Cold-related Florida manatee mortality in relation to air and water temperatures.

Many tropical and subtropical species are sensitive to sudden temperature changes, especially drops in temperature. During winters 2009-2010 and 2010-2011, unusually cold temperatures occurred in many parts of Florida, USA, resulting in increased mortality of Florida manatees, sea turtles, fish, corals, and other species. The Florida manatee, in particular, is highly susceptible to cold stress and death when water temperatures drop below 20°C.

Accuracy, precision, and error in age estimation of Florida manatees using growth layer groups in earbones.

Ages of Florida manatees () can be estimated by counting annual growth layer groups (GLGs) in the periotic dome portion of the tympanoperiotic complex of their earbones. The Florida Fish and Wildlife Conservation Commission manages an archive of more than 8,700 Florida manatee earbones collected from salvaged carcasses from 1989 to 2017. Our goal was to comprehensively evaluate techniques used to estimate age, given this large sample size and changes to processing protocols and earbone readers over time.

Influence of Manatees' Diving on Their Risk of Collision with Watercraft.

Watercraft pose a threat to endangered Florida manatees (Trichechus manatus latirostris). Mortality from watercraft collisions has adversely impacted the manatee population's growth rate, therefore reducing this threat is an important management goal. To assess factors that contribute to the risk of watercraft strikes to manatees, we studied the diving behavior of nine manatees carrying GPS tags and time-depth recorders in Tampa Bay, Florida, during winters 2002-2006.

Evaluation of adrenocortical function in Florida manatees (Trichechus manatus latirostris).

The study objectives were to determine the predominant manatee glucocorticoid; validate assays to measure this glucocorticoid and adrenocorticotropic hormone (ACTH); determine diagnostic thresholds to distinguish physiological vs. pathological concentrations; identify differences associated with sex, age class, female reproductive status, capture time, and lactate; and determine the best methods for manatee biologists and clinicians to diagnose stress. Cortisol is the predominant manatee glucocorticoid.

Hematology of healthy Florida manatees (Trichechus manatus).

Background: Hematologic analysis is an important tool in evaluating the general health status of free-ranging manatees and in the diagnosis and monitoring of rehabilitating animals.

Objectives: The purpose of this study was to evaluate diagnostically important hematologic analytes in healthy manatees (Trichechus manatus) and to assess variations with respect to location (free ranging vs captive), age class (small calves, large calves, subadults, and adults), and gender.

Methods: Blood was collected from 55 free-ranging and 63 captive healthy manatees.

Clinical biochemistry in healthy manatees (Trichechus manatus latirostris).

Florida manatees (Trichechus manatus latirostris) are endangered aquatic mammals living in coastal and riverine waterways of Florida and adjacent states. Serum or plasma biochemical analyses are important tools in evaluating the health of free-ranging and captive manatees. The purpose of this study was to measure diagnostically important analytes in the plasma of healthy manatees and to determine whether there was significant variation with respect to location (free-ranging versus captive), age class (small calves, large calves, subadults, adults), and gender.