DOI: 10.5061/dryad.5mkkwh7j1
title: Ungulate substrate use in fauna passages

description: This dataset describes the substrate used by ungulates when crossing
 through fauna passages (n=7) in boreal Sweden and Finland, as well as the
 trajectories of the ungulates when crossing. Data of crossing events in
 the Excel file and the spatial maps are linked by the "Count"
 number. For each crossing event, date and time, any occurrence of snow,
 group size, and the animal´s direction of movement are given. As
 additional information, details of the seven fauna passages (location,
 dimensions, disturbances, and the monitoring period) are provided.
description: We selected fauna passages for the study on the following
 criteria: i) minimum width 20 m and containing a variety of substrates
 (≥2) to allow animals to actively select substrate, ii) passage monitored
 for at least 1 year, iii) camera trap set up allowed equal (unbiased)
 coverage of the entire passage width. We monitored ungulates in the
 passages using motion-triggered cameras (Browning 2017 Spec Ops Advantage
 Trail in the Swedish passages, Uovision UM785-3G in the Finnish passages)
 with an infrared (IR) motion sensor, IR flash, and IR night vision. The
 trigger speed of cameras was 0.4 sec (Browning) or 0.6 sec (Uovision),
 cameras were set to rapid fire 3–5 images when being triggered, thereafter
 with a delay of 5 sec (Browning) or 60 sec (Uovision) to the next
 triggering. We mounted the cameras in the middle of the passages, at
 approximately 1 m above ground, attached to pre-existing fence poles or,
 in a few cases, new poles. We placed the cameras on one or both sides of
 the passage and facing the passage center (see spatial maps), and in one
 case, we also mounted cameras near a structure’s center pillar and facing
 the sides, accordingly aiming at covering the entire width of the passage.
 We revisited cameras once per 1–3 months in order to check functionality
 and download images. Ungulate use was recorded for a minimum of one
 year. We defined a crossing event as all consecutive
 recordings of ungulates (either single individuals or groups of
 conspecifics) at a passage separated by at least 10 min from the next
 recording. This time limit was set to avoid the most immediate temporal
 dependence between observations. We used only events that we judged
 showing animals successfully crossing the passage, i.e., coming in from
 one side and leaving towards the other. For each event, we noted the
 ungulate species and any occurrence of snow cover (as viewed from images),
 the date and time (start of event), the direction of movement (north or
 south), and the number of individuals involved (group size). We excluded a
 small number of crossing events where species could not be definitively
 identified (roe/white-tailed deer; Finnish data). For each event, we
 recorded the substrate where the animal crossed a predefined imaginary
 line over the passage in front of the cameras (hatched line in spatial
 maps). In the case of groups, we recorded only the first crossing
 individual, since we assumed that the other individuals in the group were
 likely to follow the trail of the first rather than make an independent
 decision.  Substrates were defined as follows: 1.
 Grassy/sandy = spontaneous herbaceous or graminoid vegetation on sandy
 soil, 2. Stony/rocky = stones or rocks (&gt; ca 5 cm) sometimes with
 sparse herbaceous vegetation, 3. Fiber mat = artificial coco liner, ca 5
 cm thick, rolled out on stony/rocky substrate, 4. Shrub = woody vegetation
 ca 0.5–2 m height, mainly with ground covered by low vegetation), 5. Water
 = river or stream; open water, ice covered in winter, 6. Road = local
 gravel or dirt road. Substrates, grassy/sandy, and road were only
 represented in the overpasses, while stony/rocky, fiber mat, and water
 were only represented in the underpasses. As a complement, we mapped each
 trajectory on a spatial map.
description: # Ungulate substrate use in fauna passages Dataset DOI:
 [10.5061/dryad.5mkkwh7j1](10.5061/dryad.5mkkwh7j1) ## Description of the
 data and file structure We have submitted our data on ungulate crossing
 events through fauna passages
 (Ungulate_crossing_events_through_fauna_passages_Data.xlsx) and
 complemented with illustrations of trajectories of each crossing event
 (Ungulate_crossning_events_through_fauna_passages_Spatial_maps_of_trajectories.pdf). We also provide general info about the study sites (Ungulate_crossning_events_through_fauna_passages_General_info_of_fauna_passages.pdf). #### File: Ungulate_crossning_events_through_fauna_passages_General_info_of_fauna_passages.pdf * Location: Coordinates of the site (in WGS84) * Technical label: The number of the bridge in the Swedish Transport Administration´s bridge database * Construction year: The year the bridge was constructed *  Infrastructure crossed: The name and type of the major infrastructure that the bridge crosses * Width: Width of the fauna passage; available width for the fauna, in meters, measured between perimeter fences * Height: Height of the fauna passage (underpasses); available height for the fauna, in meters, measured between ground and ceiling * Length: Length of the fauna passage; distance that fauna have to pass from one side of the infrastructure to the other, in meters, as subjectively assessed from surrounding habitats and the extended fence line along the infrastructure * Traffic through passage: Mean number of motorized vehicles through the passage per day (24h) * Other human activities in passage: Mean number of non-motorized human disturbances in the passage per day (24h) * Monitoring start: Date when camera monitoring started (yyyy-mm-dd) * Monitoring end:  Date when camera monitoring ended (yyyy-mm-dd) * Number of days: Total number of days that the fauna passage was effectively monitored * Substrates available: Total width of each substrate along the record line, in meters, and the total width of the record line  #### File: Ungulate_crossning_events_through_fauna_passages_Spatial_maps_of_trajectories.pdf Spatial maps of individual trajectories (events), separated by site, species, and season (snow-free or snow-covered ground). Each map shows: * Individual trajectories; blue solid arrows, serial numbers referring to column G in the file  Ungulate_crossning_events_through_fauna_passages_Data. * Camera placement(s); red symbols, also showing the direction of the camera * Record line; blue hatched line, along which the substrate use was recorded * Perimeter fencing of the passage; wider light blue line * Substrates; extent of substrates along the record line   #### File: Ungulate_crossning_events_through_fauna_passages_Data.xlsx Description of columns * Country: Sweden or Finland * Site: Study site, referring to sites described in the  file Ungulate_crossning_events_through_fauna_passages_General_info_of_fauna_passages.pdf * Type of passage: Underpass (bridge for passage under the major infrastructure) or overpass (bridge for passage over the major infrastructure) * Species English: Common name in English * Species Scientific: Current scientific name * Snow-covered ground: Any snow cover on the ground (Yes or No) * Count: Serial number of crossing event, referring to the respective map in the file Ungulate_crossning_events_through_fauna_passages_Spatial_maps_of_trajectories * Date: Date of event (yyyy-mm-dd) * Time (start): Time when the event started (hh:mm:00) * Direction: The animals' direction through the passage (north or south) * Number of individuals: The number of unique individuals involved  in the event (="group size") * Substrate: The substrate used when crossing the record line in the middle of the passage, separated into: * Grassy/sandy = spontaneous herbaceous or graminoid vegetation on sandy soil * Stony/rocky = stones or rocks (&gt; ca 5 cm) sometimes with sparse herbaceous vegetation * Fiber mat = artificial coco liner ca 5 cm thick, rolled out on stony/rocky substrate * Shrub = woody vegetation ca 0.5–2 m height, mainly with ground covered by low vegetation) * Water = river or stream; open water, ice covered in winter * Road = local gravel or dirt road