Patuxent Wildlife Research Center - Bird Population Studies
Estimation of Bird Community Dynamics from Breeding Bird Survey Data
Using Program COMDYN
The BBS provides a unique source of information about bird communities, and many investigators use BBS data to evaluate change in species richness over time and space (e.g., Boulinier 1998a). Unfortunately, the naive estimate of total number of observed species on a BBS routes is biased, as all observers have some chance of missing species during the counts and this chance is well known to differ among observers and routes (Boulinier et al. 1998b). This is a very real problem, and investigators who use simple counts of species on BBS routes in ecological studies must recognize that their estimates of species richness and change in richness are flawed and could be subject to criticism or rebuttal.
Luckily, estimators of species richness have been developed to estimate detection rates of species, and to accommodate variation in detection rates among species and sites (e.g. Burnham and Overton 1979). Nichols et al. (1998a,b) have developed a series of estimators for change in communities that incorporate the possibility of variation in detection rates among species. Program COMDYN (Hines et al. 1999) implements these estimators of change over time and space for the North American Breeding Bird Survey. Detailed descriptions of the estimators in program COMDYN can be found in Nichols et al. (1998a, 1998b). These papers, along with papers describing other examples and applications of species richness estimation methods, are available either from this website (as pdf files) or from the authors.
The program will respond with a list of species found on the routes, and the user must choose the appropriate species for the analysis. The default is that all species are included (all are "checked"). You can either select (or unselect) species by clicking on the buttons, or by selecting from the selection bars under the species list. Note that "Select no species" and "Select all species" are options on the list. Then, select "Compute estimates" to run the program. Results are presented on a new page, and definitions of parameters and estimates are provided below the numeric outputs.
Boulinier, T, J. D. Nichols, J. E. Hines, J. R. Sauer, C. H. Flather, and K. H. Pollock. 1998a. Higher temporal variability of forest bird communities in fragmented landscapes. Proc. Nat. Acad. Sci. 95:7497-7501.Download PDF
Boulinier, T, J. D. Nichols, J. R. Sauer, J. E. Hines, and K. H. Pollock. 1998b. Estimating species richness to make inference in community ecology: The importance of heterogeneity in species detectability as shown from capture-recapture analyses of North American Breeding Bird Survey Data. Ecology 79:1018-1028.Download PDF
Burnham, K. P. and W. S. Overton. 1979. Robust estimation of population size when capture probabilities vary among animals. Ecology 60:927-936.View Abstract
Hines, J.E., T. Boulinier, J.D. Nichols, J.R. Sauer, and K.H. Pollock. 1999. COMDYN: software to study the dynamics of animal communities using a capture-recapture approach. Bird Study 46 (suppl.):S209-217.View Abstract
Nichols, J. D., T. Boulinier, J. E. Hines, K. H. Pollock, and J. R. Sauer. 1998a. Estimating rates of local species extinction, colonization, and turnover in animal communities. Ecological Applications 8:1213-1225.Download PDF
Nichols, J. D., T. Boulinier, J. E. Hines, K. H. Pollock, and J. R. Sauer. 1998b. Inference methods for spatial variation in species richness and community composition when not all species are detected. Conservation Biology 12:1390-1398.View Abstract
ADDITIONAL REFERENCES ON COMMUNITY DYNAMICS ESTIMATION
Cam, E., J. R. Sauer, J. D. Nichols, J. E. Hines, and C. H. Flather. 2000. Geographic analysis of species richness and community attributes of forest birds from survey data in the mid-atlantic integrated assessment region Environmental Monitoring and Assessment 63:81-94.Download PDF
Cam, E., J. D. Nichols, J. E. Hines, and J. R. Sauer. 2000. Inference about nested subsets structure when not all species are detected. Oikos 91: 428-434.
Nichols, J. D., J. R. Sauer, J. E. Hines, and T. Boulinier, and K. H. Pollock. 2001. Estimation of Species Richness and Parameters Reflecting Community Dynamics Using Data from Ecological Monitoring Programs. Pages 181- 187 in Conservation of biological diversity: A key to the restoration of the Chesapeake Bay Ecosystem and Beyond. G. D. Therres, Ed. Maryland Department of Natural Resources, Annapolis, MD.
Boulinier, T. Nichols, J. D., J. E. Hines, J. R. Sauer, C. H. Flather, and K. H. Pollock. 2001. Forest fragmentation and bird community dynamics: inference at regional scales. Ecology 82:1159-1169.Download PDF
Sauer, J. R., J. D. Nichols, J. E. Hines, T. Boulinier, C. H. Flather, and W. L. Kendall. 2001. Regional patterns in proportion of bird species detected in the North American Breeding Bird Survey Pages 293-296 In R. Field, R. J. Warren, H. Okarma, and P. R. Sievert, editors. Wildlife, land, and people: priorities for the 21st century. Proceedings of the. 2nd. International Wildlife Congress. The Wildlife Society, Bethesda, MD, USA.
Cam, E., J. D. Nichols, J. E. Hines, J. R. Sauer, R. Alpizar-Jara, and C. H. Flather. 2002. Disentangling sampling and ecological explanations underlying species-area relationships. Ecology 83:1118-1130.Download PDF
Cam, E., J. D. Nichols, , J. R. Sauer J. E. Hines. 2002. On the estimation of species richness based on the accumulation of previously unrecorded species. Ecography 25:102-108.View Abstract