Waterfowl Production Research Articles

Movements and Habitat Use of Franklin's Ground Squirrels in Duck-Nesting Habitat

We used radio telemetry to determine the movements and habitat use patterns of adult Franklin's ground squirrels (Spermophilus franklinii) on a 152-ha Waterfowl Production Area (WPA) in central North Dakota. The squirrels were diurnal. Mean total distance traveled daily was 213 and 153 m for males and females, respectively. Movements of females decreased during gestation and lactation; those of both sexes decreased prior to immergence. Annual home ranges averaged 24.6 and 8.7 ha for males and females, respectively; biweekly home-range sizes exhibited seasonal patterns. Ground squirrels restricted their activities almost exclusively to the WPA. Use of blocks of herbaceous cover on the WPA could not be explained by vegetation height, density, or litter depth. Ground squirrel movements were influenced by locations of burrow systems and patchily distributed food resources. Periodic cultivation or removal of herbaceous vegetation may inhibit use of upland duck-nesting habitat by ground squirrels. J. WILDL. MANAGE. 53(2):324-331 Planting dense nesting cover (DNC) to provide upland-nesting ducks with increased security from nest predators is a common practice on areas managed for duck production in North America's prairie pothole region (Duebbert and Kantrud 1974, Duebbert and Lokemoen 1976, Higgins and Barker 1982). Although DNC is attractive to some duck species, its importance to the activities of predators of duck eggs is undetermined. The Franklin's ground squirrel inhabits dense cover throughout much of the prairie pothole region (Hall 1981). It is a predator of duck eggs (Sargeant et al. 1987) and has been implicated in severe predation on duck nests in fields of DNC in east-central North Dakota (Greenwood 1986). Past studies of Franklin's ground squirrels have emphasized natural history (Sowles 1948, Haggerty 1968, Haberman and Fleharty 1971, Iverson and Turner 1972, Murie 1973), but little information is available on their movements and use of habitat. Our objective was to describe the movements and use of habitat by Franklin's ground squirrels on a federally owned WPA where upland habitat was primarily DNC fields of different ages. We thank D. H. Johnson and J. N. Burroughs for help with data processing, R. J. Greenwood, M. A. Sovada, and D. J. Norris for field assistance and helpful suggestions throughout the study, and H. F. Duebbert and D. H. Johnson for comments on manuscript drafts. The study was funded by the U.S. Fish and Wildlife Service, Northern Prairie Wildlife Research Center; the Missouri Cooperative Fish and Wildlife Research Unit; and the Edward K. Love Foundation. The U.S. Fish and Wildlife Service, Missouri Department of Conservation, University of Missouri-Columbia, and the Wildlife Management Institute contribute to the Missouri Cooperative Fish and Wildlife Research Unit. This is Journal Series 10008, Missouri Agricultural Experiment Station Project 189.

Use of Earthen Islands by Nesting Ducks in North Dakota

We studied duck nests on 1 natural island and 21 constructed islands on the J. Clark Salyer National Wildlife Refuge (NWR), North Dakota in 1982-83. We found 286 nests of 7 species; mallard (Anas platyrhynchos), gadwall (A. strepera), and blue-winged teal (A. discors) represented >90% of all nests. The mean annual nest density was 8.7/ha with a mean Mayfield-adjusted nest success of 24%. Islands on which the most ducks were produced were 335-1,085 m offshore, surrounded by 150-200 m of open water, and contained tall, dense, brush or forb cover. Three islands with these characteristics held 37% of the nests and produced 55% of total ducklings. Although gadwalls and mallards formed dense nesting concentrations, bluewinged teal showed little nest-clumping behavior or nest cover preferences. Other factors influencing production rates included a seasonal decline in nest success and between-year variability. To be cost effective, islands located in wetlands with large mink (Mustela vison) and raccoon (Procyon lotor) populations should have adequate spatial isolation and/or predator control. J. WILDL. MANAGE. 53(2):411-417 Recruitment rates of ducks in the intensively farmed portion of the prairie pothole region are low (Cowardin et al. 1983) because of declining habitat and concentration of nest and female duck predators (Sargeant and Arnold 1984). Recent efforts to improve waterfowl production have centered on restricting predator access (e.g., electric fencing) (Lokemoen et al. 1982), cover management (e.g., dense nesting cover [DNC], burning, mowing), and construction or improvement of nesting islands. Some island habitats attract large populations of nesting ducks (Drewien and Fredrickson 1970, Browne et al. 1983) and have high nest success due to the reduced impacts of predators (Duebbert 1966, Vermeer 1968). Artificial islands can potentially produce more ducks/unit area than other habitats, but they are expensive to construct and maintain, and in many areas may not improve nest success enough to justify costs (Lokemoen 1985). Several authors have made recommendations concerning island construction (Hammond and Mann 1956, Duebbert 1982), but only recently have they been tested quantitatively (Giroux 1981, Carlsen 1984). Our objectives were to quantitatively assess selected environmental variables that best explain duck nesting use and production for a group of earthen islands, and to recommend ways to improve waterfowl production on islands. We thank R. A. Stomstad and T. B. Brokke for field assistance. We are grateful to D. Walls for logistic support and personnel to assist with field work. Additional support was provided by the University of North Dakota Biology Department and the Institute for Ecological Studies. Special thanks are extended to R. D. Sayler who provided helpful advice and reviewed the manuscript. The final draft benefited from comments made by R. C. Drewein and H. F. Duebbert. This publication is Contribution 8 of the Institute for Ecological Studies, University of North Dakota.

Nest-Site Distribution and Overland Brood Movements of Northern Pintails in Alberta

Distribution of nests of northern pintails (Anas acuta) was examined around shallow waterbodies on grazed, mixed prairie in southern Alberta. Pintails were the most common ducks nesting on the mainland prairie but not on the more densely vegetated artificial islands. Nest density on the islands for pintails (10.4/ ha) and all duck species combined (80.0/ha) was much greater than that on the mainland (pintails = 0.160.17/ha and all = 0.26-0.31/ha). Hatching sucess of pintail nests on the prairie appeared to be relatively high, probably a result of nests being widely dispersed over large areas of suitable habitat. Pintail nests on the prairie were most commonly situated 1-2 km from water. A hypothesis that pintails nest far from water to avoid male-chasing was repudiated in favor of one that such behavior reduces nest predation. Substantial overland travel by pintail broods is common, necessitated by the distance that hens nest from water. Simulated 3-km nest-to-water movements of pintail ducklings did not deplete their lipid reserves or impair growth. J. WILDL. MANAGE. 51(4):716-723 The importance of prairie breeding habitat to the overall productivity of northern pintails is evidenced by the low apparent reproductive output of arctic-nesting birds (Calverley and Boag 1977, Derksen and Eldridge 1980) and the positive correlation between continental recruitment and the relative proportion of birds inhabiting the prairies (Smith 1970). Within the prairies, the grasslands of southern Alberta support higher densities of breeding pintails than any other region (Vermeer 1972, Bellrose 1979). Much of this area is rangeland, and consequently, many of the birds breeding there nest on grazed prairie. Most information on the location of nest sites of pintails has come from Manitoba and North Dakota where pintails frequently nest, often unsuccessfully, in cultivated fields (Sowls 1955:66, Milonski 1958, Higgins 1977, Krapu 1977). Pintails reportedly nest farther from water than other ducks (Keith 1961, Bellrose 1980: 271), but no systematic searches have been conducted to determine the distribution of their nests relative to water. Nests placed far from water are often thought to result in reduced duckling survival because of the extended overland travel required to get to water; e.g., Sayler 1962, Dzubin and Gollop 1972. In areas where artificial islands have been created, the distribution of nests on the mainland can be compared to that on islands to evaluate the efficacy of the islands in increasing waterfowl production. This study examined the location of pintail nests around a number of shallow basins in grazed prairie near Brooks, Alberta. Pintail use of artificial islands for nesting sites was compared to that of the mainland and contrasted with that of other duck species. The distance of pintail nests from water was determined, and the hypothesis that male pursuit flights cause hens to nest far from water was considered. The consequences of nesting far from water were examined, particularly the effect of overland movement on the condition of ducklings. Financial support of this study was provided by grants to D. A. Boag from the Nat. Sci. and Eng. Res. Counc., and Can. Natl. Sportmen's Fund. Ducks Unlimited Can. and the Brooks Wildl. Cent. of the Gov. Alberta provided invaluable logistic support. Thanks to T. S. Coleman, R. Cotter, G. G. Gregoire, A. J. Murphy, and T. D. Sorochan for their assistance in the field. Special thanks to D. A. Boag for his comments on the manuscript and also to C. D. Ankney, S. J. Hannon, V. Lewin, A. R. Palmer, A. Shires, W. D. Wishart, and P. M. Woodard. The Bamfield Mar. Stn. provided the facilities and personal support for revision of this paper. STUDY AREA AND METHODS The study was conducted in an area of grazed prairie about 35 km southeast of Brooks, Alberta, from 1981 to 1984. The study area included 4 impoundments that are managed for waterfowl production by Ducks Unlimited, Canada. These impoundments (Tilley O, Tilley P, Kininvie F, and Kininvie S) were described by Giroux (1981). At high water levels, the areas Present address: Bamfield Marine Station, Box 99, Bamfield, British Columbia VOR 1BO, Canada.

Effect of Nesting Cover Density on American Crow Predation of Simulated Duck Nests

Predation by American crows (Corvus brachyrhynchos) on simulated duck nests was studied in Saskatchewan parklands during 1985. Survival of nests (>80% hidden) after nearby exposed decoy nests had been found was followed in cover of different heights and densities. Short cover was grass-dominant, whereas tallest and densest cover was shrub-dominant, particularly snowberry (Symphoricarpos spp.). Survival increased with cover height and density and reached maximum at about 70 cm height. It is postulated that tall, dense cover represents a behavioral deterrent as well as a physical barrier to crows hunting on foot. Our results indicated that the protection and enhancement of shrub cover would be a beneficial technique for increasing nesting success of certain duck species where crow predation is severe. J. WILDL. MANAGE. 51(2):481-485 The American crow is an important egg predator of nesting parkland ducks (Smith 1971), and the impact becomes more acute as habitat is converted to cropland. Less nesting habitat allows predators to concentrate foraging efforts on smaller patches of cover. Paradoxically, these same changes in land use apparently have caused crow populations to increase rather than decrease (Smith 1971, Houston 1977). To develop management practices to improve waterfowl production, information is needed on features of nesting cover that reduce predation. Previously, we concluded that predation by crows on partially concealed simulated nests was density dependent (Sugden and Beyersbergen 1986). At highest nest densities, crows found hidden nests while they searched cover on foot after a nearby exposed nest had been discovered. We predicted that maximum protection would occur when cover not only concealed nes s but also discouraged crows from searching on foot. In this paper we describe an experiment designed to test that hypothesis. We thank the farmers who allowed us to work on their land and R. G. Clark and G. H. Townsen for reviewing a draft of the manuscript. STUDY AREA AND METHODS The Proctor Lake Study Area, 50 km south of Saskatoon, Saskatchewan, and general techniques have been described (Sugden and Beyersbergen 1986). From 23 April through 3 June 1985, we established 45 5-nest plots within 400 m of an access road through the study area. There were 37 plots on grazed pasture and 8 on a wild hayfield. Each new plot was placed >100 m from any previous plot, active or terminated. Plots consisting of 5 artificial nests were placed in vegetation ranging from stands composed entirely of mixed grasses, through com-

Effect of Density and Concealment on American Crow Predation of Simulated Duck Nests

Predation by American crows (Corvus brachyrhynchos) on simulated duck nests was studied in the Saskatchewan parklands during 1983-84. Density dependent predation on partially concealed nests became evident at about 1 nest/ha and reached a maximum at about 6 nests/ha in plots that contained an exposed nest. Crows found few or no hidden (>60% concealed) nests that were not associated with a nearby decoy nest. Experimental nests usually were found while crows searched cover on foot after having detected the decoy nest while flying. Concealment conferred little or no protection from a walking crow. The maximum protection by nesting cover would be realized at low nest densities or in dense cover that would deter walking crows and conceal nests. Intensive farming on the prairies and parklands leaves natural nesting cover in small patches. Therefore, duck nests sometimes occur in densities that would be vulnerable to density dependent predation by crows and perhaps other predators. Our results indicate that nest losses could be reduced by land-use practices that allow ducks to disperse their nests. An alternative, at least for some species, is the development of dense cover such as patches of low shrub. J. WILDL. MANAGE. 50(1):9-14 Intensive agriculture on the northern Great Plains is considered a major factor responsible for low recruitment rates and depressed dabbling duck populations (Sellers 1973, Higgins 1977, Batt 1979). Increased predation of waterfowl nests has been linked with the extensive conversion of native upland to cultivated crops (Johnson and Sargeant 1977). Information about the relationship between intensive agricultural land use and increased predation is required to predict future trends and develop management strategies to maintain prairie duck populations. Intensive manipulation to reduce predation and/or direct management of predators will become increasingly important as managers seek ways to produce more ducks from less habitat. Although the American crow is one of the most important agents of nest loss for upland nesting ducks in the parklands (Smith 1971), little is known about its foraging strategies. Information is needed about how different predators find nests (Keppie and Herzog 1978) and what factors influence a predator's foraging decisions (Orians 1981). Such information is essential for developing sound management practices to improve waterfowl production. Several European studies concluded that corvids found proportionately more prey (eggs in most cases) as prey density increased (Tinbergen et al. 1967, Croze 1970, GSransson et al. 1975, Andersson and Wiklund 1978, Bijlsma 1980, Hill 1984a). A mathematical description of the relationship was provided by Taylor (1976). Studies concerned with the effect of conc alment on predation rates have yielded conflicting results, perhaps because different predators and/or hunting methods were involved (Keith 1961, Dwernychuk and Boag 1972, Jones and Hungerford 1972, Schranck 1972, Byers 1974, Erikstad et al. 1982). Little is known about interactions of nest density, concealment, and predation. In this paper we describe how nest density and concealment affected predation by American crows on simulated duck nests. We thank the student assistants who helped with fieldwork and the farmers who allowed us to work on their land. We are indebted to M. R. McLandress for helpful review of a draft of the manuscript.

The Effects of Weather on Local Wood Duck Production

The U.S. Fish and Wildlife Service annually considers weather to predict waterfowl production, vis-a-vis precipitation and pond counts on the prairies and snow conditions in the Arctic, but the effects of weather on cavity nesting species such as wood ducks (Aix sponsa) is generally overlooked. This paper documents the effects of unusual weather during 1982 on wood duck production in Massachusetts.

Benthic Sampling for Waterfowl Foods in Emergent Vegetation

Foods selected by dabbling ducks (Anatinae) on breeding grounds have recently been investigated to define the ecological and physiological factors that influence waterfowl production (Drobney and Fredrickson 1979, Swanson et al. 1979, Reinecke and Owen 1980). One of the major obstacles encountered in feeding ecology studies of breeding dabbling ducks has been a lack of quantitative sampling gear that will function in the seasonally flooded aquatic habitats attractive to dabbling ducks. Standard grab samplers such as the Ekman, Petersen, and Ponar will not function in highly vegetated substrates, and considerable effort is required to penetrate this type of substrate with a standard core sampler. Sampling benthic organisms in dense stands of emergent vegetation requires specialized equipment capable of rapid and deep penetration of the substrate. Greater penetration is required to compensate for the binding effect of dense root masses and rhizomes that can remove

Radium-226 and Trace Elements in Mottled Ducks

Mottled ducks (Anas fulvigula) were collected in August 1980 to determine radium-226 (226Ra), lead, arsenic, fluoride, and barium concentrations. The mean 226Ra concentration (3.08 pCi/kg) was greater (P 0.05) between areas for concentrations of lead, arsenic, fluoride, and barium in muscle tissues. Radium226 concentrations and physical condition parameters were not correlated (P > 0.05). Concentrations of 22Ra in duck muscle tissues suggest that no appreciable human health hazard exists from eating mottled duck muscle tissues. J. WILDL. MANAGE. 47(2):327-333 The United States produces 39% of the world's phosphate rock in Florida, North Carolina, Tennessee, Idaho, Montana, Utah, and Wyoming (Farmer and Blue 1978:585). Settling basins are used for the storage and settling of phosphatic waste clays resulting from the processing of phosphate ores (Farmer and Blue 1978: 603). These settling basins are attractive to migratory (Montalbano et al. 1978, King et al. 1980) and resident waterfowl in Florida (Montalbano 1980, Wenner and Marion 1981). Several authors (King et al. 1980, Montalbano 1980, Wenner and Marion 1981) have suggested that these areas should be intensively managed as waterfowl production and wintering sites. The Florida Game and Fresh Water Fish Commission operates a public waterfowl hunting area on some northern Florida settling areas and is contemplating management of similar areas in central Florida. The radioactive nuclides 226Ra and uranium-238 (238U) (Roessler et al. 1979) and the toxic (Bowen 1966) trace elements lead, arsenic, barium, and fluoride (V. Katari et al., unpubl. rep., PEDCO Environ. Spec., Inc., Cincinnati, Ohio, 1974; C. W. Hendry, unpubl. rep., Governor's Office, Tallahassee, Fla., 1978) occur in association with waste clays. Because of these materials, the Florida Game and Fresh Water Fish Commission is concerned for the welfare of both the waterfowl populations using these basins and for the human populations that might use contaminated waterfowl for food. In this study, w assessed the public health implications of the consumption by humans of waterfowl exposed to elevated 226Ra and selected toxic trace elements, and determined relationships between 226Ra exposure and physical and reproductive condition of mottled ducks. We gratefully acknowledge the cooperation of International Minerals and Chemical Corporation (IMC), which provided access to the study site, and J. N. Allen, Jr. and B. W. Breedlove for helpful suggestions on study design and methodology. M. Allen, L. Perrin, R. Krause, P. Chapman, G. Holder, and D. David assisted in the collection of specimens. M. Welton prepared specimens for radioactivity analysis and W. M. Hetrick performed the food habits analysis. T. King provided suggestions on statistical interpretation and performed statistical analJ. Wildl. Manage. 47(2):1983 327 This content downloaded from 157.55.39.56 on Tue, 18 Oct 2016 04:35:12 UTC All use subject to http://about.jstor.org/terms 328 Toxic ELEMENTS IN MOTTLED DUCKS * Montalbano et al. yses. C. E. Roessler, J. N. Allen, Jr., and L. A. Mehrhoff reviewed the manuscript.

Waterfowl Production on Three Age-Classes of Stock Ponds in Montana

Waterfowl use and productivity was studied on 27 stock ponds of 3 age-classes (0-5, 6-10, and 11+ years) in north central Montana during 1978-79. Breeding pair use was primarily a function of pond size. Brood use was influenced principally by the availability of food and cover. Brood densities were highest on ponds with emergent vegetation covering >30% of the area, submerged vegetation covering >20% of the area, and with 40% of the area <61 cm deep. Incorporation of these physical features should be considered at the time of pond construction. J. WILDL. MANAGE. 47(1):112-117 With continued wetland drainage in areas such as the prairie pothole region of North America, stock ponds are becoming increasingly important to waterfowl production. Recommendations to enhance waterfowl use of stock ponds have been made (Uhlig 1963, Lokemoen 1973, Gjersing 1975), but little information exists for some geographic areas on the relationship between waterfowl use and stock pond characteristics. The objective of this study was to compare waterfowl use and productivity with physical and vegetational features on 27 stock ponds of 3 ageclasses in Phillips County, Montana during 1978-79. The author acknowledges R. L. Eng for project planning, technical supervision, and critical review of the manuscript; R. D. Crawford for critical review of the manuscript; personnel of the U.S. Bureau of Land Management, Malta, Montana for their cooperation; and F. M. Gjersing and M. G. Miller for advice and field assis-

WETLAND CLASSIFICATION: TOWARDS AN APPROACH FOR SOUTHERN AFRICA

SUMMARY Early wetland classification systems, primarily North American, were strongly orientated towards the need to assess the value of wetlands for waterfowl production. Recently a broader interest in wetlands has led to the development of more comprehensive classification systems designed to form the basis of inventories to assist in the management of wetland resources. To date no comprehensive wetland classification system has been devised for use in southern Africa. The aim of this paper is to review the existing wetland classification systems and to propose a system appropriate for use in this region.

Blood parasites of prairie anatids and their implication in waterfowl management in Alberta and Saskatchewan.

Information on the blood parasites occurring in 3,866 anatids of 14 species collected from five locations in Alberta and Saskatchewan during 1976-80 is summarized. An overall prevalence of 26% with avian hematozoa was recorded. Leucocytozoon simondi was the most frequently encountered parasite, occurring in 17% of the ducks; Haemoproteus nettionis was observed in 11% of the birds while Plasmodium circumflexum and microfilariae (probably of Splendidofilaria fallisensis) occurred in only 2% and less than 1% of the sample respectively. Overall prevalence of infection in both immatures and adults was similar, although the sample was heavily biased in favor of the immature age class. While the overall prevalence of L. simondi was similar in both age classes, H. nettionis occurred twice as frequently in the adult birds. Infection prevalences of birds in the five geographic areas sampled were different and these differences are discussed. Prevalences also differed from year to year in birds from the various areas and these differences are attributed, in part, to the water levels encountered each year. Leucocytozoon simondi is considered a potentially limiting factor for waterfowl production in some areas of northern Alberta and Saskatchewan.

WATERFOWL PRODUCTION AND WATER LEVEL FLUCTUATION

Water level fluctuation is probably the most significant environmental factor influencing waterfowl production. The three basic life processes of waterfowl in Canada, breeding, moulting and staging, are all affected by water level changes in the long and short term. The impact of water level fluctuations on breeding success is the most important way in which waterfowl production is influenced. Habitat suitability for waterfowl tends to reflect long-term water level fluctuations while habitat utilization can be affected in the short term by seasonal and annual changes in water level. The importance of magnitude, direction, rate and timing of water level fluctuations in determining waterfowl breeding success is discussed. Although waterfowl have developed a number of adaptations to cope with water level fluctuations, these responses are normally not completely effective and result in some degree of decreased production. Although having a number of negative impacts on waterfowl production, water level fluctuation is essential for the long-term maintenance of wetland productivity.

MARSH MANAGEMENT STRATEGIES FOR EFFECTIVE WATERFOWL PRODUCTION

Effective marsh management for waterfowl production is directly related to water chemistry, depth and the presence of suitable invertebrate populations and aquatic vegetation necessary for food and cover, particularly in the nesting season. Marsh management must provide an attractive total environment to enhance waterfowl production without being deleterious to other forms of wildlife. Ultimately it is the vegetative patterns and invertebrate blooms that strongly affect waterfowl numbers and species diversity. Through water manipulation, the aquatic plant communities can be changed, thus altering the productivity of the wetland for waterfowl. Effective management strategies must deal directly with habitat, and be aimed at the species which traditionally inhabit the area. Conflicts can occur between management and public use. Caution must be exercised with wetland management to minimize wildlife depredations in surrounding lands and to avoid affecting endangered or threatened wildlife species. If waterfowl...

Changes in Marsh Area Along the Canadian Shore of Lake Ontario

Baseline marsh area is approximated for the Canadian shoreline of Lake Ontario west of the Bay of Quinte using maps dated from 1789 to 1962. The measured difference between that and the area of marsh indicated on topographical maps dated from 1977 to 1979 reveals a net loss of about 4,000 acres or 57% of the baseline area for 38 marshes. Using extrapolation for another 24 marshes, the net loss for 62 marshes is estimated at approximately 4,745 acres or 43% of the baseline area. Losses were particularly high for marshes west of and including Toronto. Estimated net loss was lower in absolute terms, but similar in proportion to that from a previous study which was based on waterfowl production habitat. Relative losses of marsh area along the Canadian shoreline of Lake Ontario are consistently higher than previous estimates for inland wetlands in counties fronting the same shoreline. This and other studies suggest that heavily settled Great Lakes environments have generally lost up to 75% of their baseline wetland area and almost 100% in a few cases. The use of historic maps provides an early baseline estimate of wetland area, in some cases the only estimate possible, but it is less subject to standardization, probably reflects emergent vegetation, and is somewhat cumbersome.

ISSUES, CONFLICTS AND STRATEGIES IN WETLAND MANAGEMENT FOR WATERFOWL

In order to address this topic one must examine both land management and water management. Wetlands are those special places where both of these challenges must be met and resolved. Sometimes conflicts have to be dealt with due to pressure from one management interest, or the other.The degree of conflict among parties interested in a wetland site has been found to vary from highly active to passive. Some of the reasons for conflict are institutional and other reasons are perceptional. It is helpful to look at these causative factors to understand past conflicts and to direct future efforts to minimizing the causes detrimental to conservation.This paper will deal with selected examples, drawn from the Ducks Unlimited experience in Canada. It will describe the issues, conflicts and solutions which arise in wetland management. The examples will demonstrate that successful multiple-benefits can be achieved which meet Ducks Unlimited’s prime objective while also providing for others. The subjects of waterfowl production, wetland wildlife in general, hydrology, water supply, flood protection, drainage, water quality, fish production and agricultural practices will be discussed.Ducks Unlimited Canada has experienced, through its 44 year history, many situations across the country when innovative solutions or stategies have been required to achieve wetlands management favourable to waterfowl as well as other interests. Ducks Unlimited is a private, non-profit, conservation organization dedicated to the perpetuation and increase of North America’s waterfowl resources through restoration, preservation and creation of prime breeding habitat.It remains committed to wetland management favourable to waterfowl and believes that this is demonstrably sound practice in the general sense of land and water management.

Effects of Cattle on Duck Food Plants in Southern Texas

Effects of livestock on waterfowl nesting cover have been studied extensively (Bue et al. 1952, Kirsch 1969, Gjersing 1975, Mundinger 1976). However, the impact of cattle on duck food plants has received less attention. Chabreck (1968) found that light to moderate on a Louisiana marsh increased the growth of Olney bulrush (Scirpus olneyi), an important food plant for wintering ducks and geese, and seashore paspalum (Paspalum vaginatum), a plant of marginal food value for waterfowl. Valentine (unpubl. rep., U.S. Fish and Wildl. Serv., Lafayette, La., 1969) reported that common barnyardgrass (Echinochloa crusgalli) and fall panicum (Panicum dichotomifloran) replaced solid stands of marshhay cordgrass (Spartina patens) after relief from year-long on a Louisiana marsh. Hoffman and Stanley (1978) recommended control of around lake shorelines to allow maximum development of vegetation. We examined the effects of cattle on the foliar cover of duck food plants in a 4-pasture, deferred-rotation system. Deferred-rotation is commonly used to increase the forage production of pastures for livestock (Drawe and Cox 1979). Gjersing (1975) and Mundinger (1976) reported an increase in waterfowl production on small ponds with deferred-rotation grazing, when compared to continuous grazing. Trampling and feeding on shoreline vegetation by ca tl were sometimes indistinguishable, so the term grazing includes both activities.

Response of Blue-Winged Teal to Range Management on Waterfowl Production Areas in Southeastern South Dakota

The blue-winged teal (Anus discors) was the predominant upland-nesting waterfowl species in Waterfowl Production Areas (WPA’s) in southeastern South Dakota. In native plant communities, factors that resulted in high nest density and success were excellent range condition (high proportion of climax vegetational and matted residual vegetation. In tame plant communities, smooth bromegrass (Bromus inermis) cover in which residual vegetation formed a matted mulch had high nest densities and nest success. Many prime wetland areas that have been acquired in the prairie pothole region of the United States by the Fish and Wildlife Service are known as Waterfowl Production Areas and are managed as breeding habitat for waterfowl. Habitat conditions for nesting waterfowl are improved by the maintenance of certain vegetative characteristics of native and tame plant communities and by controlling the state of plant succession. Conflicting opinions on proper management of grassland nesting cover for individual waterfowl species probably results from differences in habitats at different geographical locations and the proportion of different duck species on a study site. Nesting habitat in Iowa that had Kentucky bluegrass (Poa praterzsis) as the dominant cover type and that was grazed lightly to moderately was more productive of blue-winged teal than was ungrazed habitat. Overgrazing was detrimental to teal production (Bennett 1938; Glover 1956; Burgess et al. 1965). Where the surface-feeding duck population included nearly equal proportions of mallards, gadwalls, pintails, and bluewinged teal in North Dakota, overall duck production was reduced considerably by grazing (Kirsh 1969). The potential production of upland nesting waterfowl will increase as our understanding of the relationships between plant and animal communities increases. Our study was designed to determine plant community types and vegetational characteristics present on the WPA’s that provide habitat for upland-nesting waterfowl. Field work was conducted in spring and summer of 1974, while the senior author was a student employee at the Lake Andes National Wildlife Refuge, Lake Andes, South Dakota.

Waterfowl Use of Uinta Mountain Wetlands in Utah

Waterfowl use was recorded in 1965 and 1966 at different elevations of the Uinta Mountains, Utah, from spring thaw until fall freeze-up. Sixteen species were observed; mallard (Anas platyrhynchos), green-winged teal (A. crecca), pintail (A. acuta), and ring-necked duck (Aythya collaris) were the most abundant. Ninety-eight percent of the observed waterfowl were below 3,000 m. Waterfowl numbers were highest during migratory periods and lowest in the breeding season. Adult waterfowl were seen most often on natural catchment basins and beaver (Castor canadensis) ponds larger than 0.4 ha. Low-elevation wetlands ( 2,900 m) had little waterfowl food. Utilization of high mountain wetlands by spring migrants and breeders was dependent upon ice melt, whereas freeze-up did not seriously affect fall use. J. WILDL. MANAGE. 41(1):172-117 Few intensive studies are available on the ecology of waterfowl in mountainous areas, and early mountain explorers wrote only brief notes on waterfowl observations at high elevations. Frary (1954) conducted a waterfowl production study on the White River Plateau in Colorado, and Rutherford and Hays (Unpublished data) investigated waterfowl breeding in the mountains surrounding the San Luis Valley, Colorado. Mallard, green-winged teal, and shoveler (Anas clypeata) were noted by Pattie and Verbeek (1966) on Beartooth Plateau, Montana. Several studies on waterfowl use and productivity of wetlands below 1,800 m have been conducted in Utah, but none has been made on the extent to which waterfowl use high mountain wetlands in Utah, nor on the contribution they made to the waterfowl resources of that state. Objectives of this study were to investigate species composition and seasonal changes in abundance of waterfowl in a high mountain area; define the types, distribution, and use of different wetlands; and estimate waterfowl production in a high mountain habitat. We thank the personnel of the Utah State Division of Wildlife Resources and the U.S. Fish and Wildlife Service for their financial support of this study, the U.S. Forest Service and Soil Conservation Service personnel for their valuable assistance, and the many recreationists who reported waterfowl observations.

Effects of Early Water Application on Waterfowl Production

Records of nests and broods on the Monte Vista National Wildlife Refuge, Colorado, suggested that waterfowl production was high in years when water was available prior to spring migration. If sufficient water was not available until after spring migration, low production could be expected. To test this hypothesis, we divided a 241-ha habitat unit on the Refuge into 2 plots; the experimental plot was flood-irrigated 2 weeks before the peak of spring waterfowl migration and the control plot was flood-irrigated 2 weeks after the peak of migration. This treatment was applied alternately to the plots during two 3-year periods and one 2-year period. Numbers of nests and production of mallards (Anas platyrhynchos), pintails (A. acuta), shovelers (A. clypeata), teals (A. discors, A. crecca, and A. cyanoptera), and gadwalls (A. strepera) were significantly greater (P < 0.05) on one plot when early water was applied. The inability to draw down water levels sufficiently on the other plot was believed to be the reason duck production was not significantly greater on both plots during years of early water application. Economic and management implications are presented. J. WILDL. MANAGE. 40(2):227-232 Nesting and brood observations on the Monte Vista National Wildlife Refuge in southwestern Colorado from 1953 through 1964 suggested that waterfowl production was higher when water was abundant prior to spring migration, or lower if water was not available in sufficient amounts until after migration. An 8-year study was initiated in 1965 to determine if early water application would (1) increase waterfowl production and (2) be economically feasible as a management practice. We are grateful to C. R. Bryant, Manager of the Monte Vista National Wildlife Refuge, and his staff, who were extremely helpl during the investigation. C. R. Bryant and R. M. Ballou, former Refuge biologist, conceived the basic study. Special thanks are g ven M. G. Sheldon and R. A. Ryder fo their assistance and suggestions. Assistance in many facets of the study was given by personnel of the U.S. Fish and Wildlife S vice, Colorado State University, and the Co orado Division of Wildlife. The study was financed by the Division of Wildlife Refuges, U.S. Fish and Wildlife Service, th ough the Colorado Cooperative Wildlife Research Unit.

Waterfowl Response to Rest-Rotation Grazing

Waterfowl production on the stock-water reservoirs in the Milk River Association Allotment, Phillips County, Montana, was studied during 1973 and 1974 to evaluate the influence of rest-rotation grazing management. The breeding pair population increased by 42 percent, from 190 to 270 pairs, and brood production increased by 50 percent, from 127 to 191, during the study. Breeding pairs, broods, and species diversity increased on the allotment since 1970. Changes in the distribution of breeding pairs and broods suggested a positive response by waterfowl to the previous year's rest treatment, and a negative response to heavy grazing pressure during the late summer and fall of the previous year. Waterfowl responded positively to rest and deferred treatments, and negatively to spring grazing during the current season. Shoreline and upland transects established during 1974 indicated that new vegetation accumulated most rapidly in those pastures deferred from early season grazing. The greatest accumulation of residual vegetation occurred in the pasture rested and the pasture grazed only during the spring. Regrowth, following relief from grazing, contributed to the accumulation of residual vegetation. J. WILDL. MANAGE. 40(1):60-68 The construction of stock-water reservoirs has provided waterfowl breeding habitat in regions where such habitat was sparse or absent (Bue et al. 1952, Smith 1953, Uhlig 1963). The importance of these reservoirs in the annual production of waterfowl results from the comparative stability of water levels between years (Bue et al. 1964), the relatively high rate of reproductive success associated with low population densities (Smith 1953, Rundquist 1973: 62), and the large area involved (Smith 1953). A potential conflict between waterfowl and grazing animals exists on these reservoirs. Bue et al. (1952) demonstrated that grazing by cattle reduced the nesting cover rating of the upland vegetation around stock ponds. Furthermore, the quality of the shoreline cover decreased with increased grazing intensity, resulting in a reduction in use by breeding pairs and broods. Kirsch (1969) found higher nest densities and nesting success on ungrazed than on grazed plots. Rest-rotation (Hormay and Talbot 1961) is a grazing system which employs periodic rest to achieve an improved range condition. A grazing formula may be designed for maximum livestock production, but it also may consider other land uses. Gjersing (1975) demonstrated higher reproductive success and increases in waterfowl production on two allotments managed with restrotation, as compared to control units with continuous grazing. This study was a further evaluation of waterfowl response to rest-rotation management and emphasized responses to the individual treatments of the grazing formula. Field data were collected during the summer of 1973 and the spring and summer of 1974. The author gratefully acknowledges R. L. Eng for project planning, field assistance, and advice during preparation of the manuscript; D. C. Quimby and W. R. Gould for critical review of the manuscript; and F. M. Gjersing and J. D. Jones for project planning and field assistance.