Carl D. Cheney

Self-Organization of Foraging Behaviour: From Simplicity to Complexity without Goals

A herbivore faces challenges while foraging-ongoing changes in its physiological condition along with variation in the nutrient and toxin concentrations of foods, spatially and temporally-that make selecting a nutritious diet a vital affair. Foraging behaviours arise from simple rules that operate across levels of resolution from cells and organs to individuals and their interactions with social and physical environments. At all these levels, behaviour is a function of its consequences: a behaviour operating on the environment to induce changes is itself changed by those events. Thus, behaviour emerges from its own functioning-behaviour self-organizes-not from that of its surroundings. This ostensible autonomy notwith-standing, no self-organizing system (cell, organ, or individual) is independent of its environs because existence consists of an ongoing exchange of energy and matter. According to this view, the notion of cause and effect is replaced with functional relationships between behaviours and environmental consequences. Changes in physical environments alter the distribution, abundance, nutritional, and toxicological characteristics of plants, which affect food preference. Social interactions early in life influence behaviour in various ways: animals prefer familiar foods and environments, and they prefer to be with companions. Animals in unfamiliar environments often walk farther, ingest less food, and suffer more from malnutrition and toxicity than animals in familiar environments. An individuals food preferences-and its ability to discriminate familiar from novel foods-arise from the functional integration of sensory (smell, taste, texture) and postingestive (effects of nutrients and toxins on chemo-, osmo-, and mechano-receptors) effects. The ability to discriminate among foods is critical for survival: all problems with poisonous plants are due to an inability to discriminate or a lack of alternatives. Animals eat a variety of foods as a result of nearing or exceeding tolerance limits for sensory and postingestive effects unique to each food. After eating any food too frequently or excessively, the likelihood increases that animals will eat alternative foods owing to exceeding sensory-, nutrient-, and toxin-specific tolerance limits. Cyclic patterns of intake of a variety of foods reflect seemingly chaotic interactions among flavours, nutrients, and toxins interacting along continua.

Behavioral toxicology of livestock ingesting plant toxins.

Improved usage of rangelnnds for livestock production requires better ways to reduce losses caused by poisonous plants, such as management practices to minimize ingestion and treatments to improve animal tolerance of ingested poisonous plants. In ruminants, gastrointestinri microbes can detoxify piant compounds, and this capacity has been enhanced in a few cases by deliberate modification of rumen microbial populations. Some plants are poisonous because ingested plant material is made toxic by microbial fermentation in the rumen, and better understanding of such toxifications will provide opportunities to diminish poisonings of that type. Absorption of toxic substances from the gastrointestinal tract into blood and lymph may be modifled by feeding binding agents such as clay, resins, and indigestible fibers, or by pharmaceuticals that interfere with absorption of toxicants. Agents that induce or inhibit biotransformational enzymes in tissues of the host animal might modify animal tolerance of some plant toxicants. Provision of substances that serve as co-substrates of detoxification can enhance animal tolerance of other types of plant toxicants. Some reports that illustrate these approaches have been reviewed, and questions have been raised to stimulate further research.

Effects of a Flavor and Food Restriction on the Response of Sheep to Novel Foods

Abstract Two methods were used to encourage sheep to eat unfamiliar foods quickly. The first method entailed restricting the amount of food offered. Lambs were fed either 750 g day−1 alfalfa pellets (slightly in excess of maintenance and 34% of ad libitum), or 1500 g day−1 (sufficient for 250 g day−1 growth and 68% of ad libitum) for 10 days and then offered a novel food (split peas). Food restriction did not increase the rate of acceptance of peas. The second method involved increasing familiarity with a flavor (onion) added to novel foods. Lambs drank water, water with 1% onion powder, water with 7% glucose, or water with 1% onion powder and 7% glucose. By day 2, intake did not differ among groups, so lambs were offered a novel food (rice) with 1% onion from days 3 to 7. There was no increase in speed of acceptance of rice with onion by lambs that drank onion-flavored solutions. Nor was there an increase in acceptance of rye (novel grain) with 1% onion when it was offered on days 8 to 11. However, on days 12–15, lambs ate more lentils (a novel food) with than without onion, and they ate corn (a familiar food) readily with or without onion. Conversely, intake dropped sharply when lambs were given a familiar food (rice) with a novel flavor (onion). Thus, lambs were reluctant to eat foods with unfamiliar flavors, whether they were added or occurred in novel foods. Food neophobia is likely to be one facet of the general phenomenon of fear exhibited in new situations, which ensures ruminants do not over-ingest toxic or nutrient-rich foods.

Observing Behavior and Information

Pigeons were allowed to peck either of two side keys to produce (observe) a positive or a negative stimulus on a third, middle key. When pecks to one side key resulted in only the positive stimulus signaling fixed-interval 30 sec, and pecks to the other side key likewise resulted only in the negative stimulus signaling extinction 30 sec, the pigeons pecked the positive stimulus key almost exclusively. Two of three pigeons stopped observing when the positive stimulus never occurred. In a second experiment manipulation of the probability of fixed-interval components had a slight effect on observing responses but a larger effect on fixed-interval rate. These results support the inadequacy of an information account of observing behavior.

Homing performance of anosmic pigeons

Two homing experiments were conducted with control pigeons and pigeons whose nares were obstructed. Anosmia reduced return success and extended flight times. Familiarity with the route cancelled much of the difference between groups. Olfaction does appear to be a sense mode useful to homing pigeons.

Effects of forced flavor exposure on food neophobia

Abstract Food neophobia was reduced by forcing animals to ingest a novel flavor in their water. Eighteen water-deprived rats were assigned to one of three conditions: forced-exposure to mint-flavored water, forced-exposure to strawberry-flavored water, or plain water. When subsequently given access to mint-flavored food, which was a novel experience, the rats in the mint-water condition ingested significantly more (P

Functional Variables in Fixed Ratio Pausing with Rabbits

This study demonstrated systematic control of pause length in multiple FR schedules by manipulating FR size and reinforcement magnitude. Schedule control was demonstrated by randomizing the order of FR presentations and by interchanging the stimulus lights previously correlated with either the small or large FR requirements. In Exp. I pausing was longer before starting the large FR requirement and positively correlated with increases in FR size. In Exp. Ii pausing before the large FR was inversely related to the magnitude of reinforcement delivered in that component. Contrast as a function of single component manipulations was not found.

Operant techniques used in stuttering therapy: A review

Abstract This article reviews research concerning the use of operant conditioning in stuttering therapy, and discusses the clinical implications of this literature. In order to be considered for this review, a report had to treat the findings of research specifically designed to use operant conditioning in the manipulation of speech disfluency. This body of experimental literature clearly indicates that operant management techniques can effectively reduce stuttering with punishment of disfluencies producing more notable results than reinforcement of fluent responses. Operant conditioning is an effective means of modifying stuttering behavior and should be more visible in terms of procedures used by speech therapists.

Errorless Training of a Visual Discrimination in Preschool Children

This experiment sought to determine the feasibility of Terrace’s “errorless” discrimination technique in training children to make a fine color discrimination. Of five Ss (3½ to 5 years), three were trained with traditional discrimination techniques and two were trained utilizing Terrace’s techniques. No child in the traditional group made the discrimination. Both Ss in the errorless condition were successful in making the discrimination and made the transition to the final performance with very few errors.

Prophylaxis by vitamin C in starvation induced rat stomach ulceration

Abstract Rats given L-ascorbic acid in their drinking water prior to and during starvation did not develop severe ulceration in the mucosal lining of their stomachs. Control rats which were either nontreated or given deactivated L-ascorbic acid developed severe stomach pathology on the starvation regimen.