Cuthill, I., & Kacelnik, A. (1990). Central place foraging: a reappraisal of the `loading effect'. Anim. Behav., 40(6), 1087–1101.
Abstract: Animals that provision a central place usually bring back larger loads when foraging far from home. This positive correlation between average load size and distance is typically explained as rate-maximizing behaviour in the face of a trade-off between travel costs and a decelerating rate of prey gain in food patches (the `loading effect'). By using feeders to provide wild parent starlings, Sturnus vulgaris, with constant rates of prey loading, a positive load-distance correlation was shown to exist in the absence of a loading effect (experiment I). However, in a laboratory simulation where no load was transported (experiment II). the average number of prey eaten in patch visits by self-feeding starlings was invariant with travel distance, so the explanation of the load-distance correlation in experiment I must lie in featues peculiar to central place foraging. Bottlenecks in ingestion by chicks and interruption by visual detection of nest disturbance (experiment III) were rejected as causes of the correlation. Risks of dropping prey in flight appeared low, but the risk of kleptoparasitism received weak support. The travel-load size correlation may be an adaptive response to load transport costs, as return travel times increased with the load size being carried (experiment IV).
|
|
Reboreda, J. C., & Kacelnik, A. (1990). On cooperation, tit-for-tat and mirros. Anim. Behav., 40(6), 1188–1189.
|
Cuthill, I. C., Kacelnik, A., Krebs, J. R., Haccou, P., & Iwasa, Y. (1990). Starlings exploiting patches: the effect of recent experience on foraging decisions. Anim. Behav., 40(4), 625–640.
Abstract: Laboratory and field experiments have shown that, as predicted by the marginal value model, starlings, Sturnus vulgaris, stay longer in a food patch when the average travel time between patches is long. A laboratory analogue of a patchy environment was used to investigate how starlings respond to rapidly fluctuating changes in travel time in order to find out the length of experience over which information is integrated. When there was a progressive increase in the amount of work required to obtain successive food items in a patch (experiment 1), birds consistently took more prey after long than after short travel times; travel experience before the most recent had no effect on the number of prey taken. Such behaviour does not maximize the rate of energy intake in this environment. The possibility that this is the result of a simple constraint on crop capacity is rejected as, when successive prey were equally easy to obtain up until a stepwise depletion of the patch (experiment 2), birds took equal numbers of prey per visit after long and short travel times: the rate-maximizing behaviour. A series of models are developed to suggest the possible constraints on optimal behaviour that affect starlings in the type of environment mimicked by experiment 1.
|
|
Kacelnik, A. (1990). R.C. Bolies and M.D. Beecher, Editors, Evolution and Learning, Lawrence Erlbaum, Hillsdale, New Jersey (1988), p. x. Anim. Behav., 40(3), 602–603.
|
|
Cheney DL, & Seyfarth RM. (1990). Attending to behaviour versus attending to knowledge: examining monkeys' attribution of mental states. Anim. Behav., 40, 742.
|
Thouless, C. R. (1990). Feeding competition between grazing red deer hinds. Anim. Behav., 40(1), 105–111.
Abstract: The effect of social rank on the feeding behaviour of female red deer, Cervus elaphus L., on the Isle of Rhum, Scotland, was investigated. Hinds were less likely to approach and more likely to leave the vicinity of other individuals if these hinds were dominant to them. Movements away by subordinates were more likely to involve a break from feeding. Feeding rate, as measured by bite rate, increased with distance from dominant neighbours, but was unaffected by the distance to subordinates. It appears that aggressive interactions had little direct effect on access to food. Instead, it is suggested that feeding competition in red deer hinds is largely a passive process, operating through the avoidance of conflict by subordinates.
|
|
Tooze, Z. J., Harrington, F. H., & Fentress, J. C. (1990). Individually distinct vocalizations in timber wolves, Canis lupus. Anim Behav, 40.
|
|
Spear, N. E., Miller, J. S., & Jagielo, J. A. (1990). Animal Memory and Learning. Annual Review of Psychology, 41(1), 169–211.
|
Heyes, C. M., & Dawson, G. R. (1990). A demonstration of observational learning in rats using a bidirectional control. Q J Exp Psychol B, 42(1), 59–71.
Abstract: Hungry rats observed a conspecific demonstrator pushing a single manipulandum, a joystick, to the right or to the left for food reward and were then allowed access to the joystick from a different orientation. The effects of right-pushing vs left-pushing observation experience on (1) response acquisition, (2) reversal of a left-right discrimination, and (3) responding in extinction, were examined. Rats that had observed left-pushing made more left responses during acquisition than rats that had observed right-pushing, and rats that had observed demonstrators pushing in the direction that had previously been reinforced took longer to reach criterion reversal and made more responses in extinction than rats that had observed demonstrators pushing in the opposite direction to that previously reinforced. These results provide evidence that rats are capable of learning a response, or a response-reinforcer contingency, through conspecific observation.
|
|
Heyes CM, & Dawson GR. (1990). A demonstration of observational learning using a bidirectional control. Q. J. Exp. Psychol., 42, 59.
|
