Department of Environmental Conservation Grant: Research on the Endangered Snail Kite in South Florida Ecosystem

Background:

The Everglade snail kite is an endangered raptor whose distribution in the United States is restricted to the South Florida Ecosystem including watersheds of the Everglades, Lake Okeechobee, Kissimmee River, and Upper St. Johns River. Because snail kites feed almost exclusively on aquatic apple snails, their reproduction, survival and recruitment depends directly on the hydrologic functioning of the wetland systems within this region. Management induced hydrologic alterations in these wetland habitats could potentially have a substantial effect on snail availability and thus the snail kite population. Over half of the wetlands within central and southern Florida have been lost during the past century, and those that remain have been highly fragmented and severely degraded. The high level of fragmentation and loss of connectivity of the kite habitat and its potential negative effect on dispersal abilities raise new concerns regarding the resilience of the snail kite population to disturbance events, including changes in water management that may influence the snail kite’s prey base. Degradation of the wetland habitats in central and southern Florida have prompted planning for large-scale restoration efforts. Improvements in snail kite reproduction may signal the successful restoration of key hydrological and biological functions of the south Florida ecosystem. The regular, successful reproduction of Everglade snail kites may indicate that the combination of several hydrological and biological functions in the Everglades has been correctly restored.

Brief Description of Anticipated Work:

The purpose of this research is to continue field data collection of Everglade snail kite and reproductive responses in the Everglades to include Lake Okeechobee, the Water Conservation Areas, the eastern portion of Big Cypress National Preserve, and the northern portions of Everglades National Park. The overarching objective of this research is to monitor the population of snail kites, including estimating population size and trends, as well as response to environmental changes. The Everglade snail kite is a federally listed species under the Endangered Species Act. This research will play a role in further understanding how water management in south Florida influences reproduction in this species and what actions can be taken to help preserve the habitat upon which this species depends. Specifically, the objectives of this research include:

Objective 1: Estimation of survival and assessment of the effect of hydrology on Everglade snail kite survival.

Objective 2: Estimation of reproductive parameters and assessment of the effect of hydrology on reproduction of Everglade snail kites.

Objective 3: Estimation of population size and population growth rate of Everglade snail kites.

Objective 4: Identification of causes of decline and stalled recovery of Everglade snail kites.

Objective 5: Estimation of stochastic population growth rate for the Everglade snail kite.

Objective 6: Estimation of probability of quasi-extinction for the Everglade snail kite

Objective 7: Estimation of movement rates and landscape connectivity and assessment of the effect of hydrology on movement of the Everglade snail kite.

Objective 8: Evaluation of alternative management scenarios of snail kite viability.