Assessment of bias in US waterfowl harvest estimates

2012 ◽  
Vol 39 (4) ◽  
pp. 336 ◽  
Author(s):  
Paul I. Padding ◽  
J. Andrew Royle
Keyword(s):  
Survey Methodology ◽  
Management Policy ◽  
Canada Goose ◽  
Canada Geese ◽  
Correction Factors ◽  
Harvest Management ◽  
The Usa ◽  
Survey Estimates ◽  
Negative Impacts ◽  
Band Recovery

Context North American waterfowl managers have long suspected that waterfowl harvest estimates derived from national harvest surveys in the USA are biased high. Survey bias can be evaluated by comparing survey results with like estimates from independent sources. Aims We used band-recovery data to assess the magnitude of apparent bias in duck and goose harvest estimates, using mallards (Anas platyrhynchos) and Canada geese (Branta canadensis) as representatives of ducks and geese, respectively. Methods We compared the number of reported mallard and Canada goose band recoveries, adjusted for band reporting rates, with the estimated harvests of banded mallards and Canada geese from the national harvest surveys. We used the results of those comparisons to develop correction factors that can be applied to annual duck and goose harvest estimates of the national harvest survey. Key results National harvest survey estimates of banded mallards harvested annually averaged 1.37 times greater than those calculated from band-recovery data, whereas Canada goose harvest estimates averaged 1.50 or 1.63 times greater than comparable band-recovery estimates, depending on the harvest survey methodology used. Conclusions Duck harvest estimates produced by the national harvest survey from 1971 to 2010 should be reduced by a factor of 0.73 (95% CI = 0.71–0.75) to correct for apparent bias. Survey-specific correction factors of 0.67 (95% CI = 0.65–0.69) and 0.61 (95% CI = 0.59–0.64) should be applied to the goose harvest estimates for 1971–2001 (duck stamp-based survey) and 1999–2010 (HIP-based survey), respectively. Implications Although this apparent bias likely has not influenced waterfowl harvest management policy in the USA, it does have negative impacts on some applications of harvest estimates, such as indirect estimation of population size. For those types of analyses, we recommend applying the appropriate correction factor to harvest estimates.

scholarly journals Glaucous Gull Predation of Goslings on the Yukon-Kuskokwim Delta, Alaska

The Condor ◽  
2004 ◽  
Vol 106 (2) ◽  
pp. 288-298
Author(s):  
Timothy D. Bowman ◽  
Robert A. Stehn ◽  
Kim T. Scribner
Keyword(s):  
Aerial Survey ◽  
Branta Canadensis ◽  
Canada Goose ◽  
Canada Geese ◽  
Brood Rearing ◽  
Anser Albifrons ◽  
Stratified Sample ◽  
Larus Hyperboreus ◽  
Survey Estimates ◽  
Species Specific

Abstract Glaucous Gulls (Larus hyperboreus) nesting on the Yukon-Kuskokwim (Y-K) Delta frequently prey on juvenile waterfowl. We collected 434 Glaucous Gulls from late June to early August 1994 to examine diet. Identification of undigested prey tissue, based on DNA microsatellite loci, showed three species of goslings in gull stomachs: Emperor Goose (Chen canagica), White-fronted Goose (Anser albifrons), and Cackling Canada Goose (Branta canadensis minima). Gulls that nested inland and were collected >1.6 km from the coast accounted for approximately 70% of the total gull predation on Emperor and Canada Geese, and 96% on White-fronted Geese. Our stratified sample of gull stomachs and aerial survey estimates of population size and distribution of gulls and juvenile geese enabled extrapolation of species-specific predation rates to the entire Y-K Delta. We estimated that a minimum of 21 000 Emperor Goose, 34 000 Canada Goose, and 16 000 White- fronted Goose goslings were consumed by 12 600 Glaucous Gulls during the brood-rearing period on the Y-K Delta in 1994. Minimum estimated take by gulls represented 33% of Cackling Canada Goose, 47% of Emperor Goose, and 39% of White-fronted Goose eggs estimated to have hatched in the same area as gull collections. Gulls selected the three species of geese approximately in proportion to their abundance. Although gull predation caused significant gosling mortality, its role in regulating goose populations on Y-K Delta remains unresolved. Depredación de Pichones de Gansos por Gaviotas Larus hyperboreus en el Delta del Yukon-Kuskokwim, Alaska Resumen. Las gaviotas Larus hyperboreus que nidifican en el delta del Yukon-Kuskokwim (Y-K) depredan aves acuáticas juveniles con frecuencia. Para examinar su dieta, colectamos 434 gaviotas de esta especie entre finales de junio y principios de agosto de 1994. Identificamos los tejidos de presas no digeridos con base en loci de ADN microsatelital y encontramos pichones de tres especies de gansos (Chen canagica, Anser albifrons y Branta canadensis minima) en los estómagos de las gaviotas. Las gaviotas que estaban nidificando tierra adentro y que fueron colectadas a más de 1.6 km de la costa representaron aproximadamente el 70% del total de las depredaciones de C. canagica y B. canadensis y el 96% de las de A. albifrons. Nuestra muestra estratificada de estómagos de gaviotas, junto con estimaciones del tamaño poblacional de las gaviotas y gansos juveniles hechas mediante censos desde el aire, permitieron hacer extrapolaciones de tasas de depredación especie- específicas para todo el delta Y-K. Los números estimados mínimos de pichones depredados por 12 600 gaviotas en el delta durante el período de cría de 1994 fueron 21 000 C. canagica, 34 000 B. canadensis y 16 000 A. albifrons. Estimamos que en lás áreas en que fueron colectadas, las gaviotas consumieron como mínimo el 33%, 47% y 39% del número estimado de huevos allí eclosionados de B. canadensis, C. canagica y A. albifrons, respectivamente. Las gaviotas seleccionaron a las tres especies de gansos aproximadamente en proporción a su abundancia. Aunque la depredación por gaviotas causó una mortalidad significativa de los pichones, aún debe determinarse su papel en la regulación de las poblaciones de gansos en el delta Y-K.

Macroeconomic conditions are only an illusion, not the solution, to firm sustainability: unveiling the new dimension of stakeholder well-being

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zahid Irshad Younas ◽  
Mahvesh Khan ◽  
Mamdouh Abdulaziz Saleh Al-Faryan
Keyword(s):  
Well Being ◽  
Developed Countries ◽  
Macroeconomic Performance ◽  
Content Type ◽  
Macroeconomic Conditions ◽  
Us Economy ◽  
The Us ◽  
The Usa ◽  
Negative Impacts ◽  
The One

Purpose The purpose of the study is to explore the misconception that in developed countries, macroeconomic performance lead to sustainable firms or improves stakeholder well-being. The results may be the opposite or even worse. Design/methodology/approach This study examined this misconception using balanced panel data from 1,122 firms from different sectors of the US economy and data on macroeconomic performance from the World Bank. Findings The results of the one-step generalised method of moments indicate that most macroeconomic performance indicators had significant and negative impacts on firm sustainability and stakeholder well-being. Practical implications From a societal perspective, the results illustrate that the fruits of macroeconomic performance of the US economy do not reach stakeholders through firms’ sustainability. Thus, linking the economy’s macroeconomic performance with firm sustainability is vital for sustainably uplifting society and for stakeholder well-being. Originality/value From a policy perspective, this study reveals that the greater focus on macroeconomic performance in the USA over the past decades has resulted in lower firm sustainability because of the malfunctioning of social, economic, environmental and governance factors. This has negatively influenced stakeholder well-being in the country.

The effect of political neuromarketing 2.0 on election outcomes

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Islam Mohamed Hegazy
Keyword(s):  
Big Data ◽  
Political Campaign ◽  
Quality Of Democracy ◽  
Content Type ◽  
Interdisciplinary Field ◽  
The Usa ◽  
Negative Impacts ◽  
Field Of Inquiry

Purpose The purpose of this paper is the better understanding of the increasing relation between big data 2.0 and neuromarketing, particularly to influence election outcomes, along with a special aim to discuss some raised doubts about Trump’s presidential campaign 2016 and its ability to hijack American political consumers’ minds, and to direct their votes. Design/methodology/approach This paper combines deductive/inductive methodology to define the term of political neuromarketing 2.0 through a brief literature review of related concepts of big data 2.0, virtual identity and neuromarketing. It then applies a single qualitative case study by presenting the history and causes of online voter microtargeting in the USA, and analyzing the political neuromarketing 2.0 mechanisms adopted by Trump’s political campaign team in the 2016 presidential election. Findings Based on Trump’s political marketing mechanisms analysis, the paper believes that big data 2.0 and neuromarketing techniques played an unusual role in reading political consumers’ minds and helping the controversial candidate to meet one of the most unexpected victories in the presidential elections. Nevertheless, this paper argues that the ethics of using political neuromarketing 2.0 to sell candidates and its negative impacts on the quality of democracy are and will continue to be a subject of ongoing debates. Originality/value The marriage of big data 2.0 and political neuromarketing is a new interdisciplinary field of inquiry. This paper provides a useful introduction and further explanations for why and how Trump’s campaign defied initial loss predictions and attained victory during this election.

A study of Canada geese, Branta canadensis, nesting on islands in southeastern Alberta

1970 ◽  
Vol 48 (2) ◽  
pp. 235-240 ◽  
Author(s):  
Kees Vermeer
Keyword(s):  
Egg Laying ◽  
Water Levels ◽  
Branta Canadensis ◽  
Canada Goose ◽  
Canada Geese ◽  
Uniform Spacing ◽  
Incubation Periods

Canada goose clutches situated on islands in Dowling Lake and Lake Newell, Alberta, were checked from laying to hatching. Egg-laying intervals averaged 1.87 days and incubation periods 26.8 days. The distribution of nests showed a significant deviation from randomness in the direction of uniform spacing. Causes of extensive hatching failure at Dowling Lake were predation and desertion. Predation by coyotes was facilitated by low water levels. A preference for nesting on islands appears to be a mechanism to counteract mammalian predation.

scholarly journals Microbial Diversity and Host-Specific Sequences of Canada Goose Feces

2009 ◽  
Vol 75 (18) ◽  
pp. 5919-5926 ◽  
Author(s):  
Jingrang Lu ◽  
Jorge W. Santo Domingo ◽  
Stephen Hill ◽  
Thomas A. Edge
Keyword(s):  
Host Specificity ◽  
Source Tracking ◽  
Rrna Gene ◽  
Canada Goose ◽  
Fecal Dna ◽  
Canada Geese ◽  
Pcr Assay ◽  
Specific Source ◽  
The Impact ◽  
Specific Sequences

ABSTRACT Methods to assess the impact of goose fecal contamination are needed as the result of the increasing number of Canada geese (Branta canadensis) near North American inland waters. However, there is little information on goose fecal microbial communities, and such data are important for the development of host-specific source-tracking methods. To address this issue, 16S rRNA gene clone libraries for Canada goose fecal samples from Ontario, Canada, and Ohio were analyzed. Analyses of fecal clones from Ontario (447) and Ohio (302) showed that goose fecal communities are dominated by the classes “Clostridia” (represented by 33.7% of clones) and “Bacilli” (38.1% of clones) and the phylum “Bacteroidetes” (10.1% of clones). Sequences not previously found in other avian fecal communities were used to develop host-specific assays. Fecal DNA extracts from sewage plants (10 samples) and different species of birds (11 samples) and mammals (18 samples) were used to test for host specificity. Of all the assays tested, one assay showed specificity for Canada goose fecal DNA. The PCR assay was positive for Canada goose fecal DNA extracts collected from three locations in North America (Ohio, Oregon, and Ontario, Canada). Additionally, of 48 DNA extracts from Lake Ontario waters presumed to be impacted by waterfowl feces, 19 tested positive by the assay, although 10 were positive only after a nested PCR approach was used. Due to the level of host specificity and the presence of signals in environmental waters, the assay is proposed as a part of the toolbox to detect Canada goose contamination in waterfowl-contaminated waters.

scholarly journals Effectiveness of a confinement strategy for reducing campsite impacts in Shenandoah National Park

2004 ◽  
Vol 31 (4) ◽  
pp. 274-282 ◽  
Author(s):  
SCOTT E. REID ◽  
JEFFREY L. MARION
Keyword(s):  
Protected Areas ◽  
Adaptive Management ◽  
National Parks ◽  
National Park ◽  
Management Policy ◽  
Persistent Problem ◽  
Shenandoah National Park ◽  
Management Interventions ◽  
The Usa ◽  
Selection Of

The expansion and proliferation of backcountry campsites is a persistent problem in many parks and protected areas. Shenandoah National Park (SNP) has one of the highest backcountry overnight use densities in the USA national parks system. SNP managers implemented a multi-option backcountry camping policy in 2000 that included camping containment with established campsites. These actions were intended to reduce the number of campsites and the area of camping disturbance at each site. This paper describes a longitudinal adaptive management assessment of the new campsite policies, applying quantitative measures of campsite conditions to evaluate the efficacy of management interventions. Physical campsite measurements combined with qualitative visitor interviews indicated SNP had successfully reduced the number of campsites and aggregate measures of camping-related disturbance in the Park, while minimizing the use of regulations, site facilities and staff resources. Implications for managers of other protected areas are that an established site camping policy can minimize camping disturbance, including the number and size of campsites, provided managers can sustain rehabilitation efforts to close and restore unneeded campsites. Experiential attributes, such as the potential for solitude, can also be manipulated through control over the selection of established campsites. Integrating resource and social science methods also provided a more holistic perspective on management policy assessments. Adaptive management research provided a timely evaluation of management success while facilitating effective modifications in response to unforeseen challenges. Conclusions regarding the effectiveness of a visitor impact containment strategy involving an established site camping option are offered.

Agricultural Industrialization, Anticorporate Farming Laws, and Rural Community Welfare

2005 ◽  
Vol 37 (8) ◽  
pp. 1479-1491 ◽  
Author(s):  
Thomas A Lyson ◽  
Rick Welsh
Keyword(s):  
Rural Communities ◽  
Rural Community ◽  
Large Scale ◽  
Agricultural Industrialization ◽  
Negative Effects ◽  
Welfare Indicators ◽  
Industrial Farming ◽  
The Usa ◽  
Negative Impacts ◽  
Using Data

The effect on rural communities of shifts in US agriculture toward a system dominated by large-scale industrial production is a central problematic in the sociology of agriculture. Despite the importance of agriculture structure and practice to US society, most research on this topic has been confined to specialized journals. And though research in this area has found negative effects on rural communities from agricultural industrialization, there is a dearth of inquiry into public policy remedies. Using data on 433 agriculture-dependent counties in the USA, we find that counties in states with laws that limit nonfamily corporate entry into farming score higher on important welfare indicators, and that the laws mitigate negative impacts on rural communities from industrial farming.

scholarly journals A white feathered area on the forehead is more common in hybrids of Greylag Goose Anser anser and Greater Canada Goose Branta canadensis than in the parent species

Ornis Svecica ◽  
2011 ◽  
Vol 21 (1) ◽  
pp. 37-44
Author(s):  
C G Gustavsson
Keyword(s):  
Quantitative Comparison ◽  
Branta Canadensis ◽  
Canada Goose ◽  
Canada Geese ◽  
Parent Species ◽  
Anser Anser ◽  
White Area ◽  
Greylag Goose ◽  
Greylag Geese

This study evaluated prevalence and extent of white areas on heads of Greylag Goose × Greater Canada Goose hybrids. A white area which bordered the bill and then to various degrees extended over the forehead was found in 17 out of 20 hybrids. This was significantly more common in the hybrids than in the parent species. The white areas in the hybrids were also significantly larger than in those 82 out of 191 adult Greylag Geese which had some amount of white area. There were too few Greater Canada Geese with a white area outside the normal pale cheek patch to make a meaningful similar quantitative comparison also with them. No white area was seen in the three presumed 1st Calendar Year (CY) hybrids but when two of them were seen again in September of the 2nd CY there were some pale feathers that were interpreted as the beginning of white areas. The white areas in hybrids are therefore regarded to be adult features which like in several pure Anser species begin to develop during the 2nd CY.

scholarly journals Pteris multifida (spider brake).

2020 ◽  
Author(s):  
Jeanine Velez-Gavilán
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Invasive Plant ◽  
Alien Invasive Species ◽  
Natural Habitats ◽  
High Dispersal ◽  
The Usa ◽  
Pteris Multifida ◽  
Negative Impacts ◽  
Noxious Weed

Abstract Pteris multifida is a herbaceous fern native to temperate and tropical eastern Asia and naturalized on many continents as a result of being widely cultivated. Although it is an urban weed, it is not considered by most countries as an invasive or noxious weed. There is no information available on the species affecting native species or natural habitats. Although one source lists P. multifida as an invasive species in many countries outside of Africa due to it being easily dispersed by spores, there are no references or further information to support this statement. It is reported as an alien invasive species in Germany, but only as occurring in sheltered sites, growing on light-vents in cellars and walls. A species assessment for Florida, USA indicates, P. multifida is neither a weed of natural habitats nor of agriculture. The species has not been listed as an invasive plant in any state or natural areas of the USA. However, P. multifida has been assigned a Tier II Invasive Species status (defined as having moderate negative impacts on wildlife or natural communities in Louisiana), but of limited concern and/or extent in Louisiana. Pteris multifida is recorded in Cuba as potentially invasive being categorized as a species with a tendency to proliferate in some areas and capable of producing vast amounts of diaspores with high dispersal potential. No further details are given about potential invasiveness.

Methods for Improving Representativeness in a Web Survey on Sexual Assault Among College Students

2019 ◽  
Vol 34 (23-24) ◽  
pp. 4838-4859 ◽  
Author(s):  
Marcus E. Berzofsky ◽  
Lynn Langton ◽  
Christopher Krebs ◽  
Christine Lindquist ◽  
Michael Planty
Keyword(s):  
Sexual Assault ◽  
Campus Climate ◽  
Web Survey ◽  
Web Based ◽  
Sample Representativeness ◽  
Improve Estimate ◽  
Survey Estimates ◽  
Negative Impacts ◽  
Biased Estimates ◽  
Estimate Precision

Many colleges and universities conduct web-based campus climate surveys to understand the prevalence and nature of sexual assault among their students. When designing and fielding a web survey to measure a sensitive topic like sexual assault, methodological decisions, including the length of the field period and the use or amount of an incentive, can affect the representativeness of the respondent sample leading to biased or imprecise estimates. This study uses data from the Campus Climate Survey Validation Study (CCSVS) to assess how the interaction between field period length and survey incentive amount affects nonresponse, sample representativeness, and the precision of survey estimates. Research suggests that using robust incentives gives potential survey respondents a reason to complete the survey beyond their intrinsic motivation to do so. Likewise, extending the field period gives more time to people who may be less intrinsically motivated to complete the survey. Both serve to increase sample size and representativeness, minimize bias, and improve estimate precision. Schools, however, sometimes lack the time and/or resources for both a robust incentive and a lengthy field period, and this study examines the extent to which the potential negative impacts of not using one can be mitigated by the presence of the other. Findings indicate that target response rates can be achieved using a smaller incentive if the field period is lengthy but, even with a lengthy field period, the use of a smaller incentive can result in biased estimates due to a lack of representativeness. Conversely, when a robust incentive is used and weights are developed to adjust for nonresponse, a shorter field period will not have a significant impact on point estimates, but the estimates will be less precise due to fewer respondents participating in the survey.

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