Do students and canteen vendors think differently about food segregation?

In university “X” (UX), littering is no longer a problem, but segregating waste is still not evident. Logically, students and canteen vendors are the ones who produce most of the waste. In this study, the authors want to explore whether students would think differently about handling waste compared to canteen vendors. Using the theory of planned behavior as the theoretical framework, the authors indeed found that students compared with canteen vendors had significantly different attitudes, norms, and perceived behavior control. Students have a more positive attitude towards waste segregation, but they do not perceive it as an essential norm that the canteen vendors perceive. Interestingly, canteen vendors segregate food waste, but students do not segregate. After checking it qualitatively, canteen vendors segregate their waste because they are obliged to the faculty management rules. And the reason for students’ lower performance in segregating waste is that they do not know the campus’ program of waste management. It is concluded that the lack of socialization hinders student’s pro-environmental behavior, and the waste segregating behavior from canteen vendors is affected by the existing norms and rules.

Habitat and Food Segregation of Dwarf and Normal Arctic Charr (Salvelinus alpinus) from Vangsvatnet Lake, Western Norway

The aim of the present study was to test possible habitat and food segregation between two charr morphs in Vangsvatnet Lake. The charr population of Vangsvatnet consists of one pale phenotype with parr marks along the flanks and poorly developed spawning coloration (dwarf charr), and another phenotype with silvery flanks in nonbreeding condition and bright red spawning colors (normal charr). The habitus of the two morphs indicated that they were adapted to different niches during the growth season. The analyses of distribution and food showed that there was marked habitat and food segregation between the two morphs during summer, when dwarf charr dwelled deep-benthic and normal charr roamed in the limnetic zone. The segregation broke down in periods of food abundance, indicating that the habitat segregation was due to intraspecific competition for food. A comparison of charr morphs of Vangsvatnet with the nearby Lønavatnet Lake suggested that the number of charr morphs is adapted to local environmental conditions, among which lake morphology, food availability, and other fish species are important. We hypothesize that the number of charr morphs within a locality depends on the number of available niches during the growth season.Key words: polymorphism, camouflage, distribution, ontogeny, intra- and inter-specific competition

Social behavior and feeding ability of two phenotypes of Gasterosteus aculeatus in relation to their spatial and trophic segregation in a temperate lake

Significant differences in morphology, behavior, spatial distribution, and feeding habits were found between limnetic and benthic forms of the threespine stickleback (Gasterosteus aculeatus) in a small British Columbia lake. The social behavior and feeding ability of each form were studied experimentally to provide a basis for determining the mechanisms of spatial and trophic segregation observed in the lake. The hypothesis that the benthic form was solitary, aggressive, and attracted to lake-bottom cover, and the limnetic form was gregarious, nonaggressive, and attracted to lake-surface cover was supported by the laboratory experiments. Furthermore, the hypothesis that the limnetic form could feed more successfully on zooplankton, and the benthic form on macrobenthos was supported by the experiments. The benthic form spent significantly more time in search of food in lake-bottom cover than did the limnetic form. It is suggested that the two forms of stickleback had undergone extensive adaptations to very different habitats in the lake, and therefore, their spatial and food segregation was not maintained entirely by interactions, but at least partially by inherent behavioral differences.

An Experimental Study of Feeding Behavior and Interaction of Coastal Cutthroat Trout (Salmo clarki clarki) and Dolly Varden (Salvelinus malma)

Feeding behavior of cutthroat trout (Salmo clarki clarki) and Dolly Varden (Salvelinus malma) cohabiting a small coastal lake was studied experimentally to examine the importance of food exploitation as a mechanism for spatial and food segregation observed there. The hypothesis that Dolly Varden could feed more successfully on benthic prey, and cutthroat on surface prey was supported by laboratory experiments involving isolated individuals and interspecies pairs exposed to food in benthic, surface, and both locations. Differences between the species were found in resting and orientation positions and in behavior associated with food searching, location, and capture. Dolly Varden also were more successful than cutthroat in capturing benthic prey at low light intensities. Observed differences in feeding between the species were fully expressed in solitary individuals and did not appear to be magnified by interaction. It is suggested that these differences in sympatric stocks of the two species may be inherent and, therefore, that segregation is largely selective rather than interactive, even though the populations still retain considerable plasticity, enabling them to change diets or habitats when necessary or advantageous.