Survival and Recovery of Mottled Ducks in Coastal South Carolina, 2008-2018

Mottled ducks are typically geographically separated into two sub-species: peninsular Florida (Anas fulvigula fulvigula) and the western Gulf Coastal (WGC) (A. f. maculosa). Between 1975 and 1983, >1,200 mottled ducks were introduced to coastal South Carolina primarily from the WGC range. A late summer banding program was initiated in 2008 within the Santee Delta and the Ashepoo, Combahee, and Edisto Rivers Basin in South Carolina to estimate mottled duck survival and harvest probability. We acquired 3,594 banding and 525 recovery records of mottled ducks banded between 2008-2018. We used the dead recovery model with Brownie parametrization in Program MARK to estimate annual survival (S) and recovery probabilities (f) among combinations of age, sex, year, and band material (aluminum or stainless steel). Annual survival was greatest for adult males (0.60 ± 0.03 [SE]), followed by adult females (0.57 ± 0.04), juvenile females (0.44 ± 0.13), and juvenile males (0.32 ± 0.07). Recovery and harvest prob- abilities were greatest for juvenile males (0.10 ± 0.02; 14% [harvest probability assuming 73% reporting]) followed by adult males (0.08 ± 0.01; 11%), juvenile females (0.05 ± 0.01; 7%), and adult females (0.05 ± 0.01; 6%). The band material variable was absent from competing models suggesting that retention or inscription attrition did not impact recovery probabilities of individuals banded with aluminum bands. Relative to other occupied regions, juvenile male survival and recovery probabilities for South Carolina mottled ducks were low suggesting either poor post-breeding season survival prob- abilities or high dispersal rates. Survival probabilities for other age and sex classes were well within previously reported ranges and appear sufficient to maintain populations with continued recruitment.

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