Skip to Main Content
Evaluating interactions between space-use sharing and defence under increasing density conditions for the group-territorial Red-cockaded Woodpecker Leuconotopicus borealisAuthor(s): James E. Garabedian; Christopher E. Moorman; M. Nils Peterson; John C. Kilgo
Publication Series: Scientific Journal (JRNL)
Station: Southern Research Station
Download Publication (952.0 KB)
DescriptionInformation about how bird species respond to increasing density conditions through either space‐use sharing or increased territoriality, and how those changes affect fitness, is essential for effective conservation planning. We used a case study of endangered Red‐cockaded Woodpeckers Leuconotopicus borealis (RCW) to address these questions. We documented over 36 000 locations from 44 RCW groups in three density conditions on two sites in South Carolina, USA, between April 2013 and March 2015. The frequency of neighbouring group interactions differed among density conditions and was highest for high‐density groups. RCW home‐ranges and core‐areas were larger under low‐density conditions ( = 88.4 ha, = 21.0 ha) than under medium ( = 68.29 ha, = 16.6 ha) and high‐density ( = 76.3 ha, = 18.6 ha) conditions. Neighbouring RCWs maintained overlapping home‐ranges with nearly exclusive core‐areas across density conditions, but overlap tended to increase as neighbouring group density increased. Under high‐density conditions, home‐range overlap correlated inversely with clutch size (β ± se = −0.19 ± 0.09), nestling production (β ± se = −0.37 ± 0.09) and fledgling production (β ± se = −0.34 ± 0.08). Our results indicate that RCWs dedicate more effort to territorial defence under high‐density conditions, potentially at the expense of greater foraging efficiency and time allocated to reproduction, as evidenced by reduced fitness. Large home‐range overlap indicated limited territoriality farther away from cavity trees, but the existence of exclusive core‐areas suggests that RCW groups defend habitat closer to cavity trees. Thiessen partitions used to allocate critical foraging habitat offered comprehensive habitat protection for RCW but appear flawed for spatially explicit habitat assessments because they do not accurately delineate space used by individual RCW groups.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationGarabedian, James E.; Moorman, Christopher E.; Peterson, M. Nils; Kilgo, John C. 2018. Evaluating interactions between space-use sharing and defence under increasing density conditions for the group-territorial Red-cockaded Woodpecker Leuconotopicus borealis . Ibis. 160: 816-831. https://doi.org/10.1111/ibi.12576.
KeywordsCore-area, Density Dependence, Fitness, Home-range, Overlap, Red-cockaded Woodpecker, Resident species, Territoriality, Thiessen Polygons
- Effects of group size and group density on trade‐offs in resource selection by a group‐territorial central‐place foraging woodpecker
- Multiple space-use strategies and their divergent consequences in a nonbreeding migratory bird (Parkesia noveboracensis)
- Conservation implications of Golden-winged Warbler social and foraging behaviors during the nonbreeding season
XML: View XML