DOI: 10.5061/dryad.3bk3j9kv5
title: Data from: Individual responses of GPS-tagged geese scared off crops by drones or walking humans

description: Scaring of wildlife is commonly used in attempts to reduce crop damage in
 agricultural landscapes, but relatively few studies exist on its actual
 effect. We tracked GPS-tagged greylag geese (Anser anser) in south-central
 Sweden, before and after scaring by approaching them either by walking or
 by drone. On the field level we studied the scaring effect by estimating
 return rate to the field where scared. On the landscape level we tested if
 geese were less prone to use agricultural fields after being scared. Geese
 immediately left the field when scared and five minutes later they were on
 average 990 m (± 56 SE) from the scaring position. The proportion of GPS
 positions near the scaring position decreased significantly for at least 4
 hours after scaring. Geese showed a significant shift from agricultural
 fields to wetland habitats the first 4 hours after scaring. However, the
 effect of scaring soon levelled off; after 24 hours the field where
 scaring had occurred was used to the same extent as any other field in the
 landscape, and agricultural fields were used to the same extent by scared
 and undisturbed geese. We did not find any differences in response
 depending on scaring technique. The probability to return and use
 agricultural fields after scaring was higher for geese scared in the
 morning compared to in the afternoon. Moreover, the probability to return
 and use of agricultural fields were higher in spring than in other
 seasons. Synthesis and applications: We found that scared geese tend to
 visit agricultural fields soon after scaring and that scaring alone tends
 ‘to move the problem around’. This suggests that scaring needs to be
 repeated across the landscape, but also that accommodation fields where
 geese do not cause damage may be needed to keep geese off conventional
 fields. However, our study presents a glimpse of promise as the rather
 simple drone used covers large areas quickly and minimizes walking in
 growing crops. With technological advancement and possible autonomous
 techniques, drones may be capable of providing repeated scaring over large
 areas in the future.
description: Location data from GPS-tagged greylag geese. Experimental scaring
 trials (before/after) with drones and walking humans. 
description: # Data from: Individual responses of GPS-tagged geese scared off crops by
 drones or walking humans
 [https://doi.org/10.5061/dryad.3bk3j9kv5](https://doi.org/10.5061/dryad.3bk3j9kv5) ## Description of the data and file structure In June 2018 and June 2019 breeding and moulting (flightless) greylag geese (N=32) were caught.  In addition to classic tarsal metal rings, geese were provided with neck collars fitted with a solar powered GPS tracking device: Ornitela (OT-N35 or OT-N44). Geese were aged (juvenile or adult ≥2nd calendar year) based on plumage and sexed by cloacal inspection. Out of the 32 individuals, four were juveniles and 28 adults; 13 were females and 19 males. For the present study we used GPS positions from 48 hours before to 48 hours after each scaring event of an individual. The default positioning rate was set to every 30 minutes (i.e., in total 192 positions per scaring event). In addition, we tracked the geese more intensively (one position every 5 minutes) from 4 hours before to 4 hours after each scaring event (96 additional positions per scaring event). This intensive and real-time positioning allowed us to find a certain individual targeted for a trial and to follow its movements before and after scaring. Inaccurate positions, measured with dilution of precision (DOP) &gt;7, were excluded (n=534 out of 228 906 obtained positions, ~ 0.2%). The total number of positions obtained between 24 and 48 hours before scaring was 12614, and 12836 for the same duration (period) after scaring. We used the DJI Phantom 4 drone, flown in a straight line towards the flock containing the target goose at a speed of 50 km/h at an altitude of 10 m. Scaring by walking was performed by approaching the goose flock in a straight line using a normal walking pace.  ### Files and variables #### File: Geese\_scaring\_data.csv **Description:**  ##### Variables * row_number – row number of in data set * before_after – factor indicting before and after scaring (includes the scaring point “scaring”) * trial_id – factor indicting trial * device_id – factor indicting collar id * UTC_datetime – date and time (UTC) for the GPS location * time – only time (UTC) * time_num – time numerical * time_scaring – time in relation to scaring time (negative time before scaring, positive time after scaring) * time_period – time period in relation to scaring time divided into twelve time intervals: A (48 – 24 hours before), B (24 – 4 hours before), C (4 – 3 hours before), D (3 – 2 hours before), E (2 – 1 hours before), F (1 – 0 hours before), G (0 – 1 hours after), H (1 – 2 hours after), I (2 – 3 hours after), J (3 – 4 hours after), K (4 – 24 hours after), and L (24 – 48 hours after) * time_of_day – factor for time of the day when scared; morning (before 11 AM) or afternoon (after 12 AM) * scaring_method – factor for scaring method; drone versus walking * season – factor for season when scared; spring (March – April), summer (July – August), and fall (September * distance – distance (m) to the scaring point * buffer – factor if the goose was ≤300 m from the scaring point (coded as 1) or &gt;300 m from the scaring point (coded as 0) * habitat – habitat characteristics for the goose positions; agricultural field and wetland ## Code/software R (version 4.2.2, R core team 2022) and Open office