Louisiana mottled duck telemetry summer survival data 2018-2020 and water level data from Hurricane Laura surge

Tropical cyclones are the most powerful storms on earth, causing
catastrophic damage to human lives and infrastructure. Hurricanes
also cause wildlife mortality when they make landfall, but the severity of
these effects is difficult to quantify because data collection is either
logistically impossible or deprioritized in the wake of human
tragedy. On 27 August 2020, Hurricane Laura made landfall in
southwestern Louisiana with maximum sustained winds of 241 kph (150 mph),
making it one of the most powerful storms to strike the mainland United
States. Hurricane Laura passed directly over the core breeding
range of the Western Gulf Coast population of Mottled Duck (Anas
fulvigula), during a time when many adult birds were undergoing a
simultaneous wing feather molt and were flightless. We used GPS-GSM
telemetry data to evaluate survival rates of adult female Mottled Ducks in
late summer 2020 (bracketing 27 August by one month on either side)
relative to the same period in 2018 and 2019. Mortality was lower
in 2018 (12 out of 29; 41%) and 2019 (8 out of 28; 29%) than in 2020 (12
out of 18; 67%), and 7 out of 12 mortalities documented in 2020 occurred
when Hurricane Laura made landfall. Survival analyses in Program
MARK confirmed lower survival probability in 2020, but there was overlap
in 85% confidence intervals in all years. This single storm
resulted in the death of ~40% of all marked birds in our sample,
suggesting that hurricanes have the potential to influence population
demographics. In addition, Hurricane Laura resulted in widespread
habitat loss and degradation that has reduced available nesting habitat in
2021, and possibly for years to come. The acute and chronic
effects of hurricanes may exacerbate Mottled Duck population declines,
which may worsen in the face of increasingly frequent and more severe
tropical storms.