THE INFLUENCE OF DIET COMPOSITION, PLANT DEFENSIVE CHEMICALS, AND WINTER SEVERITY ON THE NUTRITIONAL CONDITION OF A FREERANGING, GENERALIST HERBIVORE

Herbivory requires animals to manage intake of toxic phytochemicals. Detoxification and excretion of these chemicals prevents toxicity, but is energetically expensive. I investigated the relationship between investment in detoxification and nutritional condition for moose on Isle Royale National Park (Alces alces) during winter, using urinary indices from urine samples collected in snow. The ratio of urinary urea nitrogen:creatinine is an indicator of nutritional condition, and the ratio of glucuronic acid:creatinine is an indicator of investment in detoxification. Nutritional condition declined with greater investment in detoxification. An alternative means of managing defensive chemical intake is to diversify the diet. Microhistological analysis of fecal pellets determined diet composition. Diet diversity was weakly associated with improved nutritional condition. However, the strongest predictors of nutritional condition were winter severity and proportion of balsam fir in the diet (a dominant food for moose in this ecosystem).

Turkey. A Generalist Approach in Social Work Education

A global review of social work education reveals considerable similarity among countries as well as significant differences. Historically, programs of social work education are informed by humanistic values and encompass knowledge of social problems, an understanding of individuals and their environment in interaction, and method of intervention into social and human difficulties. At the same time, structure of social work within the educational system and the length of training vary considerably from country to country. There is no serious international standards' setting for social work education, programs, educators and students around the world. Education programs exist at differing levels of education and for differing periods of time. There are no worldwide data on the number and qualifications of teachers of social work, the number and characteristics of social work students, variations in curricula and type of practicum (Hokeenstad and Kendall, 2001; Hokenstad, Midgley, 1998). North American and European models have had a major influence on social work educational programs in most parts of the world, especially developing countries. Still, the amount of western influence on social work education in developing countries is an issue that continues to be discussed (Hockenstad, Khinduka and Midgley, 1992; Frumkin, Lloyd, 2001). The programs in practice in Europe and North America have influenced the implementation of social work education programs. In recent years this influence has had a big part in the acceptance of the generalist approach. It is very important that social work education programs must be planned in accordance with the social structure and the development process of the society. Because of this, information on the social indicators and social welfare services will be given first then social work education will be stressed upon.

The impact of plant diversity and fertilization on fitness of a generalist grasshopper

In many environments land use intensification is likely to result in a decrease in species richness and in an increase in eutrophication. Although the importance of both factors for higher trophic levels such as insect herbivores is well documented, their impact has rarely been studied in combination. Herbivorous insects have a strong impact on the functioning of ecosystems and it is therefore important to understand how they are affected by eutrophication in high or low diversity environments. We used a grassland biodiversity experiment to investigate the combined effect of fertilization and plant diversity loss on the fitness of the generalist grasshopper Chorthippus parallelus by rearing grasshopper nymphs for four weeks in cages on unfertilized or fertilized (NPK) subplots across a species richness gradient from 1 to 60 plant species. Survival, the number of oothecae, body mass and the number of hatchlings were measured separately for each cage. Plant diversity had no effect on any of the grasshopper fitness measures, neither in unfertilized nor in fertilized plots. NPK-fertilization reduced grasshopper survival but increased body mass of males and reproductive success of the surviving females. Fertilization effects were not mediated by plant community structure, productivity or composition, suggesting that higher food plant quality was one of the main drivers. There was no interaction between plant diversity and fertilization on any of the measures. In conclusion, an increase in eutrophication, in both species-rich and species-poor grasslands, could lead to higher reproductive success and therefore higher abundances of herbivorous insects including insect pests, with fertilization effects dominating plant diversity effects.

Sizing up your enemy: individual predation vulnerability predicts migratory probability

Partial migration, in which a fraction of a population migrate and the rest remain resident, occurs in an extensive range of species and can have powerful ecological consequences. The question of what drives differences in individual migratory tendency is a contentious one. It has been shown that the timing of partial migration is based upon a trade-off between seasonal fluctuations in predation risk and growth potential. Phenotypic variation in either individual predation risk or growth potential should thus mediate the strength of the trade-off and ultimately predict patterns of partial migration at the individual level (i.e. which individuals migrate and which remain resident). We provide cross-population empirical support for the importance of one component of this model—individual predation risk—in predicting partial migration in wild populations of bream Abramis brama, a freshwater fish. Smaller, high-risk individuals migrate with a higher probability than larger, low-risk individuals, and we suggest that predation risk maintains size-dependent partial migration in this system.