Texas Waterfowl

Northern Shoveler

69 SOURCES introduction: Stark 1978; Lokemoen and Sharp 1981; Gammonley 1996; Rohwer et al. 2002. texas distribution: Traweek 1978; Pulich 1988; Lockwood and Freeman 2004; Baar et al. 2008. population status: Gammonley 1996; Sauer et al. 2008. diet: Migoya and Baldassarre 1993; Hohman and Ankney 1994; Gammonley 1995, 1996. range and habitats: Gray and Schultze 1977; Bellrose 1980; Weller 1988; Smith et al. 1989; Gammonley 1996; Elphick and Oring 1998; Gammonley and Fredrickson 1998. reproduction: Miller and Collins 1954; Hunt and Anderson 1966; Joyner 1973; Bellrose 1980; Hohman 1991; Gammonley 1996. appearance: Stark 1978; Bellrose 1980; Gammonley 1996. NORTHERN SHOVELER Anas clypeata The large, broad bill of Northern Shovelers not only sets them apart from other ducks in appearance, but also in diet. They specialize on planktonic and benthic organisms, which they filter out of the water and substrate with dense comblike projections (lamellae) that grow along the sides of their bill.They regularly forage on small food items that are seldom recorded in the diets of other ducks, such as unicellular forms of plankton. TEXAS DISTRIBUTION Breeding: Reports from early naturalists suggest Northern Shovelers may have bred throughout much of the state, including the Coastal Prairies. Although adults are uncommon to locally common throughout the state during summer, they are now rare breeders in Texas. With the exception of Bastrop and Bexar Counties, most recent records are from the High Plains and Trans-Pecos. Migration: Northern Shovelers migrate through all Texas counties. In the High Plains migrants arrive in August, and their numbers increase through early October. Their numbers decline during winter, although some remain during winter months. In the northern portions of the Rolling Plains, Post Oak Savannah–Blackland Prairies , and Pineywoods, the first migrants arrive in August or early September. Migrants arrive in the Coastal Prairies and South Texas Brush Country in September and October; their numbers do not peak in these areas until February or March. Numbers in the Coastal Prairies begin declining during April. In the High Plains, spring migrants begin increasing in early February and remain common through May. Most have left the Rolling Plains, Post Oak Savannah–Blackland Prairies, and Pineywoods by late May. dabbling ducks 70 Northern Shoveler (female). Photograph by Mark W. Lockwood, April 2, 2009, Balmorhea Lake, Reeves County, Texas. Northern Shoveler (male). Photograph by Mark W. Lockwood, January 17, 2009, Midland, Midland County, Texas. 71 Winter: From 2000 to 2008, Northern Shovelers averaged 128,680 during the Texas Mid-winter Waterfowl Survey. Most Northern Shovelers that winter in Texas occur in the Coastal Prairies, although notable numbers occur in the South Texas Brush Country, Post Oak Savannah–Blackland Prairies, Rolling Plains, and Coastal Sand Plain (TPWD unpublished). Small numbers winter throughout the rest of the state. TEXAS HARVEST From 1999 to 2006, Northern Shoveler harvest in Texas averaged 61,516 annually. This was approximately 12 percent of their annual US harvest. POPULATION STATUS In 2011 the estimated abundance of Northern Shovelers was 4.6 million, which was the highest estimate since the Waterfowl Breeding Population and Habitat Survey was initiated in 1955. Northern Shovelers have been above the North American Waterfowl Management Plan’s population goal of 2.1 million since 1994. DIET Northern Shovelers consume invertebrates (for example, snails, zooplankton, and insects) throughout the year. In Manitoba, invertebrates accounted for 93 percent of the diet of laying females. Northern Shovelers foraging in freshwater wetlands in San Patricio County, Texas, consumed 50 percent animal matter and 50 percent plant material. Water fleas and snails were the primary invertebrates consumed, and coontail was the most common plant consumed. Northern Shovelers foraging in saltwater wetlands in Refugio County consumed 80 percent animal and 20 percent plant material. Unicellular foraminifera, tiny seed shrimp, and snails were the primary invertebrates consumed; widgeongrass was the most common plant consumed. RANGE AND HABITATS Breeding: Northern Shovelers breed in North America, Europe, and Asia. They nest in Alaska and in small numbers throughout much of the western United States and Canada. They breed locally in eastern North America. The core of their North American breeding range is the Prairie Pothole Region. Breeding pairs settle in on shallow marshes and wetlands that are characterized by submersed aquatic vegetation and high invertebrate densities. All nests are found in uplands; nests are typically located in short herbaceous cover, including meadows and hayfields. Small areas of herbaceous cover associated with rock piles and fencerows are often used for...