Testing the efficacy of a thermal camera as a search tool for locating wild bumble bee nests

Abstract

Research into how bumble bee colonies respond to the stressors affecting their populations are currently studied in the laboratory using commercially reared Bombus terrestris colonies. Understanding how these stressors affect wild bumble bee colonies in the field would be a crucial step forward for the conservation of bumble bee species. Currently, visual cues are used to locate bumble bee nests, using human searchers looking for the worker nest traffic, but the limitations of this method mean that low numbers of nests are found and so a new method that looks to tackle these limitations is needed. Thermal cameras have been considered as a potential nest searching tool because they reduce the visual complexity of the environment by displaying a homogenized thermal landscape to the searcher. In this study, we compare the use of a thermal camera to human searches using two trials: (i) using inexperienced volunteers to search along the transect for a known bumble bee nest and (ii) using an experienced individual to search across a number of novel locations. We found thermal cameras are not a better nest detection technique than human searches, having low success rates across both trials. We discuss the limitations of thermal cameras as a technique and propose how the technology could be improved for future studies.

A Tracking Method for the Invasive Asian Hornet: A Brief Review and Experiments

“…Currently, animals are typically tracked using UAV, and tracking is underway for most birds [43]. Moreover, research continues to identify bumblebee and Asian hornet nests using thermal cameras [44], [45]. In this way, it is easy to determine where the density of trees makes it difficult to find nests with the naked eye.…”

A comparison of machine-learning assisted optical and thermal camera systems for beehive activity counting

“…Thermal cameras have been used to locate wild bumblebee nests [11] . In addition, they have been used to show that bees increase their body temperature before swarming, map where they sleep relative to hive temperature, and measure the heat dissipation in hives after artificial warming [12][13][14] .…”

Viability of thermal imaging in detecting nests of the invasive hornet Vespa velutina

“…This technology provides a rapid and noninvasive scanning tool that has been applied in many fields, such as physiological, medical, agricultural and natural science (Kastberger & Stachl, 2003; Mangus et al ., 2016; Osroosh et al ., 2018). Thermal imaging cameras were also used for spotting wild animals (Focardi et al ., 2001; Cilulko et al ., 2013), other colonial insects such as bumblebees (Roberts & Osborne, 2019) and in the detection of insect pests in agricultural products (Al‐doski et al ., 2016).…”