Food Search Behavior Research Articles

The Roles of Environmental Cues in Food-searching Behavior in Fimbria-fornix-lesioned Rats

The Roles of Environmental Cues in Food-searching Behavior in Fimbria-fornix-lesioned Rats

Evidence that Feeding Motivation Alone cannot Explain Oral Stereotypy in Sows

There has been much debate on the causes of stereotypy, but the motivational bases of these abnormal behaviours have yet to be fully understood. In the case of oral stereotypies in sows, there is evidence that the motivation to perform feeding behaviour may be involved. Restrictively-fed sows are highly food-motivated for large periods of the day. It has been shown that high-fed gilts perform stereotypies at a lower rate than low-fed gilts indicating that the level of feeding is important (Terlouw et al., 1991). Oral stereotypies in sows occur largely within a specific time after the daily food ration has been consumed. In sows housed in barren pens stereotypy is expressed as excessive drinking or chewing bars or chains, while sows housed on straw will nose and chew the bedding excessively in the same time period after feeding (Burbidge et al, 1993). The behaviour patterns are similar to those used in normal food-searching behaviour, but occur in the absence of reward. It has been suggested that oral stereotypy is the result of the appetitive phase of foraging entering a closed loop of repetition as the normal goal, attainment of more food, cannot be achieved (Hughes & Duncan, 1988). Two experiments were designed to examine the behavioural response to size and frequency of food rewards and they represent the first in a series of experiments which investigate the bases of stereotypies.

Correlation between survival during food deprivation and search behaviour in populations of Drosophila melanogaster

Search behaviour and survival during food deprivation were compared in six populations of Drosophila melanogaster derived from field collections. Search duration or intensity, as measured by displacement after feeding, number of revisits to the food, and tendency to fly away during food search, vary among the six different populations. Survival times during food deprivation, shown here to be a heritable trait, also differ significantly among the tested populations. Survival during food deprivation is correlated with displacement and revisits. Flies from populations with shorter displacement values (more intense search) tend to survive for shorter periods when deprived of food, whereas flies from populations with longer displacement values (less intense search) tend to survive for longer periods when deprived of food. The results support (1) a functional group of locomotory control elements influencing the outcome of a searching bout, and (2) a negative correlation between search intensity and survival during food deprivation and (3) significantly greater variability between than within populations for searching and survival.

Evolution of behaviours in Drosophila melanogaster in high temperatures: Genetic and environmental effects

Rapid evolution of behavioural and morphological adaptations were found in populations of Drosophila melanogaster exposed to laboratory natural selection in high temperatures. After 10 generations at 25, 27 and 30°C, flies were acclimated to 25°C and assayed for food-searching behaviour and preferred environmental temperature along a gradient. Flies showed significant differences in both traits. After 15 generations at the respective temperatures, flies from the 27 and 30°C populations were significantly smaller than those from the 25°C populations. These three traits were all directly correlated with the temperature treatments. As treatment temperatures increase, flies have more intense search behaviour, prefer higher temperatures and are smaller. The rearing temperatures of flies from the 25 and 30°C populations were reversed in the 12th generation, thereby changing the developmental temperature. This revealed a significant environmental effect for both behaviours. However, both behaviours were also shown to have genetic components, indicating that differences were created by the laboratory natural selection through evolutionary adaptations to temperature. Most previous studies demonstrated adaptations only after many more generations of laboratory natural selection. Additionally, development was retarded at 33°C and males were sterile at 31°C for this strain.

Effects of experience on food-searching behavior in the antFormica schaufussi (Hymenoptera: Formicidae)

Foragers of the ant Formica schaufussitend to return to and search at a site of a previous food find. The search tactic employed by a forager on its return trip is related to the type of food previously encountered: search is more persistent in response to carbohydrate than to protein food. Using different reinforcement schedules with carbohydrate and protein food rewards, we show that, on a short-term as well as on a long-term basis, the basic pattern of search observed in naive foragers is only slightly modified through foraging experience. Foragers do not increase their search effort or adjust their search pattern when either type of food is systematically renewed on a fixed reward schedule and thus do not seem to be able to learn to assess the food predictability. Collective responses that could compensate for this lack of individual flexibility and increase foraging efficiency at the colony level are discussed.

Age and Context Affect the Stereotypies of Caged Mink

AbstractThe effects of age and context on the stereotypies of caged mink were examined in order to assess the developmental changes undergone by the behaviour, and to find context-specificity that might suggest its motivational bases. Caged mink perform stereotypies consisting of a variety of movements, most commonly pacing and rearing, running in and out of the nestbox, and stationary head-twirling or nodding. Stereotypies are largely performed as feeding-time approaches, and many mink do not show them at all once fed. Stereotypies become more frequent and less variable with age; and in adults, individuals with the highest levels of stereotypy show the least variable forms of the behaviour and are most likely to perform it in more than one context, i.e. not solely in the pre-feeding period. These data suggest that mink stereotypies become 'established' with age, in the manner described for stereotypies in other species. However, the behaviour of kits does not follow the pattern seen in adults: kits performing stereotypies in more than one context do not have particularly high levels of the behaviour, nor are their stereotypies particularly unvarying. In addition, post-feeding stereotypies are commonly shown even by very young animals. Thus it cannot be the case that mink stereotypies are performed first in the pre-feeding situation and only later in other contexts via a process of emancipation. This conclusion is further supported by the finding that the forms of the behaviour often differ pre- and post-feeding. The specific forms and contexts of mink stereotypies suggest certain motivational bases for the behaviour. The rise in stereotypies as feeding time approaches and the sustained levels seen when the animals are not fed indicate hunger as an important factor, and in one dataset, the individuals whose stereotypies were solely pre-feeding used the most Longitudinal movements (i.e. pacing and its variants). This suggests that stereotypies, and pacing movements in particular, may stem from appetitive, food-searching behaviour. In contrast, Stationary movements such as head-twirling are performed more in the hours after feeding, and in one group of mink their levels declined over the pre-feeding period as feeding time approached. The physical appearance of such movements suggests they might be derived from attempts to escape the cage. Thus mink stereotypies areprobably seen in a range of contexts because they develop from several different behaviour patterns, with different motivational bases. The link, in adults, between performance in this range of contexts and the degree of establishment of the behaviour may be explained in one of two ways. In one adult group the data suggest that animals with stereotypy in more than one context incorporate the typically post-feeding Stationary movements into their pre-feeding behaviour, as if emancipation of this movement had occurred. However, data from the other adult group do not support this hypothesis, and the degree of establishment and the number of contexts in which stereotypies are performed may not be causally linked at all, but instead the independent products of individual propensities to develop stereotypic behaviour. Sex and site differences have yet to be fully explained. Females show consistently higher levels of stereotypy than males, as if perhaps they find the environment more frustrating. There are also enormous differences in the frequency and incidence of the behaviour on the two different sites studied.

Variation in behavioural indices of fearfulness and fatigue in transported broilers

Several behavioural measures were used to determine fearfulness and fatigue in broiler chickens subjected to fasting and/or transportation. There was considerable variability between four replicates, although measures within replicates were acceptably consistent. There was no uniform effect of fasting or transport on behaviour. The most cogent results were obtained by monitoring post-journey behaviour. In the few hours after transport, fasted and transported birds stood more than control birds which could be explained by increased food-searching behaviour and/or arousal. It is argued that the high variability between replicates indicates that considerable efforts must be made to control environmental variables in studies of behaviour after transporting chickens.

Subsistence, Technology, and Adaptive Variation in Middle Paleolithic Italy

This collaborative study addresses questions about variation in behavior within the Middle Paleolithic period of west‐central Italy. The findings are directly relevant to the evolutionary “fate” of Neandertals and the appearance of anatomically modern humans in Europe. Analyses focus on variation in a number of dimensions of subsistence and technology, including patterns of ungulate procurement, food transport, and tactics of stone tool manufacture and use. All of these dimensions exhibit marked, possibly “vectored” change in the study area between 110,000 and 35,000 years ago. Interpretations of the archeological data are supported by independent studies linking food search, procurement, and transport behaviors to ecological rules affecting all large terrestrial predators. In this way, variation observed in the faunal and lithic data sets can be shown to reflect startling diversity in the responses of Mousterian hominids to the world around them. The data provide important insights into the nature of adaptive “raw material” already in place during the Middle Paleolithic, the foremost conclusion of this study. That this variation in resource exploitation and land use also appears directional is more difficult to evaluate. It could be explained by hominids' adjustments to local changes in coastal habitat as sea level regressed or, alternatively, an evolutionary shift in hominid capabilities. The first interpretation is preferred, on the basis of available evidence, but cannot be advanced as a certain conclusion. This question provides much stimulus for continued research in the study area and other regions, using the methods presented.

Effect of thymosin and B-activin on lateralization of sensomotor control in rats

Characteristics of regulatory effects of B-activin and thymosin (fraction 5) on the activity of right and left hemispheres were studied in rats. The results obtained were estimated basing on the analysis of the following components of food-searching behavior: lateralization of a single conditioned-reflex response; preference of right or left paw; spontaneous rotations. Opposite effects of thymosin and B-activin were found at different stages of the food-searching behavior. Thymosin activated structures of the left hemisphere. A conclusion is made on the possibility of application of these drugs for targeted influencing the balance of intra-hemispheric activity in the brain functional pathology and during the compensatory process.

Avian Resource Use in a Caribbean Pine Plantation

I studied resource use by birds in a Caribbean pine (Pinus caribaea) plantation in Luquillo Experimental Forest, Puerto Rico, from 1981 to 1986. I used multivariate analyses to quantify and provide a classification of foraging relationships among bird species. The analysis of food-searching behavior by birds indicated that resource use was closely associated with vegetation physiognomy. The presence of specific kinds of vegetation was important in determining the presence and abundance of some bird species. Frugivores and nectarivores foraged in understory flowering and fruiting shrubs. Among insectivores, foliage-gleaners were found mainly in the canopy and hoverers were concentrated in the understory. Dead hanging leaves and vine thickets provided important foraging substrates for some species. Forest managers can improve habitat for birds in plantations by providing habitat heterogeneity through maintenance and encouragement of understory vegetation diversity, vine thickets, and native upperstory trees. J. WILDL. MANAGE. 52(2):274-279 Information on the impacts of land management practices on neotropical birds, and particularly the changes that occur when heterogenous tropical forest ecosystems are converted to pine plantations, is limited. In Australia, exotic pine (Pinus radiata) plantations supported 50% of breeding bird species found in the original eucalyptus forests (Gepp 1976, Suckling et al. 1976, Driscoll 1977). Only Falkenberg et al. (1983) has investigated bird communities in neotropical pine plantations; they found fewer birds in Caribbean pine plantations than in native forest sites in Jamaica. Resource use by birds in neotropical pine plantations has not been quantitatively examined. Information on bird use of neotropical pine plantations is needed because 33% of all tropical plantations are in the neotropics and the most commonly planted species are pine (Pinus spp.) (Evans 1982). The objectives of my research were to describe avian resource use in a Caribbean pine plantation and analyze niche structure, food resource relationships, and other factors associated with the bird assemblage patterns. This study was conducted under the auspices of the Institute of Tropical Forestry, U.S. Forest Service, Puerto Rico, and the U.S. Man and the Biosphere Program on Tropical Forests. I am indebted to A. E. Lugo for guidance, cooperation, and helpful suggestions. I also profited from discussions with W. J. Arendt, G. P. Bauer, C. E. Bock, B. B. Cintron, C. A. Delannoy, J. C. Figueroa, G. E. Freeman, J. A. Moreno, T. K. Nakamura, T. R. Strong, F. H. Wadsworth, P. L. Weaver, and J. W. Wiley. I gratefully acknowledge the valuable field assistance of A. Arendt, W. J. Arendt, and E. Hernandez-Prieto and the forest structural information provided by A. E. Lugo. Financial support came from a National Research Council (Ford Found.) Postdoctoral Fellowship, Grant-in-Aid from the University of Colorado, and a National Geographic Society Grant.

Food search behavior in arctic charr,Salvelinus alpinus (L.), induced by food extracts and amino acids

Food search behavior in Arctic charr (Salvelinus alpinus) to extracts of granulated food was quantified and compared with the response to solutions of amino acid mixtures. The concentration of each of 18 amino acids was analyzed in the food extract and similar pure amino acid solutions were prepared. Earlier published electrophysiological data and the data of concentrations in the test area were used to order the amino acids with respect to their presumed contribution to the stimulatory effect of the food extract. The 18 amino acids were tested collectively (18 aa) or were divided into two groups, one group containing 7 amino acids (7 aa) which was presumed to have a high stimulatory effect and the other group containing the remaining 11 amino acids (11 aa). The solutions of 7, 11, and 18 aa were stimulatory at concentrations between 2 and 5 × 10(-6) M, but no significant responses were observed at 2-5 × 10(-9) M. This can be compared with the food extract which elicited response at all concentrations tested, i.e., the total concentrations of 18 amino acids were 5 × 10(-9), 5 × 10(-8), 5 × 10(-7), and 5 × 10(-6) M. The response to the 18 aa solution was compared with the food extract and was shown to be significantly lower at 5 × 10(-9) M but not at 5 × 10(-6) M. These results show that amino acids induce food search behavior in Arctic charr, but there are other substances which also contribute to the stimulatory effect of the food extract.

Search Tactics of Insectivorous Birds Foraging in an Australian Eucalypt Forest

Abstract The different ways birds searched for food in an Australian Eucalyptus forest led them to detect and capture different kinds of prey. Five major searching modes were identified among 23 common, mostly insectivorous bird species. These were distinguished largely by the rates, distances, and angles moved by birds while foraging and by their prey-capture behavior. Some bird species typically moved slowly, visually examining substrates at relatively long distances, and then took flight to capture prey (e.g. whistlers, flycatchers, muscicapid robins, cuckoos). Others moved at more rapid rates and either gleaned small prey from nearby substrates (e.g. thornbills, treecreepers) or flushed insects that were then pursued (e.g. fantails). Two species (Eastern Shrike-Tit, Falcunculus frontatus; White-eared Honeyeater, Meliphaga leucotis) were specialized substrate-restricted searchers, seeking invertebrate and carbohydrate foods among the exfoliating bark of Eucalyptus. The search tactics of birds in this south temperate Australian forest were similar to those of birds in a north temperate forest in New Hampshire, USA, previously reported by Robinson and Holmes (1982). The differences in food-searching behavior between these phylogenetically distinct avifaunas (e.g. search flight and prey-attack flight lengths, hop/flight ratios, foraging rates) reflect the effects of unique foliage structures (e.g. spacing of branches, arrangements of leaves) and food resources at each site. These findings support the hypothesis that habitat structure and food availability provide opportunities and constraints on how birds search for and capture food in forest habitats. These in turn are postulated to affect the success of particular bird species exploiting those habitats and thus influence bird community patterns.

Food-search behavior and its relation to the central excitatory state in the genetic analysis of the blow fly Phormia regina..

Food-search behavior and its relation to the central excitatory state in the genetic analysis of the blow fly Phormia regina..

Food-search behavior and its relation to the central excitatory state in the genetic analysis of the blow fly Phormia regina.

Dethier (1957) described an aspect of food-search behavior in Phormia regina as the blow fly dance. A hungry fly walks in relatively straight lines with its proboscis retracted until it encounters food (sucrose). After ingesting even a small amount of sucrose, the fly begins making frequent, tight turns, flexes its front tarsi to bring more chemosensory hairs into contact with the substrate and repeatedly extends and retracts its proboscis. Like the central excitatory state (CES), which causes an increase in proboscis extensions to water when a fly is stimulated with sucrose, the dance lasts longer in hungrier flies or with higher sucrose concentrations. It was considered that dance behavior might be an ethologically relevant manifestation of CES. In order to test this hypothesis, dance duration in lines selected for high- and low-CES levels was measured. As predicted, flies from the high-CES line danced longer than those from the low-CES line, and the CES-dance correlation in individual flies was high. This phenotypic correlation disappeared in the F2 generation of a cross between the high- and low-CES lines, a result indicating that the observed variations in CES and dance duration were not caused by the same set of genes. Further characterization of the underlying genetic system showed that several linked autosomal genes with digenic epistatic interactions and a complex pattern of maternal inheritance were responsible for the difference in dance durations between the high- and low-CES lines.

Food-searching behaviour of the common merganser (Mergus merganser) I: Functional responses to prey and predator density

The hunting performance of the common merganser (Mergus merganser) was evaluated in relation to prey density and merganser flock size by stocking three enclosed sections of a natural stream with known densities of juvenile coho salmon (Oncorhynchus kisutch). Two size classes of coho were stocked: smolt averaging 43 g at densities of 0.02–0.65/m2, fry averaging 2 g at 0.08–1.6/m2 and various mixtures of smolt and fry at a combined density of 0.65/m2. The stream enclosures differed in the amount of cover available to fish. Mergansers were less successful at capturing coho smolt or fry in the enclosures wth cover from undercut banks. Smolt exposed to mergansers earlier that day were less vulnerable than smolt with no previous exposure. The feeding success of individual mergansers was not significantly affected by flock size for flocks of 25 birds or less. A smoothly asymptotic functional response (type II) was observed under all experimental conditions. Coho smolt were selected over coho fry. It is concluded that a merganser's average daily food requirement (ca. 400 g) can be satisfied at smolt densities of 0.02–0.30/m2 depending on the availability of cover for smolt and their previous exposure to mergansers.

Food-searching behavior of cats in a multiple-choice elimination problem

Twelve cats were individually exposed to a four-point elimination problem for 50 consecutive days. The problem for the animals consisted of choosing a series of different points where they found, and were allowed to eat, a piece of meat, without returning to any previously visited point. The order of elimination was not controlled in any way by the experimenter. Results indicated that cats were able to solve this problem. All subjects showed a strong tendency to make successive runs toward points situated as far apart as possible. Moreover, a relation was shown between performance and the tendency to follow this high divergence principle. This result is discussed in terms of subjects' ability to process information about the spatial characteristics of the experimental situation. This ability might in fact be related to the behavioral plasticity of animals in spatial problems according to the difficulty of the task.

Failure of mice to demonstrate spatial memory in the radial maze

The radial maze performances CD-1 mice and S-1 (Berkeley strain) rats were compared. Rats readily learned to solve the maze. In contrast, mice gave no indication of improved performance beyond that exhibited during the first days of training. Several interpretations of this finding are discussed. These data provide evidence against the hypothesis that rodents readily solve this maze because the reinforcement contingencies are consonant with those that naturally occur when foraging for food. It was concluded that one cannot be certain that radial maze performance necessarily reflects specific innate foot-search behaviors of animals until more investigations are carried out on food-search behaviors in the field, variables that affect search behaviors, and how these factors directly influence radial maze performance.

Dopaminergic agonistic and antagonistic drugs in the ventral tegmentum of rats inhibit and facilitate changes of food-search behaviour

The proposal that an increase of dopaminergic activity in the mesocorticolimbic pathway increases the probability of behavioural change is tested. Rats were trained to search for 4 food pellets in a 16-hole board arena. Groups of rats received lesions of the ventral tegmental area (VTA) or injections of spiroperidol or apomorphine into the VTA after sessions 4 and 7 (max. 9 sessions). Spiroperidol-treated and lesioned animals changed their preferred food-hole visit sequences more often than controls. After session 7 the apomorphine-treated group changes less often than controls. It is proposed that increased dopaminergic activity in the mesocorticolimbic pathway facilitates changes of behavioural strategy.

Olfactory responses of yellowfin tuna (Thunnus albacares) to prey odors: Chemical search image

Yellowfin tuna can detect and distinguish between odors of intact prey organisms, responding to odor quality of various prey rinses with different amino acid profiles. Chemical fractions of natural prey odors and synthetic mixtures of amino acids are less effective than whole natural rinses. Assuming uniform dilution, tuna can detect amino constituents of prey odors at about 10−11 M. Intensity of the behavioral response is modified by hunger. Feeding experience with new prey causes a gradual shift to maximum responses to its odor. We propose that one of the functions of the tuna's olfactory system is to form “chemical search images” which focus food search behavior for specific prey. The search image is thought to be modifiable and to be induced by prevailing prey abundance, so as to optimize the predator's feeding efficiency.

Enzyme activities of fish skeletal muscle and brain as influenced by depth of occurrence and habits of feeding and locomotion

Activities of lactate dehydrogenase (LDH), pyruvate kinase (PK), malate dehydrogenase (MDH) and citrate synthase (CS) were measured in the white skeletal muscle of marine fishes having different depths of occurrence and different feeding and locomotory strategies. There were significant depth-related differences in the two glycolytic enzymes, LDH and PK. LDH activity was most variable, and differed by 3 orders of magnitude between the most active shallow-living species and certain deep-sea fishes likely to have only minimal capacities for active locomotion. Superimposed on the depth-related patterns was a high degree of interspecific variation (up to 20-fold) in enzymic activity among species from any given range of depth of occurrence. Variation of both LDH and PK activities, noted for shallow- and deep-living fishes, seems to be largely accounted for by differences in feeding habits and locomotory performance. Active pelagic swimmers have much higher activities of LDH and PK than, for example, deep-living sit-and-wait predators. Benthopelagic fishes like rattails and the sablefish have the highest activities found among deep-living fishes, suggesting that these species engage in relatively active food-searching behavior compared to most other deep-sea fishes. The activity of CS, an enzyme of the citric acid cycle and an indicator of aerobic metabolism, varied little among species. Thus, the large interspecific variation in glycolytic potential (LDH and PK) among species is not associated with a similar variation in aerobic metabolism of white muscle. The much higher and more variable activity of MDH relative to CS suggests that, in addition to its function in the citric acid cycle, MDH may play an important role in redox balance in fish white muscle. In a comparison of white muscle composition between the shallow- and deep-living species, water content did not differ significantly, but protein content was significantly higher in shallow- than in deep-living fishes (211 and 130 mg g-1 wet wt of muscle, respectively). The differences in muscle protein content are small relative to the differences between shallow- and deep-living species in LDH, PK and MDH activities. Thus, depthrelated differences in muscle enzymic activity are caused by factors other than enzyme dilution. Enzyme activities (LDH, PK and CS) in brain tissue were relatively constant among species regardless of depth of occurrence or feeding and locomotory habits. Habitat and lifestyle do not seem to influence the demands for overall metabolic function in brain. The utility of muscle enzymic activity data for making predictions about the ecological characteristics of difficult-to-observe, deep-living, fishes is discussed.