Abstract The Skellam model describes discrete‐time population dynamics of a single species assuming uniform (i.e., random or Poissonian) individual distribution and intraspecific contest competition. Apart from studies on individual‐based models derived from first principles it has been rarely applied in ecological research although in specific situations it may be more appropriate than, for instance, the frequently used Ricker model, which is derived assuming scramble competition among the individuals. In this article, we offer an insight into the first principles underlying the Skellam model and provide an alternative parameterization of the model in terms of two commonly used parameters: intrinsic rate of population increase and carrying capacity. We also provide guidelines and software for fitting the Skellam model to discrete population time series data. In light of these findings, the Skellam model may be a useful alternative for a range of purposes where it has been earlier overlooked.

Urban wildlife is an important component of biodiversity. Human-urban wildlife interaction has been changing, but public opinions, especially individualized opinions, are not being sufficiently incorporated into urban wildlife management decisions. This study aims to fill this gap by investigating people's preference heterogeneity of browse lines, a unique tree landscape altered by wild deer (Cervus nippon) in Japan, as an example. We apply a latent class model to identify people's preference heterogeneity for browse lines when people are not exposed to deer. We also apply split-sample design to examine whether people's preferences change when they are informed that the deer created the landscape. The results confirm the existence of preference heterogeneity among people. However, we did not find a change in the aggregated willingness to pay for the park landscape after information provision. It may suggest that people are tolerant for the impact of urban wildlife even if they are not exposed to creatures. We also highlight how the results can be used by real-life urban parks and wildlife management to recognize people's preference heterogeneity and select strategies that can most effectively address disparate views.

This study aims to investigate the influence of trust, satisfaction, values, and brand image on the loyalty of MaxxCoffee. Data collection in this study was conducted using a questionnaire given to students of Universitas Pelita Harapan as respondents. The research design uses convenience sampling with a total sample of 249 samples. The data collection method is utilizing questionnaires and the data is analyzed by the Partial Least Square of Structural Equation Modeling (PLS-SEM). The findings of this study are trust, satisfaction, and value have a positive effect on loyalty. Conversely, the brand image has no positive effect on Maxx Coffee customers’ loyalty. The contribution of this study is providing input to the management of Maxx Coffee to concern and maintain their trust, satisfaction, value, and brand image of Maxx Coffee to maintain the customers’ loyalty.

We apply a choice experiment to estimate additional willingness to pay for Campylobacter-reduced chicken compared with normal chicken. We select Japanese consumers as an example because Japan is the world's largest chicken importer. The additional willingness to pay is estimated to be 38.87 JPY (about 0.39 USD)/150 g (when food poisoning levels reduced from 1/500 to 1/1,000) and 80.29 JPY (about 0.80 USD)/150 g (1/2,000). These values are high enough to cover additional associated costs, implying that producers’ spontaneous provision of Campylobacter-reduced chicken is feasible. Our study is the first to confirm this fact. In addition, we elucidate consumers’ characteristics that push up additional willingness to pay, thereby drawing useful implications for promoting safer chicken. Good progress in providing safer chicken in Japan would create more global business opportunities for companies and might trigger expansion of pathogen-reduced table meat worldwide. [EconLit citations: Q13, Q18].

Purpose: This study aims to examine whether citizens of non-Muslim countries accept products with a “halal” logo. In the era of globalization, one of the most crucial issues for Muslim travelers is reliable halal foods when visiting non-Muslim countries. If people in non-Muslim countries accept imported products containing halal certification logos, and such products are readily available in shops, this issue could be substantially improved. Design/methodology/approach: Malaysia and Japan were selected as Muslim and non-Muslim countries, respectively, to conduct a choice experiment (CE) for 656 non-Muslim subjects, and estimated willingness to pay (WTP) for mineral water with and without the halal logo. A random parameter logit model was used for estimation. Findings: The difference between the WTP for mineral water with and without the halal logo was \5 however, the associated coefficient is not statistically significant. This implies that the halal logo has no impact on non-Muslim subjects’ purchasing behavior. From this, we can infer that the halal products with certification logo would be accepted in Japanese shops, which may foster foreign Muslim visits. Research limitations/implications: As the results are based on a couple of countries (Malaysia and Japan) and only one product (mineral water), further investigation using other products in different countries would be necessary. However, as suggested in the main text, the results enjoy a degree of generalizability. Originality/value: The results of this study support the possibility of circulating halal products in non-Muslim countries and thus promoting Muslim travel abroad. No such study has examined this issue using CE.

Substantial food loss and waste occur worldwide; approximately one third of produced food is lost or wasted annually, which worsens problems such as starvation and environmental degradation. This study examines the possibility of selling reprocessed meat products made from raw meat near its sell-by date, using Japanese fried chicken as an example. If reprocessed products are accepted by consumers, this will significantly contribute to reducing food waste in grocery stores. Because reprocessing does not require a reduction in current meat consumption, selling reprocessed foods is a more feasible and realistic way to reduce food waste compared to other initiatives, such as "Meat Free Monday." We use a choice experiment to elicit consumer preference for reprocessed fried chicken. Our results show that the willingness to pay for reprocessed fried chicken is above 90% of that of regular chicken, which implies a high feasibility of selling such products. (C) 2017 Elsevier Ltd. All rights reserved.

Japanese sika deer (Cervus nippon nippon) were introduced at the turn of nineteenth and twentieth century to many countries in Eurasia, North America and Australasia. Subsequently, free-living invasive populations have become established in several countries, including the Czech Republic, where the expanding sika population causes serious problems through overgrazing, damage through browsing and through competition and hybridisation with native red deer. 122 Japanese and 221 Czech samples were used to examine the genetic diversity, genetic structure, and the level of genetic differentiation between native populations and those introduced to the Czech Republic. Analyses of 22 microsatellite loci revealed, for both countries, evidence of isolation by distance and clear sub-structuring of populations, different from patterns previously revealed by mtDNA markers. The high number of private alleles (58 within the Czech Republic and 84 within Japan), the Fst values, factorial correspondence analysis and Bayesian clustering support a high level of divergence between the source and introduced populations. Genetic variability was generally low due to recent demographic events (founder effect in the Czech population, bottlenecks in Japanese populations); however, the values of expected heterozygosity differed greatly between subpopulations and were not the lowest in the introduced Czech populations. Multiple introductions, rapid population growth, and possible hybridisation with red deer seem to have helped the successful expansion of sika within the Czech Republic. The results also indicate that male-mediated gene flow and human-mediated translocations have significantly influenced the current genetic structure of native sika populations in Japan.

An individual perceived risk often differs from an objective risk based on the scientific evidence; risks about nuclear power generation and food technology including genetic modification and food irradiation are typical such cases. However, the extent to which welfare loss is caused by the disparity between perceived and scientific risks is unclear. Based on this gap in the literature, we conduct a discrete choice experiment to estimate the welfare loss. At the same time, we must tackle two issues arising in the estimation: endogeneity and ambiguity in the perceived risk. We construct an empirical model based on maxmin expected utility to consider ambiguity and apply a control function approach to alleviate endogeneity bias. The results show that 1) the disparity between perceived and scientific risks causes a significant welfare loss; 2) the ambiguity in the perceived risk exacerbates the welfare loss; and 3) endogeneity largely biases welfare measurement.

Sika deer (Cervus nippon), native to Asia, formed two well-established free-living populations in the Czech Republic over the last century and continue to spread. Sika are also maintained in a large number of enclosures; these continue to introduce new individuals from the places of its origin as well as from other European countries. Despite extensive research into the morphology and ethology of the Czech sika deer, conducted over the last three decades, no study using genetic methods has been done. This study aimed to determine the genetic variability and the geographic origin of the Czech sika deer population. Two mitochondrial markers, the cytochrome b and the control region were analyzed in this study. Analysis of the two markers confirmed that the founder individuals of the Czech population originated from both native island (Japanese Islands) and native mainland (Far East Russia) populations. Results showed that the genetic variability of the Czech sika deer population is lower than the variability of the native Japanese population, but higher than that of the sampled part of the native Russian population. Also, the genetic variability was found to be higher within the samples from enclosures.

This study proposes a new fishery resource recovery strategy and empirically examines its feasibility. The proposed strategy is unique because it may help fishermen recover fishery resources by closing for the first several months of the fishing season without decreasing their average annual landings. If demand is elastic, it is feasible that they could recover biomass without reducing average annual revenue. To demonstrate the validity of this strategy, this study empirically examines the ocellate puffer in the vicinity of Japan, as it has experienced a drastic depletion of biomass. The results indicate that if fishing were to be prohibited, for example, between October and February (current fishing season is between October and March), ocellate puffer recovery in the first year would be 30,453 kg, which would have the same effect as an 18.4% reduction in the current average landings. The price elasticity for ocellate puffer is elastic, which implies not only that fishery revenue would not decrease, but that the strategy could be a promising means of recovering ocellate puffer stocks. (C) 2012 Elsevier B.V. All rights reserved.

This study is the first to value the mortality risk incurred from wildlife reintroduction. We conducted choice experiments on wolf reintroduction in Hokkaido, Japan, in order to value the resulting mortality risk. This process involves three unique factors: the mortality risk is zero before the reintroduction, the increment of the risk caused by the reintroduction is substantially small, and the risk largely depends on citizens' individual characteristics concerning reintroduction. Because of these factors, the heterogeneity of risk preference is expected to be large. In order to examine these heterogeneous risk preferences, we use a random parameter logit model. The estimation results confirm that considerable heterogeneous risk preferences exist. Finally, the mean marginal willingness to pay to prevent the loss of one person per one billion people because of wolf reintroduction is several hundred yen. (C) 2012 Elsevier B.V. All rights reserved.

In general, the environmental quality worsens in the early stage of economic growth; however, in some cases, the quality begins to improve after further economic growth. This paper presents a simple model to explain situations in which environmental quality improves or worsens. Changes were focused on the following: economic affluence, preference for natural environment, and the opportunity cost of conserving the natural environment. The results suggest that the second factor is the most important in improving conservation and environmental quality; this is because it is artificially manageable and has a substantial impact on the choice of the conservation level.

Petty-Clark's law suggests that as the economy of a country develops, its proportion of primary industries declines while those of its secondary and tertiary industries increase. Traditionally, hunting has played a crucial role in a country's food supply however, currently, it is increasingly viewed as a leisure activity. This paper empirically examines whether Petty-Clark's law holds in case of hunting in European countries. The results reveal that the proportion of hunters across countries increases when the per capita GDP is between 5,000 and 15,000 USD. Once the per capita GDP crosses the 15,000 USD mark, two major trends are detected: the number of hunters continues to increase in some countries but decreases in some other countries. Finally, the number of hunters in a country stabilizes when its per capita GDP reaches around 25,000 to 30,000 USD.

In Hokkaido, Japan, the number of Yezo deer (Cervus nippon yesoensis) has recently increased drastically,causing a large number of deer-vehicle traffic accidents. This paper examines conditions relatedto deer-vehicle traffic accidents by analysing the following relationships: time of accident andlunar phase; time of accidents and time of sunrise/sunset; likelihood of accidents and rainfall patterns,temperature and season (particularly snow and hunting seasons). The results suggest that the potentialfor deer-vehicle traffic accidents increases during hunting and non-snow seasons when there is littleor no rainfall, just before sunrise or just after sunset, or during a full, first quarter, or third quartermoon. A statistically significant relationship between temperature and deer-vehicle traffic accidentswas not detected.http://tru.uni-sz.bg/bjvm/bjvm.htm

It is pointed out that large carnivores such as wolves prey on weak individuals in ungulate populations, which results in a healthier local ungulate population. However, this hypothesis has not been fully evaluated. The purpose of the paper is to examine whether human hunting can improve the health status of local ungulate populations. To accomplish this, we focus on disease and build an epidemiological Susceptible-Infected-Recovered model. On the basis of numerical simulations of our model, we demonstrated that although human hunting helps prevent the spread of disease, it does not help in the selective removal of infected individuals in a population.

The purpose of this paper is to estimate ecological carrying capacity (K) and growth rate (r) of Lithuanian wolf based on the estimated population sizes and number of harvests from 1966 to 2007. We used the modified Schaefer model where population dynamics is described by the logistic-equation-type growth function with time lag operator (τ) and harvest. We statistically selected the best model whose τ value was 4 and estimated value of K and r were 626 heads for the total Lithuanian territory and 0.776/ year, respectively. Then we examined the appropriateness of the values from the ecological point of view and concluded that ecological carrying capacity is supported by the prey base of wild animals, mainly cervids, and also by depredation on domestic animals. In 1994-1998, the population was near ecological carrying capacity or exceeding it, what we explain by high ecological plasticity of the species and increased use of domestic animals.

Large carnivores such as the wolf (Canis lupus) and the lynx (Lynx lynx) have never been eradicated in Latvia and their numbers particularly increased from the early 1970s onwards, which brought some conflict between the large carnivores and human interests. Therefore, it has always been a challenge for both gamekeepers and conservationists to reveal relationships between ungulates and large carnivores as well as to figure out relevant implications for their management. The purpose of this paper is to reveal the above-mentioned relationships using statistical data. Fortunately statistics on the abundance and hunting bag size of some game species in Latvia have been collected since the early 20th century The study uses these data to examine four types of relationship within the period 1958 - 2005: (1) prey-prey relationships between the population estimates of moose (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus), wild boar (Sus scrofa), (2) predator-prey relationships in the above four ungulate species, wolf and lynx; (3) relationships between the estimated numbers of wolf and lynx; (4) relationships among hunting bags in some of the species listed above. We applied unit root test to check if our statistical results suffered from the spurious correlation. We used regression analysis (dynamic OLS and generalized least square) to reveal statistical findings and examine them from the ecological point of view in order to check the validity of our results. Our statistical results suggest that (1) For the red deer, roe deer is a competitor and vice versa. For the roe deer, moose is also a competitor in addition to the red deer. For the moose, red deer is a competitor. (2) For the wolf, red deer, roe deer and moose are prey whereas for the lynx, only roe deer is prey. (3) For lynx, wolf is a competitor, but for the wolf, lynx is not. (4) The elasticity of hunting with respect to population size is 2.55%, 0.91%, 2.14, 0.42% and 0.82%, for roe deer, red deer, moose, wolf and lynx, respectively. Most of the results are consistent with empirical findings from the field.

The purpose of this study is to estimate the carrying capacity (K) of the wolf and lynx in Latvia using time series data of the estimated population size and number of harvests from 1958 to 2005. We modified the Schaefer model by adding a lag operator. First, we performed the unit root test. In this study, all the time series data are stationary, indicating freedom from spurious correlation. We set both the lag value and estimation period (starting year changed from 1959 to 1968) and searched for the best model based on Akaike information criteria (AIC). The results indicated that τ= 3 is the best value and the estimated value of K is 1,066-1,092 individuals for the wolf, with the starting year changed from 1959 to 1968. For the lynx, we could not select the value of τ the estimated value of K was stable and determined as 971-1,188 individuals.

Travel cost method is one of the most prevailing approaches to estimate the benefit of natural environment. However, the high survey expense limits its application. What is now required is to develop new survey method which needs less cost. One possibility may be to utilize existing data: for example, data of permit or registration form can be used for estimation. In this paper, we use the latter data to estimate the benefits of Kiritappu wetland located in eastern Hokkaido.
Registration form is one kind of on-site data, but it has some difference since it is composed of the data of whole seasons. Usually, on-site survey is conducted in a certain period of the year, which may cause bias in the estimated benefit, especially when the living place distribution of samples (visitors to the site) is widely different from that of samples collected through the year.
We treated this issue by using registration form. Estimated benefits of the certain period and whole seasons are 1200 million yen and 2024 million yen, respectively. It suggests that estimation using a certain period on-site data may cause bias.

There are three main results. First, we investigated the feasibility of utilizing wild game meats and pointed out the price of game meats were normally higher than consumers’ acceptable price range. Second, we developed fish culture feed that contained residue of fruits and compared the costs for the developed feeds with that of normal feed. We showed the possibility of reducing costs of fish culture feed by adding residue of fruits. Third, we compared citizens’ willingness to pay for watching wild/tame otters and showed that citizens prefer watching wild ones as long as the possibility of watching them is high enough.

This study includes six main contributions. First, we extend an existing natural resource model to be applicable for underuse issues. Second, we develop a unit-free index for the wildlife management and apply it for Latvian game animals. Third, we propose a simple and cost-effective method to prevent Japanese sika deer browsing/grazing and empirically confirm its effects. Fourth, we estimate the upper limit of the annual growth rate of the Eurasian beaver in Latvia. Fifth, we examine a possibility of reintroducing the gray wolf into Japan. Finally, we examine a feasibility of maintaining the hunter population in Japan.

The natural capitals have their distinct structure, function and dynamism, providing us with livelihood and defining our lives as a basis of our various daily activities. It appears that the recent circumstances surrounding the natural capitals are changing increasingly, such as rapid development towards globalization, and the number of challenges needing solutions seems to be ever on the increase. This research attempts to elucidate the following : how we may define the criticality of natural capital, how to develop them into workable concepts, to use them as beacons in taking relevant and necessary policy measures and community activities, and to ameliorate such measures and activities further.