DOI: 10.5061/dryad.kd51c5bbh
title: Data from: Woodpeckers in the city: abundances are highest in large green spaces with complex understories

description: We documented occurrence and relative abundance (henceforth abundance) of
 five woodpecker species in 36 forested green spaces in Portland, Oregon
 (USA), to estimate minimum area requirements (MAR; 0.5 probability of
 occurrence) and to test for potential influences of green space area and
 type (heavily treed manicured green spaces versus undeveloped natural
 forests), habitat features, and landscape composition on the abundance of
 woodpeckers. Abundances of all species increased with green space area.
 Manicured and natural green spaces did not differ in canopy cover or total
 basal area, but woodpecker abundances were greater in natural than
 manicured green spaces for all species except Northern Flickers (Colaptes
 auratus). Flickers and Downy Woodpeckers (Picoides pubescens) were most
 abundant; MAR of both were under 1.5 ha, and both were found in
 essentially all green spaces. Hairy (P. villosus) and Pileated (Dryocopus
 pileatus) woodpeckers were least abundant, and with MAR of 34 and 51 ha,
 respectively, exhibited pronounced area-sensitivity. Red-breasted
 Sapsuckers (Sphyrapicus ruber) were intermediate in abundance and MAR to
 the two former and two latter species. The most important habitat
 variables associated with variation in abundance among green spaces were
 the contribution of deciduous trees to the canopy (Downy Woodpecker [+],
 Pileated Woodpecker [+] and Northern Flicker [-]), canopy cover (Hairy
 Woodpecker [+] and Northern Flicker [+]), and log density (Hairy
 Woodpecker [+], Red-breasted Sapsucker [-]). At the landscape level, lower
 woodpecker abundance was associated with increased urbanization
 (Red-breasted Sapsucker and Northern Flicker), while increasing forest
 cover influenced abundance of Northern Flicker (-) and Pileated Woodpecker
 (+). Highest woodpecker abundances were thus found in large green spaces
 with complex understories that were embedded in relatively undeveloped
 treed landscapes. Management of forested urban green spaces should
 prioritize needs of the area-sensitive species because ensuring their
 continued presence benefits the entire avian community.
description: This dataset includes abundance and occurrence data for 5
 woodpecker species, as well as vegetation data and basic landscape and
 urbanization measurements taken throughout 36 urban greenspaces in
 Portland, OR during 2015-2016. Standard passive point counts and audio
 broadcasts were used to survey woodpeckers, and circular plot drop-point
 vegetation surveys were used to capture habitat data. Highest woodpecker
 abundances were found in large green spaces with complex understories that
 were embedded in relatively undeveloped treed landscapes. We calculated
 minimum area requirements and found that the two most area-sensitive
 species (Hairy and Pileated woodpecker) had area requirements of 34 and 51
 ha, respectively. We propose that management policies should be driven by
 the needs of species with the largest area requirements and greatest
 dependence on structurally complex vegetation structure.
description: Descriptive statistics were performed using Statistix
 (v. 9; Statistix 2009) Logistic regressions were
 performed using R 3.2.3 Generalized linear models
 were constructed using JMP (1989-2019)