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Food Cues (food + cue)
Selected AbstractsThe Influence of Flowing Water on the Resource Pursuit-Risk Avoidance Tradeoff in the Crayfish Orconectes virilisETHOLOGY, Issue 4 2006Keith W. Pecor The influence of hydrodynamics on chemically mediated behavioral tradeoffs has received little attention. We tested the hypothesis that individuals of the crayfish Orconectes virilis would be more sensitive to chemical cues in flowing water than in still water. Orconectes virilis is a good subject for this test, because it is found in both still water (e.g. ponds), and flowing water (e.g. rivers). A factorial design was used, with two stimulus treatments and two habitat types. Crayfish were exposed to either food cue or food + alarm cue in either still water or flowing water in an artificial stream arena. Habitat use and activity were significantly influenced by stimulus treatment, with more time spent away from the stimulus source and less activity in the food + alarm treatment than in the food treatment. Neither habitat type nor the interaction of stimulus treatment and habitat type had a significant effect on the response variables. Given the natural history of O. virilis, we suggest that selection has favored the ability to equally utilize chemical cues in both still and flowing water. We acknowledge that different flow conditions may influence chemical ecology in this species and caution against the view that tests in flowing waters necessarily provide a more accurate approximation of natural responses. [source] Sex-dependent use of information on conspecific feeding activities in an amphibian urodelianFUNCTIONAL ECOLOGY, Issue 2 2009Pedro Aragón Summary 1Animals can make decisions by observing the behaviour of others. Their decisions vary depending on whether the benefits of using such information exceed the costs. Thus, it is worthwhile to explore the potential costs associated with different sources of information to understand the consequences of sociality. Previous studies focused mainly on the costs inherent to information gathering, whereas sex differences with regard to the costs arising from information use have received less attention. 2To explore this further I performed two complementary experiments. The first experiment aimed to examine individual responses to different combinations of information types that are likely to appear in nature, to test whether there is a sex-dependent response in the Bosca's newt, Lissotriton boscai. I tested the time needed for individuals to eat food items by trial-and-error tactics (personal information), and when a conspecific, which was eating or not, was added to the food cue. The second experiment aimed to evoke social interactions that are likely to arise after the choice of using information on conspecific feeding activities is made. I examined the potential costs associated with direct competition between same-sex pairs in food-limited conditions. 3Results of experiment 1 revealed that in both sexes the latency to eat food items was shorter in the presence of non-feeding conspecifics, but only females took advantage when information related to feeding activities where added to the food cue. Results of experiment 2 showed that when faced with a limited resource of food, females were more prone to engage in costly interactions. 4This study suggests that the balance between costs and benefits associated with the short-term use of information on conspecific feeding behaviour in combination with food cues may differ between sexes. Differential information uses by sexes might have profound consequences in intraspecific relationships and in the evolution of vertebrates' social systems. [source] Daily Meal Timing is Not Necessary for Resetting the Main Circadian Clock by Calorie RestrictionJOURNAL OF NEUROENDOCRINOLOGY, Issue 2 2008J. Mendoza In rodents, entrainment and/or resetting by feeding of the central circadian clock, the suprachiasmatic nucleus (SCN), is more efficient when food cues arise from a timed calorie restriction. Because timed calorie restriction is associated with a single meal each day at the same time, its resetting properties on the SCN possibly depend on a combination of meal time-giving cues and hypocaloric conditions per se. To exclude any effect of daily meal timing in resetting by calorie restriction, the present study employed a model of ultradian feeding schedules, divided into six meals with different durations of food access (6 × 8-min versus 6 × 12-min meal schedule) every 4 h over the 24-h cycle. The effects of such an ultradian calorie restriction were evaluated on the rhythms of wheel-running activity (WRA) and body temperature (Tb) in rats. The results indicate that daily/circadian rhythms of WRA and Tb were shifted by a hypocaloric feeding distributed in six ultradian short meals (i.e. 6 × 8-min meal schedule), showing both phase advances and delays. The magnitude of phase shifts was positively correlated with body weight loss and level of day-time behavioural activity. By contrast, rats fed daily with six ultradian meals long enough (i.e. 6 × 12-min meal schedule) to prevent body weight loss, showed only small, if any, phase shifts in WRA and Tb rhythms. The results obtained reveal the potency of calorie restriction to reset the SCN clock without synchronisation to daily meal timing, highlighting functional links between metabolism, calorie restriction and the circadian timing system. [source] Macaque,human interactions and the societal perceptions of macaques in SingaporeAMERICAN JOURNAL OF PRIMATOLOGY, Issue 10 2009John Chih Mun Sha Abstract Humans and long-tailed macaques (Macaca fascicularis) interface in several locations in Singapore. We investigated six of these interface zones to assess the level of conflict between the two species. We observed macaque-to-human interactions and distributed questionnaires to residents and visitors of nature reserves. We observed an average of two macaque-to-human interactions per hour at the sites, which included affiliative or submissive behaviors (46.9%), aggression (19.1%), taking food and other items (18.5%) searching bins, cars, and houses (13.4%), and nonaggressive contact (2.1%). Two-thirds of interactions occurred when a human was carrying food or food cues, and one-quarter occurred when a human provoked macaques. Only 8% of interactions occurred without a clear human-triggered context. Our interview showed one-third of respondents experienced nuisance problems from macaques. They had items taken from them (50.5%) and received threats (31.9%). Residents reported more nuisance problems than visitors, and their perceptions toward macaques differed. Residents were more aware of the consequences of food provisioning and that there were regulations against feeding. Residents fed macaques less and held more negative sentiments toward macaques. Nearly half of the interviewed people held neutral attitudes toward macaques and only 26.2% of respondents thought conflict with macaques warranted urgent action. Nearly two-thirds of the respondents supported education programs to ameliorate human,macaque conflict, and less than 15% supported removing or eradicating macaques. 87.6% felt that it is importance to conserve and protect macaques. Our results show that human,macaque conflict exists in Singapore, but that it may not be severe. Human behavior is largely responsible for macaque-to-human interactions, and thus could be lessened with management of human behavior in interface zones (i.e. restrict food carrying and provocation). Moreover, our interviews shows people living in Singapore value macaques, do not wish them entirely removed, prefer education-based solutions, and consider conservation and protection of them important. Am. J. Primatol. 71:825,839, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||