Authors:
Koch, Veronika Paulina (a,b); Bolte, Leonard (a,c); Harms, Wiebke (a,b); Henle, Klaus (a); Grimm-Seyfarth, Annegret (a,b)
a - UFZ – Helmholtz Centre for Environmental Research, Department of Conservation Biology, Permoserstr. 15, 04318 Leipzig, Germany
b - Wildlife Detection Dogs e.V., Immenkorv 19, 24582 Bordesholm, Germany
c - University of Leipzig, Institute of Biology, Molecular Evolution and Systematics of Animals, Talstrasse 33, 04103 Leipzig, Germany

Contact details:
veronika.koch@ufz.de (corresponding author, phone: +49 341 60253904, ORCID 0009-0007-7139-8887),
leonard.bolte@ufz.de (ORCID 0000-0002-6885-5641),
wiebke.harms@ufz.de (ORCID 0009-0009-2390-7258),
klaus.henle@ufz.de (ORCID 0000-0002-6647-5362),
annegret.grimm@ufz.de (ORCID 0000-0003-0577-7508)

Data description – dog_evaluation

• This data was collected between 2021 and 2023 in Saxony, Saxony-Anhalt and Hesse (Germany)
• We were granted a nature conservation exemption from the prohibitions under §44 para. 1 no. 1 and 2 of the Federal Nature Conservation Act (BNatSchG) and §4 para. 1 no. 1 of the Federal Species Protection Ordinance (BArtSchV) by the respective responsible lower nature conservation authorities (permit number: 364.620/65/15/1) for capturing and handling living natterjack toads (Epidalea calamita).

Variable description – dog_evaluation

• Date – date of test
• Time – time of test (NA: not available, was forgotten to note down)
• Location – location of test
• Transect – individual transect plot ID, plot IDs refer to transects within the open cast lignite mine (NA: not available, applies mostly to training and test data outside the lignite mine)
• Dog - dog used in test: dog 1, 2, 3 or 4 (for more information see table 1 in the manuscript)
• Handler – dog handler (Person A, Person B)
• Assistant – Person helping and assisting, e.g. hiding target odour (NA: not available, either no assistant was present (not blind searches) or assistant was forgotten to note down)
• InclDaysWorked – number of days the dog has been working prior to the day of the test
• TrainingDay – indicates how many days of training the dog has had in total
• TrialNumber – the consecutive numbering of the tests conducted. The numbering of the tests may differ from the total number of tests, as not all tests were included in the analysis (e.g. indoor trainings).
• SessionDuration - the duration of the whole session with each session comprising between 1 and 15 tests and occasionally short training units
• Temperature - temperature in °C measured with a TFA Dostmann thermometer. Temperature data of the fieldwork obtained from the meteorological station in Pegau, using daily average temperatures
• Humidity - Humidity in % (NA: not available, either no hygrometer present or forgotten to write down)
• Weather – weather during the test. Sunny: no clouds visible; partly cloudy: clouds visible but cover less than ¾ of the sky without rain; cloudy: clouds cover at least ¾ of the sky without rain; drizzle: drizzling rain; raining: more than drizzling rain; snowy rain: partly rain, partly snow
• Wind – Wind condition during the test. Wind condition checked by scattering some baby powder and observing trees following Isyumov and Davenport (1975); none, slight, intermittent, moderate, or severe, referring to Beaufort scale 0-1, 2, 3, 4, 5 or more, respectively
• Terrain - predominant microhabitat type of the search area; grassland, high herbs: grassland with high grass / herbs above 20 cm height; grassland, low herbs: grassland with low grass / herbs up to 20 cm height; shrubland: almost no trees, many shrubs; forest, open understory: forest with up to ¼ of the search area covered with shrubs; forest, dense understory: forest with more than ¼ of the search area covered with shrub; plaines, sands and rocks: plaines with less than 50 % herbs and grasses, sandy ground and rocks; anthropogenic: any kind of anthropogenic habitat with concrete, no parks
• Slope - inclination change and slope: level: no inclination (<0.5°); slight: slight inclination throughout the search area (0.5-10°); medium: intermediate inclination throughout the search area (11-20°); steep: high inclination throughout the search area (> 20°); mix: only some parts of the search area with inclination
• Insect presence - quantity of flying insects present: none, few, or many, referring to no, single, or clouds of individuals, respectively
• Leash – indicates whether the dog was without, on a short or long leash during the test
• SearchArea - size of the area searched by the dog in m2
• Blindness – referring to the blindness of the test. Not blind: the handler and the assistant knew the position of the natterjack toad in the test; single blind: only the assistant but not the handler knew the position of the natterjack toad in the test; double blind: neither the assistant nor the handler knew the position of the natterjack toad in the test
• Site - Surface on which the target odour (natterjack toad) was placed
• Visibility - invisible: the placed individual toad was not visible to the handler and the dog upon alert; visible: the placed individual toad was visible to the handler and the dog upon alert
• ToadCondition - alive: training or wild toad was alive; dead: training toad was dead
• ToadAge - age categories based on size (adults > 47 mm SVL, subadults 30 - 47 mm SVL, juveniles < 30 mm SVL)
• ToadSex – female, male or individual of unknown sex
• FoundFirstAttempt – the toad was found by the dog at the first attempt, i.e. after covering the search area once
• FoundSecondAttempt – the toad was found by the dog at the second attempt, i.e. after covering the search area twice (NA: not available as the dog found the target at first attempt)
• FoundThirdAttempt – the toad was found by the dog at the third attempt, i.e. after covering the search area three times (NA: not available as the dog found the target at first or second attempt)
• Alert – indicates whether the dog alerted independently or assisted, strong or light at the target odour (NA: not available, dog did not find the target i.e. no alert)
• DogBehaviour - cooperative: dog obviously showed targeted searching with an upright posture and without panting during the search; distracted: dog did not clearly show targeted searching and also showed other behaviour (this could include listening to noises, observing people/dogs or obviously sniffing other traces such as those of other dogs or game); fatigued: dog showed targeted searching but without an upright posture and / or with panting during the search as well as a slower movement; unresponsive: dog would stop searching at all (Grimm-Seyfarth, 2022)

Data description – method_comparison

• This data was collected between 2021 and 2023 in Saxony and Saxony-Anhalt (Germany)
• We were granted a nature conservation exemption from the prohibitions under §44 para. 1 no. 1 and 2 of the Federal Nature Conservation Act (BNatSchG) and §4 para. 1 no. 1 of the Federal Species Protection Ordinance (BArtSchV) by the respective responsible lower nature conservation authorities (permit number: 364.620/65/15/1) for capturing and handling living natterjack toads (Epidalea calamita).

Variable description – method_comparison

• date – date of the survey
• year – year of the survey
• survey_nr – number of the survey
• method – method of the seurvey, ACB: artificial cover board, WDD: wildlife detection dog transect
• habitat – habitat type of the survey, 1: open ground, low herb layer (mean = 17 cm), few plots with higher tree density, some shrubs as well as few hiding places, 2: open ground, higher herb layer (mean = 37 cm), some individual trees and shrubs
  as well as few hiding places, 3: little open ground, very rich in vegetation with high herb layer (mean = 38 cm), some hiding places
• inds - number of individuals found
• age – referring to size classes of toads (“juveniles” < 30 mm snout-vent-length (SVL) and “adults” ≥ 30 mm SVL)
• prec – precipitation on survey day in mm
• prec_1, prec_2, prec_3, prec_4 - accumulated rainfall over one, two, three or four days prior to the survey
• temp – temperature in °C, obtained from the meteorological station in Pegau, using daily average temperatures
• number of plots/habitat/day - number of surveyed plots per habitat per day
• success – success rate, calculated as number of individuals caught per method, habitat type and day divided by the number of plots surveyed in these categories and multiplied by 100