Status of American woodcock in Nebraska with notes on a recent breeding record
Abstract has not been submitted
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Abstract has not been submitted
Abstract has not been submitted
Abstract has not been submitted
Stomach contents of 70 red foxes (Vulpes vulpes) shot in east-central North Dakota during January 1982 and January 1983 were examined. Commercial sunflower seeds were the most frequently found food item, occurring each year in three-fourths of the stomachs and composing about half of the contents. The remainder of the diet was primarily mammals, but included birds, insects, amphibians, and refuse.
We summarized biological and ecologic characteristics of 2490 nests of 16 species of upland-nesting, non-passerine birds of northern grasslands found during 1963 through 1991. Nest initiation and hatch dates, clutch sizes, nest fates, causes of failure, success rates of nests among major habitat types and land uses, and vegetation measurements at nest sites are analyzed.
We recorded flowering events for 97 species of prairie plants for 2-6 years near Woodworth, ND. Earliest and latest flower initiation dates varied by year. Temperature seemed much more important than precipitation in influencing phenology of species that bloom from late March through May, but no strong climatic effect was evident for plants that bloom later in the growing season.
We monitored individual radio-equipped Canada geese (Branta canadensis) associated with a federal refuge to assess flight activities from late fall through spring. The number of flights per day was lowest in late fall when most geese remained within the refuge and highest in spring when they moved increasingly beyond the refuge area. The only significant seasonal difference in flight time occurred between late fall and late winter 1986. Over all seasons, diurnal flight time averaged 9.4 i?? 2.4 min (SE) and ranged from 0 to 33 min. Geese spent more time flying in afternoon periods during late winter 1986 and early winter 1987. Because of low goose populations on the refuge and abundant food resources in 1986-87, flight activity was probably lower than in most other years. Conservative estimates of average daily energy expenditures for flight ranged from 65 kJ/day in late fall to 200 kJ/day in early winter and were as high as 450 kJ/day. Additional energy costs for flight, when expressed as a percentage of daily energy expenditures, increased from fall (3%) to spring (10%). Highest estimates total daily energy costs (2987 kJ/day, equivalent to 178 g corn) appear to be within reasonable estimates of daily energy consumption. During periods of severe cold or limited food availability, however, additional energy demands for flight (e.g., due to disturbances or long foraging flights) may become important in the daily energy balance of individuals.
We examined diets of canvasbacks (Aythya valisineria) breeding in southwestern Manitoba during 1977-81. Percent volume of animal foods consumed did not differ between males and females nor among prenesting, rapid follicle growth, laying, incubation, and renesting periods in females (mean = 50.1%). Tubers and shoots of fennelleaf pondweed (Potamogeton pectinatus) and midge larvae (Chironomidae) were the predominant foods, comprising on average 45% and 23% of the diet volume, respectively. Continued importance of plant foods to canvasbacks throughout reproduction contrasts with the mostly invertebrate diets of other prairie-breeding ducks, and does not fit current theories of nutritional ecology of breeding anatids (i.e., females meet the protein requirements of reproduction by consuming a high proportion of animal foods).
Habitat use and survival by nine mallard (Anas platyrhynchos) broods from nests on the James River floodplain and adjacent drift plain were monitored during summer 1987. Radio-marked broods were relocated an average of 22% of the time in the river channel, 22% in oxbow ponds, 43% in a large sewage lagoon complex, and 13% in basin wetlands. Four of the six broods hatched on the floodplain stayed primarily in riverine wetlands throughout the brood-rearing period. Seven of nine broods fledged at least one young; a total of 27 ducklings survived to fledging of the 82 that hatched. The seven hens that fledged young used an average of two wetlands each from hatching to fledging. Mink and raptor predation and adverse weather conditions were the principal identified causes of mortality. Potential effects on waterfowl production of planned downstream irrigation, a part of the Reformulated Garrison Diversion Unit, are discussed and recommendations are made to reduce adverse impacts to wildlife.
Canvasback (Aythya valisineria) broods (n = 69) accompanying marked females were observed during five summers in southwestern Manitoba. We evaluated movements of broods of different age classes ( 14 days old, 15-28 days old, and >28 days old) among ponds of different size and wetland class. Of 202 brood sightings, 7% occurred on seasonal ponds, 81% on semipermanent ponds, and 12% on permanent ponds. Pond size ( 0.2 ha vs. >0.2 ha) was a significant factor in brood use whereas wetland class was not. Canvasback broods used larger ponds as brood age class increased. Broods moved an average of 195 m between sightings. Eighty-three percent of broods observed within seven days of hatching (n = 46) had moved from the nesting pond. No significant differences in frequency or distance of movements were detected among years or among brood age classes. Extensive movements among ponds of various sizes and classes emphasize the importance of wetland complexes for providing diverse habitats needed for nesting and brood-rearing canvasbacks.
Populations and distribution of breeding birds occupying wooded draws were studied in a five-county region of western North Dakota during June 1982. Wooded draw vegetation was dominated by green ash, which occurred in 96% of the draws sampled. Chokecherry and juneberry were the most frequent shrub species. I recorded 49 bird species in the 30 draws censused. Rufous-sided towhee, brown-headed cowbird, house wren, and American goldfinch were the most numerous bird species present. Significant correlations were found between (1) the number of live trees and bird species evenness, (2) density of dead trees and bird species diversity and richness, (3) density of shrubs with bird species evenness, and (4) foliage volume in the high ground layer and bird species evenness.
Abstract has not been submitted
Abstract has not been submitted