<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>In the last decade, the use of drones has proven to be the major innovation for studying various aspects of waterbird breeding biology, overcoming the environmental obstacles inherent in monitoring their breeding sites. The Squacco Heron <italic>(Ardeola ralloides)</italic> represents an example of the aforementioned difficulties, since it nests in impenetrable reed beds and nearby bushes, trees and shrubs. The present work reports the results of drone assessment of nest counting and reproductive success of the Squacco Heron in a colony in the Po Delta (NE Italy). At the beginning of the breeding season, far more nests (46) were found using drones than by eye from the nearest embankment (12). After four weeks (estimated hatching period), only ten nests were relocated by drone, due to vegetation overgrowth. All relocated nests were placed directly either within reed beds or on lower branches of shrubs, but always without higher branches obstructing the view from above. Finally, in the fledging period, no nest was relocated on drone imagery, due to further vegetation growth. Only 27 juveniles were found by drone, mostly perching on the canopy, without any evidence of nest failure, suggesting a critical underestimation. In conclusion, drone use improves accuracy of counting nesting Squacco Herons, but fails to assess productivity.</p>
</abstract>

In the last decade, the use of drones has proven to be the major innovation for studying various aspects of waterbird breeding biology, overcoming the environmental obstacles inherent in monitoring their breeding sites. The Squacco Heron (Ardeola ralloides) represents an example of the aforementioned difficulties, since it nests in impenetrable reed beds and nearby bushes, trees and shrubs. The present work reports the results of drone assessment of nest counting and reproductive success of the Squacco Heron in a colony in the Po Delta (NE Italy). At the beginning of the breeding season, far more nests (46) were found using drones than by eye from the nearest embankment (12). After four weeks (estimated hatching period), only ten nests were relocated by drone, due to vegetation overgrowth. All relocated nests were placed directly either within reed beds or on lower branches of shrubs, but always without higher branches obstructing the view from above. Finally, in the fledging period, no nest was relocated on drone imagery, due to further vegetation growth. Only 27 juveniles were found by drone, mostly perching on the canopy, without any evidence of nest failure, suggesting a critical underestimation. In conclusion, drone use improves accuracy of counting nesting Squacco Herons, but fails to assess productivity.

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

Ornis Hungarica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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

In the last decade, the use of drones has proven to be the major innovation for studying various aspects of waterbird breeding biology, overcoming the...

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

Published Online: Nov 25, 2022

Page range: 176 - 187

Received: Aug 19, 2022

Accepted: Oct 25, 2022

DOI: https://doi.org/10.2478/orhu-2022-0028

Keywords
counting, disturbance, drone monitoring, productivity, Squacco Heron

© 2022 Roberto G. Valle et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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

Published Online: Nov 25, 2022

Page range: 176 - 187

Received: Aug 19, 2022

Accepted: Oct 25, 2022

DOI: https://doi.org/10.2478/orhu-2022-0028

Keywordscounting, disturbance, drone monitoring, productivity, Squacco Heron

© 2022 Roberto G. Valle et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
counting, disturbance, drone monitoring, productivity, Squacco Heron