DOI: 10.5061/dryad.mpg4f4rc1
title: Landscape features affect occupancy probability of Antrostomus vociferus (Eastern Whip-poor-will) in West Virginia managed forests

description: Antrostomus vociferus (Eastern Whip-poor-will) have experienced a greater
 population decrease range wide than any other caprimulgid in North
 America. Hypotheses for this population reduction include conversion of
 open pasture to forest, increasing levels of urbanization, and the
 reduction of naturally occurring forest fires. Antrostomus vociferous
 forage over low forest canopies within early successional areas such as
 farmland intermixed with woody vegetation, forest patches recently cleared
 by fires and timber harvesting, and large artificial canopy breaks created
 by roads and power-line cuts. On institutional timber-harvest land in
 south-central West Virginia, we examined what site-specific and landscape
 features were positively associated with A. vociferus detection and
 occupancy probability. In June 2021 and 2022, we used autonomous recording
 units (ARUs) to estimate occupancy on a ~104,000 ha working forest. To
 estimate occupancy, we targeted surveys in regenerating clear-cut forest
 stands with ages ranging from recently harvested (2021) to ~20 years since
 harvest. Antrostomus vociferus detection probability was positively
 related to lunar illumination, increasing by 10% for every 20% increase in
 illumination. Occupancy at sites above 900 m a.s.l. elevation was below
 40% and decreased with distance from riparian zones. Antrostomus vociferus
 occupancy decreased as tree diameter increased and occupancy was
 positively related to the amount of grass ground cover. Thus, in a
 timber-harvested landscape with forest heterogeneity, A. vociferus were
 negatively associated with increasing elevation but occurred near riparian
 areas with open grassy areas and smaller trees. Implications of this study
 suggest that the management of mosaic forests at certain elevational
 thresholds (approximately  800 m) will increase the probability
 of A. vociferus occupancy.
description: # Landscape features affect occupancy probability of Antrostomus vociferus
 (Eastern Whip-poor-will) in West Virginia managed forests Dataset DOI:
 [10.5061/dryad.mpg4f4rc1](https://doi.org/10.5061/dryad.mpg4f4rc1) ##
 Description of the data and file structure We have submitted our raw
 occupancy data (**EWPW_occu.csv**) which include presence/detection and
 landscape covariates. We have also included (**EWPW_veg_occu.csv**) which
 includes all vegetation-related covariates for all the same sampled
 sites.  ## Descriptions *Data set 1 - Detection/Occupancy* ARU_30(and 5) -
 data not used in the models but represent total (undivided) detection
 throughout the whole 30 minute recording periods.  interval(s)_1 and 2 -
 two possible intervals of detection for EWPW. Two intervals of time used
 for occupancy probability models. Intervals 1 and 2 represent the first
 and last 5 minutes respectively of the 30 minute recording periods.  ID -
 Forest stand ID Rip - presence or absence of riparian within stipulated
 distance age_years - stand age  basal - basal area of the given site
 dist_rip - distance from riparian zone (transitional zone) cor_date -
 Julian date lab_date - labeled date moon_perc - percent moon illumination
 perc_esf - percent early successional forest  dom_type - dominant forest
 type considered by GIS files dom_type_num - numerical equivalent of
 dom_type min_sunset - minutes since sunset on that given day obs_date -
 Date *Data set 2 - Vegetation*  all vegetation covariates begin with
 "perc", representative of percentage cover of that particular
 vegetation cover type. All other covariates included in this dataset are
 also precent in Data set 1 (listed above).  perc_canopy - the total
 percent *canopy* cover at a given site perc_grass - the total percent for
 *grass* ground cover at a given site perc_forb - the total percent for
 *forb* ground cover at a given site perc_solidago - the total percent for
 *Solidago* ground cover at a given site perc_vine - the total percent for
 *vine* ground cover at a given site perc_rubus - the total percent for
 *Rubus* ground cover at a given site perc_shrub - the total percent for
 *shrub* ground cover at a given site perc_sapling - the total percent for
 *sapling* ground cover at a given site ( &lt; 8cm diameter at breast
 height) elevation_m - the elevation (in meters) at a particular site
 dist_edge_m - distance to a forest edge (where mature forest met either
 early-successional or recently cleared/logged) from the point and
 recording unit placement ## Software used Package "unmarked"
 (Fiske and Chandler 2011) in R version 4.1.1