Past Research

Snail kites in the United States occur only within the Central and South Florida Ecosystem including watersheds of the Everglades, Lake Okeechobee, the Kissimmee River, and the Upper St. Johns River. Because snail kites feed almost exclusively on one species of aquatic snail, their survival depends directly on the hydrologic functioning of these watersheds. Each of these watersheds has experienced, and continues to experience, substantial degradation resulting in the current planning for what probably will amount to the largest scale ecosystem restoration effort ever undertaken. Although, other endangered species occur within this ecosystem, snail kites probably are the only one which is restricted to the watersheds within the South Florida Ecosystem and depend on the entire network of wetlands within this ecosystem.

Because of these concerns, most of our past research has focused on estimating survival and movement patterns of snail kites throughout Florida. The underlying purpose the study was to better understand snail kite population dynamics and how they are influenced by environmental conditions, such as hydrology. The ultimate goal of this research was to enable a wide variety of modeling and assessment based on valid parameter inputs. We believe that the parameters we have estimated will provide a reliable basis for the development of individual or population-based models of kites for a variety of purposes (e.g., risk assessment, viability analyses, or population projection). We anticipate that these will ultimately lead to an improved predictive and risk-assessment capability which will be highly beneficial and would greatly reduce existing controversies based on anecdotal evidence.

This work has been summarized in the numerous publications listed below:

PUBLICATIONS

Book Chapters

Bennetts, R.E., J.D. Nichols, J.D. Lebreton, R. Pradel, J.E. Hines, and W.M. Kitchens. 2001.  Methods for estimating dispersal probabilities and related parameters using marked animals.  Pages 3-17 In Dispersal (J. Clobert, J. D. Nichols, E. Danchin, and A. Dhondt, eds). Oxford University Press, Oxford, UK.

Kitchens, W. M., R.E. Bennetts, and D. L. DeAngelis. 2002.  Linkages between the snail kite population and wetland dynamics in a highly fragmented South Florida hydroscape. Pages 183-203 In The Everglades, Florida Bay, and Coral Reefs of the Florida Keys: An ecosystem sourcebook (J. W. Porter and K. G. Porter, eds.).  CRC Press, Boca Raton, FL.

DeAngelis, D.L., W.M. Mooij, P. Nott, and R.E. Bennetts. 2001.  Individual-based models: Tracking variability among individuals.  Pages 171-195 In  Modeling in natural resource management: valid development, interpretation, and application (T.M. Shenk and A.B. Franklin, eds.). Island Press, Washington, DC.

Bennetts, R.E., M.W. Collopy, and J.A. Rodgers. 1994.  The Snail Kite in the Florida Everglades: a food specialist in a changing environment.  Pages 507-532 In.   Everglades: The Ecosystem and its Restoration (S. M. Davis and J. C. Ogden, eds.). St. Lucie Press, Delray Beach, FL.

Papers Submitted, In Press, or Published in Peer-Reviewed Scientific Journals

Miller, S.J., R.E. Bennetts, and W.M. Kitchens.  A simple technique for a standardized measure of regional patterns of water levels and hydrologic events.  Wetlands (submitted).

Bennetts, R.E., W. M. Kitchens, and V. J. Dreitz.  2002. Influence of an extreme high-water event on survival, reproduction, and distribution of Snail kites in Florida. Wetlands 22: 366-373.

Dreitz, V. J., R. E. Bennetts, B. Toland, W. M. Kitchens, and M. W. Collopy. 2002.  Snail Kite nest success and water levels: A reply to Beissinger and Snyder. Condor: 216-221.

Mooij, W. M., R. E. Bennetts, D. L.  DeAngelis, and W. M. Kitchens.  2002. Exploring the effect of drought extent on the Florida Snail Kite: interplay between spatial and temporal scales. Ecological Modelling 149: 25-39.

Dreitz, V.J.,  J. D. Nichols, J. E. Hines, R. E. Bennetts, W. M. Kitchens, and D. L. DeAngelis.  2002. The Use of resighting data to estimate the rate of population growth of the Snail Kite in Florida. Journal of Applied Statistics 29:609-623.

Dreitz, V. J., R. E. Bennetts, B. Toland,W. M. Kitchens, and M. W. Collopy.  2001. Spatial and temporal variability in nest success of Snail Kites in Florida:  A meta-analysis.  Condor 103: 502-509.

Nasution, M. C. Brownie, K.H. Pollock, and R.E. Bennetts.  2001. Joint analysis of resighting and radio-telemetry data.  Journal of Agricultural, Biological, and Environmental Statistics 6: 461-478.

Bennetts, R.E., and W.M. Kitchens. 2000.  Factors influencing movement probabilities of a nomadic food specialist: proximate foraging benefits or ultimate gains from exploration? Oikos 91:459-467.

Bennetts, R.E., W.A. Link, J.A. Sauer, and P.W. Sykes. 1999.  Factors influencing counts in an annual survey of Snail Kites in Florida. Auk 116: 316-323.

Bennetts, R.E. V. J. Dreitz, W.M. Kitchens, J.E. Hines, and J.D. Nichols.  1999. Annual survival of Snail Kites in Florida with comparisons between radio telemetry and capture-resighting data.  Auk 116:435-447.

Bennetts, R.E., and W.M. Kitchens. 1999.  Within-year survival patterns of Snail Kites in Florida.  Journal of Field Ornithology 70:268-275.  Bennetts, R.E., K. Golden, V.J. Dreitz, and W.M. Kitchens.  1998. Estimates of the proportion of Snail Kites attempting to breed and the number of attempts per year in Florida.  Florida Field Naturalist 26:77-83.

Bennetts, R.E., W.M. Kitchens, and D.L. DeAngelis. 1998.  Recovery of the snail kite in Florida: beyond a reductionist paradigm.  Transactions North American Wildlife and Natural Resources Conference.  63:486-501.

Bennetts, R.E., M.R. Shannon, and W.M. Kitchens. 1998.  Causes of mortality of post-fledging juvenile and adult Snail Kites in Florida. Florida Field Naturalist 26:84-87.

Valentine-Darby, P.L., R.E. Bennetts, and W.M. Kitchens. 1998.  Seasonal patterns of habitat use by Snail Kites in Florida. Journal of Raptor Research 32:98-103.

Bennetts, R.E. and W.M. Kitchens.  1997. Population dynamics and conservation of Snail Kites in Florida: the importance of spatial and temporal scale.  Colonial Waterbirds 20:324-329.

Bennetts, R.E., and V.J. Dreitz.   1997.   Possible use of wading birds as beaters by Snail Kites, Boat-tailed Grackles, and Limpkins.  Wilson Bulletin 109:169-173.

Eisemann, J.D., W.N. Beyer, R.E. Bennetts, and A. Morton.  1997.   Mercury residues in South Florida apple snails.  Bulletin of Environmental Contamination and Toxicology 58:739-743.

Darby, P.V., R.E. Bennetts, and W.M. Kitchens. 1997.  Patterns of breeding-season masses of Snail Kites in Florida. Florida Field Naturalist 25:60-63.

Darby, P.C., P.V. Darby, and R.E. Bennetts.  1996. Spatial relationships of foraging and roost sites used by Snail Kites at Lake Kissimmee and Water Conservation Area 3A, Florida. Florida Field Naturalist 24:1-9.

Sykes, P.W., J.A. Rodgers Jr., and R.E. Bennetts. 1995.  Snail Kite. Pages 1-32 in A. Poole, P. Stettenheim, and F. Gill (Eds.). The Birds of North America, No. 171. The Academy of Natural Sciences, Washington,  D.C.

Bennetts, R.E. 1993.  The Snail Kite, a wanderer and its habitat. Florida Naturalist 66:12-15.  Bennetts, R.E., and E.L. Caton. 1988.  An observed incident of rat snake predation on Snail Kite chicks in Florida. Florida Field Naturalist 16:14-16.