An individual-based, spatially-explicit simulation model of the population dynamics of the endangered red-cockaded woodpecker, Picoides borealis

Spatially-explicit population models allow a link between demography and the landscape. We developed a spatially-explicit simulation model for the red-cockaded woodpecker, Picoides borealis, an endangered and territorial cooperative breeder endemic to the southeastern United States. This kind of model is especially appropriate for this species because it can incorporate the spatial constraints on dispersal of helpers, and because territory locations are predictable. The model combines demographic data from a long-term study with a description of the spatial location of territories. Sensitivity analysis of demographic parameters revealed that population stability was most sensitive to changes in female breeder mortality, mortality of female dispersers and the number of fledglings produced per brood. Population behavior was insensitive to initial stage distribution; reducing the initial number of birds by one-half had a negligible effect. Most importantly, we found that the spatial distribution of territories had as strong an effect on response to demographic stochasticity as territory number. Populations were stable when territories were highly aggregated, with as few as 49 territories. When territories were highly dispersed, more than 169 territories were required to achieve stability. Model results indicate the importance of considering the spatial distribution of territories in management plans, and suggest that this approach is worthy of further development.

[1]  J. Walters,et al.  Delayed Dispersal and Reproduction as a Life-History Tactic in Cooperative Breeders: Fitness Calculations from Red-Cockaded Woodpeckers , 1992, The American Naturalist.

[2]  M. Shaffer.  Viable Populations for Conservation: Minimum viable populations: coping with uncertainty , 1987 .

[3]  J. Walters,et al.  Induction of red-cockaded woodpecker group formation by artificial cavity construction , 1991 .

[4]  W. Koenig,et al.  Reproductive Sociality. (Book Reviews: Cooperative Breeding in Birds. Long-Term Studies of Ecology and Behavior.) , 1990 .

[5]  Roland H. Lamberson,et al.  Reserve Design for Territorial Species: The Effects of Patch Size and Spacing on the Viability of the Northern Spotted Owl* , 1994 .

[6]  M. Gilpin,et al.  Minimum viable populations : Processes of species extinction , 1986 .

[7]  Hal Caswell,et al.  Matrix Methods for Avian Demography , 1993 .

[8]  T. Burkey,et al.  Extinction in nature reserves: the effect of fragmentation and the importance of migration between reserve fragments , 1989 .

[9]  L. Crowder,et al.  Evaluating Management Alternatives for Red-Cockaded Woodpeckers: A Modeling Approach , 1994 .

[10]  M. Soulé,et al.  Conservation Biology: The Science of Scarcity and Diversity , 1986 .

[11]  J. Michael Reed,et al.  Effective Population Size in Red‐Cockaded Woodpeckers: Population and Model Differences , 1993 .

[12]  M. Soulé,et al.  Viable Populations for Conservation: List of contributors , 1987 .

[13]  Jianguo Liu,et al.  Population Dynamics in Complex Landscapes: A Case Study. , 1992, Ecological applications : a publication of the Ecological Society of America.

[14]  B. Danielson,et al.  Spatially Explicit Population Models: Current Forms and Future Uses , 1995 .

[15]  R. Lande.  Genetics and demography in biological conservation. , 1988, Science.

[16]  Mark L. Shaffer,et al.  Determining Minimum Viable Population Sizes for the Grizzly Bear , 1983 .

[17]  J. Walters.  Application of Ecological Principles to the Management of Endangered Species: The Case of the Red-Cockaded Woodpecker , 1991 .

[18]  Michael J. Conroy,et al.  Parameter Estimation, Reliability, and Model Improvement for Spatially Explicit Models of Animal Populations , 1995 .

[19]  O P Judson,et al.  The rise of the individual-based model in ecology. , 1994, Trends in ecology & evolution.

[20]  P. Kareiva.  Population dynamics in spatially complex environments: theory and data , 1990 .

[21]  R. Lande,et al.  Mutation and Conservation , 1995 .

[22]  Roland H. Lamberson,et al.  Conservation planning for species occupying fragmented landscapes: the case of the northern spotted owl , 1993 .

[23]  S. Haig,et al.  Population Viability Analysis for a Small Population of Red-Cockaded Woodpeckers and an Evaluation of Enhancement Strategies , 1993 .

[24]  C. I. Bliss,et al.  FITTING THE NEGATIVE BINOMIAL DISTRIBUTION TO BIOLOGICAL DATA AND NOTE ON THE EFFICIENT FITTING OF THE NEGATIVE BINOMIAL , 1953 .

[25]  G. Wilhere,et al.  Population Viability Analysis for Red-Cockaded Woodpeckers in the Georgia Piedmont , 1995 .

[26]  William Gurney,et al.  Individual-based models: combining testability and generality , 1992 .

[27]  Gary K. Meffe,et al.  Principles of Conservation Biology , 1995 .

[28]  J T Pfeffer,et al.  Population dynamics in anaerobic digestion. , 1967, Journal - Water Pollution Control Federation.

[29]  A. Poole,et al.  Red-cockaded Woodpecker (Picoides borealis). , 1994 .

[30]  S. Baird,et al.  The birds of North America , 1974 .

[31]  J. Walters.  Cooperative Breeding in Birds: Red-cockaded Woodpeckers: a ‘primitive’ cooperative breeder , 1990 .

[32]  P. Holgate,et al.  Matrix Population Models. , 1990 .

[33]  Peter Kareiva,et al.  Biotic interactions and global change. , 1993 .

[34]  M. Turner,et al.  Usefulness of spatially explicit population models in land management , 1995 .

[35]  R. Hooper,et al.  Red-cockaded woodpecker : recovery, ecology and management , 1995 .

[36]  M. Shaffer.  Minimum Population Sizes for Species Conservation , 1981 .

[37]  S. Levin.  Patchiness in marine and terrestrial systems: from individuals to populations , 1994 .