Objective 1: Identify habitat use patterns on a seasonal and annual basis.

Radio telemetry will be used to monitor habitat use by female mottled ducks throughout their annual cycle. Each year during August and September in and around the Everglades Agricultural Area (EAA), Lake Okeechobee, the lower Kissimmee River Basin (KRB), and the suburban areas to the east, a total of 100 adult female mottled ducks will be captured using night-lighting techniques. After capture, birds will be taken to a processing site where morphological measurements will be taken, standard U.S. Fish and Wildlife Service leg bands will be affixed, and a VHF radio transmitter implanted abdominally. The radios will have an expected life of 13 months. After a recovery and observation period (12-18 hours), birds will be released at their capture site.

Immediately after release, birds will be monitored daily from trucks equipped with dual 4-element null-peak detection systems and at least weekly from an aircraft (Cessna or similar) equipped with two 4-element Yagi antennas. For as many locations as possible, the habitat being used will be determined and recorded, that is, a visual will be made of the radio-marked bird. Examples of habitats to be categorized include 1) natural marsh, 2) intensively managed marsh, 3) flooded pasture, 4) flooded EAA field, 5) prairie pond, 6) flooded prairie, 7) flooded cattle pond, 8) flooded citrus impoundment, 9) flooded management area impoundment, 10) flooded ditch, 11) flooded canal 12) flooded rice, 13) other flooded agriculture, 14) upland habitat, 15) everglades marsh, 16) river, 17) lake, 18) lake Okeechobee marsh, or 19) AHRES project wetland. Additional categories will be added as necessary to describe habitats used by radio-marked birds. These data will be analyzed to determine which habitats are used most often (based on the proportion of individual bird’s locations that occur within the different habitats), and if habitat use patterns vary by period of the annual cycle, year, and bird catch location. Habitat use patterns of birds from this study also will be compared to birds tracked during an earlier study of mottled duck habitat use in the SJRB.

Objective 2: Describe/characterize, in detail, wetlands used heavily by dabbling ducks.

Radio-marked mottled ducks will be used to obtain an unbiased sample of wetlands/wetland complexes being used heavily by dabbling ducks throughout the year. These wetland areas will be characterized by collecting data on average depth, mean percent vegetative cover, predominant vegetation types, bottom make-up, water level variability, water chemistry, distance to nearest human activity, distance to other water source, as well as other parameters. These data will be used to build a profiles for highly productive wetlands.

Objective 3: Compare heavily used wetlands to random and AHRES wetlands to Identify wetland characteristics that influence use by dabbling ducks.

Data collected to meet objective two will be compared to similar data collected from random wetlands and wetlands restored by the AHRES. These comparisons will be made to elucidate which parameters influence use of wetlands by mottled ducks and other dabbling ducks. Moreover, these comparisons will us to evaluate the effectiveness of current AHRES wetland enhancement practices with regard to their creating preferred habitat for dabbling ducks.

Objective 4: Determine if surface water availability influences habitat use, movement, and survival patterns of mottled ducks and habitat use patterns of other dabbling ducks.

Fifteen to 20 water bodies (5 each with hydrologic permanency classes of temporary, semi-permanent, and permanent) will be randomly selected from those within the study area. These wetlands will be monitored on a weekly basis to determine if surface water is present and to what extent the area of surface water has changed from the previous week. These data will be included as a predictor in the analysis of habitat use, movement, and survival data to determine if surface water availability influences these aspects of mottled duck and dabbling duck ecology.

Objective 5: Calculate annual and season-specific survival rates and determine if female survival differs among years, periods of the annual cycle and catch location.

Radios will be equipped with a 12-hour mortality sensor. Females will be monitored daily throughout the annual cycle to determine their status (i.e., dead or alive). Proportional hazards regression will be used to test for differences in survival in relation to period of annual cycle, year, and catch location.