Evaluating the Movement Patterns and Survival of Juvenile Everglade Snail Kites (Rostrahamus sociabilis plumbeus) at Lake Okeechobee

Description

The Everglade snail kite is a federally listed endangered species. The principal threat to the snail kite is the loss, fragmentation, and degradation of wetlands in central and southern Florida resulting from urbanized and agricultural development and alterations to wetland hydrology through ditching, impoundment, and water level management. The Central and Southern Florida (C&SF) Project, which was originally designed and constructed to serve flood control and water supply purposes, has disrupted the volume, timing, direction, and velocity of freshwater flow and has resulted in habitat loss and degradation in the Water Conservation Areas (WCAs) and other portions of the historic Everglades. Drainage of Florida’s interior wetlands has reduced the extent and quality of habitat for both the apple snail and the snail kite. The fragmentation or loss of wetland habitat significantly limits the snail kites’ ability to be resilient to disturbance events such as various climatic events. As wetland habitats become more fragmented, either through destruction or as the result of hydrologic management, their dispersal distances become greater, putting increased stress on dispersing kites that may not be able to replenish energy supplies. This agreement represents an opportunity to enter into a cooperative agreement for monitoring juvenile snail kite movement and survival patterns on Lake Okeechobee. Monitoring will focus on Lake Okeechobee, because this is a critical wetland habitat for snail kites and helps link populations in the Kissimmee Chain-of-Lakes to the population in the Everglades. The purpose of this research is to understand how current water management operational plans for lake stage and releases at structures and resulting changes in hydrology affect snail kite reproductive success, survival, demography, and population. This project is being conducted to meet a requirement of a Biological Opinion (BO) from the U.S. Fish and Wildlife Service (USFWS) in association with the current regulation schedule for Lake Okeechobee (e.g. 2008 LORS and the anticipated Lake Okeechobee System Operating Manual (LOSOM)) and the Endangered Species Act (ESA). Monitoring and reporting requirements of the BO identify the need to tag up to twenty near fledgling aged snail kites (i.e., 24 days old) with the best proven tags (radio, satellite, or cell) and monitor for up to five months, depending on survival. This period coincides with the lowest survival rates for fledglings as they learn to forage for themselves and begin moving beyond their nest area. Tagging is to commence during the spring recession season. The mechanism for water management effects on juvenile snail kite survival is primarily related to foraging habitat and food availability (but can also include increased predation). For example, rapidly receding water levels or low lake levels in general that occur during the first months of a juvenile fledging the nest can affect food availability through reductions in foraging habitat. These effects may be detectable through fledgling movement patterns or decreased survival if a large enough database is established for comparison. This project will play a critical role in building the knowledge base on juvenile movement and survival patterns under a variety of conditions.

Agency Contact

More from Engineer Research and Development Center