Rapid drone semi‐automated counts of wintering Greater Flamingos (Phoenicopterus roseus) as a tool for amateur researchers

Abstract

Drone‐conducted aerial counts of waterbirds are at least as accurate as traditional ground counts and drastically reduce fieldwork resource expenditures, but the image processing can be very time‐consuming. The aim of the present study was to compare the accuracy, precision and time requirement of semi‐automated counts, using drone‐derived imagery, carried out with the open‐access ImageJ software, in comparison with conventional ground methods for counting wintering Greater Flamingos Phoenicopterus roseus. Semi‐automated counts were easy to execute, affordable and safe for birds. They were faster and yielded more reliable and consistent results than traditional ground count approaches, providing a simple, accessible method for use by amateur ornithologists.

Drone monitoring improves nest detection of Squacco Herons Ardeola ralloides, but fails to assess its productivity

“…In recent years, evidence on the superiority of drone monitoring in terms of accuracy and precision for counting breeding waterbirds has been numerous and nearly unequivocal. Gulls, terns, flamingos, and grebes were reported to have been counted faster and frequently better in term of accuracy and precision using drones in comparison to traditional ground counts (Hodgson et al 2018, Lachman et al 2020, McKellar et al 2021, Valle 2022. More controversial is the question when considering sites where vegetation occludes nests causing low detection probabilities on UAV (unoccupied aerial vehicles)-derived photographic surveys (but also on by eye monitoring).…”

“…In the post-processing phase, individual nests were assigned a number and counts were performed by two observers on a personal computer using DotDotGoose's count tool v. 1.3.0 (https://biodiversityinformatics.amnh.org/open_source/dotdotgoose/) on images directly shot in the field or selected frames obtained from videos automatically stitched together using ICE (Microsoft's Image Composite Editor, release 2.0; www.microsoft. com); a grid was overlaid on all images and we performed a systematic counts of nests, grid cell-by-grid cell (Valle 2022).…”

One Thousand Nesting Pairs Packed into One Hundred Square Metres: The Sad Story of the Sandwich Terns Thalasseus Sandvicensis of the Venice Lagoon

“…Between ten and 15 sites, both natural and artificial, are used each year by single- or multi-species colonies of gulls and terns. The community of breeding waterbirds is one of the largest in the Mediterranean, with some 8000 pairs (Scarton & Valle, 2021). The Venice Lagoon has the largest tidal range in the Mediterranean, about one metre, sometimes higher due to meteorological factors [storm surges] (Zoccarato & Da Lio, 2021).…”

“…Drone counts were performed on a personal computer using the DotDotgoose count tool v. 1.3.0 (Ersts, 2019) on images taken directly in the field or from selected frames obtained from videos automatically stitched together using ICE (microsoft's Image Composite Editor, release 2.0; www.microsoft.com). In the post-processing phase, a 10 × 10m grid was overlaid on drone imagery and individual nests and chicks were counted grid cell by grid cell (Valle, 2021). all counts were performed by two observers independently.…”

“…In the Venice Lagoon, Sandwich Terns traditionally nested on salt marsh islets (Scarton & Valle, 1998), placing nests on clumps of dead plant material, such as seagrass leaves and large green algae, lying on the top of salt marsh vegetation and/or bivalve shell heaps (Valle & Scarton, 2022). Nevertheless, in the past decade an increasing occupation of artificial sites has been reported (Scarton & Valle, 2021); these hosted a fluctuating fraction of the breeding population ranging from zero to 100% in some seasons (pers. obs.).…”