Stanley C. Ratner

Immobility reactions (fear) of domestic fowl as a function of age and prior experience

Abstract Two experiments were performed to investigate the effects of age and prior testing on immobility reactions of chickens from two through 66 days of age. In each experiment, one group was tested repeatedly while different subgroups were tested only once at the ages of the repeated test group and then discarded. Tests were conducted by turning each of the 305 birds on its side and holding it down for 15 seconds after which the immobility reactions were observed and timed. The immobility reaction was found to be virtually absent until seven to ten days of age, after which the response reached and maintained the arbitrary maximum duration of twelve minutes until birds were 59 days of age. Prior testing and the handling associated with it significantly reduced duration and incidence of immobility at all ages after nine days. The results are interpreted in terms of immobility as part of a fear reaction.

Effect of learning to be submissive on status in the peck order of domestic fowl

Abstract The present study was designed to investigate the effects on rank in the peck order of encounters between experimental birds, which were taken from intact peck orders, and a despotic bird not involved in the peck orders. Four groups with 14 birds in a group were observed to determine the peck orders. A total of eight experimental birds was selected from these groups and each had a number of encounters with a despotic bird which was not a member of any of the groups. The peck orders were then redetermined to evaluate the effects of the encounters on the ranks of the experimental birds. Seven of the eight birds showed reductions in rank after the encounters, and the eighth showed an increase. The characteristics of the encounters were related to the changes in ranks of several of the experimental birds. Tranquilizers were found to have little effect on the behaviour of the despot or the experimental birds. The effects of the encounters are interpreted in terms of conditioning of submissive and avoidance responses which generalized to the home pens.

Development of freezing and immobility, predator defenses, in the bobwhite quail (Colinus virginianus)

In two experiments freezing and immobility responses were investigated with Bobwhite quail ( Colinus virginianus ). Posttest responses were also recorded. Groups of birds were tested at 4–5, 9–10, 14–15, 19–20, and 29–30 days of age. Durations of immobility increased from 0 sec at 5 and 10 days to more than 60 sec from 15 to 30 days. Durations of freezing increased from 0 sec at 4 and 9 days to 10 sec at 29 days. Freezing was a more probable response at 9 days than immobility at 10 days. Posttest distress calls and locomotion were greater after freezing than after immobility, but both decreased with age. The results are discussed in relation to studies of freezing and immobility of other birds.

The variable of concurrent action in the language of children: Effects of delayed speech feedback

A postulated variable in the speaking interaction (the concurrent action of hearing oneself speak) was examined in 50 children, ranging in age from 6 to 13 years, while they spoke under conditions of Delayed Speech Feedback (DSF). Effect of DSF on subsequent speaking interbehavior was determined in terms of loudness, syllable duration (rate of speaking), and articulatory errors. Differential effects were found in terms of the ages of the Ss. These results are interpreted as suggesting that the concurrent action of hearing oneself speak is an important variable in the analysis of the speaking interaction (in terms of the DSF technique), and that this variable has a different effect on the speaking interbehavior of younger Ss than on that of older Ss.

Animal’s Defenses: Fighting in Predator-Prey Relations

This chapter deals with a special case of fighting among animals. It deals with fighting and associated behaviors when a prey animal is attacked by a predator. An analysis of these behaviors serves at least two purposes. On one hand, it leads to the examination of defensive behaviors that probably have different evolutionary and functional meanings from defensive behaviors involving conspecifics. On the other hand, it permits comparison between these two types of fighting behaviors—the behaviors of fighting predators and fighting conspecifics. Investigators of each process may learn from the other. For example, investigators have their attention drawn to questions such as: the similarity in fighting with a predator and fighting with a member of the same species, the uses of threat displays in the two situations, and the sequences of defensive reactions in the two situations.

Behavioral Characteristics and Functions of Pheromones of Earthworms

Abstract2 behavioral functions of mucus that is secreted by worms (L, terrestris) are investigated in four experiments. One function is an alarm pheromone function in which mucus from one worm leads to rapid escape by other worms. This occurs with mucus from electrically shocked worms, as previously reported, and from pinched worms. Neither mucus nor a pheromone effect occurs if worms are stimulated by moderate tactile stimulation or bright light. If worms that secrete mucus are kept at room temperature or if worms that react to the mucus are chilled, the pheromone effect does not occur. A second function of the mucus is a predator repellent function. Mucous covered worms are actively rejected by several types of predators that regularly eat worms.

Annelids and Learning: A Critical Review

The study of annelid learning appears to be moving from its second infancy. The brief flurry of work about fifty years ago seemed to establish clear evidence of annelid learning for a number of species. But the annelids and problems associated with interpretation of their learning were then retired into brief statements in general texts that alluded to “the facts.” The move from the second infancy of the study of annelid learning began after a long delay when investigators began applying more stringent definitions of learning and requiring more precise specification of conditions associated with learning. Thus, the literature on annelid learning now contains more than 50 references and the repertoire of an infant probably contains more than 50 units. But the problem is the degree of coherence and development of these units.

Acquisition and extinction in the earthworm, Lumbricus terrestris

Three groups of earthworms, Lumbricus terrestris, were run in a straight alley for 5 trials per day for 36 consecutive days. The groups were differentiated in terms of characteristics of the goal area, particularly the presence or absence of moist sphagnum moss. The level of illumination was constant and low for all goal conditions. The results indicated acquisition of a locomotor response to a goal box containing moist sphagnum moss and extinction of that response upon removal of the moss. It was concluded that the behavior changes could be considered to be learning and not phototactic responses. A fourth group of worms was run after 25 habituation trials. Their learning curve showed a more regular decline than other groups.

Worms in a straight alley: Acquisition and extinction or phototaxis

This study investigated the behavior changes of worms in a straight alley with two different goal conditions and levels of illumination. A straight-alley (plastic tube) was selected to avoid problems that seem inherent in the maze as used with worms. Earthworms, Lumbricus terrestris, were assigned among three groups. Groups 1 and 2 were run into a darkened goal box with different conditions of illumination over the alley. Group 3 was run into an open area. Goal conditions were then shifted so that Groups 1 and 2 ran to the open area while Group 3 ran to the darkened goal box. Worms going to the goal box showed a rapid decrease in time to traverse the alley (acquisition), and a rapid increase when goal conditions were shifted (extinction). Worms going to the open area showed higher and more variable response times until shifted to the goal box condition. Conditions of illumination over the alley had little effect on response times. The behavior changes are discussed in terms of the alternatives of learning and phototactic responses.

Kinetic movements in magnetic fields of chitons with ferro-magnetic structures.

A number of species of chitons (mollusks) have radulae (tongues), that are covered by ferro-magnetic denticles. The radulae and shells of two previously untested species were studied. The radulae of Acompapleura granulata (Gmenin) and Chiton Squamosis (Linne) were found to be ferro-magnetic but the shells were not. Live specimens of the chiton, Chaetopleura apiculata , that also have ferro-magnetic radulae, were observed in a weak magnetic field and the earths field. Results from three indexes of movement under these two conditions show that animals rotate more and move farther in a weak than in the earths magnetic field. These results together with others suggest that the chiton is responsive to magnetic fields and shows kinetic movements within them.