Tuning the Diversity of Open-Ended Responses from the Crowd

Crowdsourcing can solve problems that current fully automated systems cannot. Its effectiveness depends on the reliability, accuracy, and speed of the crowd workers that drive it. These objectives are frequently at odds with one another. For instance, how much time should workers be given to discover and propose new solutions versus deliberate over those currently proposed? How do we determine if discovering a new answer is appropriate at all? And how do we manage workers who lack the expertise or attention needed to provide useful input to a given task? We present a mechanism that uses distinct payoffs for three possible worker actions---propose,vote, or abstain---to provide workers with the necessary incentives to guarantee an effective (or even optimal) balance between searching for new answers, assessing those currently available, and, when they have insufficient expertise or insight for the task at hand, abstaining. We provide a novel game theoretic analysis for this mechanism and test it experimentally on an image---labeling problem and show that it allows a system to reliably control the balance betweendiscovering new answers and converging to existing ones

TRACING THE HISTORY OF BLACKBIRD RESEARCH THROUGH AN INDUSTRY\u27S LOOKING GLASS: THE SUNFLOWER MAGAZINE

The Sunflower magazine, the voice of the National Sunflower Organization, featured articles in January 1978 and December 1996 that began with these words, If Old King Cole was a merry old soul, it was probably because he had only four and twenty blackbirds to contend with, and they were all out of commission! This quotation captures the sentiments of sunflower growers, who have identified blackbirds as a major production problem since the 1960s. The National (formerly Denver) Wildlife Research Center, a unit within the U.S. Department of Agriculture\u27s Animal and Plant Health Inspection Service Wildlife Services, is charged with both improving and developing new methods for managing blackbird damage to sunflower. The Sunflower has chronicled these research efforts championing studies with clear objectives and opposing studies, sometimes vehemently, that use resources for seemingly esoteric research. In this paper, the history of blackbird research in the northern Great Plains is traced through The Sunflower

Movement Behavior of Radio-Tagged European Starlings in Urban, Rural, and Exurban Landscapes

Since their intentional introduction into the United States in the 1800s, European starlings (Sturnus vulgaris) have become the fourth most common bird species and a nuisance bird pest in both urban and rural areas. Managers require better information about starling movement and habit-use patterns to effectively manage starling populations and the damage they cause. Thus, we revisited 6 radio-telemetry studies conducted during fall or winter between 2005 and 2010 to compare starling movements (n = 63 birds) and habitat use in 3 landscapes. Switching of roosting and foraging sites in habitat-sparse rural landscapes caused daytime (0900–1500 hours) radio fixes to be on average 2.6 to 6.3 times further from capture sites than either urban or exurban landscapes (P \u3c 0.001). Roosts in urban city centers were smaller (100,000 birds) 6–13 km away in industrial zones. Radio-tagged birds from city-center roosts occasionally switched to the outlying major roosts. A multitrack railroad overpass and a treed buffer zone were used as major roosts in urban landscapes. Birds traveling to roosts from primary foraging sites in exurban and rural landscapes would often pass over closer-lying minor roosts to reach major roosts in stands of emergent vegetation in large wetlands. Daytime minimum convex polygons ranged from 101–229 km2 (x̄ = 154 km2). Anthropogenic food resources (e.g., concentrated animal feeding operations, shipping yards, landfills, and abattoirs) were primary foraging sites. Wildlife resource managers can use this information to predict potential roosting and foraging sites and average areas to monitor when implementing programs in different landscapes. In addition to tracking roosting flights, we recommend viewing high-resolution aerial images to identify potential roosting and foraging habitats before implementing lethal culls (e.g., toxicant baiting)

Aerial Mass Color - Marking of Blackbird Roosts

We use mass color-marhng to track the local and regional movements of large roosts of blackbirds (Icteridae). Several marhngs have been done by National Wildlife Research Center scientists, including marhng of spring roosts in northeastern Missouri and eastern South Dakota (Knittle et al. 1987, Knittle et al. 1996, Homan et al. 2004), fall roosts in central North Dakota (Linz et al. 1991, Homan et al. 2005), and winter roosts in the southern U.S. (Harsch 1995). Here, we provide a description of the process and methodology of aerial mass color-marhng with fluorescent particles

Assessment of Woven Wire for Reducing Predation on Red-Winged Blackbird Nests

Red-winged blackbirds (RWBL) are a polygynous species, and disruptions to either territorial behavior or reproductive fitness of the males has potential to lower annual productivity of several females. A reduction in the number of fledglings produced per territory could ultimately result in lower damage to grain crops, at least on a local scale. It is thus feasible that socially acceptable nonlethal methods, including reproductive inhibition through either physical or chemical means, may accomplish a reduction in crop damage. Scientists at the USDA, Wildlife Services\u27 National Wildlife Research Center have shown that reproductive inhibition is an effective method for reducing local populations of some bird species. None of the studies, however, have had to meaningfully incorporate loss of statistical power through predation events on nests or eggs. We expect a crippling reduction in sample size (i.e., nests, eggs, nestlings, and fledglings) to occur over the course of any field experiment intended to measure the effects of reproductive inhibition on RWBL. Thus, developing a methodology to reduce predation of nests is a preliminary yet necessary step in the process of conducting any subsequent field-level tests. We assessed the efficacy of 2.54-cm x 2.54-cm woven wire cylinders (measuring 366- cm height x 183-cm diameter) for reducing mammalian predation on nests of RWBL. If effective at reducing nest predation, we will use these exclusion devices to enhance sample sizes in future experiments designed to assess effects of reproductive inhibition by chemical or physical methods on annual productivity of RWBL

Dogs increase recovery of passerine carcasses in dense vegetation

Wildlife managers use carcass searches to assess mortality resulting from biological (e.g., diseases) and physical (e.g., structure collisions) sources. Carcass searches may occur over large areas and need to be completed rapidly because of scavenging and decomposition. However, small carcasses are often missed when dense vegetation is searched. We placed carcasses of house sparrows (Passer domesticus) in dense cover of residual and newly grown vegetation and compared searching efficiency of humans and canines. Dogs received no special training in searching for passerine carcasses. In 36 trials conducted in 5 x 40-m plots, human searchers found 45% (SD=19) of the carcasses compared to 92% (SD=13) for dogs (P=0.005). The ratio of recovered to missed carcasses was approximately 12:l for dogs and 1 :I for humans. The improvement in searching efficiency using dogs was similar (P=0.58) between residual cover (searched in April) and new growth cover (searched in August). A greater rate of searching efficiency is obtained per unit of time by using dogs. Greater efficiency improves quantitative and qualitative assessments of avian mortality in the field

Winter Habitat Use and Survival of Female Ring-necked Pheasants (\u3ci\u3ePhasianus colchicus\u3c/i\u3e) in Southeastern North Dakota

From 1992 to 1995 we used radiotelemetry to monitor winter habitat selection and survival of female ring-necked pheasants (Phasianus colchicus) in southeastern North Dakota. We captured 100 birds at nine sites in six study blocks centered on cattail-dominated (Typha spp.) semi-permanent wetlands. Pheasants showed nonrandom habitat use at two hierarchical scales. At the second-order scale (23-km2 blocks) semi-permanent wetlands were preferred during two winters in which habitat selection could be assessed (1992–1993 and 1994–1995). An additional second-order preference for grass-covered uplands was shown during the mild 1994–1995 winter. At the third-order scale (home-range) pheasants preferred the edges of wetlands in 1992–1993 and 1994–1995. The central portions of wetlands were preferred in 1992–1993 and used proportionately in 1994–1995. Seasonal wetlands were avoided at the third order scale during 1992–1993 and 1994–1995. The average winter survival rate was 0.41, with rates ranging from 0.04–0.86 and differing significantly among winters. Survival was lower during early winter and midwinter periods for birds weighing less than 1090 g and for birds captured in semi-permanent wetlands under private ownership. A 1 C increase in the mean weekly maximum temperature decreased the probability of death by 0.06 and a 2.5 cm increase in new snow raised the probability of death by 0.08

Evaluation of Lorsban®-4E Aerially Sprayed on Sunflower Plots for Bird Repellency

Ripening sunflower fields in the northern Great Plains provide blackbirds with easily accessible sources of high-energy food. As many growers can attest, blackbirds can be nearly impossible to discourage from foraging in favored fields. To date, no single management method has been especially effective at consistently discouraging blackbirds

Evaluation and Development of Blackbird Repellents for Agricultural Applications

We evaluated several registered fungicides and insecticides, and several natural compounds as candidate blackbird repellents for protecting agricultural production. We tested more than 750 red-winged blackbirds at the National Wildlife Research Center’s outdoor animal research facility in Fort Collins, CO to evaluate (1) their preference for treated versus untreated rice and sunflower seeds and (2) their consumption of seeds treated with varying concentrations of candidate repellents. Concentrations were varied between 10% and 200% of labeled application rates. With few exceptions, blackbirds discriminated between untreated seeds and seeds treated with one of the candidate repellents. We observed greatest repellency with caffeine + sodium benzoate, GWN-4770, Lorsban, and Tilt. Additional lab efficacy tests are planned for anthraquinone seed treatments, Flock Buster repellent, and Cobalt insecticide. Field residue and efficacy tests are also needed to evaluate and develop promising foliar repellents for protection of ripening crops