DOI: 10.5061/dryad.1c59zw43q
title: Data from: Machine learning identification of microhabitat features associated with occupancy of artificial nestboxes by hazel dormice (Muscardinus avellanarius) in a UK woodland site

description: Hazel dormice (Muscardinus avellanarius) have severely declined since 2000
 leading to increased legislative protection in the UK and Europe.
 Artificial nestboxes are widely used for its conservation and monitoring.
 Previous research has focused on how to identify suitable areas for
 nestboxes, but where to place individual boxes to promote occupancy is
 less well understood. Here, we demonstrate the use of machine learning
 Random Forest regression to predict nestbox occupancy from a wide range of
 microhabitat variables using a UK woodland as a case study. Random forest
 models are powerful predictive tools that allow simultaneous testing of
 many predictors with relatively few observations. Field data included
 observed nestbox occupancy (2017-2021) and measurements of 76 microhabitat
 variables collected in the summer of 2021 from 45 occupied and unused
 nestboxes located in a deciduous woodland in Berkshire, UK. We applied
 Random Forest regression to identify important variables and predict
 nestbox occupancy demonstrating robust approaches to tune model
 hyperparameters and evaluate importance metrics. In our study area,
 nestboxes were more likely to be occupied in sites with more hazel
 (Corylus avellana), greater overall tree abundance but not fully closed
 canopies (optimal 80-85%), more honeysuckle (Lolium periclymenum) and
 hawthorn (Crataegus monogyna), and when located further from footpaths and
 woodland margins. Occupancy over the study period was well predicted using
 microhabitat variables (13.3% OOB error) but future occupancy was more
 uncertain (33.3% error for 2021-2023 records). Modelling approaches that
 allow consideration of numerous variables from few locations or
 observations can be help identify relevant features and predict desirable
 outcomes of conservation actions. Here we demonstrate this approach
 identifying microhabitat variables that influence artificial nestbox
 occupancy by hazel dormice in a UK woodland. Findings offer some
 recommendations for local management that could promote nestbox occupancy
 and improve monitoring and conservation efforts.
description: <em>Study area and dormice
 surveys</em> The study area was within the
 grounds of Basildon Park House (BPH), a National Trust property with
 extensive woodland, located in Berkshire, UK (see paper for further
 details).<strong> </strong> In 2013, 144
 nestboxes were erected at two different woodland areas within BPH: 78 were
 located in clusters within the <em>northern</em> site, and 66
 were positioned along three distinct lines in the
 <em>southern</em> site. Within
 the <em>northern</em> site, mature beech (<em>Fagus
 sylvatica</em>), ash (<em>Fraxinus excelsior</em>) and
 oak (<em>Quercus </em>spp.) are the most frequent tree species
 with sweet chestnut (<em>Castanea sativa</em>) and field elm
 (<em>Ulmus minor</em>) occasional. Hawthorn and coppiced hazel
 are dominant in the understorey layer, with holly (<em>Ilex
 aquifoliaceae</em>)<em> </em>and young sycamore
 (<em>Acer pseudoplatanus</em>) frequent, and other species
 such as field maple (<em>Acer campestre)</em>, whitebeam
 (<em>Sorbus aria</em>) and rowan (<em>Sorbus
 aucuparia</em>) occasional. Bramble (<em>Rubus fruticosus
 </em>agg.)<em> </em>and honeysuckle are abundant in both
 the understorey and field layer. In the <em>southern</em>
 site, nestboxes in the densest lines are closest to the boundary between
 woodland and arable land (in 2021 the crop was rapeseed <em>Brassica
 napus</em>), amongst what used to be a hedge, but is now a line of
 mature scrub. The main tree canopy species here are oak, lime
 (<em>Tilia x europaea</em>) and beech, which are frequent,
 although there are some sections where there are no canopy tree species
 present. In the understorey cherry plum (<em>Prunus
 cerasifera</em>) is dominant, with occasional European spindle
 (<em>Euonymus europaeus</em>) and young oaks. The other two,
 more sparse lines of boxes within the <em>southern </em>site
 extend northwards into more mature woodland, where the dominant tree
 canopy species are beech and oak, with hazel dominant in the understorey,
 and hawthorn and young sycamore frequent. Bramble is dominant in the
 understorey and field layer species. All nestboxes at
 BPH have been regularly monitored by the Berkshire Mammal Group since
 2017, up to four times a year as part of the National Dormouse Monitoring
 Programme (NDMP). No monitoring occurred between 2013 and 2016. During
 each survey, nestboxes are recorded as occupied by hazel dormice if a
 dormouse is present, or if there is a nest with evidence of recent
 occupation. Otherwise, they are recorded as empty. Using the full survey
 records between 2018 and July 2021 we classified nestboxes as
 historically<em> occupied</em> (occupied at least once since
 2018) or <em>unoccupied</em> (not occupied since 2018). We did
 not include existing occupancy records from 2017 to reduce the time lag
 from recorded occupancy to habitat recorded; such that we focus on
 nestboxes occupied in the four years prior to recording habitat. We
 focused on 13 <em>occupied</em> nestboxes at the<em>
 northern </em>site and all 6 <em>occupied</em> nestboxes
 at the <em>southern</em> site (total 19
 <em>occupied</em> nestboxes). In the <em>northern
 </em>site we focused on nestboxes occupied frequently (in more than
 one survey) and/or recently (occupied at least once in the last three
 years). If two nestboxes in close proximity (&lt;10m) met these
 criteria, we randomly selected one of them to avoid replicating
 microhabitat data. We also selected 26 historically
 <em>unoccupied</em> nestboxes (12 in the
 <em>northern</em> site and 14 in the
 <em>southern</em> site) using the SelectRandomByPercent
 function in ARCGIS 10.5.1 excluding any nestboxes within 10m of selected
 <em>occupied</em> nestboxes. If two selected
 <em>unoccupied</em> nestboxes were in close proximity
 (&lt;10m) we located an alternative pair in the area at least 10m
 apart. <em>Microhabitat
 surveys</em> In March 2021, all selected
 nestboxes were cleaned and we recorded GPS coordinates (using Handy GPS on
 iPhone 11, accurate to 3m), tree species on which the nestbox was
 installed, height from the base of the nestbox to the ground, and the
 orientation of the front of the nestbox. Microhabitat data were collected
 during May and June 2021 at four scales: directly above the nestbox,
 within a 5 m radius of each box, in four 2 m x 5 m quadrats starting 5 m
 from the nestbox, and using existing GIS layers (see paper for further
 details and figures). Within the 5 m radius cover was visually estimated
 within four levels: tree canopy, understorey, field layer and ground layer
 (Eden 2009). Tree canopy reflected trees taller than 4 m, with trees
 &lt; 4m classified as part of understorey (Berg & Berg 1998).
 The four 2 m x 5 m quadrats started at the edge of the 5m radius running
 with orientations N, E, S and W. Sampling areas which intersected
 footpaths or trackways were still assessed as dormice can occasionally
 cross open ground when foraging or looking for nesting
 materials (Mortelliti et al. 2013). We acknowledge that the collected
 microhabitat data represent a particular time of the year and cannot
 capture seasonal or interannual variability, which may be important for
 site selection in hazel dormice. <em>GIS
 information</em> Nestbox locations
 were collected via GPS with a minimum of 3m accuracy and mapped using
 ARCGIS. Footpaths around the site, and the woodland margin were walked and
 recorded using GPS and added as a new layer. These layers were then used
 to calculate the minimum distance to the woodland margin, the closest
 footpath, and the nearest neighbouring nestbox.
description: # Data from: Machine learning identification of microhabitat features
 associated with occupancy of artificial nestboxes by hazel dormice
 (*Muscardinus avellanarius*) in a UK woodland site Malyan, J; Lloyd, AJ;
 González-Suárez, M (2024) [Machine learning identification of microhabitat
 features associated with occupancy of artificial nestboxes by hazel
 dormice (*Muscardinus avellanarius*) in a UK woodland
 site](https://doi.org/10.1002/wlb3.01185). *Wildlife Biology *2024:*
 *e01185.* *DOI: 10.1002/wlb3.01185 ## Description of the data and file
 structure Two datasets in csv format describing hazel dormice occupancy
 and microhabitat features for 45 artificial nestboxes in a UK woodland,
 and one R script (Rmd format) providing all code necessary to recreate the
 analyses and graphs presented in the published paper. ###### **Dataset 1
 "MalyanetalDataPub1.csv" main dataset describing nestbox
 occupancy and microhabitat variable data collected in May 2021.** The
 dataset contains 46 rows (1 header with variable names and 45
 observations, 1 per studied nestbox) and 75 columns (variables). Variables
 are described in the table below. Missing data is indicated by NA. |
 **Variable Name** | **Description** | | :--------------------- |
 :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Box | Unique alphanumerical code of the artificial nestbox considered in our study | | Sited\_tree | Species of the tree in which the nestbox was located (not used in the analyses, for information only) | | Height\_(mm) | Height from the ground in mm at which the artificial nestbox was located. Measured to the bottom of the nestbox | | Orientation | General orientation (aspect) of the entrance of the nestbox. Eg, N means the entrance of the nestbox was facing North  | | Dis\_fpath\_(m) | Distance in metres from focal nestbox to the nearest footpath. Collected via GPS with minimum 3m accuracy and mapped using ARCGIS | | Dis\_add\_nestbox\_(m) | Distance in metres from focal nestbox to the nearest nestbox (all nestboxes, not only those for which habitat data were collected, were considered to measure distance). Collected via GPS with minimum 3m accuracy and mapped using ARCGIS | | Dis\_mar\_(m) | Distance in metres from focal nestbox to the nearest woodland margin. Collected via GPS with minimum 3m accuracy and mapped using ARCGIS | | Canopy\_May\_(%) | Total percentage of tree canopy and understorey vegetation cover above the focal nestbox estimated in May 2021. Cover was defined as the percentage of black pixels in processed photos taken with an Apple iPhone 11 levelled-flat on a tripod set at 1 metre from the ground and as close to the nestbox as possible without including the box in the photo. Original photos were desaturated to grayscale with the colour curve adjusted to make all pixels either black or white using GIMP 2.10.24. | | Canopy\_July\_% | Total percentage of tree canopy and understorey vegetation cover above the focal nestbox estimated in July 2021. Cover was defined as the percentage of black pixels in processed photos taken with an Apple iPhone 11 levelled-flat on a tripod set at 1 metre from the ground and as close to the nestbox as possible without including the box in the photo. Original photos were desaturated to grayscale with the colour curve adjusted to make all pixels either black or white using GIMP 2.10.24. | | Canopy\_mean | Total percentage of tree canopy and understorey vegetation cover above the focal nestbox estimated as the average cover from two measurements in May and July (to account for seasonal variability in leaf growth). Cover was defined as the percentage of black pixels in processed photos taken with an Apple iPhone 11 levelled-flat on a tripod set at 1 metre from the ground and as close to the nestbox as possible without including the box in the photo. Original photos were desaturated to grayscale with the colour curve adjusted to make all pixels either black or white using GIMP 2.10.24. | | c\_Ash | Percentage of the tree canopy (in 10% increments) occupied by Ash Fraxinus excelsior trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Oak | Percentage of the tree canopy (in 10% increments) occupied by Oak Quercus spp. trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Beech | Percentage of the tree canopy (in 10% increments) occupied by Beech Fagus sylvatica trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Sycamore | Percentage of the tree canopy (in 10% increments) occupied by Sycamore Acer pseudoplatanus trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Lime | Percentage of the tree canopy (in 10% increments) occupied by Lime Tilia x europaea trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Yew | Percentage of the tree canopy (in 10% increments) occupied by Yew Taxus baccata trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Chestnut | Percentage of the tree canopy (in 10% increments) occupied by Sweet Chestnut Castanea sativa trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_FieldElm | Percentage of the tree canopy (in 10% increments) occupied by Field Elm Ulmus minor trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_FieldMaple | Percentage of the tree canopy (in 10% increments) occupied by Field Maple Acer campestre trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Holly | Percentage of the tree canopy (in 10% increments) occupied by Holly Ilex aquifolium trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_DougFir | Percentage of the tree canopy (in 10% increments) occupied by Douglas Fir Pseudotsuga menziesii trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | c\_Larch | Percentage of the tree canopy (in 10% increments) occupied by European Larch Larix decidua trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | C\_WRCedar | Percentage of the tree canopy (in 10% increments) occupied by Western Red Cedar Thuja plicata trees taller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. | | u\_Hazel | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Hazel Corylus avellana | | u\_Hawthorn | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Hawthorn ‎Crataegus monogyna | | u\_Sycamore | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Sycamore Acer pseudoplatanus | | u\_CherryPlum | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Cherry Plum Prunus cerasifera | | u\_FieldMaple | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Field Maple Acer campestre | | u\_Holly | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Holly Ilex aquifolium | | u\_Blackthorn | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Blackthorn Prunus spinosa | | u\_Spindle | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Spindle Euonymus europaeus | | u\_Elder | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Elder Sambucus nigra, | | u\_Oak | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Oak Quercus spp. | | u\_Buckthorn | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Alder buckthorn Frangula alnus | | u\_WayfaringTree | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Wayfaring Tree Viburnum lantana | | u\_WildCherry | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Wild Cherry Prunus avium | | u\_Lime | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Lime Tilia x europaea | | u\_Ash | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Ash Fraxinus excelsior | | u\_Beech | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Beech Fagus sylvatica | | u\_FieldElm | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Field Elm Ulmus minor | | u\_Rowan | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Rowan Sorbus aucuparia | | u\_Whitebeam | Percentage of the canopy (in 10% increments) occupied by trees of the same species smaller than 4 m within a 5m radius circular area around the focal nestbox. Estimated visually. Species: Whitebeam Sorbus aria | | f\_DogsMercury | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Dogs Mercury Mercurialis perennis | | f\_Bramble | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Bramble Rubus fruticosus agg. | | f\_Bluebells | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Bluebells Hyacinthoides non-scripta, | | f\_Cleavers | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Cleavers Galium aparine | | f\_LordsandLadies | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Lords and Ladies Arum maculatum | | f\_Honeysuckle | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Honeysuckle Lonicera pericylmenum | | f\_Nettles | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Nettles Urtica dioica | | f\_Fern | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Fern group (not identified to species) | | f\_Grass | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Grass (graminoid group, not identified to species). | | f\_GIvy | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Ground Ivy Glechoma hederaceae | | f\_Ivy | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Ivy Hedera helix  | | f\_YArchangel | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Yellow Archangel Lamiastrum galeobdolon | | f\_GMustard | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Garlic Mustard Alliaria petiolata | | f\_MButtercup | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Meadow Buttercup Ranunculus acris | | f\_CParsley | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Cow Parsley Anthriscus sylvestris | | f\_Dockspp | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Docks Rumex spp. | | f\_SWoodruff | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species:  Sweet woodruff Galium odoratum | | f\_RCurrant | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Redcurrant Ribes rubrum | | f\_Speedwellspp | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Speedwell Veronica spp. | | f\_HRobert | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Herb Robert Geranium robertianum | | f\_Hwoundwort | Percentage of the field layer (in 10% increments) occupied by plants of the same species within a 5m radius circular area around the focal nestbox. Climbing species cover was estimated up to a height of 10 m. Estimated visually. Species: Hedge Woundwort Stachys sylvatica | | g\_Moss | Percentage of the ground (in 10% increments) occupied by bryophytes within a 5m radius circular area around the focal nestbox. Estimated visually. | | g\_Fungi | Percentage of the ground (in 10% increments) occupied by fungi within a 5m radius circular area around the focal nestbox. Estimated visually. | | g\_BareGround | Percentage of the ground (in 10% increments) occupied by bare ground within a 5m radius circular area around the focal nestbox. Estimated visually. | | g\_LeafLitter | Percentage of the ground (in 10% increments) occupied by leaf litter within a 5m radius circular area around the focal nestbox. Estimated visually. | | Occ2017 | Nestbox occupancy for year 2017. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | | Occ2018 | Nestbox occupancy for year 2018. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | | Occ2019 | Nestbox occupancy for year 2019. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | | Occ2020 | Nestbox occupancy for year 2020. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | | Occ2021pre | Nestbox occupancy for year 2021 after August 2021. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | | Occ2021post | Nestbox occupancy for year 2021 before August 2021. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | | Occ2022 | Nestbox occupancy for year 2022. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | | Occ2023 | Nestbox occupancy for year 2023. If during any survey that year nestbox was recorded as occupied the variable takes a value of 1, otherwise of 0. Occupancy was determine when one or more dormice were present during nestbox inspection, or if there was a dormice nest with evidence of recent occupation.  | ###### **Dataset 2 "MalyanetalDataPub2.csv" second dataset describing microhabitat variable data collected in May and July 2021.** The dataset contains 46 rows (1 header with variable names and 45 observations, 1 per studied nestbox) and 37 columns (variables). Variables are described in the table below. | Variable Name | Description | | :--------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Box | Unique alphanumerical code of the artificial nestbox considered in our study | | N\_Hazel | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Hawthorn | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Beech | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Oak | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Field\_Maple | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Sycamore | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Yew | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Holly | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Guelder\_Rose | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Wayfaring\_Tree | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Plum | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Ash | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Sweet\_Chestnut | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Spindle | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Lime | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Cherry\_Plum | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Elder | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Honeysuckle | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Bramble | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | N\_Clematis | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running North | | E\_Hazel | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Hawthorn | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Beech | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Sycamore | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Oak | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Holly | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Ash | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Field\_Elm\_Sapling | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Wild\_Cherry | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Douglas\_Fir | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Wayfaring\_Tree | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Field\_Maple | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Goat\_Willow | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Blackthorn | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Western\_Red\_Cedar | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Elder | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Honeysuckle | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | E\_Bramble | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running East | | S\_Hazel | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Hawthorn | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Beech | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Oak | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Field\_Maple | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Sycamore | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Plum | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Wayfaring\_Tree | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Ash | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Wild\_Cherry | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Guelder\_Rose | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Holly | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Elder | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Cherry\_Plum | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Yew | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Honeysuckle | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | S\_Bramble | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running South | | W\_Hazel | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Hawthorn | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Beech | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Oak | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Holly | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Yew | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Ash | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Privet | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Guelder\_Rose | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Field\_Maple | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Sycamore | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Field\_Elm | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Wild\_Cherry | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Sweet\_Chestnut | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Spindle | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Cherry\_Plum | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Elder | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Honeysuckle | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Bramble | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | W\_Red\_Currant | Mean percentage cover of individual species over four 2m x 5m quadrats starting 5 m from the focal nestbox and running West | | Hazel5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Hawthorn5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Beech5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Cherry\_plum5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Sycamore5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Oak5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Field\_maple5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Douglas\_fir5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Holly5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Elder5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Lime5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Ash5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Spindle5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Yew5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Western\_red\_cedar5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Chestnut5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Guelder\_Rose5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Wayfaring\_tree5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Cherry5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Privet5m | Number of individual tree species with a trunk circumference &gt;40cm within a 5m radius from the focal nestbox. | | Total\_Hazel | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Hawthorn | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Beech | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Field\_Maple | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Holly | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Guelder\_Rose | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Wayfaring\_Tree | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Plum | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Ash | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Sweet\_Chestnut | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Sycamore | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Oak | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Field\_Elm | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Wild\_Cherry | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Douglas\_Fir | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Goat\_Willow | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Yew | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Privet | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Spindle | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Cherry\_Plum | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Lime | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Elder | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Blackthorn | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Western\_Red\_Cedar | Number of individual tree species within a 10m radius from the focal nestbox. Obtained by adding the total number of individual trees with a trunk circumference &gt;40cm within a 5m radius circular area and in four 2m x 5m quadrats starting 5 m from the focal nestbox and running North, South, East and West. Abundance within the 5m radius area included every individual tree, whilst the four quadrats provided relative abundance within the area 5m-10m from the nestbox based on quadrat totals. | | Total\_Treespp | Combined relative tree abundance. Sum of "Total\_" variables for all 20 recorded species at each nestbox. | | Total\_number\_tree\_species | Observed tree species richness calculated adding all species with Total\_Treespp&gt;0 for each nestbox. | ## Code/Software The file "Malyanetal_CodePublication.Rmd" provides all necessary code to complete all analyses presented in the paper and to create the graphs. The code was run in R version 4.1.0 (2021-05-18) -- "Camp Pontanezen", using RStudio 2021.09.0 Build 351