DOI: 10.5061/dryad.tdz08kq59
title: Data from: drones as a tool to study and monitor endangered Grey Crowned Cranes (Balaerica regulorum): behavioural responses and recommended guidelines

description: These data detail the results of an investigation into the impact of
 drones and on-foot approaches on the behaviour of the endangered Grey
 Crowned Crane (Balearica regulorum). In total, 313 drone flights and 56
 on-foot approaches were conducted over three different Grey Crowned Crane
 group types - pairs (110 flights, 26 on-foot), families (66 flights, 7
 on-foot), and flocks (110 flights, 23 on-foot). Response data describe the
 number of birds exhibiting a particular behaviour (1 - no behaviour
 change, 2 - heads raised to observe surroundings, 3 - wings raised, 4
 -moving away, and 5 - flying away) based on a photograph taken during the
 approach. Predictor data include the distance between the drone or on-foot
 observer and the bird grouping and a description of the group type. The
 number of individuals in the group can be inferred from the response data.
description: Experiment 1: Monitoring method
 comparison experiment Trial observations included
 recording the behavioural cues of GCC groupings (pairs, families, and
 flocks) in response to either of the two monitoring methods (on-foot,
 drone) across various distances and flight heights. Behavioural cues were
 categorised as follows: no behaviour change (1), heads raised to observe
 surroundings (2), wings raised (3), moving away (4), and flying away (5)
 (Figure 1). All trial observations were undertaken by the same observer
 and care was taken to wear similarly coloured clothing for each of the
 trials. On-foot monitoring Upon
 locating a GCC grouping, the observer approached the group at a constant
 walking speed of approximately 1 m.s<sup>-1</sup>, making a
 reasonable effort not to disturb the grouping (e.g., avoiding noises and
 sudden movements). Observations were noted at the start of each trial,
 every 10<sup> </sup>– 15<sup>th</sup> step
 thereafter, and again if any change in GCC behaviour was observed. Each
 observation included measuring the distance between the observer and the
 grouping using a range finder (Vortex Crossfire HD LRF-CF1400 Rangefinder)
 and taking a photograph (Nikon D7200 with 100-400mm Sigma lens) of the
 group which enabled <em>post hoc</em> behaviour coding.
 Observations were recorded until groupings displayed a type 5 response
 (flying away). Drone methodology
 The drone pilot positioned herself at least 100 m from GCC
 groupings before drone take-off and at a similar altitude to the GCC
 grouping. On rare occasions the pilot found it practically impossible to
 position herself at 100 m, but all drone experimental approaches were
 conducted from distances of at least 80 m from the GCC groupings. The
 drone was deployed from the pilot’s location to a randomly pre-selected
 flight height (10, 30, 50, or 70 m above the deploy point), then flown
 over the grouping at the selected flight height at a speed of 5
 m.s<sup>-1</sup> with video recording activated to facilitate
 <em>post hoc</em> behaviour coding. After reaching the
 grouping, the drone was flown ± 80 m beyond the grouping and then returned
 to the deploy point to avoid flying over the grouping during the return
 flight. All drone flights were conducted using a standard Mavic Air 2S
 drone (DJI Technology Co., Shenzhen, China) (595 g, 1-inch 20MP sensor, 8×
 zoom, 65dB low noise propeller). The precise height of
 the drone above the grouping was difficult to determine <em>in
 situ</em> as the drone only reports flight height relative to the
 take-off point. The flight height above GCC groupings was therefore
 determined post-hoc by extracting altitude values for the drone deployment
 and subject locations from a high-resolution (± 2 m) digital elevation
 model of the study area using the coordinates as recorded by the drone’s
 Global Positioning System. Data collection from each
 grouping continued until a maximum of four trials had been recorded (with
 a 10-minute interval to allow birds to return to their prior behaviour) or
 until the subjects exhibited a type 5 response. As a precaution, the drone
 was always flown manually to allow the pilot to easily manoeuvre and
 control the drone to avoid any potentially aggressive behaviour from the
 target or non-target species in the study area. Each site was scanned for
 non-target species using binoculars before beginning a drone mission.
 Whilst in flight, the pilot remained aware of any new individuals of the
 target or non-target species entering the site. As far as practically
 possible, we avoided flights over any non-target species. If any
 non-target species displayed discomfort in the presence of the drone, the
 pilot avoided flying whilst that species was near the flight route; and if
 territorial, future flights at that site were terminated.
 Post-hoc behavioural coding Video and photo
 footage were assessed <em>post hoc</em> by a single person.
 Each photo taken during the on-foot monitoring experiment was considered
 an observation. From each video recorded during the drone monitoring
 experiment the frame directly above the grouping was extracted and used as
 the observation. If birds responded with a type 5 response before the
 drone reached the grouping, the frame closest in time was used to
 determine the position of the drone whilst focusing on the initiated
 flight response of the grouping. For each observation, each bird’s
 behaviour was identified and the total number of subjects displaying each
 of the five behaviours was recorded for each observation.
 Experiment 2: Nesting approach experiment We
 identified breeding behavioural cues consisting primarily of a lone crane
 foraging close to a water body or wetland. A drone flight was initiated to
 locate either a nest site or the breeding birds themselves. If either of
 these were located, we considered it an observation. At ± 20 m from the
 subject, the drone was lowered to a flight height of ± 20 m. The drone was
 then manoeuvred towards the subjects either by flying diagonally (an angle
 of ± 45°) or vertically (flying horizontally until above the subjects and
 then descending at an angle of ± 90°), slowly descending until ± 7.5 m
 from the subjects. Because of the limitations of determining distances
 <em>in situ</em> via the drone the distances given here are
 approximate. Video recording was enabled throughout the approach to
 facilitate <em>post hoc</em> behavioural coding as follows;
 (1) little disturbance (either looking, remaining sitting, holding ground,
 or standing up), (2) moderate disturbance (raising wings, walking, or
 running away from offspring), or (3) major disturbance (flying away from
 offspring).
description: # Data from: drones as a tool to study and monitor endangered Grey Crowned
 Cranes (Balaerica regulorum): behavioural responses and recommended
 guidelines This README file was generated on 2024-02-27 by Stuart Demmer.
 GENERAL INFORMATION 1. Title of Dataset: Drones as a tool to study and
 monitor endangered Grey Crowned Cranes (*Balearica regulorum*):
 Behavioural responses and recommended guidelines 2. Author Information A.
 Principal Investigator Contact Information Name: Carmen Rosa Demmer
 Institution: University of South Africa Address: Howick, KZN South Africa
 Email: [carmenrdemmer@gmail.com](mailto:carmenrdemmer@gmail.com) B.
 Associate Contact Information Name: Stuart Demmer Institution: NA Address:
 Howick, KZN South Africa Email:
 [stuart.demmer@gmail.com](mailto:stuart.demmer@gmail.com) B. Supervisor
 Contact Information Name: Trevor McIntyre Institution: University of South
 Africa Address: Pretoria, GAU South Africa Email:
 [mcintt@unisa.ac.za](mailto:mcintt@unisa.ac.za) 3. Date of data collection
 (single date, range, approximate date): 2022-2023 4. Geographic location
 of data collection: Southern Drakensberg, KwaZulu-Natal, South Africa 5.
 Information about funding sources that supported the collection of the
 data: No formal funding SHARING/ACCESS INFORMATION 1.
 Licenses/restrictions placed on the data: CC0 1.0 Universal (CC0 1.0)
 Public Domain 2. Links to publications that cite or use the data: Demmer,
 C. R., Demmer, S., & McIntyre, T. (2024). rones as a tool to study and
 monitor endangered Grey Crowned Cranes (*Balearica regulorum*):
 Behavioural responses and recommended guidelines. Ecology and Evolution.
 [https://doi.org/10.1002/ece3.10990](https://doi.org/10.1002/ece3.10990)
 1. Links to other publicly accessible locations of the data: None 2.
 Links/relationships to ancillary data sets: None 3. Was data derived from
 another source? No A. If yes, list source(s): NA 4. Recommended citation
 for this dataset: Demmer, C. R., Demmer, S., & McIntyre, T. (2024).
 Data from: Drones as a tool to study and monitor endangered Grey Crowned
 Cranes (*Balearica regulorum*): Behavioural responses and recommended
 guidelines. Dryad Digital Repository.
 [https://doi.org/10.5061/dryad.tdz08kq59](https://doi.org/10.5061/dryad.tdz08kq59) DATA & FILE OVERVIEW 1. File List: A) 0_Drone_deploy_distance_assessment.csv B) 1_Method_comparrison.csv C) 2_On-foot_method_assessment.csv D) 3_Drone_method_assessment.csv E) 4_1_Flock_on-foot_method_assessment.csv F) 4_2_Flock_drone_method_assessment.csv G) 5_Approach_angle.csv 1. Relationship between files, if important: None 2. Additional related data collected that was not included in the current data package: None 3. Are there multiple versions of the dataset? No A. If yes, name of file(s) that was updated: NA i. Why was the file updated? NA ii. When was the file updated? NA \######################################################################### DATA-SPECIFIC INFORMATION FOR: 0_Drone_deploy_distance_assessment.csv 1. Number of variables: 3 2. Number of cases/rows: 516 3. Variable List: * behaviour_type: type of behaviour displayed * proportion: proportion of birds in the grouping that displayed the behaviour type * drone_deploy_distance: distance from drone deployment site to bird grouping (in meters) 4. Missing data codes: None 5. Specialized formats or other abbreviations used: None \######################################################################### DATA-SPECIFIC INFORMATION FOR: 1_Method_comparrison.csv These are the data used to determine the average distance at which observations were able to be made between two monitoring methods; dones and on-foot approaches. 1. Number of variables: 5 2. Number of cases/rows: 804 3. Variable List: * subject_grouping_id: id of bird grouping * group_type: bird grouping type * monitoring_method: type of monitoring method used when approaching the bird groupings * behaviour_type: type of behaviour displayed by the grouping * distance: distance at which the behaviour type was displayed (in meters) 4. Missing data codes: NA (data not available) 5. Specialized formats or other abbreviations used: None \######################################################################### DATA-SPECIFIC INFORMATION FOR: 2_On-foot_method_assessment.csv These are the data used to determine the distance at which different behaviours were displayed by the birds when approached on-foot. 1. Number of variables: 6 2. Number of cases/rows: 288 3. Variable List: * subject_grouping_id: id of bird grouping * group_type: type of bird grouping * monitoring_method: type of monitoring method used * behaviour_type: type of behaviour exhibited by a proportion of the birds in the grouping at the given distance * proportion: proportion of birds in the grouping exhibiting the behaviour type * distance: distance of the observer to the bird grouping where the observation was made (in meters) 4. Missing data codes: NA (data not applicable) 5. Specialized formats or other abbreviations used: None \######################################################################### DATA-SPECIFIC INFORMATION FOR: 3_Drone_method_assessment.csv These are the data used to determine the distance at which different behaviours were displayed by the birds when approached by a drone. 1. Number of variables: 5 2. Number of cases/rows: 516 3. Variable List: * group_type: type of bird grouping * monitoring_method: type of monitoring method used * behaviour_type: type of behaviour exhibited by a proportion of the birds in the grouping at the given distance * proportion: proportion of birds in the grouping exhibiting the behaviour type * distance: distance of the drone to the bird grouping where the observation was made (in meters) 4. Missing data codes: None 5. Specialized formats or other abbreviations used: None \######################################################################### DATA-SPECIFIC INFORMATION FOR: 4_1_Flock_on-foot_method_assessment.csv These are the data used to determine the change in behavioural response by grey crowned crane flocks of different sizes to on-foot approaches. 1. Number of variables: 6 2. Number of cases/rows: 158 3. Variable List: * group_type: type of bird grouping * monitoring_method: type of monitoring method used * behaviour_type: type of behaviour exhibited by a proportion of the birds in the grouping at the given distance * flock_size: the total number of birds in the flock * proportion: proportion of birds in the grouping exhibiting the behaviour type * distance: distance of the drone to the bird grouping where the observation was made (in meters) 4. Missing data codes: None 5. Specialized formats or other abbreviations used: None \######################################################################### DATA-SPECIFIC INFORMATION FOR: 4_2_Flock_drone_method_assessment.csv These are the data used to determine the change in behavioural response by grey crowned crane flocks of different sizes to drone approaches. 1. Number of variables: 6 2. Number of cases/rows: 286 3. Variable List: * group_type: type of bird grouping * monitoring_method: type of monitoring method used * behaviour_type: type of behaviour exhibited by a proportion of the birds in the grouping at the given distance * flock_size: the total number of birds in the flock * proportion: proportion of birds in the grouping exhibiting the behaviour type * distance: distance of the drone to the bird grouping where the observation was made (in meters) 4. Missing data codes: None 5. Specialized formats or other abbreviations used: None \######################################################################### DATA-SPECIFIC INFORMATION FOR: 5_Approach_angle.csv These are the data used to assess the reponse of breeding grey crowned crane parents with offspring (either nesting or with hatchlings) to drone approaches from two angles. 1. Number of variables: 4 2. Number of cases/rows: 315 3. Variable List: * nest_site_id: the ID of the nest site being measured * breeding_stage: the stage of nesting, either before ("During nesting") or after eggs are hatched ("After nesting") * approach_angle: the angle at which the drone was flown while approaching the nest (vertical = approx. 90°, diagonal = approx. 45°) * disturbance_type: the level of disturbance experienced by the grouping because of the approach (1 = minor - no response, looking , 2 = modertate - standing, wings raised or walking away, 3 = major flying away) 4. Missing data codes: None 5. Specialized formats or other abbreviations used: None