DOI: 10.5061/dryad.nzs7h4505
title: Data from: The multi‐functional use of large tree cavities by arboreal vertebrates in a temperate broadleaved forest of Eastern Europe

description: Tree cavities offer protected shelters and resources for arboreal
 vertebrates worldwide. In general, cavities with larger openings are
 better accessible for predators and are avoided by smaller species for
 breeding, but can still be attractive for occasional use. The current
 study explores the diversity of functional use types and species
 interactions at the largest available tree cavities (entrance width
 ≥ 10 cm) in a temperate European forest with a low number of large
 cavity‐breeding species. Year‐round camera observations at 9 cavities
 (range 0.7–3.5 years) revealed 34 visiting species of birds and mammals,
 including non‐cavity‐breeding species. The top predator threatening other
 large‐cavity users was European pine marten (Martes martes), which
 regularly visited each cavity year‐round, on average every 0.7 months.
 Tawny owl (Strix aluco) was the only species successfully breeding in
 cavities, arguably because of its ability to defend the nests. However,
 other species visited cavities at an average rate of 1.5 visits per day,
 making predominantly short visits (less than 30 s) interpreted as
 exploration, searching for food, or inspecting for the presence of owls
 (mobbing). Making short visits and time segregation with predators was a
 behavioural strategy to exploit cavities for most species. These results
 confirm that, similarly to other keystone structures (large arboreal
 nests, ground burrows, etc.), large tree cavities attract a significant
 part of the arboreal vertebrate community and enrich their habitats. To
 sustain these functions in wooded ecosystems, management should provide a
 surplus of available cavities and diversity of their characteristics even
 when the apparent number of breeding species is low.
description: <strong><em>Data
 collection</em></strong> Data were
 collected as images produced by remote cameras (camera traps) installed in
 front of tree cavity entrances. Cameras were set to still mode, making 3
 captures per trigger with the delay time 5 seconds, trigger sensitivity
 was set to the highest. The unit of observation was a
 visit by a vertebrate defined as an image or a series of images of one
 species obtained within 30 seconds before and after other visits. When
 animals used cavities for roosting, a ‘visit’ was one roosting event per
 day, irrespective of its length. If two or more species were observed
 within one event, they were treated as one visit for each
 species. The information recorded for each visit was:
 animal species, number of specimens, time and date of observation, time
 spent, activity type. Activity types were classified into five categories:
 passing with no interest to cavity (excluded from analysis), approaching
 and looking inside, entering the cavity, roosting and breeding in
 cavities. <strong><em>Data
 pre-processing</em></strong> Relevant
 information (animal species, activity types, notes on behaviour etc.) was
 assigned to images as tags using DigiKam software (www.digikam.org). To
 get table with event data (observations.csv), image metadata with tag
 information were extracted from images and grouped into events with 30-sec
 lag using R package ‘camtrapR’.
description: # Data from: The multi-functional use of large tree cavities by arboreal
 vertebrates
 [https://doi.org/10.5061/dryad.nzs7h4505](https://doi.org/10.5061/dryad.nzs7h4505) ## Description of the data and file structure ***observations.csv*** | Field | Description | | :---------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | DateTimeOriginal | Date and Time in original format as exported from exif images | | Date | Date in format "2018-01-20" | | Time | Time in format "2018-01-20 10:04:18" | | cavity | Number of tree cavity | | visit\_n | Unique identifier of each observation (visit) | | index | If several species were observed in one observation, information on each species is in separate rows. For example, when two species were simultaneously observed, there are two rows with different indices (for species a and species b, respectively), but same visit identifier (visit\_n) | | Species | Latin name of observed species | | n\_specimens | Number of observed specimens | | Individual | Age, sex or color morph of individual. As exported from jpeg tags, this field can contain several values separated by \| | | category\_a | Cavity use types observed: Looking, Entering, and Roosting (see Methods) | | category\_b | Additional notes about animal behavior, including feeding. As exported from jpeg tags, this field can contain several values separated by \| | | duration\_sec | Duration of observation. Minimum duration is 5 seconds as it was a delay time set on cameras. Not stated for roosting events | | Interaction | Was interaction with other species observed (simultaneous observation)? 0 - no interaction, 1 - interaction | | Interact\_spec\_a | Interacting species if interaction was observed | | Interact\_spec\_b | Interacting species if interaction was observed | | br\_status | Whether a cavity was used for breeding by any species during the observation. Breeding – used, Nb – not used | | br\_species | Latin name of breeding species, if cavity was used for breeding during the observation. NA – no breeding in a cavity | | days\_obs | Number of days when camera operated at the current cavity during the current month. This field was needed to calculate visitation rates | ***cavities_coord.csv*** Tree species and coordinates of studied tree cavities in WGS84: y – latitude, x – longitude. ***camop_table.csv*** Camera operation data according to the format shown in [https://jniedballa.github.io/camtrapR/articles/camtrapr3.html](https://jniedballa.github.io/camtrapR/articles/camtrapr3.html) For each cavity, series of observations are shown with camera setup and retrieval dates. ***summer_v_birds.csv*** Data on summer bird assemblage in the studied region and bird species visiting observed tree cavities. | Field | Description | | :--------------- | :-------------------------------------------------------------------------------- | | species\_lat | Latin species name | | rel\_abundance | Relative abundance of a current species in summer bird assemblage | | visits.share | Relative share of visits of a current species observed on camera images | | OakF\_cavNesters | Is current species a cavity-nester. yes – cavity-nester, no – not a cavity-nester | | bodyLength | Average body length of a species, cm | ***monthly_observations.csv*** Numbers of days of observations of each cavity in each year and month. Data were needed to get visitation rates. | Field | Description | | :----------------- | :---------------------------------------------------- | | cav\_month\_unique | Unique identifier of cavity/year/month of observation | | cavity | Cavity number | | year.month | Year and month number | | days\_obs | Number of observation days | | monthno | Number of month |  ***interact_matrix_Br.csv, interact_matrix_Nb.csv*** Matrices showing the total number of interactions observed between each pair of species at cavities with active nests and no nests, respectively. ## Code/Software ***observations_analysis.R*** R script to reproduce the results presented in the original publication. This can be found at the Software link in the Related Works section.