The desert termite Gnathamitermes tubiformans and its unique foraging tubes are a common fixture in rangelands across Arizona, New Mexico, northern Mexico, and Texas. Although it is a native species and has thrived for millions of years, recent droughts have made its activity more visible and raised questions about its impact on vegetation. Since G. tubiformans prefers grasses as food, there has been a concern about competition between livestock and termites. Monitoring of desert termite activity was conducted through two experiments focusing on foraging distances and forager population sizes. The foraging distances experiment used circular grids in 5 m x 5 m plots to map the movement of marked G. tubiformans released from the center of the grid. Analyses showed no significant correlations between distances moved and abundance or type of vegetation. Movement of marked termites did not favor any compass directions. The second experiment used a mark-recapture estimation model to predict G. tubiformans forager populations in 5 m x 5 m plots. Linear regression analyses showed a significant positive correlation between size of the forager population and amount of total vegetation. In addition, linear regression analyses showed a significant positive correlation between total estimated number of collected termites during early recruitment and amount of vegetation cover, specifically grasses. Desertification of rangelands used by G. tubiformans and livestock is a worry with few known solutions. Elucidating answers to this problem involves ferreting out the sources of the degradation. The results of this thesis shed light on the role G. tubiformans plays in its habitat, and infer that degraded habitats with low amounts of vegetation will exhibit low termite populations.

Three colonies of wood-ants Formica lugubris were taken from native Caledonian pinewoods and re-established in the laboratory. Experiments were conducted during which each of these colonies was provided with two discrete patches at which foragers could drink from filter papers saturated with aqueous solutions of sucrose; these patches were replenished continuously with the solutions. Three series of experiments were conducted in which the hypothesis tested was that the ants would distribute themselves between the patches according to the ideal free distribution. During the first series of experiments, the rate of supply of sucrose was manipulated by changing the concentrations of the solutions while maintaining equal rates of supply. Under each concentration ratio an equilibrium distribution was established. When the concentrations were equal, foragers distributed in a ratio of 1:1. When the concentrations were unequal the proportion of foragers at the richer patch was consistently less than the proportion of sucrose available there; ratios of sucrose of 1:2 and 1:4 were associated with equilibrium distributions of foragers in the ratios of approximately 1:1 and 1:2 respectively. In the second series of experiments, it was shown that these ratios were dependent on the overall rate of regeneration of the solutions; increases in the overall rate of regeneration were associated with increased proportional occupation of the richer patch. Throughout this experiment, the concentrations of the solutions were 7% w/v and 28% w/v and the rates of regeneration of the solutions at both patches were equal. Distributions were established at four different rates of regeneration. At the lowest rate of regeneration (0.2ml.h-1) the proportion of foragers at the richer patch was significantly lower than the ideal free prediction of 0.8. At the three higher rates of regeneration (0.4ml.h-1, 0.6ml.h-1 and 0.8ml.h-1) the proportion of foragers at the richer patch was significantly greater than the proportion of sucrose available there.

This dissertation expands current theoretical and practical knowledge of variability in the technological strategies practiced by past forager societies. Specifically, it examines the interplay between raw material innate and working properties, and tool design as they relate to skeletal media and technologies. Data were synthesized from existing biomedical literature on the structure and mechanical properties of technologically-relevant osseous media, including bird and cetacean bone, and antler. Original laboratory tests were then conducted to determine the mechanical properties of Young's modulus (intrinsic stiffness), intrinsic strength, and fracture resistance of the compact tissue of reindeer antler, cervid long bones, and the limb bones of the California sea lion. Cervid compact limb tissue is stiff, strong, and brittle, while reindeer antler is flexible and highly fracture-resistant (tough). Air-drying hardens all skeletal tissues, and greatly increases investment times for creating tool blanks of both antler and cervid limb bone. Water -soaking can soften dry antler, but may have little effect on the workability of previously-dried land mammal limb bone. Finally, data on the mechanical and working properties of osseous tissues were applied to an analysis of the raw material selection and tool design strategies practiced by protohistoric Alutiiq foragers of Alaska's Kodiak region. Drawing on a sample of over 300 osseous tools and tool blanks, the engineering designs of five tool types were investigated: unbarbed arrows, barbed sea mammal harpoons, fishing harpoon tips, woodworking wedges, and awls. By employing multiple analytical scales, the study points to multiple design pathways toward a generalized goal of maximizing tool longevity, or circulation time. Tool fracture potential can be reduced through raw material selection and stress-reducing structural design. Alutiiq designs for longevity include nested fish harpoon valves, and the off-set line holes on unilaterally barbed harpoons. Also, both tool types were created most frequently from tough but non-local antler. Tool recycling and conservation to avoid drying and fracture can likewise increase tool use-lives. For osseous tools, maximizing longevity might offset high initial tool production investments. The results are applicable to processes of technology transfer in many protohistoric contexts and the Upper Paleolithic of Eurasia.

A research of foraging represents a relatively new phenomenon abroad. In Czechia, on the other hand, this is an ordinary issue with a long-time tradition, but until recently it has not received much attention by the scientific community. For this reason, the following diploma thesis deals with this activity. It consists of two main units. The first part aims to create the theoretical framework necessary for the introduction into the foraging study. It includes a familiarization with the trend of the self-provisioning in general both in Czechia and abroad. A substantial part of the theoretical framework deals with the quantity and the typology of harvested products, the reasons for foraging, the characteristics of the harvesters, etc. It also outlines the problem of western academics' interpretation of foraging in post-communist conditions as a survival strategy. In the second part, using the mixed research methods, the thesis seeks to find out what is the tradition of foraging in Czech conditions during recent decades, who are the harvesters and what are the reasons and motivations to harvest. By statistical data analysis and by interviewing method, it is confirmed that people across a variety of demographic and socio-economic characteristics are harvesting and motivation is certainly not a bad...

Honey bees utilize their circadian rhythms to accurately predict the time of day. This ability allows foragers to remember the specific timing of food availability and its location for several days. Previous studies have provided strong evidence toward light/dark cycles being the primary Zeitgeber for honey bees. Work in our laboratory described large individual variation in the endogenous period length of honey bee foragers from the same colony and differences in the endogenous rhythms under different constant temperatures. In this study, we further this work by examining the temperature inside the honey bee colony. By placing temperature and light data loggers at different locations inside the colony we measured temperature at various locations within the colony. We observed significant oscillations of the temperature inside the hive, that show seasonal patterns. We then simulated the observed temperature oscillations in the laboratory and found that using the temperature cycle as a Zeitgeber, foragers present large individual differences in the phase of locomotor rhythms for temperature. Moreover, foragers successfully synchronize their locomotor rhythms to these simulated temperature cycles. Advancing the cycle by six hours, resulting in changes in the phase of activity in some foragers in the assay. The results are shown in this study highlight the importance of temperature as a potential Zeitgeber in the field. Future studies will examine the possible functional and evolutionary role of the observed phase differences of circadian rhythms.

Our understanding of the Later Stone Age (LSA) on the Greater Mapungubwe Landscape has until now been fairly limited. However, it is a landscape upon which foragers witnessed and partook in agriculturalist state formation between AD 900 and 1300, altering their cultural behaviour to suit their changing social and political topography. Nowhere else in southern Africa were foragers part of such developments. For this project a landscape approach was used to study the various changes in the regional LSA record as well as the way in which foragers interacted with farmers. In order to address these issues, data were obtained from an archaeological survey followed by an excavation of seven sites in north-eastern Botswana, part of the Greater Mapungubwe Landscape. These finds indicate that the local forager record varies chronologically and spatially, which had not previously been recorded. Foragers also used a variety of site types and in each a different forager expression was deposited, providing indications of their changing settlement pattern. Notably, this included a gradual movement into agriculturalist homesteads beginning by at least AD 1000 and concluding by AD 1300, when the Mapungubwe capital was abandoned. Thus, interactions, at least in some cases, led to assimilation. There is also clear evidence of exchange with agriculturalists at many of the excavated sites, but this does not always seem to be related to their proximity with one another. Performing a landscape study has also made it possible to make two general conclusions with regard to LSA research. First, these data challenge ethnography, displaying its limitations particularly with linking modern Bushman practices, such as aggregation and dispersal patterns or hxaro gift exchange, to LSA foragers. Second, a full landscape understanding combines the archaeology of multiple cultural landscapes and in this case also crosses national borders, two themes often neglected in southern African archaeological studies.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-10-09T19:44:11Z No. of bitstreams: 1 marleneaparecidacantarino.pdf: 735316 bytes, checksum: 7742165e1a5022ea995802f6cc85e19d (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-10-09T20:04:22Z (GMT) No. of bitstreams: 1 marleneaparecidacantarino.pdf: 735316 bytes, checksum: 7742165e1a5022ea995802f6cc85e19d (MD5) / Made available in DSpace on 2017-10-09T20:04:22Z (GMT). No. of bitstreams: 1 marleneaparecidacantarino.pdf: 735316 bytes, checksum: 7742165e1a5022ea995802f6cc85e19d (MD5) Previous issue date: 2017 / Mahanarva spectabilis (Hemiptera:Cercopidae)(Distant, 1909) vem comprometendo a produção de leite e carne pelos danos causados às forrageiras e métodos de controle desse inseto praga têm sido pesquisados. Dessa forma objetivou-se avaliar o efeito do nitrogênio na mediação da tolerância de Brachiaria ruziziensis Germain e Everard, à M. spectabilis. Vasos contendo solo e plantas de B. ruziziensis foram adubadas com nitrogênio nas doses 0, 50, 100, 200 e 400 kg/ha, divididas em três aplicações. Decorrendo doze dias da última adubação, as plantas receberam ninfas de M. spectabilis nas densidades 0, 5, 10, e 15. Após 10 dias avaliou-se: teor de clorofila, danos na área foliar, altura das plantas e qualidade bromatológica da forrageira. Posteriormente, avaliou-se a porcentagem de emissão de perfilhos (10 e 28 dias após a retirada das ninfas). Os ensaios foram conduzidos em delineamento em blocos casualizados em esquema fatorial. Não houve interação entre os componentes estudados (nitrogênio x densidade de ninfa) para nenhuma das variáveis. O nitrogênio mediou a tolerância, promovendo redução nas injúrias causadas por M. spectabilis em plantas de B. ruziziensis, com aumento do índice de clorofila à medida que aumentava as doses de nitrogênio; redução dos danos na área foliar para as doses 50 e 100 kg/N/ha; aumento na altura das plantas e também aumento na porcentagem de emissão de perfilhos responsivos ao aumento das doses. Constatou-se, também, alteração na qualidade da forragem, com redução da celulose, aumento da porcentagem de proteína bruta, redução dos teores de fibra de detergente neutro e consequentimente elevação da DIVMS. Em contrapartida o aumento da densidade de ninfas de M. spectabilis promoveu reducão no teor de clorofila, na emissão de perfilhos, assim como aumento de dano na área foliar. Também alterou a qualidade da forragem, com redução de lignina, proteína bruta, digestibilidade in vitro matéria seca e aumento fibra de detergente neutro. Assim, o nitrogênio atuou como mediador de tolerância em plantas de B. ruziziensis submetidas a diferentes densidades de ninfa de M. spectabilis. / Mahanarva spectabilis (Hemiptera: Cercopidae) (Distant, 1909) has been compromising the production of milk and meat because the damages caused to the forage and control methods of this insect pest, that have been researched. The objective of this study was to evaluate the effect of nitrogen on the tolerance mediation of Brachiaria ruziziensis Germain and Everard, Mahanarva spectabilis. Pots containing soil and plants of B.ruziziensis were fertilized with nitrogen at doses 0, 50, 100, 200 and 400 kg/ha, divided into three applications. After twelve days of the last fertilization, the plants received nymphs of M. spectabilis at densities 0, 5, 10, and 15. After 10 days, chlorophyll content, leaf area damage, plant height, and forage bromatological quality were evaluated. Posteriorly the percentage of tiller emission (10 and 28 days after withdrawl of the nymphs) was evaluated. The experiment were conducted in a randomized complete block design in a factorial scheme. There was no interaction between the studied components (nitrogen x nymph density) for any of the variables. Nitrogen mediated tolerance, promoting reduction in the injuries caused by M. spectabilis in B. ruziziensis plants, with an increase in the chlorophyll index as nitrogen doses increased; reducing leaf area damage at doses 50 and 100 kg/N/ha; increase in the height of the plants and also increase in the percentage of shoots responding to the increase of the doses. It was also found alteration in forage quality, with reduction of the cellulose, increase the percentage of crude protein, reduce the levels of neutral detergent fiber and consequently elevation of IVDMD. In contrast the increase of the nymph density of M. spectabilis promoted reduction in chlorophyll content, in the emission of tillers, as well as increase of leaf area damage. Also altered forage quality, with reduced lignin, crude protein, digestibility in vitro dry matter and increased neutral detergent fiber. So the nitrogen acted as a tolerance mediator in B. ruziziensis plants submitted to different nymph densities of M. spectabilis.

Abstract. The circadian locomotor (walking) rhythms of forager honeybees (Apis mellifera ligustica L.) were entrained to eight different 24 h light‐dark cycles. The phases of activity onset, peak activity, and offset were correlated with the lights‐off transition, suggesting lights‐off as the primary zeitgeber for the rhythm. Further support for this hypothesis was provided by LD 1:23 experiments, in which entrainment occurred when the light pulse was situated at the end, but not at the beginning, of the subjective photophase. Steady‐state entrainment of the locomotor rhythm was achieved with square‐wave temperature cycles of 10oC amplitude under constant dark: most of the activity occurred within the early thermophase. Smaller amplitude temperature cycles yielded relative coordination of the rhythm. Interactions of temperature and light‐dark cycles resulted in entrainment patterns different from those elicited in response to either cycle alone or those formed by a simple combination of the two separate responses. Furthermore, temperature cycles having amplitudes insufficient for entrainment of the rhythm nevertheless modified the pattern of entrainment to light ‐ dark cycles, suggesting a synergism of light and temperature effects on the underlying circadian clock system.

Made available in DSpace on 2014-08-20T14:38:45Z (GMT). No. of bitstreams: 1 dissertacao_otavio_matos_tavares.pdf: 665334 bytes, checksum: 9d1b76916bd06ebd657d489b448639b6 (MD5) Previous issue date: 2012-06-29 / The experiment, divided into two phases (Phase I and Phase II), had as its objective to evaluate forage production of annual ryegrass (Estanzuela LE 284) of natural reseeding subjected to nitrogen fertilization in the succession of a soybean crop in crop-livestock integration and the residual effect of fertilization on the production of corn grains (crop successor). Treatments of Phase I consisted of four levels of nitrogen fertilization (urea 45%) of coverage (N0 = 0 kg/ha de N, N1 = 22,5 kg/ha de N, N2= 67,5 kg/ha de N e N3 = 135 kg/ha de N) and two levels base fertilization (B1= no fertilization; B2= with fertilization in the order of 170 kg/ha of the formula 05-25-25). The pasture was managed by cutes in accordance with its height. Each time the pasture reached the average canopy height from 20-25 cm, two samples (circular cuts - 0,0881 m²) were made leaving a residue of 10-12 cm. During this occasion a sample was collected with a square of 0,04 m² to determine the number of tillers and leaf area index (LAI). The entire profile of the canopy was cut. Phase II consisted of the evaluation of the residual effect of the fertilization treatments of Phase I on the production of corn grains. The base fertilization (NPK) and the application of nitrogen in coverage, significantly increase forage production of annual ryegrass of natural reseeding in soybean stubble in crop-livestock integration. Nitrogen fertilization linearly increase the weight of tillers and leaf blades. The averages of remaining ryegrass straw added to the soybean crop residues meet the appropriate amount for the implementation of the summer crop in the SPD. Nitrogen fertilization presents no residual effect on the crop yield of corn for grain in succession. / O experimento, dividido em duas fases (Fase I e Fase II), teve como objetivo avaliar a produção de forragem de azevém anual (Estanzuela LE 284) de ressemeadura natural na sucessão da cultura da soja submetido à adubação nitrogenada em integração lavoura-pecuária e o efeito residual da adubação na produção de grãos de milho (cultura sucessora). Os tratamentos da Fase I constaram de quatro níveis de adubação nitrogenada (ureia 45%) em cobertura (N0 = 0 kg/ha de N, N1 = 22,5 kg/ha de N, N2= 67,5 kg/ha de N e N3 = 135 kg/ha de N) e dois níveis de adubação de base (B1= sem adubação; B2= com adubação, na ordem de 170 kg/ha da fórmula 05-25-25). O pasto foi manejado por cortes seguindo um protocolo de altura. A cada vez que o pasto atingia altura média do dossel entre 20-25 cm eram efetuadas duas amostragens (cortes) circulares (0,0881 m²), deixando-se um resíduo de 10-12 cm. Na mesma ocasião era coletada uma amostra com um quadro de 0,04 m² para determinação do número de perfilhos e índice de área foliar (IAF), sendo coletado todo o perfil do dossel. A Fase II consistiu da avaliação do efeito residual dos tratamentos de adubação da Fase I sobre a produção de grãos de milho. As adubações de base (NPK) e de nitrogênio em cobertura aumentam a produção de forragem de azevém anual de ressemeadura natural em resteva de soja no sistema de integração lavoura-pecuária. A adubação nitrogenada aumenta de forma linear o peso de perfilhos e de lâminas foliares. As médias da palhada remanescente de azevém somadas aos resíduos da cultura da soja atendem a quantidade adequada para a implantação da lavoura de verão no SPD. A adubação nitrogenada não apresenta efeito residual sobre a cultura do milho para grãos em sucessão.

As relações entre a variabilidade e a variação dos conjuntos líticos de dois abrigos-sob-rocha do carste de Lagoa Santa - MG são analisadas em relação às estratégias de sobrevivência empregadas pelos grupos caçadores-coletores locais para lidar com as mudanças na disponibilidade de recursos no decorrer do Holoceno Inicial e Médio. Os processos de longa duração que atuaram na formação do registro arqueológico da Lapa do Santo e da Lapa das Boleiras são investigados através do estudo das continuidades e mudanças nas estratégias de procura, confecção, utilização e descarte dos materiais líticos. / The relationships between variability and variation in the lithic assemblages of two rock-shelters from Lagoa Santa are analyzed in respect to the survival strategies employed by local hunter-gatherers to deal with changes in resource's availability during the Early and Middle Holocene. The long-term processes involved in the formation of the archaeological record of Lapa do Santo and Lapa das Boleiras are investigated by the study of continuities and changes in the strategies to acquire raw materials and production, use and discard of lithic tools.