Project: Estimation of Critical Parameters in Conjunction with Monitoring The Florida Snail Kite Population

Project Start Date: 10/01/2000 Project End Date: 09/30/2003

Web Sites: ATLSS.ORG

Location: The Greater Everglades ecosystem

Funding Source: Critical Ecosystems Studies Initiative

Principal Investigator: Wiley M. Kitchens, USGS-BRD, Florida Cooperative Fish & Wildlife Research Unit, 117 Newins-Ziegler Hall, Gainesville, Florida 32611, kitchensw@wec.ufl.edu

Project Personnel: Donald L. DeAngelis, Phone: 305-284-1690 e-mail: ddeangelis@umiami.ir.miami.edu

Other Supporting Organizations: USGS/BRD, NPS

Associated Projects: Component of ATLSS Program

Overview & Status: The snail kite (Rostrhamus sociabilis) is an endangered species that resides in the highly fluctuating ecosystem in the central and southern Florida wetlands. Many demographic traits, such as stage-dependent survival, reproduction, and movement of the snail kite vary both temporally and spatially. How these demographic parameters vary as a function of environmental conditions, hydrology in particular, is crucial for understanding how the snail kite will respond to proposed changes in water regulation in South and Central Florida. In particular, these data are needed for testing and improving the existing spatially-explicit, individual-based ATLSS snail kite model, EVERKITE, developed by Mooij and Bennetts, which has recently been delivered to Department of Interior and other agencies. From these data and the model, projections can be made on snail kite response to any hydrologic scenario. Also, continued estimates will be made of the rate of population growth (). Assessing as well as the demographic parameters, is critical for identifying and evaluating the effectiveness of management actions and conservation strategies. The task of this project is to do the following: (1) To monitor the status of the snail kite population trends in central and southern Florida. (2) To provide estimates of demographic parameters for the spatially explicit individual-based model in ATLSS. (3) To collaborate with Dr. Wolf Mooij of the Netherlands Institute of Ecology to use snail kite data to validate EVERKITE.

Needs & Products: This study is providing reliable estimates of critical temporal and spatial factors structuring the demographic responses of snail kites as well as to provide a sound monitoring program during implementation of restoration. It is important to recognize that for the snail kite, the argument as to whether a single general factor, such as some hydrological variable, regulates or limits the population becomes problematical when interactions are considered. The influence of hydrology on the population dynamics of the snail kite varies depending on changes in other factors (i.e., food resources, vegetation structure, climate). We believe that our proposed approach will aid in statistically resolving the magnitude and relative importance of these often closely correlated factors. This will then allow refinement to the management models providing critical linkage to the design and evaluation of restoration alternatives. Another aspect that we are presently investigating is the response of the bird in terms of movement. By combining radiotelemetry and mark-resight data under a multistate modeling framework we intend to estimate yearly movement probabilities between critical habitats, and test biological hypotheses about the processes driving the long term movement patterns. This information together with some further investigation of within year movement patterns, should help improve the predictive performance (in particular the spatial component) of the spatially explicit individual based kite model.