021.766348. eCollection 2021.
The selection of a survey method of free-roaming dog populations should be based on analyses of local capacities and management priorities. Here, we compare the results of surveys of the stray dog population in Quito, Ecuador, using two different methodologies and propose an alternative method for future surveys in the city. We carried out all surveys in ~5 km-transects in a sample of eight urban and eight rural parishes (16 transects total). In 2018, we used the capture-recapture method to estimate absolute population size and 95% CI. We began transect surveys at 04 h 00 (local time) and identified individuals with photographs. The main limitations of this method were errors in identifying individuals, since photographs were not always clear, partly due to low light conditions during the surveys. This method also required more time and more complex logistics. In 2019, we used distance sampling to estimate population density and began the surveys at 08 h 00 (local time). Errors in the estimation of animal-observer distances and angles were our main concern when using this method. For future surveys, we propose to carry out direct observations of dog abundance (number of free-roaming dogs/km) during street counts, complemented with capture-recapture surveys every 5 years. This alternative method albeit simple, is sensitive enough to (1) provide local authorities with objective assessments of management interventions, (2) better understanding the dynamics of free-roaming dog populations and (3) increasing public awareness about the problem of pet abandonment through citizen participation in the surveys.
自由放养犬类种群调查方法的选择应基于对当地能力和管理重点的分析。在此，我们比较了采用两种不同方法对厄瓜多尔基多流浪狗种群进行调查的结果，并为该市未来的调查提出了一种替代方法。我们在8个城市教区和8个农村教区的样本中，沿着约5公里的样带进行了所有调查（共16条样带）。2018年，我们使用捕获再捕获法来估计绝对种群数量和95%置信区间。我们在当地时间04:00开始样带调查，并用照片识别个体。该方法的主要局限性在于个体识别存在误差，因为照片并不总是清晰，部分原因是调查期间光线较暗。这种方法还需要更多时间和更复杂的后勤保障。2019年，我们使用距离抽样法来估计种群密度，并在当地时间08:00开始调查。使用这种方法时，我们主要担心动物与观察者之间距离和角度的估计误差。对于未来的调查，我们建议在街道计数期间直接观察犬类数量（每公里自由放养犬的数量），并每5年辅以捕获再捕获调查。这种替代方法虽然简单，但足够灵敏，能够（1）为地方当局提供管理干预的客观评估，（2）更好地了解自由放养犬类种群的动态，以及（3）通过公民参与调查提高公众对宠物遗弃问题的认识。
