Date of Award

1996

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Renewable Natural Resources

First Advisor

Alan D. Afton

Abstract

I developed portable platforms for setting rocket nets in open-water habitats, and used them to capture 1116 waterfowl of 7 species during winters 1991-92 and 1992-93 in southwestern Louisiana. Distance and duration of evening flights of female northern pintails (Anas acuta; hereafter pintails) from Lacassine National Wildlife Refuge increased with date within wintering period, and generally were greater than previously reported estimates for wintering waterfowl. I found that diurnal use of refuges by females increased during hunting seasons, contradicting Tamisier's hypothesis that use of refuges by pintails in southwestern Louisiana is not influenced by hunting. Female pintails extensively used privately owned rice and fallow (idle) agriculture, particularly at night. Use of mini-refuges was low relative to that of large permanent pools. This finding does not support Rave and Cordes' prediction that mini-refuges would prove to be more important than pools to wintering pintails. I attribute low use of mini-refuges during my study primarily to lack of water and cover management, but location, small size, and irregular shape of some of these areas may preclude extensive use by pintails. Early mortality (death within the first 4 days after radio-tagging) of females was related to flight quality (scored as good, moderate, or poor upon release). Early mortality and flight quality, in turn, were related to the interaction of holding time (time from capture until release) and number of waterfowl captured in rocket nets. Survival of females in southwestern Louisiana was lower during hunting than during non-hunting seasons, and immatures survived at lower rates than adults. Despite conservative hunting regulations (30-day season and 1 pintail daily), hunting mortality rates (0.165 $\pm$ 0.034 (SE) for adults and 0.315 $\pm$ 0.053 for immatures) of female pintails in southwestern Louisiana were higher than estimates for other female dabbling ducks (within age classes) during winter. If lower daily energy expenditure and hunting mortality of female pintails are management goals, I recommend that availability of moist-soil and agricultural foods on key refuges be increased as a first step.

ISBN

9780591204124

Pages

134

DOI

10.31390/gradschool_disstheses.6304

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