We have studied marked populations of red-cockaded woodpeckers (RCWs) in the North Carolina Sandhills since 1980, at Marine Corps Base Camp Lejeune in coastal North Carolina since 1986, and at Eglin Air Force Base in the western panhandle of Florida since 1995. As of 2019, with a record representing a bird-year (i.e., one record for each bird alive each breeding season), our databases contain 46,577 records, 11,499 records, and 3,555 records respectively. The Sandhills study area includes a mix of federal (Fort Bragg army base), state (Sandhills Gamelands) and private (towns of Southern Pines and Pinehurst and rural areas) properties and encompasses approximately half of the RCW population. The Camp Lejeune study area is confined to the Base, and encompasses the entire population. At Eglin, we study only a small portion of the population. In the past, we have also studied RCWs on Croatan National Forest in coastal North Carolina and the Savanna River Site near the South Carolina – Georgia border.
Links to our long-term study sites
Red-cockaded Woodpeckers live in family groups comprised of a breeding pair and 0-6 adult helpers. Helpers do not produce offspring, but assist the breeders in incubating eggs, feeding young, defending the territory and excavating cavities. Most helpers are males that remain on their natal territory and assist relatives, but some are natal females, and others are males and females from elsewhere that join the group and assist breeders unrelated to them. Helpers look for opportunities to acquire a breeding position, and thus staying at home is a means to becoming a breeder. Both this helping strategy and the “normal” strategy of dispersing in the first year to seek a breeding position are common in RCWs. We take advantage of this fact, and sex differences in the relative frequency of the two strategies, to investigate the evolutionary basis of cooperative breeding in this species. This work includes both examining the fitness costs and benefits of the two strategies, and determining the ecological factors that drive those costs and benefits.
Current graduate student Amber Wendler, co-advised by Dr. Walters and Dr. Ignacio Moore, is studying the cooperative breeding system of the Puerto Rican Tody. This species is thought to be a cooperative breeder in some habitats but not others, providing a unique opportunity to investigate the ecological factors that promote cooperative breeding.
Relevant Publications:
Walters, J. R., P. D. Doerr and J. H. Carter, III. 1992. Delayed dispersal and reproduction as a life history tactic in cooperative breeders: fitness calculations from red‑cockaded woodpeckers. Am. Nat. 139:623‑643.
Walters, J. R., C. K. Copeyon and J. H. Carter, III. 1992. Test of the ecological basis of cooperative breeding in red‑cockaded woodpeckers. Auk 109:90‑97.
Khan, M. Z. and J. R. Walters. 2002. Effects of helpers on breeder survival in the red-cockaded woodpecker (Picoides borealis). Behav. Ecol. Sociobiol. 51:336-344.
Walters, J. R. and V. Garcia. 2016. Red-cockaded woodpeckers: alternative pathways to breeding success. Pages 58-76 in Cooperative breeding in vertebrates: studies of ecology, evolution, and behavior, W. D. Koenig and J. L. Dickinson, eds. London: Cambridge University Press.
Differences in dispersal behavior are a component of the two alternative life history strategies practiced by RCWs. The two strategies differ in dispersal outcomes (i.e., distances and directions moved) and behavior during movement. Helpers engage in short-distance forays to neighboring territories, and have a limited dispersal range. Juveniles dispersing in their first year engage in longer-distance forays to visit distant as well as nearby territories. Most disperse within foraying range, which is roughly twice the range of helpers. However, some juveniles become jumpers, dispersing long distances quickly. Most jumps are moves of tens of kilometers accomplished in a single day, but jumps of up to 200 km over many days have been recorded. We investigate both dispersal outcomes and, using radio-telemetry, dispersal behavior, to assess the social factors and habitat features affecting dispersal, and the fitness consequences of alternative dispersal behaviors.
Relevant Publications:
Daniels, S. J. and J. R. Walters. 2000. Inbreeding depression and its effects on natal dispersal in red-cockaded woodpeckers. Condor 102:482-491.
Daniels, S. J. and J. R. Walters. 2000. Between-year breeding dispersal in red-cockaded woodpeckers: multiple causes and estimated cost. Ecology 81:2473-2484.
Pasinelli, G. and J. R. Walters. 2002. Social and environmental factors affect natal dispersal and philopatry of male red-cockaded woodpeckers. Ecology 83:2229-2239.
Pasinelli, G., K. Schiegg and J. R. Walters. 2004. Genetic and environmental influences on natal dispersal distance in a resident bird species. Am. Nat. 164:660-669.
Kesler, D. C., J. R. Walters and J. J. Kappes, Jr. 2010. Social influences on dispersal and the fat-tailed dispersal distribution in red-cockaded woodpeckers. Behav. Ecol. 21:1337-1343.
Trainor, A. M., J. R. Walters, W. F. Morris, J. Sexton and A. Moody. 2013. Empirical estimation of dispersal resistance surfaces: a case study with red-cockaded woodpeckers. Landscape Ecol. 28:755-767.
Our studies of the evolutionary basis of cooperative breeding suggested a new management paradigm for this endangered species. To demonstrate its effectiveness, we applied this management strategy in “proof of concept” studies at our Camp Lejeune and Eglin study areas. Both previously declining populations increased dramatically (by 348% and 152% respectively, as of 2020) under the new management regime. The new management paradigm was codified as policy in the 2003 Recovery Plan for the species. Whereas no RCW populations were increasing in the mid-1980s, 67% of RCW populations have increased over the past 20 years in response to the new management strategy. We continue to apply our research findings to improve management and otherwise engage in applied research on RCWs.
Relevant Publications:
Copeyon, C. K., J. R. Walters and J. H. Carter, III. 1991. Induction of red‑cockaded woodpecker group formation by artificial cavity construction. J. Wildl. Manage. 55:549‑556.
Walters, J. R. 1991. Application of ecological principles to the management of endangered species: the case of the red‑cockaded woodpecker. Annu. Rev. Ecol. Syst. 22:505‑523.
Walters, J. R., K. E. Gault, B. W. Hagedorn, C. J. Petrick, L. F. Phillips. Jr., J. Tomcho, Jr. and A. Butler. 2004. Effectiveness of recruitment clusters and intrapopulation translocation in promoting growth of the red-cockaded woodpecker population on Eglin Air Force Base, Florida. Pages 325-334 in R. Costa and S. J. Daniels, eds. Red-cockaded Woodpecker: Road to Recovery. Hancock House Publishing, Blaine, WA.
Walters, J. R. 2004. Unusual dynamics in a rapidly increasing population of red-cockaded woodpeckers at Camp Lejeune, North Carolina. Pages 256-267 in R. Costa and S. J. Daniels, eds. Red-cockaded Woodpecker: Road to Recovery. Hancock House Publishing, Blaine, WA.
Rudolph, D. C., R. N. Conner and J. R. Walters. 2004. Red-cockaded woodpecker recovery: an integrated strategy. Pages 70-76 in R. Costa and S. J. Daniels, eds. Red-cockaded Woodpecker: Road to Recovery. Hancock House Publishing, Blaine, WA.
Although many of the factors that caused RCWs to become endangered have now been addressed through management, new threats are arising. Chief among these are changes resulting from the warming of our planet. Many RCW populations are in coastal areas and hence threatened by the increasing frequency of strong hurricanes, which increase mortality and destroy cavity trees. Changing climate appears to be improving conditions for RCW reproduction at the northern end of the species’ range, but causing conditions in the southwestern portion of the range to deteriorate, including at our Eglin study site. We are investigating the relationship between weather and productivity of RCWs, with an eye toward mitigating the causes of declining productivity in the southwestern part of the range.
Relevant Publications
Schiegg, K., G. Pasinelli, J. R. Walters and S. J. Daniels. 2002. Inbreeding and experience affect response to climate change by endangered woodpeckers. Proc. Royal Soc. London (B) 269:1153-1159.
DeMay, S. M. and J. R. Walters. 2019. Variable effects of a changing climate on lay dates and productivity across the range of the Red-cockaded Woodpecker. The Condor: Ornithological Applications 121:1-14.
Fullerton, M. R., J. R. Walters, R. E. Will and S. R. Loss. 2021. Inter-annual climate variation influences nest initiation date and nest productivity of the Red-cockaded Woodpecker at the northwestern edge of its range. The Condor: Ornithological Applications 123:1-17.