WILDLIFE DAMAGE TO CROPS: PERCEPTIONS OF AGRICULTURAL AND WILDLIFE PROFESSIONALS IN 1957 AND 1987

We surveyed state wildlife agencies, state agricultural departments, Wildlife Extension Specialists, U.S.D.A. Animal Damage Control agents, and state Farm Bureau officials to develop a national perspective of wildlife damage to agricultural crops in the U.S. A broad concensus existed that wildlife damage was a major problem, although groups often differed in their perceptions of the seriousness of specific problems. The complexity of the wildlife damage problem was apparent in that 27 different wildlife species were cited as causing the greatest problem to a state\u27s farmers. Nevertheless, 38-80% of the respondents from every group surveyed stated that deer were their worst problem. Most respondents believed that wildlife damage had increased in the last 30 years. Increasing levels of wildlife damage also were apparent when we compared our findings to those of a similar survey conducted in 1957 (McDowell and Pillsbury 1958). For instance in 1957, 16 states reported that deer were either no problem or only caused localized problems, while in our survey, 15 of these 16 states stated that deer were now causing more damage to crops than any other wildlife species

Nutrient Recycling by Eared Grebes in the Great Salt Lake

Nitrogen (N) and phosphorus (P) cycling in lakes can be impacted by numerous abiotic and biotic factors. Large animals, such as birds and mammals, may recycle nutrients within a system or bring them in from surrounding habitats or different landscapes. Eared Grebes (Podiceps nigricollis) congregate in large numbers in the fall on the Great Salt Lake (GSL), Utah, and may have an important role in recycling nutrients from macroinvertebrates back into the water column. We evaluated the role of Eared Grebes in N and P cycling within the GSL by estimating the magnitude of their nutrient recycling capacity. We estimated Eared Grebe population size on the GSL over 5 years at 300,000 to over 4,300,000 birds. We used a previously published food intake model to estimate monthly recycling of N (5 to 300 tonnes) and P (0.4 to 25 tonnes). The maximum estimates of N and P loading by Eared Grebes are about 25% of nutrient recycling in the GSL caused by turnover in the water column. Eared Grebes may speed up nutrient recycling, making nutrients available to primary producers sooner. The contribution of waterbirds to nutrient cycling is important for the entire N and P cycles within the GSL

Predators, Predator Removal, and Sage-Grouse: A Review

Populations of sage-grouse (Centrocercus urophasianus; i.e., sage-grouse) have been in a decline since the nineteenth century. We used our research, unpublished reports, and scientific literature to identify which predators kill greater sage-grouse and to assess whether lethal control of these predators benefited the species. We also asked state wildlife biologists and scientists if they had ever witnessed a predator kill sage-grouse. We identified 266 instances where the predator responsible for depredating nests or killing juvenile or adult sage-grouse could be ascertained. Most adult sage-grouse were killed by eagles (Accipitridae), owls (Strigiformes), or coyotes (Canis latrans), except where red foxes (Vuples vulpes) were abundant. Based on nest-cameras, most depredated eggs are taken by common ravens (Corvus corax), badgers (Taxidae taxus), or coyotes. There are too few studies to conclude that predator removal increases survival rates of juvenile or adult sage-grouse. No study has been conducted to determine if badger removal increases nest success of sage-grouse, and the only study on coyote removal produced ambiguous results. Several studies reported that more sage-grouse nests are successful (i.e., ≥1 eggs hatched) in areas where common ravens were removed or in areas where raven densities were lower than in other areas. Populations of sage-grouse have been in a decline for over a century, and predators are unlikely to have played a role in the decline during most of this period, but increasing numbers of ravens since the 1970s may have contributed to the declining sage-grouse populations in recent decades

Factors Influencing Reproductive Success of Ferruginous Hawks in the Uintah Basin, Utah

We examined factors that potentially influenced reproductive success in Ferruginous Hawks (Buteo regalis) in the Uintah Basin, Utah, and determined whether oil and gas well development was one of those factors. For three breeding seasons (2002–2004), we measured the number of nestlings, fledglings, and dispersed young that were produced by pairs of Ferruginous Hawks nesting within 2365 km2 managed by the Bureau of Land Management. We hypothesized that reproductive success would be influenced by nesting substrate, abundance of prey, distance to the closest occupied raptor nest, and distance to the closest active well. Although the Uintah Basin experienced a drought during our entire study, reproductive success was within the range of estimates reported in other studies in the Intermountain West. Each nesting pair produced an average of 1.9 nestlings, 1.3 fledglings, and 0.9 dispersed young. During our study, 17 nestlings and 14 fledglings died; 55% were due to avian predators, 16% to mammalian predators, 10% to unknown predators, 16% to natural causes, and 3% to unknown causes. Avian depredation may have resulted from increased competition among avian predators for scarce prey resources, or from increased use of juvenile Ferruginous Hawks as an alternative prey source by Golden Eagles (Aquila chrysaetos) in years of low lagomorph abundance. Our results suggest that the level of oil development that occurred during this study did not have an adverse effect on Ferruginous Hawk reproduction; the effect of a higher level of oil development was beyond the scope of this study

Using wedelia as ground cover on tropical airports to reduce bird activity

aircraft collisions (i.e., bird strikes) are a major problem at airports worldwide, often because birds are attracted to airfields to feed on seeds, insects, or rodents that abound in the grassy areas near runways and taxiways. We compared an alternative ground cover, wedelia (Wedelia trilobata), to existing vegetation (control plots) on the airfield at Lihue Airport, Kauai, Hawaii, to determine if bird populations on the airport could be reduced by eliminating their forage base. We studied wedalia because it is a low-growing plant that did not need mowing, was easily established in plots, and out-competed other plants, resulting in a significant decrease in plant diversity. Thus, wedelia indirectly results in a decreased seed base for granivorous birds. Total invertebrate biomass was 41% lower in wedelia plots than in other vegetation plots (control plots). Rodent populations were 67% lower in wedelia than in control plots. Zebra doves (Geopelia striata), spotted doves (Streptopelia chinensis), and mannikins (Lonchura spp.) used wedelia plots significantly less than control plots, whereas, the lesser Pacific golden-plover (Pluvialis fulva) was unaffected. By reducing seed production, insect densities, and rodant populations, wedalia should be a useful ground cover on tropical airports to reduce bird use and, ultimately, bird strikes on the airport

WEDELIA: A POTENTIAL GROUND COVER FOR REDUCING THE ATTRACTIVENESS OF TROPICAL AIRFIELDS TO BIRDS

Airport environments frequently provide ideal feeding and loafing habitats for many bird species. Bird strikes at most airports involve predominantly insectivorous species. However, the Lihue Airport on the island of Kauai, Hawaii has had a severe problem with bird strikes involving 4 granivorous species: the zebra dove (Geopelia striata), spotted dove (Streptopelia chinensis), chestnut mannikin (Lonchura malacca), and nutmeg mannikin (L. punctulato). Two owl species, the common barn owl (Tyto alba) and Hawaiian short-eared owl (Asio flammeus sandwhichensis), have also been involved in aircraft collisions at Lihue. Shooting and hazing techniques to disperse birds have proven ineffective or unacceptable; therefore, an alternative ground cover, wedelia (Wedelia trilobata), was tested to determine if the airfield environment could be rendered unattractive to birds. Volunteer stands of wedelia throughout the airfield were delineated and additional plantings established. We used bird activity, exclusion of seed-producing plants, rodent abundance, and invertebrate populations as indicators of effectiveness. Utilization of test plots by rodents and the four major seed-eating birds was significantly lower than in the corresponding control plots. The nearly monotypic stands of wedelia resulted in decreased seed availability to birds and rodents. Because of the ease of establishing and maintaining wedelia on airfields, its dominance over palatable seed producing plants, exclusion of rodent populations, low fire hazard, and decreased utilization by critical bird species, wedelia shows great promise as an alternative ground cover in tropical airfield environments

Progress Report: Effects of Condensed Corn Distillers Solubles on Steer Performance and Carcass Composition

Condensed, corn, distillers solubles provides an effective energy supplement for finishing cattle across a number of finishing systems

Progress Report: Pasture Finishing of Beef Steers Using Contemporary Feedlot Protocols

Environmental regulations in Iowa can place animal population restrictions on a given site. This study explores the possibility of finishing cattle in a remote pasture location to handle an overflow of animals and yet remain in compliance with environmental mandates

High connectivity among locally adapted populations of a marine fish (Menidia menidia)

Author Posting. © Ecological Society of America, 2010. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 91 (2010): 3526–3537, doi:10.1890/09-0548.1.Patterns of connectivity are important in understanding the geographic scale of local adaptation in marine populations. While natural selection can lead to local adaptation, high connectivity can diminish the potential for such adaptation to occur. Connectivity, defined as the exchange of individuals among subpopulations, is presumed to be significant in most marine species due to life histories that include widely dispersive stages. However, evidence of local adaptation in marine species, such the Atlantic silverside, Menidia menidia, raises questions concerning the degree of connectivity. We examined geochemical signatures in the otoliths, or ear bones, of adult Atlantic silversides collected in 11 locations along the northeastern coast of the United States from New Jersey to Maine in 2004 and eight locations in 2005 using laser ablation inductively coupled plasma mass spectrometry (ICP-MS) and isotope ratio monitoring mass spectrometry (irm-MS). These signatures were then compared to baseline signatures of juvenile fish of known origin to determine natal origin of these adult fish. We then estimated migration distances and the degree of mixing from these data. In both years, fish generally had the highest probability of originating from the same location in which they were captured (0.01–0.80), but evidence of mixing throughout the sample area was present. Furthermore, adult M. menidia exhibit highly dispersive behavior with some fish migrating over 700 km. The probability of adult fish returning to natal areas differed between years, with the probability being, on average, 0.2 higher in the second year. These findings demonstrate that marine species with largely open populations are capable of local adaptation despite apparently high gene flow.This work was funded by the National Science Foundation (grant OCE-0425830 to D. O. Conover and grant OCE- 0134998 to S. R. Thorrold) and the New York State Department of Environmental Conservation