Corey D. Mason

Winter Time-Activity Budgets of Diving Ducks on Eastern Texas Reservoirs

Abstract. Wintering diving duck (Aythya spp.) time-activity budgets have been developed for many species in different regions. As such, direct comparisons can be made among studies where substantial deviations in “normal” activity budgets can provide insight as to how location, food resources, habitat, weather and human disturbance may differentially influence behavior (s) during winter. To examine how diving ducks use large reservoirs in eastern Texas, 1,275 individual time-activity budgets were quantified for Canvasback (Aythya valisineria), Lesser Scaup (A. affinis) and Ring-necked Duck (A. collaris) wintering on B.A. Steinhagen, Sam Rayburn and Toledo Bend Reservoirs during winter 2003/2004 and 2004/2005. Behaviors varied among species (P< 0.001), where food acquisition, locomotion and resting-related behaviors dominated time-activity budgets. All three species spent similar time feeding compared to other studies in the southeastern United States, but spent substantially more time locomoting than previously reported. Human disturbances from boat traffic were associated with time spent locomoting, but no species dramatically increased time feeding to compensate for increased time locomoting. Wintering diving duck activity budgets on these large eastern Texas reservoirs were generally similar to previous studies in the southeast. However, the (in) direct impacts of boat disturbances warrants closer investigation, specifically related to wintering waterfowl responses and the potential utility or value of voluntary avoidance areas during winter.

Seed bank potential of moist-soil managed wetlands in east-central Texas

Proper management techniques on moist-soil wetlands provide methods for enhancement of established wetlands, restoration of former wetlands, and creation of new wetland habitat. These techniques also create suitable wetland habitat for non-breeding waterfowl and other wetland dependent species during winter. To understand moist-soil managed wetland vegetative patterns, aspects such as plant species distribution, reproductive strategy, seed bank composition and viability should be thoroughly characterized. We investigated soil seed bank potential of moist-soil managed wetlands on Richland Creek Wildlife Management Area, Texas to determine which treatment (i.e., drawdown or flooded) produced the most desirable moist-soil plants. A total of 27 species germinated, producing 3,731 and 3,031 seedlings in drawdown and flooded treatments, respectively. There were also differences in stem densities between treatments of desirable and non-desirable species. Drawdown treatments had more seedlings germinate than flooded treatments, validating the notion that drawdown treatments provide favorable conditions for seed germination. Drawdown and flooding techniques, when properly timed, will allow managers to drive and directly influence managed wetland plant communities based on seed bank composition and response to presence or absence of water during the germination period.

Time-activity Budgets of Waterfowl Wintering on Livestock Ponds in Northeast Texas

Abstract We developed individual time-activity budgets for Anas platyrhynchos (Mallard; n = 281), A. strepera (Gadwall; n = 251), and Aythya collaris (Ring-necked Duck; n = 144) wintering on livestock ponds in the Blackland Prairies Ecological Region of Texas in January and February, 2000 and 2001. Feeding (32–38%), locomoting (24–49%), and resting (10–36%) dominated the activity budgets for each species. Behaviors varied between years, probably due to the 3-fold increase in precipitation that raised water levels in livestock ponds. In 2000 and 2001, Mallards fed nearly 50% and 20% of their time, respectively, with comfort and resting occupying 60% in 2001. Gadwalls locomoted nearly 50% of their time each year, but increased surface feeding 2-fold in 2001. Finally, Ring-necked Ducks spent about a third of their time locomoting, another third resting, and the remainder subsurface feeding in 2001. Focal species activity budgets were generally similar to those developed throughout their ranges. Livestock ponds in northeast Texas provide small but regionally widespread habitats for wintering waterfowl. Future work should focus upon diet and landscape occupancy rates of waterfowl using these habitats during winter.

Immigration and Recruitment in an Urban White-Winged Dove Breeding Colony

Abstract Dove population management necessitates estimates of vital rates for use in mechanistic models used to evaluate and predict population responses to environmental variation and/or alternati...

Aquatic invertebrate production in moist-soil managed wetlands on Richland Creek Wildlife Management Area, east-central Texas

Abstract Aquatic invertebrates have significant value to wetland-dependent species as well as to wetlands themselves. They process organic matter through producer and detritus food webs, modify wetland habitats, and provide a food resource to wetland-dependent species such as waterfowl and shorebirds. Timely flooding and drawdown of water within moist-soil managed wetlands will increase invertebrate diversity and abundance, allowing wetland managers to maximize the production of such areas. We examined how flood timing and duration influenced aquatic invertebrate density, diversity, richness, and production within four moist-soil managed wetlands on Richland Creek Wildlife Management Area, east-central Texas from January 2004 through December 2006. A total of 12,089 aquatic invertebrates from 41 aquatic invertebrate families were collected. Overall, diversity indices were 0.76 (Simpsons Index) and 2.47 (Shannon-Wiener Index). Most common aquatic invertebrates were Crustacea (n = 3,568) and Ephemeroptera (n = 2,080). Differences in aquatic invertebrate density and biomass varied depending on the presence of water over time. Invertebrate community diversity and production peaked early but experienced a nearly sixfold decline over 3 y due to atypical and prolonged inundation regimes in these managed wetlands. Proper inundation duration and timing regimes are key to maintaining invertebrate community diversity and production in moist-soil managed wetlands.

Pilot Study for Aging Classification Criteria of Fledged Juvenile Eastern White-winged Doves

Abstract Nineteen eastern white-winged doves Zenaida asiatica asiatica were hatched and raised in captivity and used to develop an aging key that 1) quickly identifies juveniles based on a series o...

Decomposition of Three Common Moist-Soil Managed Wetland Plant Species

Abstract Moist-soil wetland management is used to precisely control delivery, duration, and timing of water addition to, and removal from, managed wetlands with targeted responses including germination and growth of desirable moist-soil plant species. Similarly, water delivery and removal drives decomposition of moist-soil plants as well as nutrient cycling within these systems, which is a key driver of productivity in such managed wetlands. Through deployment of litter bags, we examined rate of mass loss and decay coefficients of three locally abundant moist-soil annual species that are potentially valuable wintering-waterfowl food sources (nodding smartweed Persicaria lapathifolia, red-rooted flatnut sedge Cyperus erythrorhizos, and toothcup Ammannia coccinea) within man-made moist-soil managed wetlands on the Richland Creek Wildlife Management Area in East-central Texas. All three species lost nearly 100% of their mass during an 11-mo deployment period, where rate of mass lost and decay coefficient rat...