Use of a Pole-Mounted Camcorder for Indirect Inspection of Nest Contents in Tree-Nesting Grey HeronsArdea cinerea

Faster and Better: Comparison between Traditional and Drone Monitoring in a Cryptic Species, the Purple Heron Ardea purpurea

“…Ground counts were conducted according to standard field techniques (Fasola et al 2010). Researchers provided an estimate of the total number of nests per colony through three techniques: 1) ground counts of all the nests were used only for easily accessible, small and monospecific heronries; 2) nests located in impenetrable, small bushes (mostly Elmleaf Blackberry Rubus ulmifolius ) or reedbeds (pure stands of Common Reed Phragmites australis ) were mapped through an action cam (Apeman 4K) mounted on the tip of a telescopic stick circling the colony on foot or from a boat, which was driven around the colony boundaries (Manikowska-Ślepowrońska et al 2016); 3) nests located in large/huge impenetrable reedbeds or bushes, were estimates counting visible birds from vantage points (when available) and/or foraging flights, observed from the colony edge. Raw counts obtained in both techniques were considered to conduct the methodological comparison.…”

“…Thus, monitoring waterbird populations is crucial, but monitoring schemes have to be designed properly to provide with trustable data that allows for population trend's studies (Atkinson et al 2006), even at a species-specific level. However, waterbird monitoring is difficult, as traditional methods involve accessing on foot the breeding grounds, usually located in inaccessible reedbeds (Afán et al 2018), and counting the nests in the ground when possible, relying on mounted cameras or estimates from boats or vantage points otherwise (Manikowska-Ślepowrońska et al 2016). The recent development of uncrewed aerial vehicles (UAVs), commonly referred to as drones, has provided useful to overcome the aforementioned limitations (Anderson & Gaston 2013).…”