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Survival estimates for Florida manatees from the photo-identification of individuals

January 1, 2004

We estimated adult survival probabilities for the endangered Florida manatee (Trichechus manatus latirostris) in four regional populations using photoidentification data and open-population capture-recapture statistical models. The mean annual adult survival probability over the most recent 10-yr period of available estimates was as follows: Northwest - 0.956 (SE 0.007), Upper St. Johns River - 0.960 (0.011), Atlantic Coast - 0.937 (0.008), and Southwest - 0.908 (0.019). Estimates of temporal variance independent of sampling error, calculated from the survival estimates, indicated constant survival in the Upper St. Johns River, true temporal variability in the Northwest and Atlantic Coast, and large sampling variability obscuring estimates for the Southwest. Calf and subadult survival probabilities were estimated for the Upper St. Johns River from the only available data for known-aged individuals: 0.810 (95% CI 0.727–0.873) for 1st year calves, 0.915 (0.827–0.960) for 2nd year calves, and 0.969 (0.946–0.982) for manatee 3 yr or older. These estimates of survival probabilities and temporal variance, in conjunction with estimates of reproduction probabilities from photoidentification data can be used to model manatee population dynamics, estimate population growth rates, and provide an integrated measure of regional status.

Publication Year 2004
Title Survival estimates for Florida manatees from the photo-identification of individuals
DOI 10.1111/j.1748-7692.2004.tb01171.x
Authors C.A. Langtimm, C.A. Beck, H.H. Edwards, K.J. Fick-Child, B.B. Ackerman, S.L. Barton, W.C. Hartley
Publication Type Article
Publication Subtype Journal Article
Series Title Marine Mammal Science
Index ID 1008516
Record Source USGS Publications Warehouse
USGS Organization Florida Integrated Science Center