New insights from an attempt to reintroduce Red-cockaded Woodpeckers in northern Florida

Abstract

Red‐cockaded Woodpeckers (Leuconotopicus borealis) were extirpated from Tall Timbers Research Station in the early 1980s. To help meet conservation goals established for this imperiled species in north Florida, we attempted to reintroduce the woodpecker to the research station by constructing artificial cavities and translocating 27 subadult woodpeckers from 2006 to 2010. Successful nesting occurred during the breeding season following the initial translocation of four male–female pairs. Translocations were suspended in 2011 when breeding groups occupied 6 of 12 available clusters of cavity trees. The population increased steadily after 2011 and, in 2015, totaled 28 adults distributed among nine breeding groups plus a single territorial male. The 2015 population included 22 individuals produced at Tall Timbers, an immigrant female, and five birds originally translocated as subadults. Seven breeding groups in 2015 also had non‐breeding helpers. New milestones documented during this reintroduction attempt included recruitment of locally produced birds into the breeding population, excavation of natural cavities, two immigration events, and natural expansion into an unoccupied area. We also documented the threat that heavy rains may pose to small populations. Expenses totaled $211,000 during the first 5 yr when translocations and cavity construction were the primary activities. After translocations were suspended, recurring management expenses were ~ $6500 annually. Because our founding population was small (N = 12), intermittent translocations will likely be needed in the future to offset the deleterious effects of inbreeding.

Chainsaw-Carved Cavities Better Mimic the Thermal Properties of Natural Tree Hollows than Nest Boxes and Log Hollows

“…Despite initial trials investigating mechanical excavation of hollows in trees being conducted several decades ago in North America [32,103,104], these techniques have not been widely adopted (but see [31,105]). The lack of uptake has likely been due in part to such techniques being contradictory to widely adopted prescriptive guidelines for pruning amenity trees (i.e., trees with recreational, functional, environmental, ecological, social, health or aesthetic value, rather than for production purposes [106]).…”

Changes in genetic diversity and differentiation in Red‐cockaded woodpeckers (Dryobates borealis) over the past century

“…For example, 11 of the 17 sampling locations for the 2010–2014 period in the Western Region have been translocation recipients (W. McDearman personal communication). Translocations have long been used as a strategy to facilitate RCW population recovery (USFWS, ), and individuals have been artificially moved throughout their range (Allen, Franzreb, & Escano, ; Carrie, Conner, Rudolph, & Carrie, ; Costa & DeLotelle, ; Cox & McCormick, ; Connor, Rodolph, & Bonner, ; Franzreb, ; Haig et al, ; Rudolph, Conner, Carrie, & Schaefer, ). While more detailed analyses are still required, it remains feasible that the cumulative effects of translocations over the decades following their initiation may have reversed the loss of genetic diversity that was detected in this subset of the species' range.…”

Evaluating interactions between space‐use sharing and defence under increasing density conditions for the group‐territorial Red‐cockaded Woodpecker Leuconotopicus borealis

“…). Territorial interactions can confound relationships between habitat quality and population density by influencing spacing patterns (Brown & Orians ), accessibility of limited resources including cavity trees and foraging habitat (Cox & McCormick ), and prospecting for potential dispersal destinations (Kesler & Walters ). With the rapid growth of many RCW populations over recent decades, concomitant increases in territorial interactions between neighbouring groups could confound studies of resource selection used to develop standards of habitat quality (Walters , James et al .…”

“…), minimum area requirements to support viable RCW populations (Reed et al . , Zeigler & Walters ) and even retention of translocated RCWs in restored habitat (Cox & McCormick ).…”

“…The fact that territorial interactions increased with density may help explain inconsistencies in the literature regarding relationships between RCW fitness and foraging habitat quality (Garabedian et al 2014a). Territorial interactions can confound relationships between habitat quality and population density by influencing spacing patterns (Brown & Orians 1970), accessibility of limited resources including cavity trees and foraging habitat (Cox & McCormick 2016), and prospecting for potential dispersal destinations (Kesler & Walters 2012). With the rapid growth of many RCW populations over recent decades, concomitant increases in territorial interactions between neighbouring groups could confound studies of resource selection used to develop standards of habitat quality (Walters 1991, James et al 2001, Macey et al 2016, minimum area requirements to support viable RCW populations (Reed et al 1988, Zeigler & Walters 2014) and even retention of translocated RCWs in restored habitat (Cox & McCormick 2016).…”