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Full-Text Articles in Behavior and Ethology
Calf Development: Most Births At Night, Robert H.I. Dale
Calf Development: Most Births At Night, Robert H.I. Dale
Robert H. I. Dale
For many years, field researchers studying both African (Loxodonta africana) and Asian (Elephas maximas) elephants have indicated that they have observed relatively few births in situ, suggesting that most elephant dams give birth at night. For example, according to Cynthia Moss, "Possibly the majority of births occur at night and perhaps those that do take place in the daytime happen in secluded places" (1988, p. 151). Others, for example, Clive Spinage, have referred to "the old beliefs that the cows retreated to 'calving grounds' or that birth took place at night." (Spinage, 1994, p. 90). Although observers in several areas …
Variations In Radial Maze Performance Under Different Levels Of Food And Water Deprivation, Robert H.I. Dale, William A. Roberts
Variations In Radial Maze Performance Under Different Levels Of Food And Water Deprivation, Robert H.I. Dale, William A. Roberts
Robert H. I. Dale
Four groups of rats were tested on an eight-arm radial maze under a free-choice procedure. The subjects were maintained at either 80% or 100% of their preexperimental free-feeding weights through restricted access to either food or water. Water-deprived subjects received water in the maze; food-deprived subjects received food. Water-deprived subjects learned the task faster than food-deprived subjects. The four groups developed different response patterns. These were measured by the mean transition size, the average angular distance (in 45° units) between consecutively chosen arms. Rats foraging for food and water developed different search strategies, with water-deprived subjects exhibiting lower mean transition …
Spatial And Temporal Response Patterns On The Eight-Arm Radial Maze, Robert H.I. Dale
Spatial And Temporal Response Patterns On The Eight-Arm Radial Maze, Robert H.I. Dale
Robert H. I. Dale
Six maze-experienced hooded rats were timed during five trials on which they collected water from all arms of an eight-arm radial maze, then made five more choices. All subjects frequently exhibited a “task-completion pause:” The subjects rarely spent more than 1 sec in the center of the maze between choices until they had entered all eight arms, then stopped in the center of the maze. In contrast, the time spent in each arm gradually increased until all of the water had been obtained, then decreased slightly. Four subjects began every trial by choosing eight consecutive adjacent arms. The task-completion pause …
Spatial Memory In Pigeons On A Four-Arm Radial Maze, Robert H.I. Dale
Spatial Memory In Pigeons On A Four-Arm Radial Maze, Robert H.I. Dale
Robert H. I. Dale
Pigeon spatial memory was examined using a four-arm radial maze. The maze had four arms, spaced at 90° intervals, extending radially from a central choice area. Subjects were forced into three arms, then permitted two choices to enter the remaining ann. Five subjects chose accurately (90% correct) with delays of 5 min or less, their choices depended on extramaze cues, and the food in the target arm provided no essential cues. After an incorrect first choice, subjects' second choices were more accurate than chance. These data suggest that, while spatial memory has many similar characteristics in rats and pigeons, pigeon …
A Survey Of The Management And Development Of Captive African Elephant (Loxodonta Africana) Calves: Birth To Three Months Of Age, Nicole L. Kowalski, Robert H.I. Dale, Christa L. H. Mazur
A Survey Of The Management And Development Of Captive African Elephant (Loxodonta Africana) Calves: Birth To Three Months Of Age, Nicole L. Kowalski, Robert H.I. Dale, Christa L. H. Mazur
Robert H. I. Dale
We used four surveys to collect information about the birth, physical growth, and behavioral development of 12 African elephant calves born in captivity. The management of the birth process and neonatal care involved a variety of standard procedures. All of the calves were born at night, between 7PM and 7AM. The calves showed a systematic progression in behavioral and physical development, attaining developmental milestones at least a quickly as calves in situ. This study emphasized birth-related events, changes in the ways that calves used their trunks, first instances of behaviors, and interactions of the calves with other, usually adult, elephants. …
The Relative Attenuation Of Self-Stimulation, Eating And Drinking Produced By Dopamine-Receptor Blockade, E. T. Rolls, B. J. Rolls, P. H. Kelly, S. G. Shaw, R. J. Wood, Robert H.I. Dale
The Relative Attenuation Of Self-Stimulation, Eating And Drinking Produced By Dopamine-Receptor Blockade, E. T. Rolls, B. J. Rolls, P. H. Kelly, S. G. Shaw, R. J. Wood, Robert H.I. Dale
Robert H. I. Dale
Spiroperidol, which blocks dopamine (DA) receptors, attenuated self-stimulation of the nucleus accumbens, septal area, hippocampus, anterior hypothalamus and ventral tegmental area. Dopamine is thus involved in self-stimulation of many sites (in addition to the lateral hypothalamus). The attenuation was not a simple motor impairment of the speed of bar-pressing in that the nucleus accumbens and septal self-stimulation rates were lower than those in treated animals self-stimulating at other sites (Experiment 1). Feeding was partly attenuated, and drinking was much less attenuated by the spiroperidol. Since the rats bar-pressed for brain- stimulation reward, chewed pellets to eat, and licked a tube …
Limitations On Spatial Memory In Mice, Robert H.I. Dale, Martin Bedard
Limitations On Spatial Memory In Mice, Robert H.I. Dale, Martin Bedard
Robert H. I. Dale
Rats have an impressive ability to remember locations they have visited. Two experiments used an eight-arm radial maze to determine whether mice showed two important characteristics of this spatial memory: its durability, and its dependence on stimuli outside the maze (extreme stimuli). In Experiment 1, food-deprived mice were allowed to eat from four of the eight arms of the maze then, after delays of 5 sec, 1 min, or 5 min, they were permitted to choose the remaining arms. Choice accuracy declined significantly with the longer delays, but always remained above chance. In Experiment 2, the maze was rotated 180° …
Interactions Between Response Stereotypy And Memory Strategies On The Eight-Arm Radial Maze, Robert H.I. Dale, Nancy K. Innis
Interactions Between Response Stereotypy And Memory Strategies On The Eight-Arm Radial Maze, Robert H.I. Dale, Nancy K. Innis
Robert H. I. Dale
Three groups of water-deprived rats collected water from the ends of the 8 arms of an 8-arm radial maze. Sighted subjects, and subjects blinded either with or without pre-enucleation experience on the radial maze, all retrieved the water efficiently. Most of the subjects exhibited the same response stereotypy, regularly choosing 8 adjacent arms of the maze, then stopping in the center of the maze. The strategies underlying this performance were analyzed by interrupting trials and rotating the maze 180° after the subject had made 3 choices. Sighted subjects depended on extramaze stimuli, naive-blind subjects depended on intramaze stimuli and experienced-blind …