Subsistence hunting and conservation issues in the game reserve of Gile, Mozambique

Ethnozoological research was conducted to gather information on the hunting activities and their relevance for the subsistence of local people in 8 villages around the game reserve of Gile, Mozambique. Two series of data were gathered by questionnaires to: (a) 510 householders from eight villages located in the outskirts of the Reserve; (b) 10 hunters from the village of Gile, the main centre of the study area. Several hunting techniques were recorded: spears, nets, traps (including gin-traps) and wildfires, while the use of guns did not appear relevant. The importance of subsistence hunting for local people was underlined by the high percentage of respondents who declared that they usually conduct this activity and sell bushmeat. The proportion of hunters per village was related to the village size but not to its geographical location of villages and the household composition. A positive relationship existed between the proportion of hunters, crop production and fishing activities, indicating that hunting is part of an integrated system of subsistence activities. Most animals harvested were mammals (89.5%, of which 46.7% were ungulates) and most were captured within the Reserve (96%). A higher percentage of animals was sold (56%), representing a relevant income source for the villagers. Small animals were mainly captured by traps during solitary hunting, medium-sized animals in collective net hunting; larger prey were captured by gin-traps adopted by both solitary and collective hunting. In the diet of the local people wild animals represented a higher protein source than domestic animals.     

Diets in Transition: Hunter-Gatherer to Station Diet and Station Diet to the Self-Select Store Diet

The transition of Australian Aborigines from a diet based on hunting and gathering to an essentially Western diet has been proceeding for almost 200 years, but in some regions was greatly delayed. In 1966/1967 G ould (1980) studied operational aspects of hunting-gathering in desert regions of northwestern Australia and recorded sufficient quantitative and species-specific data to allow definition of the diet over 5 months. By 1966, many Aboriginal people in that region had been displaced from their hunting grounds and were living in camps on cattle stations or in missions. Aboriginal diet on cattle stations in the north-westwas studied in 1951 (Commonwealth Departmentof Health) and shown to consist chiefly of fresh meat, wheaten flour, and sugar with small amounts of vegetables and dairy products. With the granting of citizenship in 1967, most Aborigines were dismissed from cattle stations and were moved first to town camps and later formed remote Aboriginal communities. Studies in the 1980s showed that the self-selected diet in such communities reflected the station diet to a greater extent than the traditional diet. Quantitative presentation of the above three diets, in terms both of foods and of major nutrients, show that many of the dietary inadequacies of the station diet identified in 1951 still persisted in self-selected Aboriginal diets in the 1980s. A comparison of the three diets with a modern recommended dietsupports the nutritional adequacy of the hunter-gatherer diet. Traditional cultural values assigned to food preferences continued to influence food choices in all three diets.     

The Economic Importance of Communal Net Hunting Among the BaAka of the Central African Republic

This article examines current net hunting practice by BaAka Pygmies of central Africa. In terms of time allocation, net hunting remains the single most important activity for the BaAka, But net hunting is only one in a range of subsistence and economic activities among which individuals switch on a daily basis. Returns from net hunting are roughly equivalent to those from competing activities. Several factors encourage the decline of net hunting and its replacement with snare hunting: enforcement of park regulations, higher individual returns to snare hunting, and greater involvement in formal employment and agriculture. However, net hunting has not been abandoned completely for several reasons: the local market demand for bushmeat is growing, numerous forest products besides meat are collected on net hunts, and economic alternatives remain irregular and unreliable.     

What are we missing with only ground‐level mist nets? Using elevated nets at a migration stopover site

ABSTRACT Mist nets deployed in a standard ground‐level fashion capture birds approximately 0.5–2.6 m above the ground. In habitats where the vegetation extends above this height, standard mist net deployment may inadequately sample the targeted avian community and age‐ and sex‐classes within species. Such sampling biases may raise questions regarding studies based on data from mist‐net captures. To determine if birds were equally likely to be captured by mist nets at different heights, we constructed a series of paired ground‐level and elevated mist nets (hereafter “net rigs”) at a research station in western New York State. Net rigs were operated during 14 migration seasons from 2000 to 2006 (spring and fall each year), and 19,735 birds of 118 species were captured. Capture rates were significantly higher in ground‐level nets, but 12 species were only captured in elevated nets. Of 44 species with at least 50 captures, 25 species were more likely to be captured in the ground‐level nets and two species in the elevated nets. For four of 18 species, more birds were captured in the elevated nets during fall migration than during spring migration. We conclude that standard ground‐level net placement was more efficient in capturing birds in the secondary growth habitats that we sampled. However, ground‐level nets may not adequately sample the entire targeted community or all age‐ or sex‐classes within species.     

Hunting strategies employed by bird hunters with economic pursuit in the city of Guiyang,Southwest China

Understanding hunter motivations and strategies is of particular importance in regions fraught with wildlife hunting, due to the critical hunter’s role in linking wildlife supply and consumption. However, such information is extremely scarce in China despite the worrisome situation of wildlife hunting. This study documents the techniques, motivations and hunting frequencies of bird hunters who have economic interests in the city of Guiyang, Southwest China, where numerous wild birds have been observed in trade. The data were collected using semi-structured questionnaires given to 50 hunters in a public market between March and July 2015. At least 9 kinds of tools and 10 kinds of techniques have been employed in local bird hunting practices. Up to eight factors have stimulated the collection of wild birds, of which commercial benefit was undoubtedly the most important. Hunting activities were conducted throughout the year, and efficient and low-cost hunting techniques, such as hunting with nets and neck snares were the predominant hunting techniques. The use of bait birds, whistles and bird song recordings was common, with the aim of improving the harvest by finding and attracting target species, highlighting a preference for hunting certain species of birds. The various hunting motivations underscore the complexity of the current hunting issue. Conservation management was discussed by considering the hunting strategies employed and the needs of hunters, as well as the market demand, which highlights the necessity of the combined actions of law enforcement, commercial breeding, social welfare, the development of hunting grounds and environmental education.     

Use of Bed Nets and Factors That Influence Bed Net Use among Jinuo Ethnic Minority in Southern China

Background

Insecticide-treated nets (ITNs) are an integral part of vector control recommendations for malaria elimination in China. This study investigated the extent to which bed nets were used and which factors influence bed net use among Jinuo Ethnic Minority in China-Myanmar-Laos border areas.

Methods and Findings

This study combined a quantitative household questionnaire survey and qualitative semi-structured in-depth interviews (SDI). Questionnaires were administered to 352 heads of households. SDIs were given to 20 key informants. The bed net to person ratio was 1∶2.1 (i.e., nearly one net for every two people), however only 169 (48.0%) households owned at least one net and 623 (47.2%) residents slept under bed nets the prior night. The percentages of residents who regularly slept under nets (RSUN) and slept under nets the prior night (SUNPN) were similar (48.0% vs. 47.2%, P>0.05), however the percentage correct use of nets (CUN) was significantly lower (34.5%, P<0.0001). The annual cash income per person (ACIP) was an independent factor that influenced bed net use (P<0.0001), where families with an ACIP of {"type":"entrez-protein","attrs":{"text":"CNY10000","term_id":"895491745","term_text":"CNY10000"}}CNY10000 or more were much more likely to use nets. House type was strongly associated with bed net use (OR: 4.71, 95% CI: 2.81, 7.91; P<0.0001), where those with traditional wood walls and terracotta roofs were significantly more likely to use nets, and the head of household''s knowledge was an independent factor (OR: 5.04, 95% CI: 2.72, 9.35; P<0.0001), where those who knew bed nets prevent malaria were significantly more likely to use nets too.

Conclusions

High bed net availability does not necessarily mean higher coverage or bed net use. Household income, house type and knowledge of the ability of bed nets to prevent malaria are all independent factors that influence bed net use among Jinuo Ethnic Minority.     

Net hunters vs. archers: Variation in women's subsistence strategies in the Ituri Forest

BaMbuti of the Ituri Forest, Zaire, employ two primary hunting techniques: net hunting, in which women routinely participate, and bow hunting, in which women rarely participate. We hypothesize that the value of women's labor devoted to different subsistence activities, combined with the exchange value of meat, will determine whether women participate in hunts. Field observations were conducted in four different areas: two exploited by archers and two by net hunters. Results indicate that women in nethunting areas earn more calories per unit time by hunting than by working in agriculturalists' gardens; whereas women in archer areas earn more calories by working for agriculturalists than by hunting. We found no significant difference in the composition or diversity of the forests exploited by net hunters and archers. The results are discussed in light of the longstanding debate concerning the factors that account for distribution of net hunting and archery in the Ituri Forest.     

象山港两种网目网采浮游动物群落比较

分别于2010年3月(春)、7月(夏)、9月(秋)、12月(冬),用浮游生物Ⅰ型(网目505 μm)、Ⅱ型(网目160 μm)网同步在象山港进行6站位2重复的浮游动物取样,比较分析了不同时空下两种网目采集的浮游动物群落差异.结果表明：两网间的浮游动物种类数、丰度、生物量、优势种和群落格局都存在极大差异.其中,Ⅰ网的种类数(61种,包括幼虫)、平均丰度(139.0 ind·m^-3)和平均生物量(86.1 mg·m^-3)显著低于Ⅱ网(分别为84种、3780.2 ind·m^-3和191.1 mg·m^-3).在优势种中,除太平洋纺锤水蚤和墨氏胸刺水蚤为两网共有优势种外,其余优势种完全不同.Ⅰ网未检出周年的优势种,而Ⅱ网的周年优势种是针刺拟哲水蚤和桡足类幼体.相似性分析(ANOSIM)和nMDS排序结果显示,两网群落格局不仅在时空上存在显著差异,而且Ⅰ网群落比Ⅱ网更离散.相似性百分比(SIMPER)分析进一步揭示,两网群落格局间平均非相似性高达75%以上,造成两网群落时空非相似性差异的主要判别种是：针刺拟哲水蚤、桡足类幼体、强额拟哲水蚤和短角长腹剑水蚤,而这些种均为Ⅱ网的优势种.表明象山港浮游动物调查时以Ⅱ网更具代表性.     

A stitch in time: a cross-sectional survey looking at long lasting insecticide-treated bed net ownership, utilization and attrition in SNNPR, Ethiopia

ABSTRACT: BACKGROUND: Since 2002/03, an estimated 4.7 million nets have been distributed in the Southern Nations, Nationalities and Peoples Region (SNNPR) among an at risk population of approximately 10 million people. Evidence from the region suggests that large-scale net ownership rapidly increased over a relatively short period of time. However, little is known about how coverage is being maintained given that the last mass distribution was in 2006/2007. This study sought to determine the status of current net ownership, utilization and rate of long lasting insecticide-treated nets (LLIN) loss in the previous three years in the context of planning for future net distribution to try to achieve sustainable universal coverage. METHODS: A total of 750 household respondents were interviewed across malarious, rural kebeles of SNNPR. Households were randomly selected following a two-stage cluster sampling design where kebeles were defined as clusters. Kebeles were chosen using proportional population sampling (PPS), and 25 households within 30 kebeles randomly chosen. RESULTS: Approximately 67.5% (95%CI: 64.1-70.8) of households currently owned at least one net. An estimated 31.0% (95%CI 27.9-34.4) of all nets owned in the previous three years had been discarded by owners, the majority of whom considered the nets too torn, old or dirty (79.9%: 95%CI 75.8-84.0). Households reported that one-third of nets (33.7%) were less than one year old when they were discarded. The majority (58.8%) of currently owned nets had 'good' structural integrity according to a proportionate Hole Index. Nearly two-thirds of households (60.6%) reported using their nets the previous night. The overriding reason for not using nets was that they were too torn (45.7%, 95% CI 39.1-50.7). Yet, few households are making repairs to their nets (3.7%, 95% CI: 2.4-5.1). CONCLUSIONS: Results suggest that the life span of nets may be shorter than previously thought, with little maintenance by their owners. With the global move towards malaria elimination it makes sense to aim for sustained high coverage of LLINs. However, in the current economic climate, it also makes sense to hark back to simple tools and messages on the importance of careful net maintenance, which could increase their lifespans.     

Niche construction and Dreaming logic: aboriginal patch mosaic burning and varanid lizards (Varanus gouldii) in Australia

Anthropogenic fire is a form of ecosystem engineering that creates greater landscape patchiness at small spatial scales: such rescaling of patch diversity through mosaic burning has been argued to be a form of niche construction, the loss of which may have precipitated the decline and extinction of many endemic species in the Western Desert of Australia. We find evidence to support this hypothesis relative to one keystone species, the sand monitor lizard (Varanus gouldii). Paradoxically, V. gouldii populations are higher where Aboriginal hunting is most intense. This effect is driven by an increase in V. gouldii densities near successional edges, which is higher in landscapes that experience extensive human burning. Over time, the positive effects of patch mosaic burning while hunting overwhelm the negative effects of predation in recently burned areas to produce overall positive impacts on lizard populations. These results offer critical insights into the maintenance of animal communities in the desert, supporting the hypothesis that the current high rate of endemic species decline among small animals may be linked to the interaction between invasive species and mid-century removal of Aboriginal niche construction through hunting and patch mosaic burning.     

Participation of African social scientists in malaria control: identifying enabling and constraining factors

Background

Insecticide-treated nets represent currently a key malaria control strategy, but low insecticide re-treatment rates remain problematic. Olyset? nets are currently one of two long-lasting insecticidal nets recommended by WHO. An assessment was carried out of the effect of Olyset? nets after seven years of use in rural Tanzania.

Methods

A survey of Olyset? nets was conducted in two Tanzanian villages to examine their insecticide dosage, bioassay efficacy and desirability compared with ordinary polyester nets.

Results

Of 103 randomly selected nets distributed in 1994 to 1995, 100 could be traced. Most nets were in a condition likely to offer protection against mosquito biting. Villagers appreciated mainly the durability of Olyset? nets and insecticide persistence. People disliked the small size of these nets and the light blue colour and preferred a smaller mesh size, features that can easily be modified. At equal price, 51% said they would prefer to buy an Olyset? net and 49% opted for an ordinary polyester net. The average permethrin content was 33%-41% of the initial insecticide dose of 20,000 mg/Kg. Bioassay results indicated high knock-down rates at 60 minutes, but the mosquito mortality after 24 hours was rather low (mean: 34%). No significant correlation was found between bioassay results and insecticide concentration in and on the net.

Conclusions

Olyset? nets are popular, durable and with a much longer insecticide persistence than ordinary polyester nets. Hence, Olyset? nets are one of the best choices for ITN programmes in rural malaria-endemic areas.     

A comparison of bridled and bridle‐less ichthyoplankton nets in a variable flow estuarine environment

The effectiveness of bridled and bridle‐less plankton nets for sampling ichthyoplankton from a fixed structure in a variable flow environment was examined. From 22 June to 19 September 2011, larval and juvenile fishes were collected weekly during night flood tides from the Moon River, an estuarine tidal creek south of Savannah, Georgia, USA. Passive horizontal tows were made from a fishing pier using two ichthyoplankton nets, each with a 1 m diameter hoop and 1 mm mesh. A bridled plankton net was configured with a tow rope attached to a traditional three‐point bridle anchored to the hoop and a closed, 1 L collection jar at the cod end. A bridle‐less net was configured with a tow rope and a float tied to the top of the hoop while a weight was tied to the bottom of the hoop. The cod end of the bridle‐less net had an open collection bucket with 1 mm mesh. Nets were deployed simultaneously in the water column, just below the surface, for three consecutive 30‐min tows. For each sampling date, pair‐wise comparisons of nets were performed on mean values of fish abundance, species richness, species diversity, and species evenness. Mean abundance was the only consistent difference between bridled and bridle‐less nets, with the bridle‐less net having on average 4.870 times more fishes. Species richness (as measured by both number of species and Margalef's species richness index) tended to be greater in the bridle‐less net, but not significantly greater. Species diversity (Shannon‐Wiener diversity index) and species evenness (Pielou's evenness index) were also not significantly different between the two nets.     

Types and extent of fishing gear losses and their causes in the artisanal fisheries of Istanbul,Turkey

Fishing gear losses remain a serious problem for marine life; these losses are also the source of an invisible fishing mortality. This study is an analysis of this problem within the artisanal fisheries of Istanbul. From September 2009 through May 2010, face‐to‐face interviews were conducted in 27 fishing ports for a total of 282 questionnaires. Estimates of lost fishing gear were 229.48 km of set nets, 2700 m of longlines, and 14 fish traps. Turbot nets had the highest loss ratio (54.73%), followed by bonito nets (16%), red mullet nets (7.36%), and encircling trammel nets (4.83%). The four major causes of net loss were: conflicts with other gear types (trawl and purse seine), conflicts with cargo vessels, bottom structure hindrances, and bad weather conditions. Bottom structures were the single factor in net losses for longlines and fish traps. The study observed that large quantities of nets had been lost, and that each net type showed a positive relationship between the number of nets used and the number of nets lost. Separate zones for artisanal and industrial fisheries are recommended as a realistic approach to reduce the losses of fishing gear and the impact of ‘ghost fishing’.     

Sampling and filtration efficiency of two commonly used plankton nets. A comparative study of the Nansen net and the Unesco WP 2 net

The paper presents the results from a study in which two commonlyused plankton nets, the Nansen net and the WP 2 net, were compared.The study was performed at six stations in the Baltic Sea andthe samples were collected during seasons of both high and lowparticle abundance. The comparison included both qualitativeand quantitative filtration capacity of the nets under differentenvironmental conditions. Different mesh sizes were also tested.The results show that the Nansen net has an efficiency of 50–70%compared to the WP 2 net under favourable conditions. When conditionsare unfavourable, i.e. during periods of high particle abundanceor during long hauls, the efficiency may be as low as 25–30%.The mesh size of the nets proved to be of decisive importancefor the qualitative composition of the samples. Most of thesmaller size fractions such as rotifers, copepod nauplii andyoung copepodites passed through the 160 and 200 µm meshes.The 90 µm nets sampled these fractions well but with thedrawback of retaining vast amounts of phytoplankton at certaintimes of the year.     

Aboriginal Burning Regimes and Hunting Strategies in Australia’s Western Desert

A large complement of Australia’s biotic web is dependent on a regular regime of burning, much of which is the result of firing by humans. Many researchers have suggested that moderate and repeated burning by Aborigines is a tool designed to enhance hunting efficiency. We present the first test of this with data on contemporary Martu Aboriginal burning and hunting strategies in the arid spinifex savanna of the Western Desert during the cool-dry season (May–August). Our results show a strong positive effect of mosaic burning on the efficiency of hunting burrowed prey (primarily conducted by women), but not larger mobile prey (primarily conducted by men). We suggest that regular anthropogenic disturbance through burning in Australia’s Western Desert may be important for sustaining biodiversity and habitat mosaics, but these effects may be maintained primarily by women’s hunting of burrowed game. We discuss the implications of these results for understanding variability in hunting strategies, issues of conservation, and land management policy for the region.     

A moorable,automated plankton sampler

A moorable, automated plankton sampler is described, designed to obtain series of plankton samples over extended time periods in the absence of a surface vessel. The sampler consists of one or more net-containing boxes, a unit for generating as well as measuring water flow through the net boxes, a programmeable control unit, and a frame. Each net box contains several nets on a vinyl strip, used to move the nets from the storage chamber into the fishing position and then into the preservative chamber. Preservation of samples is in a formalin-brine mixture.Net boxes can be added and the number of nets per box changed; the prototype is described with 1 net box with 10 nets. Volume of water to be filtered, time between sample collections, number of net boxes and the number of nets in each box is programmed into the control unit before sampler deployment. Collections made with the sampler are compared with those made with a SCOR net and a pump.     

Tests to confirm quantitative sampling of young fish by the Bagenal buoyant net

SUMMARY. Buoyant nets had been developed and used for several years to sample young fish quantitatively. Tests were carried out to verify the quantitative aspect of sampling. Using nets of 1-m and 0.5-m mouth diameter, over several months, the catches of the two net sizes were compared. There was no significant difference in the lengths of the fish caught in the two sizes of net nor in the population estimates derived from their catches. These results indicate that there is no avoidance of the nets and that they can be considered to sample quantitatively.     

Mesh-size effects on drift sample composition as determined with a triple net sampler

Nested nets of three different mesh apertures were used to study mesh-size effects on drift collected in a small mountain stream. The innermost, middle, and outermost nets had, respectively, 425 µm, 209 µm and 106 µm openings, a design that reduced clogging while partitioning collections into three size groups. The open area of mesh in each net, from largest to smallest mesh opening, was 3.7, 5.7 and 8.0 times the area of the net mouth. Volumes of filtered water were determined with a flowmeter. The results are expressed as (1) drift retained by each net, (2) drift that would have been collected by a single net of given mesh size, and (3) the percentage of total drift (the sum of the catches from all three nets) that passed through the 425 µm and 209 µm nets. During a two day period in August 1986, Chironomidae larvae were dominant numerically in all 209 µm and 106 µm samples and midday 425 µm samples. Large drifters (Ephemerellidae) occurred only in 425 µm or 209 µm nets, but the general pattern was an increase in abundance and number of taxa with decreasing mesh size. Relatively more individuals occurred in the larger mesh nets at night than during the day. The two larger mesh sizes retained 70% of the total sediment/detritus in the drift collections, and this decreased the rate of clogging of the 106 µm net. If an objective of a sampling program is to compare drift density or drift rate between areas or sampling dates, the same mesh size should be used for all sample collection and processing. The mesh aperture used for drift collection should retain all species and life stages of significance in a study. The nested net design enables an investigator to test the adequacy of drift samples.     

Homogeneous nets of neuron-like elements

Propagation and reverberation of excitation patterns are investigated for 1-dimensional and 2-dimensional homogeneous nets of neuron-like elements. A 1-dimensional net has a proper set of excitation patterns which only can be conducted in the net. Such a net has an ability of discriminating and shaping stimulus signals. Two types of self-reproducing reverberatory excitation patterns are shown for 2-dimensional homogeneous nets. An algebraic theory of general homogeneous nets is also developed.     

Control of switching nets

Switching nets have long been used as models of biological phenomena. In this paper, control properties of switching nets are discussed. Bounds on control parameters for general nets, linear nets and nets with linear inputs are obtained. In particular, bounds are obtained on the maximum distance between two states and on the length of input sequences needed to synchronize two copies of the same net. Bounds on the number of input lines that must be added to an autonomous net to make it controllable are obtained in terms of the number of cycles and transient chains of the net.