- EXCLUSIVE DEALING CLAUSES FACILITATE ENTRY

Firms willing to enter a market with a new product often face the problem that the market does notknow its quality. Selling through a retailer might avoid excessive entry costs by renting thereputation of an incumbent. The incumbent can apply excusive dealing clauses to his retailer. Weshow that the incumbent enforces the clause only againts low quality entrants and that exlusivedealing clauses lead to a more fragmented industry and improve welfare. However, if theincumbent can undertake e.g. brand differentiating investments at the retailer (which are welfareenhancing under perfect information), the overall effect of exlusive dealing clauses may be welfarereducing under asymmetric information.Retailing, vertical restraints, market entry

Grassland Bird Monitoring at Agate Fossil Beds National Monument, Nebraska: 2001-2006 Status Report

Between 2001 and 2006, 54 plots (14 riparian, 40 prairie) were visited during annual surveys to characterize the breeding bird population at Agate Fossil Beds National Monument. Thirty-nine species occurred in riparian habitat, 43 in prairie habitat. Accounting for species overlap between habitats, 60 different species occurred on the monument. Only nine species breed on the monument annually, however: Common Yellowthroat, Mourning Dove, Marsh Wren, Common Snipe, and Mallard in the riparian zone; Grasshopper Sparrow and Lark Sparrow in the prairie; and Red-winged Blackbird and Western Meadowlark in both habitats. Seven grassland obligates were observed: Dickcissel, Grasshopper Sparrow, Horned Lark, Northern Harrier, Upland Sandpiper, Vesper Sparrow and Western Meadowlark. Partners in Flight, a consortium of bird conservation agencies and interested individuals, lists seven of the species observed as “species of continental importance”: Brown Thrasher, Dickcissel, Grasshopper Sparrow, Lark Bunting, Sharp-tailed Grouse, Swainson’s Hawk, and White-crowned Sparrow. Four of these species (Grasshopper Sparrow, Lark Bunting, Sharp-tailed Grouse, and Swainson’s Hawk), along with Upland Sandpiper, are species of conservation importance for the shortgrass prairie ecotype. The most commonly recorded species on the Monument across habitats was the Redwinged Blackbird. Management decisions aimed at influencing bird populations should center on those species identified as being of local or continental importance. Yet even species common at the site, such as the Red-winged Blackbird, face regional population declines

Grassland Bird Monitoring at Agate Fossil Beds National Monument, Nebraska and Tallgrass Prairie National Preserve, Kansas

During the breeding seasons of 2001 through 2003, a total of 517 variable circular plots were surveyed for birds and assessed for habitat composition at Agate Fossil Beds National Monument, Nebraska and Tallgrass Prairie National Preserve, Kansas. Systematic 400 x 400 meter grids, originating from random start points, were used to locate 40 permanent variable circular plots in upland habitat at Agate Fossil Beds National Monument and 242 at Tallgrass Prairie National Preserve. An additional 14 permanent plots were established in the less common but important riparian habitat at Agate Fossil Beds National Monument, and 18 plots were added in riparian areas at Tall grass Prairie National Preserve. Variable circular plots in riparian habitat were spaced at 250 meter intervals throughout each area

With a Little Help from my Enemy: Comparative Advertising

Comparative advertising content differs from generic. We discover that dissipative advertising has consequences depending upon content and cost. Comparison advertising may trigger legal action by rival firms that are named. In the model an entrant signals its product quality. By a comparative ad the entrant refers to the incumbent’s product. We show that comparison can enhance the signaling potential of dissipative advertising. From the viewpoint of the entrant, the choice of comparative advertising empowers the rival with the right to sue; generic does not. Consumers therefore infer that if the entrant uses comparative instead of generic ads it has a strong case

Effects of Retained Pine and Hardwood Basal Areas on Percent Cover of Plants Utilized by Bobwhite Quail

Percent cover of seven forage species utilized by bobwhite quail (Colinus virginianus) was determined before thinning and 2 and 4 years after thinning a 35-year-old loblolly pine-hardwood stand. Combinations of three loblolly pine (15, 18, and 21 m2/ha) and three hardwood (0, 3.5, and 7 m2/ha) basal areas were replicated three times. Percent cover was determined for American beautyberry (Callicarpa americana), blackberry (Rubus spp.), tick trefoil (Desmodium spp.), lespedeza (Lespedeza spp.), panic grass (Panicum spp.), yellow wood sorrel (Oxalis stricta), and three-seeded mercury (Acalypha spp.). Percent cover of American beautyberry and blackberry increased with time. Tick trefoil and panic grass were negatively related to time after thinning. However, lespedeza, yellow wood sorrel, and three-seeded mercury were not influenced significantly by time after thinning. Blackberry and panic grass were negatively related to pine basal area, while all other plant species were not affected. Three-seeded mercury was the only species not negatively related to hardwood basal area. Canopy cover and relative light intensity in the understory demonstrated an inverse relationship

Essential Amino Acid Nutritional Ecology of Cottontail Rabbits (Sylvilagus Floridanus)

Wildlife and Fisheries Ecolog

Bird Monitoring at Homestead National Monument of America, Nebraska, Status Report 2009–2017

Executive Summary In 2009, the Heartland Inventory Monitoring Network initiated breeding bird surveys on Homestead National Monument of America, Nebraska, to address two objectives: (1) to monitor changes in bird community composition and abundance, and (2) to improve our understanding of relationships between breeding birds and habitat, and the effects of management actions on those relationships. This report evaluates trends in the park’s breeding bird populations in the context of trends observed within the North American Bird Conservation Initiative’s (NABCI) Central Mixed Grass Prairie Bird Conservation Region, the region in which the park is located. By doing so, we can assess the influence of park habitat management on bird populations with an understanding of regional population trends that are outside the influence of natural resource management activities at the Homestead national Monument of America. Eighty-six species of birds were recorded during May and June site visits in the nine years since initiating monitoring. Seventy-four of the species are considered breeding species because they are permanent or summer residents. Two of the breeding species recorded on Homestead National Monument of America are species of concern for the Central Mixed Grass Prairie Bird Conservation Region. Thirteen species were observed during the survey period in sufficient numbers to calculate annual abundances and trends with some degree of confidence. The American Goldfinch (Spinus tristis), Dickcissel (Spiza americana), House Wren (Troglodytes aedon), and Red-winged Blackbird (Agelaius phoeniceus) were the most abundant and widespread species on Homestead National Monument of America. Comparing population trends of the thirteen most recorded species on the park with regional trends for the Central Mixed Grass Prairie Bird Conservation Region were inconclusive, but suggest that trends in populations on the park were similar to trends in populations found region-wide for most species present. However, some differences in population trends were observed between the park and the region. This report provides current regional and local trends for breeding birds for future comparisons with bird data collected as part of the long-term monitoring efforts at Homestead National Monument of America. This information will help park staff plan management objectives, and assess the effectiveness of management alternatives. These monitoring data also provide park staff with additional information for interpreting natural resources

AQUATIC INVERTEBRATE COMMUNITY STRUCTURE IN THE NIOBRARA RIVER, AGATE FOSSIL BEDS NATIONAL MONUMENT, NEBRASKA, 1996-2009

Aquatic invertebrates were sampled annually in the Niobrara River, Nebraska, during the period 1996-2009 using Hester-Dendy multiplate samplers. Collections indicated the invertebrate community in the river has shifted from one dominated by Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa to one dominated by Chironomidae and Amphipoda. Generally, EPT richness and percentage abundance of EPT of the total community, as well as percentage abundance of Heptageniidae and Leptophlebiidae, has declined across the years. During that same period, percentage abundance of Amphipoda and Chironomidae, taxa evenness, Shannon\u27s Index, and the Hilsenhoff Biotic Index have increased. Stream discharge decreased significantly during the 15-year period when invertebrates were collected (Mann-Kendall trend test, P = 0.04). Water-surface elevation of the river measured with staff gages also gradually increased over time, although the trends were not significant (P \u3e/= 0.15). Although not analyzed statistically, water temperature (Degrees C), conductivity (uS/cm), and pH gradually increased over time while dissolved oxygen concentration (mg/liter) decreased over time. Although other factors cannot be ruled out, a proposed reason for the observed changes in invertebrate community structure may be related to changes in the physical habitat condition in the Niobrara River associated with encroachment of the nonnative and invasive emergent aquatic plant, yellow flag (Iris pseudacorus L.). This weed has expanded into the stream channel, where it blocks streamflow

Bird Monitoring at Herbert Hoover National Historic Site, Iowa, Status Report 2005–2017

Executive Summary In 2005, the Heartland Inventory & Monitoring Network initiated breeding bird surveys on Herbert Hoover National Historic Site, Iowa, to address two objectives: (1) to monitor changes in bird community composition and abundance, and (2) to improve our understanding of relationships between breeding birds and habitat, and the effects of management actions on those relationships. This report evaluates trends in the park’s breeding bird populations in the context of trends observed within the North American Bird Conservation Initiative’s (NABCI) Eastern Tallgrass Prairie Bird Conservation Region , the region in which the park is located. By doing so, we can assess the influence of park habitat management on bird populations with an understanding of regional population trends that are outside the influence of natural resource management activities at Herbert Hoover National Historic Site. Sixty-eight species of birds were recorded during May and June site visits in the twelve years since initiating monitoring. Sixty-seven of the species are considered breeding species because they are permanent or summer residents. Seven of the breeding species recorded on Herbert Hoover National Historic Site are species of concern for the Eastern Tallgrass Prairie Bird Conservation Region. Eight species were observed during the survey period in sufficient numbers to calculate annual abundances and trends with some degree of confidence. The American Robin (Turdus migratorius) and Red-winged Blackbird (Agelaius phoeniceus) were the most abundant and widespread species on Herbert Hoover National Historic Site. Comparing population trends on the park with regional trends suggest that populations of the most common species on the park were similar to those of the region, especially for American Goldfinch (Spinus tristis), Common Grackle (Quiscalus quiscula), Common Yellowthroat (Geothlypis trichas), Dickcissel (Spiza americana), and Mourning Dove (Zenaida macroura). The population of Eastern Meadowlark (Sturnella magna) on the park was doing slightly better than the population region-wide. One of the species that was common and widespread on the park, American Robin, had an uncertain park population trend, but a region-wide trend that was increasing. The other common and widespread species, Red-winged Blackbird, had a population trend that was declining both on the park and across the region. This report provides current regional and local trends for breeding birds for future comparisons with bird data collected as part of the long-term monitoring efforts at Herbert Hoover National Historic Site. This information will help park staff plan management objectives and assess the effectiveness of management alternatives. These monitoring data also provide park staff with additional information for interpreting natural resources