Applications of Unmanned Aerial Vehicles to Survey Mesocarnivores

Abstract

With the widespread extirpation of top predators over the past two centuries, mesocarnivores play an increasingly important role in structuring terrestrial trophic webs. However, mesocarnivores are difficult to survey at a population level because their widely spaced territories and nocturnal behavior result in low detection probability. Existing field survey techniques such as track plates and motion-sensitive camera traps are time-consuming and expensive, and yet still yield data prone to systematic errors. Unmanned Aerial Vehicles (UAVs) have recently emerged as a new tool for conducting population surveys on a wide variety of wildlife, eclipsing the efficiency and even accuracy of traditional methods. We used a UAV equipped with a thermal imaging camera to conduct nighttime mesocarnivore surveys in the prairie pothole region of southern Manitoba, Canada. This was part of a much larger ecological study evaluating how lethal removal of mesocarnivores affects duck nest success. Here, our objective was to describe methods and equipment that were successful in detecting mesocarnivores. We used a modified point-count survey from six waypoints that surveyed a spatial extent of 29.5 ha. We conducted a total of 200 flights over 53 survey nights during which we detected 32 mesocarnivores of eight different species. Given the large home ranges of mesocarnivores relative to the spatial and temporal scale of our spot sampling approach, results of these types of point-count surveys should be considered estimates of minimum abundance and not a population census. However, more frequent sampling and advanced statistics could be used to formally estimate population occupancy and abundance. UAV-mounted thermal imaging cameras appear to be an effective tool for conducting nocturnal population surveys on mesocarnivores at a moderate spatial scale.

Application of Unmanned Aerial Vehicles and Thermal Imaging Cameras to Conduct Duck Brood Surveys

“…Miniaturization of thermal imaging cameras has made them light enough to be attached to UAVs, and these systems are potentially useful for surveying endothermic wildlife (Christiansen et al 2014). For example, Bushaw et al (2019) used a quadcopter UAV equipped with a thermal camera to locate and identify nocturnal mesocarnivores in southern Canada and reported being able to detect animals as small as rodents in grassy fields. Scholten et al (2019) used a UAV and thermal camera to locate small, well‐hidden field sparrow ( Spizella pusilla ) nests in grasslands in the northern United States, and Bushaw et al (2020) used a similar system to locate diving duck nests in prairie Canada.…”

Applications of an unmanned aerial vehicle and thermal‐imaging camera to study ducks nesting over water

“…Recent weight reductions of thermal‐imaging cameras have allowed their attachment to UAVs, and these systems have been used to monitor wildfires (Ambrosia et al 2003), conduct search‐and‐rescue missions (Rudol and Doherty 2008), and survey wildlife (Haschberger 1996, Elsey and Trosclair 2016, Scholten et al 2019). UAVs and thermal‐imaging cameras have been used to detect large mammals, such as Roe deer ( Capreolus capreolus ) (Israel 2011) and chimpanzees ( Pan troglodytes ) (Van Andel et al 2015), and have also been found to reliably detect mesocarnivores in prairie landscapes (Bushaw et al 2019). Recently, UAVs and thermal‐imaging cameras have also been used to detect bird nests.…”

Unmanned aerial vehicles as a useful tool for investigating animal movements

“…Unmanned aerial vehicles (UAVs) are currently installed in wildlife monitoring, and it is often combined with thermal imaging (Bushaw et al, 2019). Spaan et al (2019) investigated the abundance of spider monkeys ( Ateles spp.…”