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1.
Nature ; 625(7993): 85-91, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38172362

ABSTRACT

The world's population increasingly relies on the ocean for food, energy production and global trade1-3, yet human activities at sea are not well quantified4,5. We combine satellite imagery, vessel GPS data and deep-learning models to map industrial vessel activities and offshore energy infrastructure across the world's coastal waters from 2017 to 2021. We find that 72-76% of the world's industrial fishing vessels are not publicly tracked, with much of that fishing taking place around South Asia, Southeast Asia and Africa. We also find that 21-30% of transport and energy vessel activity is missing from public tracking systems. Globally, fishing decreased by 12 ± 1% at the onset of the COVID-19 pandemic in 2020 and had not recovered to pre-pandemic levels by 2021. By contrast, transport and energy vessel activities were relatively unaffected during the same period. Offshore wind is growing rapidly, with most wind turbines confined to small areas of the ocean but surpassing the number of oil structures in 2021. Our map of ocean industrialization reveals changes in some of the most extensive and economically important human activities at sea.


Subject(s)
Human Activities , Industry , Oceans and Seas , Satellite Imagery , Humans , COVID-19/epidemiology , Deep Learning , Energy-Generating Resources/statistics & numerical data , Food Supply/statistics & numerical data , Geographic Information Systems , Geographic Mapping , Human Activities/economics , Human Activities/statistics & numerical data , Hunting/statistics & numerical data , Industry/economics , Industry/statistics & numerical data , Ships/statistics & numerical data , Wind
2.
Nature ; 575(7781): 98-108, 2019 11.
Article in English | MEDLINE | ID: mdl-31695208

ABSTRACT

Much of the Earth's biosphere has been appropriated for the production of harvestable biomass in the form of food, fuel and fibre. Here we show that the simplification and intensification of these systems and their growing connection to international markets has yielded a global production ecosystem that is homogenous, highly connected and characterized by weakened internal feedbacks. We argue that these features converge to yield high and predictable supplies of biomass in the short term, but create conditions for novel and pervasive risks to emerge and interact in the longer term. Steering the global production ecosystem towards a sustainable trajectory will require the redirection of finance, increased transparency and traceability in supply chains, and the participation of a multitude of players, including integrated 'keystone actors' such as multinational corporations.


Subject(s)
Biomass , Ecosystem , Energy-Generating Resources , Feedback , Food Supply , Human Activities , Sustainable Development , Agriculture/economics , Animals , Commerce/economics , Energy-Generating Resources/economics , Food Supply/economics , Forestry , Groundwater/analysis , Human Activities/economics , Humans , Sustainable Development/economics
3.
Int J Qual Health Care ; 33(1)2021 Feb 20.
Article in English | MEDLINE | ID: mdl-33470405

ABSTRACT

Since the beginning of Coronavirus 2019 (COVID-19) disease outbreak, there has been a heated debate about public health measures, as they can presumably reduce human costs in the short term but can negatively impact economies and well-being over a longer period. MATERIALS AND METHODS: To study the relationship between health and economic impact of COVID-19, we conducted a secondary research on Italian regions, combining official data (mortality due to COVID-19 and contractions in value added of production for a month of lockdown). Then, we added the tertiles of the number of people tested for COVID-19 and those of health aids to evaluate the correspondence with the outcome measures. RESULTS: Five regions out of 20, the most industrialized northern regions, which were affected both earlier and more severely by the outbreak, registered both mortality and economic value loss above the overall medians. The southern regions, which were affected later and less severely, had low mortality and less economic impact. CONCLUSIONS: Our analysis shows that considering health and economic outcomes in the assessment of response to pandemics offers a bigger picture perspective of the outbreak and could allow policymakers and health managers to choose systemic, 'personalized' strategies, in case of a feared second epidemic wave.


Subject(s)
COVID-19/economics , COVID-19/mortality , Cost of Illness , Pandemics/economics , Public Health , Epidemiological Monitoring , Human Activities/economics , Humans , Italy/epidemiology , Quarantine/economics , SARS-CoV-2
4.
Proc Natl Acad Sci U S A ; 114(7): 1512-1517, 2017 02 14.
Article in English | MEDLINE | ID: mdl-28137850

ABSTRACT

Coastal hypoxia (dissolved oxygen ≤ 2 mg/L) is a growing problem worldwide that threatens marine ecosystem services, but little is known about economic effects on fisheries. Here, we provide evidence that hypoxia causes economic impacts on a major fishery. Ecological studies of hypoxia and marine fauna suggest multiple mechanisms through which hypoxia can skew a population's size distribution toward smaller individuals. These mechanisms produce sharp predictions about changes in seafood markets. Hypoxia is hypothesized to decrease the quantity of large shrimp relative to small shrimp and increase the price of large shrimp relative to small shrimp. We test these hypotheses using time series of size-based prices. Naive quantity-based models using treatment/control comparisons in hypoxic and nonhypoxic areas produce null results, but we find strong evidence of the hypothesized effects in the relative prices: Hypoxia increases the relative price of large shrimp compared with small shrimp. The effects of fuel prices provide supporting evidence. Empirical models of fishing effort and bioeconomic simulations explain why quantifying effects of hypoxia on fisheries using quantity data has been inconclusive. Specifically, spatial-dynamic feedbacks across the natural system (the fish stock) and human system (the mobile fishing fleet) confound "treated" and "control" areas. Consequently, analyses of price data, which rely on a market counterfactual, are able to reveal effects of the ecological disturbance that are obscured in quantity data. Our results are an important step toward quantifying the economic value of reduced upstream nutrient loading in the Mississippi Basin and are broadly applicable to other coupled human-natural systems.


Subject(s)
Commerce/trends , Ecosystem , Fisheries/economics , Penaeidae/physiology , Seafood/economics , Water Pollution/adverse effects , Water Pollution/economics , Animals , Body Size , Commerce/statistics & numerical data , Conservation of Natural Resources , Fertilizers/adverse effects , Gulf of Mexico , Human Activities/economics , Oxygen/analysis , Seasons , Seawater/chemistry , Water Pollutants, Chemical/adverse effects
7.
Environ Manage ; 55(1): 159-70, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25234049

ABSTRACT

The coyote (Canis latrans) has dramatically expanded its range to include the cities and suburbs of the western US and those of the Eastern Seaboard. Highly adaptable, this newcomer's success causes conflicts with residents, necessitating research to understand the distribution of coyotes in urban landscapes. Citizen science can be a powerful approach toward this aim. However, to date, the few studies that have used publicly reported coyote sighting data have lacked an in-depth consideration of human socioeconomic variables, which we suggest are an important source of overlooked variation in data that describe the simultaneous occurrence of coyotes and humans. We explored the relative importance of socioeconomic variables compared to those describing coyote habitat in predicting human-coyote encounters in highly-urbanized Mecklenburg County, North Carolina, USA using 707 public reports of coyote sightings, high-resolution land cover, US Census data, and an autologistic multi-model inference approach. Three of the four socioeconomic variables which we hypothesized would have an important influence on encounter probability, namely building density, household income, and occupation, had effects at least as large as or larger than coyote habitat variables. Our results indicate that the consideration of readily available socioeconomic variables in the analysis of citizen science data improves the prediction of species distributions by providing insight into the effects of important factors for which data are often lacking, such as resource availability for coyotes on private property and observer experience. Managers should take advantage of citizen scientists in human-dominated landscapes to monitor coyotes in order to understand their interactions with humans.


Subject(s)
Coyotes/physiology , Ecosystem , Human Activities/economics , Animals , Cities/economics , Human Activities/psychology , Humans , North Carolina , Socioeconomic Factors
8.
PLoS One ; 16(5): e0251288, 2021.
Article in English | MEDLINE | ID: mdl-34010277

ABSTRACT

To measure the effects of air pollution on human activities, this study applies statistical/econometric modeling to hourly data of 9 million mobile phone users from six cities in China's Zhejiang Province from December 18 to 21, 2013. Under a change in air quality from "Good" (Air Quality Index, or AQI, between 51 and 100) to "Heavily Polluted" (AQI between 201 to 300), the following effects are demonstrated. (i) Consistent with the literature, for every one million people, 1, 482 fewer individuals are observed at parks, 95% confidence interval or CI (-2, 229, -735), which represents a 15% decrease. (ii) The number of individuals at shopping malls has no statistically significant change. (iii) Home is the most important location under worsening air quality, and for every one million people, 63, 088 more individuals are observed at home, 95% CI (47, 815, 78, 361), which represents a 19% increase. (iv) Individuals are on average 633 meters closer to their home, 95% CI (529, 737); as a benchmark, the median distance from home ranges from 300 to 1900 meters across the cities in our sample. These effects are not due to weather or government regulations. We also provided provisional evidence that individuals engage in inter-temporal activity substitutions within a day, which leads to mitigated (but not nullified) effects of air pollution on daily activities.


Subject(s)
Air Pollution/adverse effects , Cell Phone Use/statistics & numerical data , Human Activities/statistics & numerical data , Air Pollution/analysis , Air Pollution/economics , Air Pollution, Indoor/adverse effects , Air Pollution, Indoor/analysis , Cell Phone , China , Cities , Environmental Exposure/adverse effects , Geographic Information Systems , Human Activities/economics , Humans , Leisure Activities , Models, Econometric , Models, Statistical , Parks, Recreational , Recreation , Seasons , Weather
9.
Nat Commun ; 11(1): 584, 2020 02 04.
Article in English | MEDLINE | ID: mdl-32019915

ABSTRACT

Zoos contribute substantial resources to in situ conservation projects in natural habitats using revenue from visitor attendance, as well as other sources. We use a global dataset of over 450 zoos to develop a model of how zoo composition and socio-economic factors directly and indirectly influence visitor attendance and in situ project activity. We find that zoos with many animals, large animals, high species richness (particularly of mammals), and which are dissimilar to other zoos achieve higher numbers of visitors and contribute to more in situ conservation projects. However, the model strongly supports a trade-off between number of animals and body mass indicating that alternative composition strategies, such as having many small animals, may also be effective. The evidence-base presented here can be used to help guide collection planning processes and increase the in situ contributions from zoos, helping to reduce global biodiversity loss.


Subject(s)
Animals, Zoo/classification , Conservation of Natural Resources/methods , Animals , Biodiversity , Conservation of Natural Resources/economics , Endangered Species/economics , Endangered Species/statistics & numerical data , Human Activities/economics , Humans , Socioeconomic Factors
10.
Chemosphere ; 151: 303-9, 2016 May.
Article in English | MEDLINE | ID: mdl-26950020

ABSTRACT

The correlations between polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) releases and factors relevant to human social-economic activities (HSEAs) were analyzed. The multiple linear regression model was successfully developed to estimate the total global PCDD/F release. The PCDD/F releases significantly correlated with population, area, GDP and GNI, suggesting that "quantity" of HSEAs have significantly contributed to the PCDD/F releases. On another aspect, advanced technologies are usually adopted in developed countries/regions, and hence reduce the PCDD/F release. The significant correlation between PCDD/F release and CO2 emission implies the potential of simultaneous reduction of CO2 emission and PCDD/F release. The total global PCDD/F release from 196 countries/regions was estimated to be 100.4 kg-TEQ yr(-1). The estimated annual PCDD/F release per unit area ranged from 0.007 to 28 mg-TEQ km(-2). Asia is estimated to have the highest PCDD/F release of 47.1 kg-TEQ yr(-1), almost half of the total world release. Oceania is estimated to have the smallest total release but the largest per-capita release. For the developed areas, such as Europe and North America, the PCDD/F release per unit GDP is lower, while for Africa, it is much higher.


Subject(s)
Benzofurans/analysis , Developed Countries/economics , Developing Countries/economics , Environmental Pollutants/analysis , Polychlorinated Dibenzodioxins/analogs & derivatives , Africa , Asia , Dibenzofurans, Polychlorinated , Europe , Human Activities/economics , Humans , Models, Theoretical , North America , Polychlorinated Dibenzodioxins/analysis , Principal Component Analysis , Socioeconomic Factors
11.
Int J Pediatr Otorhinolaryngol ; 69(7): 929-36, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15911011

ABSTRACT

OBJECTIVES: The objectives of this study are to estimate time and out-of-pocket costs incurred by families attending a pediatric cochlear implant programme. In addition, qualitative data examine the intangible costs faced by families. METHODS: Data was collected during semi-structured face-to-face interviews with parents of children with a cochlear implant attending a clinic visit at Nottingham Cochlear Implantation Programme (NPCIP), UK. Information supplied included socio-demographic characteristics, mode of travel, out-of-pocket expenses, time foregone, and details of companions. Quantitative data was stored and analysed in SPSS version 11.5. RESULTS: Two hundred and sixteen face-to-face interviews were conducted with parents of children implanted for between 1 month and 13 years. Time and out-of-pocket costs were significantly higher for those in the first 2 years of the programme, mean UK pound 3090 per annum compared to UK pound 2159 per annum for those in years >2-5 and UK pound 1815 per annum for those in years >5 (P<0.001). The biggest component of this was time costs, although the sensitivity analysis revealed that these were also most variable depending on the methods used to estimate them. The largest out-of-pocket cost incurred by families was travel costs which accounted for 44%, although 16% of families received some financial help with travel costs. The qualitative findings are consistent with these findings, also showing that over time the financial and intangible costs incurred as a result of cochlear implantation decline. CONCLUSIONS: This study is the first to obtain primary data on the time and out-of-pocket costs incurred by families attending a pediatric cochlear implant programme in the UK. It finds that these costs are greatest for those families in the first 2 years of the programme and/or who live furthest from the programme.


Subject(s)
Cochlear Implantation/economics , Cost of Illness , Health Expenditures , Absenteeism , Adult , Child , Child, Preschool , Female , Human Activities/economics , Humans , Infant , Male , Middle Aged , Socioeconomic Factors , Time Factors , Transportation/economics , United Kingdom
12.
Sci Rep ; 4: 5215, 2014 Jun 12.
Article in English | MEDLINE | ID: mdl-24921192

ABSTRACT

This paper develops a framework to determine the sustainability of a general activity. We define an activity as an action or process that uses one or more resources and that responds either wholly or partially to a demand. A definition for sustainability is developed and is contingent on whether or not an activity can be sustained according to the available resources, the duration of an activity, the cost of its execution, or whether substitution is possible. A sustainability condition is met when the duration, cost and the chain of dependent activities satisfies the demand. Two conditions for sustainability are developed: a strong condition when the demand is met with no substitution and a weak condition when the demand is met via substitution. In the latter case, we show that the set of all sustainable activities is a subset of a N-level union of sustainable activities and forms a topological cover.


Subject(s)
Human Activities/economics , Human Activities/standards , Models, Theoretical , Humans
13.
J Gerontol B Psychol Sci Soc Sci ; 69(5): 809-21, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24526690

ABSTRACT

OBJECTIVES: In this study, we advance knowledge about activity engagement by considering many activities simultaneously to identify profiles of activity among older adults. Further, we use cross-sectional data to explore factors associated with activity profiles and prospective data to explore activity profiles and well-being outcomes. METHOD: We used the core survey data from the years 2008 and 2010, as well as the 2009 Health and Retirement Study Consumption and Activities Mail Survey (HRS CAMS). The HRS CAMS includes information on types and amounts of activities. We used factor analysis and latent class analysis to identify activity profiles and regression analyses to assess antecedents and outcomes associated with activity profiles. RESULTS: We identified 5 activity profiles: Low Activity, Moderate Activity, High Activity, Working, and Physically Active. These profiles varied in amount and type of activities. Demographic and health factors were related to profiles. Activity profiles were subsequently associated with self-rated health and depression symptoms. DISCUSSION: The use of a 5-level categorical activity profile variable may allow more complex analyses of activity that capture the "whole person." There is clearly a vulnerable group of low-activity individuals as well as a High Activity group that may represent the "active ageing" vision.


Subject(s)
Aging , Human Activities/classification , Black or African American , Aged , Aged, 80 and over , Cohort Studies , Cross-Sectional Studies , Employment/economics , Employment/psychology , Female , Florida/ethnology , Health Surveys , Hispanic or Latino/ethnology , Human Activities/economics , Humans , Male , Middle Aged , Models, Psychological , Motor Activity/physiology , Prospective Studies , Regression Analysis , United States
14.
Sci Total Environ ; 458-460: 419-26, 2013 Aug 01.
Article in English | MEDLINE | ID: mdl-23685367

ABSTRACT

The processes of karst rocky desertification (KRD) have been found to cause the most severe environmental degradation in southwestern China. Understanding the driving forces that cause KRD is essential for managing and restoring the areas that it impacts. Studies of the human driving forces of KRD are limited to the county level, a specific administrative unit in China; census data are acquired at this scale, which can lead to scale biases. Changshun County is studied here as a representative area and anthropogenic influences in the county are accounted for by using Euclidean distances for the proximity to roads and settlements. We propose a standard coefficient of human influence (SOI) that standardizes the Euclidean distances for different KRD transformations to compare the effects of human activities in different areas. In Changshun County, the individual influences of roads and settlements share similar characteristics. The SOIs of improved KRD transformation types are almost negative, but the SOIs of deteriorated types are nearly positive except for one form of KRD turning to the extremely severe KRD. The results indicated that the distribution and evolution of the KRD areas from 2000 to 2010 in Changshun were affected positively by human activities (e.g., KRD restoration projects) and also negatively (e.g., by intense and irrational land use). Our results demonstrate that the spatial techniques and SOI used in this study can effectively incorporate information concerning human influences and internal KRD transformations. This provides a suitable approach for studying the relationships between human activities and KRD processes at fine scales.


Subject(s)
Conservation of Natural Resources/methods , Human Activities/economics , Models, Theoretical , China , Data Mining , Geological Phenomena , Humans
15.
PLoS One ; 8(5): e65051, 2013.
Article in English | MEDLINE | ID: mdl-23741450

ABSTRACT

As manta rays face increased threats from targeted and bycatch fisheries, manta ray watching tourism, if managed properly, may present an attractive economic alternative to consumptive use of these species. Both species in the genus Manta (Manta alfredi and Manta birostris) are classified by the International Union for the Conservation of Nature Red List as species Vulnerable to extinction in the wild, and are considered unsustainable as fisheries resources due to their conservative life history characteristics, which considerably reduce their ability to recover population numbers when depleted. Utilising dive operator surveys, Internet research, and a literature review, this study provides the first global estimate of the direct economic impact of manta ray watching tourism and examines the potential socio-economic benefits of non-consumptive manta ray watching operations relative to consumptive use of manta rays as a fishery resource. In the 23 countries in which manta ray watching operations meeting our criteria were identified, we estimated direct revenue to dive operators from manta ray dives and snorkels at over US$73 million annually and direct economic impact, including associated tourism expenditures, of US$140 million annually. Ten countries account for almost 93% of the global revenue estimate, specifically Japan, Indonesia, the Maldives, Mozambique, Thailand, Australia, Mexico, United States, Federated States of Micronesia and Palau. In many of the areas where directed fisheries for manta rays are known to occur, these activities overlap with manta ray tourism sites or the migratory range of the mantas on which these sites depend, and are likely to be unsustainable and detrimental to manta ray watching tourism.


Subject(s)
Human Activities/economics , Skates, Fish , Animals , Costs and Cost Analysis , Geography , Surveys and Questionnaires
16.
Rev. int. med. cienc. act. fis. deporte ; 17(65): 1-26, mar. 2017. tab, graf
Article in Spanish | IBECS (Spain) | ID: ibc-161552

ABSTRACT

El artículo presenta la primera fase de un estudio del fútbol español, cuyo objetivo es averiguar si es rentable jugar en Primera División de fútbol (1ª) para cualquier equipo profesional y si todos los clubes de 2ªA deberían aspirar al ascenso. Se comparan resultados en la población seleccionada y en dos grupos de la misma: equipos que se han mantenido en 1ª y equipos ascensor. Se examinan mediante análisis exploratorio de datos resultados económicos y deportivos, se identifican factores que influyen en su variación y se clasifican los clubes según dichos factores. También se determina la influencia de ascensos y descensos en los resultados. Se deduce que los equipos ascensor obtienen peores resultados aun jugando en la misma liga. Además, a su estabilidad económico financiera le afecta más el ascenso y descenso continuo que el mantenerse en una categoría concreta. Finalmente, que la «gestión del miedo» no siempre conduce a una mejor clasificación y añade tensión financiera. Se concluye que no a todos los clubes les conviene militar en 1ª división de fútbol, que ésta debe reestructurarse y se debe reforzar la 2ªA (AU)


The paper presents the first phase of a Spanish football study. The aim is to determine if it is profitable to play in 1ª D league for any professional team and if all clubs in 2ª A division should aspire to climb. Various results are compared in the selected population and also in two groups identified: equipment that have remained in 1ªD and «elevator teams». The economics and sports results are examined by exploratory data analysis. We identify factors that are influence in change and the teams are classified according to these factors. Finally the influence of promotion and relegation in these results is determined. It follows that the «Fear Management» doesn’t always lead to better classification and adds financial stress, «elevator equipment» that perform worse even playing in the same league and its economic and financial stability will most affect the rise and decline that continued the stay in a particular category. We conclude: not all clubs suit them military in 1ª, it would be to restructure and strengthen the 2ª A (AU)


Subject(s)
Humans , Male , Sports/physiology , Soccer/trends , Soccer/economics , Sports/economics , Sports/legislation & jurisprudence , Socioeconomic Factors , Social Conditions/economics , Human Activities/economics , Factor Analysis, Statistical , 16949
17.
Biotechnol Prog ; 28(4): 893-8, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22718309

ABSTRACT

A high level of human development is dependent on energy consumption (roughly 4 kW per person), and most developed countries that have reached this level have done so through the extensive use of fossil energy. However, given that fossil resources are finite, in order for developed countries to maintain their level of development and simultaneously allow developing countries to reach their potential, it is essential to develop viable renewable energy alternatives. Of particular importance are liquid fuel replacements for petroleum, the fossil resource that primarily drives commerce and economic growth. The intent of this article is to remind our fellow biofuel researchers, particularly those involved in lignocellulosic pretreatment, of these global issues and the serious nature of our work. We hope that this will inspire us to generate and report higher quality and more thorough data than has been done in the past. Only in this way can accurate comparisons and technoeconomic evaluations be made for the many different pretreatment technologies that are currently being researched. The data that primarily influence biorefinery economics can be subdivided into three main categories: yield, concentration, and rate. For these three categories we detail the specific data that should be reported for pretreatment research. In addition, there is other information that is needed to allow for a thorough comparison of pretreatment technologies. An overview of these criteria and our comparison of the current state of a number of pretreatment technologies with respect to these criteria are covered in the last section.


Subject(s)
Biofuels/economics , Biotechnology/methods , Energy-Generating Resources/economics , Lignin/chemistry , Biofuels/analysis , Biomass , Biotechnology/economics , Developed Countries/economics , Developing Countries/economics , Human Activities/economics , Humans
18.
J World Hist ; 22(2): 243-72, 2011.
Article in English | MEDLINE | ID: mdl-22073435

ABSTRACT

Following the considerable increase in the interactions between Ottomans and Europeans, Ottoman port cities, referred to here as "borderlands," became meeting places of distinct worlds. Ottoman and British people met, clashed, and grappled with each other in the borderlands of the Ottoman Empire. There was unbalanced, disparate, and disproportionate, but also mutual and constant interchange between the two societies. This article discusses one facet of this interchange: the Anglo-Ottoman exchange of women's costumes.


Subject(s)
Clothing , Commerce , Cultural Diversity , Interpersonal Relations , Population Groups , Clothing/economics , Clothing/history , Clothing/psychology , Commerce/economics , Commerce/education , Commerce/history , Europe/ethnology , History, 19th Century , History, 20th Century , Human Activities/economics , Human Activities/education , Human Activities/history , Human Activities/legislation & jurisprudence , Human Activities/psychology , Humans , Interpersonal Relations/history , Ottoman Empire/ethnology , Population Groups/education , Population Groups/ethnology , Population Groups/history , Population Groups/legislation & jurisprudence , Population Groups/psychology
19.
PLoS One ; 5(9): e12866, 2010 Sep 22.
Article in English | MEDLINE | ID: mdl-20877564

ABSTRACT

We explore variation in the prices paid by recreational hunters of trophy animals in Africa and its possible causes, including perceived rarity. Previous work has raised the possibility that extinction can result if demand rises fast enough as a species becomes rarer. We attempt to disentangle this from other inter-correlated influences affecting price. Species with larger body sizes and larger trophies were more valuable. Value increased less steeply as a function of size for bovids than for felids and the effect was consistent across countries. Power laws, ubiquitous in physical and social systems, described the trends. The exponent was approximately 0.4 for bovids, compared with approximately 1.0 for felids. Rarity (as indexed by IUCN score) influenced the value of bovid trophies - price was higher for species in categories denoting higher global threat. There was substantial variation in price among and within families not explained by either size or rarity. This may be attributable to a 'charisma' effect, which seems likely to be a general attribute of human perceptions of wildlife. Species where prices were higher than predicted by size or rarity are ranked high in published accounts of desirability by hunters. We conclude that the valuation of these species is explicable to a large extent by body size and perceived rarity, and that differences in valuation between taxonomic groups are related to less easily quantified 'charisma' effects. These findings are relevant for conservationists considering the threat status of species exploited in open access markets, and where license quotas are adjusted in response to changes in perceived rarity.


Subject(s)
Animals, Wild/physiology , Body Size , Conservation of Natural Resources/economics , Human Activities/economics , Africa , Animals , Humans
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