Proper flight technique for using a small rotary-winged drone aircraft to safely, quickly, and accurately survey raptor nests

Abstract

Small rotary-winged unmanned aerial vehicles or "drones" mounted with a small video camera were successful in surveying the nest contents of four species of raptor, including Osprey (Pandion haliaetus), Bald Eagle (Haliaeetus leucocephalus), Ferruginous Hawk (Buteo regalis), and Red-tailed Hawk (B. jamaicensis) in an accurate and safe manner when the proper flight technique was employed. A total of 110 surveys were completed in 2013 and 2014 with quality images of nest contents obtained in 106 or (96.4%) of flights. A successful and safe flight requires two personnel: the pilot who controls the aircraft and the spotter who monitors the behaviour of the adult birds defending the nest and keeps the pilot updated on all potentially dangerous interactions between aircraft and the birds. With the video camera recording, the aircraft is flown above the nest to a predetermined location that allows an unobscured camera shot of the nest. This technique can be readily adapted to a variety of habitat types and species. The accuracy of data obtained combined with the flexibility, low cost, and speed of this technique make it a useful technological alternative to the safety risks and obtrusiveness associated with traditional survey techniques.Key words: nest defense behaviour, unmanned aerial vehicles (UAV), raptor, nest productivity, drone.Résumé : En utilisant des petits véhicules aériens sans pilote (UAV) à voilure tournante, ou des « drones », équipés d'une petite caméra vidéo, on a réussi en employant la technique de vol appropriée à inventorier de manière précise et sécuritaire le contenu des nids de quatre espèces de rapaces, y compris le Balbuzard pêcheur (Pandion haliaetus), le Pygargue à tête blanche (Haliaeetus leucocephalus), la Buse rouilleuse (Buteo regalis) et la Buse à queue rousse (B. jamaicensis). On a complété un total de 110 relevés en 2013 et 2014 donnant des images de qualité du contenu des nids dans le cas de 106 vols (96,4 %). Un vol réussi et sécuritaire nécessite deux personnes : le pilote qui contrôle l'aéronef et l'observateur qui surveille le comportement des oiseaux adultes défendant le nid et qui tient le pilote au courant de toutes interactions potentiellement dangereuses entre l'aéronef et les oiseaux. Alors que la caméra vidéo enregistre, on pilote l'aéronef au-dessus du nid vers un emplacement prédéterminé qui permet une prise de vue dégagée du nid. On peut aisément adapter cette technique à une variété de types d'habitat et d'espèces. Cette technique, qui procure l'exactitude des données obtenues combinée à la flexibilité, un coût abordable et la rapidité, offre une solution de rechange aux techniques de levé traditionnelles de nature envahissante et présentant des risques pour la sécurité.[Traduit par la Rédaction.] Mots-clés : comportement de défense du nid, véhicule aérien sans pilote (UAV), rapace, productivité de nid, drone.

Wildlife research and management methods in the 21st century: Where do unmanned aircraft fit in?

“…Small mammals and small birds, for their part, tend to be too small or concealed to be surveyed by conventional aircraft and overflight-style UAS missions. However, there may be much potential for such animals to be surveyed close-up by rotary-wing UAS wherever they occur in hard-to-reach places or are otherwise challenging or dangerous to approach, a technique that has already been applied to surveying raptor and corvid nests (Potapov et al 2013;Junda et al 2015;Weissensteiner et al 2015) as well as approaching individual bears (Ditmer et al 2015) and killer whales (Durban et al 2015). Moreover, there may be potential for close-up UAS flights to survey or observe tree-or cliff-dwelling bats as well as primates, which are generally constrained to being observed from the ground.…”

“…Examples in the literature include surveying Steller's sea eagle (Haliaeetus pelagicus) nests (Potapov et al 2013) and hooded crow (Corvus cornix) nests (Weissensteiner et al 2015), while Junda et al (2015) put forward a standard operating procedure for surveying raptor nests based on trials carried out at 110 nests of osprey (Pandion haliaetus), bald eagles (H. leucocephalus), ferruginous hawks (Buteo regalis), and red-tailed hawks (B. jamaicensis). Mulero-Pazmany et al (2014a) also succeeded in capturing close-up imagery of white stork (Ciconia ciconia) nests atop transmission towers with a fixed-wing UAS.…”

Use of visible spectrum sUAS photography for land cover classification at nest sites of a declining bird species (Falco sparverius)

“…Flights were conducted by two researchers: one pilot responsible for flying the sUAS and image acquisition, and one spotter to monitor reactions and proximity of kestrels and other birds (as in Junda et al. ). At study sites where kestrels were known to be present, UAV flights elicited either no reaction or an alert reaction ( sensu Mulero‐Pázmány et al.…”

“…Flights were conducted by two researchers: one pilot responsible for flying the sUAS and image acquisition, and one spotter to monitor reactions and proximity of kestrels and other birds (as in Junda et al 2015). At study sites where kestrels were known to be present, UAV flights elicited either no reaction or an alert reaction (sensu Mulero-P azm any et al 2017), consistent with findings by other researchers that flights by electric UAV 20-45 m from focal species are unlikely to provoke strong behavioral responses (Mulero-P azm any et al 2017).…”

A comment on the limitations of UAVS in wildlife research – the example of colonial nesting waterbirds

“…Indeed, growing literature has shown the validity of using drones to assess colony dynamics and population estimates of breeding bird colonies (McEvoy et al 2016, Hodgson et al 2018. Current research into UAVs spans ethical guidelines (Vas et al 2015), recreating environmental data input from bird flight paths (Rodríguez et al 2012), monitoring nesting status (Weissensteiner et al 2015, Junda et al 2015, and both manual and automated detection routines for groups of birds and nest counts (Trathan 2004, Chabot and Bird 2013, Sardà-Palomera et al 2012, Chabot and Francis 2016, Hodgson et al 2016. However, understanding of interactions between birds and UAVs remains relatively poor, particularly with regards to any potential negative impacts of UAV research for monitoring colonially breeding waterbirds.…”