Survival, Habitat Use, and Movements of Female Mallards Wintering in Southwestern Louisiana
Little information is available concerning survival, habitat use, and movements of mallards (Anas platyrhychos) wintering on the Gulf Coast Chenier Plain (GCCP). Quantitative data on these parameters would be useful in making effective management decisions by GCCP waterfowl managers. Accordingly, I radio-marked 135 female mallards during winters 2004-2005 and 2005-2006 in southwestern Louisiana. My estimated survival rate for both winters combined was 0.68 Â± 0.06 and did not differ by female age. Hazard ratios indicated that radio-marked females were 21-24 times more likely to die during hunted time periods than during non-hunted time periods. Estimated hunting and non-hunting mortality rates were 0.279 Â± 0.062 (Â± SE) and 0.067 Â± 0.029 (Â± SE), respectively, and did not differ between winters. Estimated product limit survival rates were 0.81 Â± 0.05 (Â± SE) and 0.54 Â± 0.09 (Â± SE) for HIGH and LOW condition birds, respectively. I found that diurnal use of areas closed to hunting was greater during hunted time periods in winter 2005-2006 than in winter 2004-2005. Nocturnally, use of areas closed to hunting was greater during SHUNT than during POST, and immatures used CLOSED lands more so than did adults. Diurnally, use of MARSH was 3.3 times greater than that of other habitats during both winters. Use of RICE and IDLE appeared to be related to availability of these habitats within the core study area. RICE acreage and use was greater in winter 2004-2005 than in winter 2005-2006, whereas IDLE acreage and use was greater in winter 2005-2006 than in winter 2004-2005. Female mallards used freshwater marsh habitats extensively; brackish or salt marsh was used much less frequently. Diel movements of female mallards generally were short (mean Â± SE = 5.0 Â± 0.2 km) and mean flight distances of individual females (n = 141) ranged from 3-15 km. My results suggest that mallards wintering in this area would benefit from programs and activities that target freshwater marsh for restoration and management. Management activities that increase mallard foraging habitats on areas closed to hunting may decrease hunting mortality rates and possibly increase female body condition.
Advisor:Robert. R. Cox, Jr.; Kevin S. McCarter; Alan D. Afton
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Keywords:renewable natural resources
Date of Publication:11/14/2007