Conditioned taste aversion in lesser bandicoot rat, Bandicota bengalensis

The lesser bandicoot rat after ingesting a sublethal dose of 0.025% zinc phosphide, in preferred food millet (Pennisetum typhoides) grains, for 4 days, showed aversion for 5-6 days towards plain millet offered in choice with the less preferred sorghum (Sorghum vulgare) grains. The aversion response to nontoxic bait was stronger (aversion index greater than 0.7) for first 3-4 days in individual and for 1-2 days in paired rats. 100% or more shift in aversion index from pre-treatment to post-treatment periods indicated that the aversive and naive partners of the heterosexual and unisexual female pairs mutually influence the feeding preferences of each other as a result of which they showed aversion for first 2-3 days to the plain food in which poison was given to one of the partner earlier.     

根田鼠母体摄食经历对幼体食物选择的影响

社会学习是动物的一种可塑性行为表型,能使动物个体获得提高其适合度的行为模式。母体对幼体的食性形成具有重要的影响。本文以栖息于青藏高原的根田鼠作为研究对象,在实验室条件下,根田鼠母体怀孕后期及哺乳期分别供给以0.01%糖精或0.1%橘子汁处理的食物,当幼体断乳时,同时供给断乳幼体糖精和橘子汁分别处理的食物,测定其食物选择。结果表明:根田鼠母体在怀孕期和哺乳期摄食经橘子汁处理的食物,断乳幼体在同时供给经橘子汁处理的食物和糖精处理的食物时,断乳幼体喜食经橘子汁处理的食物;而母体在怀孕期和哺乳期摄食经糖精处理的食物,断乳幼体在同时供给根田鼠断乳幼体经橘子汁处理和糖精处理的食物时,断乳幼体喜食经糖精处理的食物。说明根田鼠在断乳后仍喜食母体在怀孕期和哺乳期摄食过的食物种类。根田鼠栖息于季节性变化剧烈的环境中,幼体通过母体尽早学习食物选择是一种可塑性表型方式,利于其获得适应栖息地的行为模式。     

Ovipositional preferences and larval performances of two populations of Indianmeal moth, Plodia interpunctella

Oviposition decisions by female insects can determine the survival and fitness of their offspring. In this study, we assessed the larval performance and adult oviposition preferences of two populations of the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), one a long-term laboratory colony and another recently collected from the field. Development assays on a variety of foods were conducted on individual larvae in small shell vials, and data were collected for survival (percent), development time (days), and adult weight (mg). Larvae from both populations did not survive on ground walnut, pecan, coriander, and fennel. There were significant differences in larval survival on laboratory diet, chick pea, and soybean between the two populations. Development times were the longest on prunes and barley. Mean adult weights were the highest on chick pea, laboratory diet, and soybean for the laboratory moths whereas soybean and chick pea were very suitable for the field moths. Overall, field moths weighed significantly less than the laboratory moths. Adult ovipositional preferences were assessed in no-choice and four-choice oviposition bioassays in plastic boxes containing diets differing in quality. In a no-choice situation, the numbers of eggs laid by laboratory moths on soybean, apricots, and wheat were not significantly different. Field moths laid significantly greater numbers of eggs on soybean, and those numbers were similar to those laid on barley. In four-choice bioassays, laboratory moths oviposited in diets previously determined to be unsuitable for their progeny survival. Field moths were more selective and laid significantly greater numbers of eggs on soybean than in dishes containing barley, coriander, or an empty dish. Our studies clearly showed that laboratory colonization of Plodia interpunctella for long periods can alter the behavioral patterns of immatures and adults.     

Avoidance of potentially harmful food cannot be socially transmitted between rats

The social transmission of food preferences(STFP) is a behavioural task of olfactory memory, in which an observer rat learns safe food odours from a demonstrator rat, and shows preference for this odour in a subsequent choice test. However, previous studies have failed to detect the transmission of information about food of potential danger and food aversion using STFP test. In this study, we tested how demonstrators' health affects the exchange of odour information and whether observers can learn danger information from an unhealthy demonstrator. As expected, the observer rat formed an odour preference after interacting with a demonstrator rat that had just eaten food containing a new odour, however, odour preference rather than aversion was also formed after interacting with a demonstrator rat injected with LiCl(used to induce gastric malaise). Furthermore, anaesthetized demonstrator rats and half-anaesthetized demonstrator rats, which showed obvious motor deficits suggesting an unhealthy state, also socially transmitted food preferences to observers. These results suggest that the social transmission of food preferences task is independent of a demonstrators' health, and that information about dangerous foods cannot be transmitted using this behavioural task.     

Variation in ephippial buoyancy in Daphnia pulicaria

1. Freshwater zooplankton often produce diapausing eggs to survive environmental stress. The diapausing eggs of Daphnia (Crustacea, Cladocera) are encased in an ephippium that either floats at the surface or sinks to the sediment. These two types of ephippia may represent different strategies between spatial (floaters) and temporal (sinkers) dispersal of offspring. 2. We observed floating and sinking characteristics of ephippia obtained from eight lakes. We then conducted an experiment with 26 Daphnia pulicaria clones obtained from six of these lakes and observed the production of buoyant and non‐buoyant ephippia under high and low food conditions. 3. Ephippia were more often non‐buoyant than buoyant both from females caught in nature and those reared in the laboratory. The experiment revealed that each clone was able to produce both types of ephippia, but that there was considerable among‐clone variation in the percentage of non‐buoyant ephippia produced. 4. We conclude that production of non‐buoyant versus buoyant ephippia may be driven by both genetic and environmental factors.     

Do colours that deter birds affect cereal bait acceptance by possums (

Poisonous baits used for pest control in New Zealand commonly contain green dye and cinnamon oil to make them less attractive to birds. Research aimed at reducing the impact of poison based pest control on birds has shown that some birds are initially deterred from feeding on blue or, to a lesser extent, green coloured food and are attracted to yellow or red food. We determined whether colours that deter or attract birds affected the acceptance of non-toxic and toxic cereal baits by captive brushtail possums (Trichosurus vulpecula). Individual possums were offered, daily, a choice between a standard green dyed non-toxic cereal bait and either a blue dyed(17 possums) or yellow dyed non-toxic bait (16 possums) for 10 days. Following this, for the first group of 17 possums, 1080 toxin was added to either the green bait (9 possums) or blue bait (8 possums) and possums were offered the green versus blue choice again. Two additional groups that had not previously been fed cereal baits were also given a choice between blue and green baits, one of which was toxic. All possums offered non-toxic bait ate less on the first day of presentation than on subsequent days. There was no difference in acceptance of either blue or yellow coloured non-toxic bait compared to the standard green non- toxic bait on any days. Bait colour appeared to be unimportant in cereal bait choice and did not deter possums from eating any of the baits. The addition of toxin to baits did not significantly alter bait choice in any groups, although some individuals which had no previous experience with baits ate more toxic than non-toxic bait. These data suggest that adding a stronger bird deterring colour (i.e., blue) to poisonous baits is unlikely to adversely affect the acceptance of baits by possums.     

Laboratory and field performance of an imidacloprid gel bait against German cockroaches (Dictyoptera: Blattellidae)

An experimental 2.15% imidacloprid gel bait containing approximately 44% water was evaluated in laboratory and field studies against the German cockroach, Blattella germanica (L). In continuous exposure tests, toxicity and presumably bait consumption varied with cockroach stage, deprivation of competitive food, and temperature. The LT50 values for cockroaches provided with competitive food ranged from approximately 0.9 h for adult females to 190 h for small nymphs. The LT50s for cockroaches not provided competitive food ranged from approximately 1.7 h for adult females to approximately 31 h for adult males. The LT50s decreased exponentially with temperature between 10 and 30 degrees C. Even though the bait was significantly more repellent (approximately 38%) than an untreated control (approximately 14%) when tested in Ebeling choice boxes, performance index values were positive and increased to nearly 100 (indicating high mortality and low repellency) after 14 d. When applied at 15-45 g per kitchen, the bait significantly reduced German cockroach trap catch in infested homes during a 4-wk period. There was a approximately 50% reduction after 1 wk and approximately 80% reduction 4 wk after treatment.     

Bait worm packaging as a potential vector of invasive species

Invasive species have become an increasingly greater concern for the ecological health of coastal ecosystems, yet vectors of these introductions often are unclear. This project evaluated the potential for the brown seaweed Ascophyllum nodosum ecad scorpiodes (Hauck) Reinke, packaged with bait worms (Nereis virens) harvested from the coast of Maine (USA), as a vector of invasive marine fauna and flora. Often, the seaweed and contents of the bait boxes are discarded into the water by recreational fishermen after using the bait worms, and any included non-native species may then be introduced. Bait boxes were purchased from several commercial vendors in Connecticut and New York over a two-year period. Subsamples of the seaweed were placed in laboratory culture and the growth of associated macro- and microalgae was monitored. Marine invertebrate species present in the samples were also identified and quantified. Results indicated 13 species of macroalgae and 23 species of invertebrates were associated with baitboxes. Among the highly diverse microbial assemblage detected, two species of potentially toxic marine microalgae, Alexandrium fundyense Balech and Pseudonitzschia multiseries (Hasle) Hasle, were found both prior to and after incubation at various temperatures, indicating these harmful algae are brought to and can survive in receiving waters. These findings highlight the need to consider alternative choices of bait box packaging materials or appropriate disposal methods of the seaweed in order to minimize the transport of species which are not native to the receiving coastal waters.     

Food choice in the laboratory pigeon

Although food reward plays a large role in learning and behavioral experiments, there have been few studies examining the most motivating food reward for pigeons. Brown (1969) found that pigeons had a tendency to prefer peas, while Killeen et al. (1993) found pigeons to prefer peas and popcorn in Experiment 1A. We looked to further explore these options as well as expand upon the types of foods examined beyond mainly grains and seeds. Pigeons were presented with six novel foods (granulated peanuts, popping corn, freeze-dried mealworms, bread crumbs, split peas, and sunflower hearts) allocated into two sets of three food items. Once the most consumed food from each food set was determined, they were pooled together with sorghum seeds (a familiar food) to form a third set. Sunflower hearts were the most consumed of all the food items, followed by corn and granulated peanuts. We discuss the potential factors mediating consumption choice, including nutritional profile and food particle size.     

植食性哺乳动物食物选择的生态学意义及行为机制

综述了植食性哺乳动物食物选择行为机制的研究进展。植食性动物的食物选择是觅食生态学研究最为活跃的领域,动物食物选择对策主要有营养选择、植物次生化合物假设、营养平衡假设、最优觅食理论和条件性气味回避假设。动物学习食物选择的行为过程中,觅食个体能通过其认知过程和感知过程来处理食物信息、学习选择食物项目是一种可塑性行为方式,有利于动物获得适应栖息地的行为模式。幼体通过社会学习自母体学习的觅食经验,在幼体一生的食物选择中均具有重要的作用。在环境条件相对稳定条件下,幼体可模仿成体的食物选择模式;在环境剧烈变化的条件下,动物通过试错学习选择的食物项目可能较模仿成体所摄取的食物项目营养含量更丰富。     

Bait delivery for oral rabies vaccine to gray foxes

Rabies is a widespread zoonotic disease that has reached epizootic proportions in gray foxes (Urocyon cinereoargenteus) in central Texas. Because each species of carnivore has different food preferences and foraging strategies, it is essential that the efficacy of a bait delivery program be examined for gray foxes prior to an oral vaccination program being attempted. Field trials were conducted to determine bait preferences of free-ranging gray foxes to selected baits and odor attractants. Baits consisted of polymer cubes made of either dog food meal or fish meal, and a wax-lard cake that was enhanced with marshmallow flavoring. Attractants added to baits exuded sulfurous, fatty, cheesy, or sweet odors and flavors. During 3,589 operable bait station nights, gray fox visitation and bait uptake rates were 9.2% and 8.3%, respectively. Gray foxes exhibited no preference in bait uptake rates between bait and odor attractant combinations. Gray foxes exhibited no difference in cumulative bait uptake rates between onroad and offroad sites; however, the uptake rate by raccoons was significantly greater for baits placed on roads than for baits randomly placed. Raccoons were the major non-target species competing for baits, being attributed with 73% of the total uptake. Visitation and bait uptake rates by raccoons significantly increased after a 7-day lethal removal of raccoons (n = 37) from the study area. Random distribution of baits is recommended; it reduced bait uptake by non-target species without adversely affecting uptake by gray foxes.     

Linking risk attitudes,time preferences,and body mass index in Catalonia

Obesity is projected to increase in the coming years, despite the various socioeconomic policies implemented by governments and policy makers. As a result, some studies have suggested that obesity should be looked at from a psychological point of view, that is, individuals’ propensity to become addicted to the consumption of fat-rich foods. Although previous studies have supported this, the results have been inconclusive: methodologically and geographically. This study uses a robust approach to elicit the risk and time preferences of food consumers. It goes further to ascertain the correlations between these parameters and obesity. Despite the methodological and geographical differences, our results support a strong relationship between body mass Index and risk aversion, but not for loss aversion. In addition, time discounting significantly influences individuals’ propensity to increase body mass Index.     

Field preferences of the Social Wasp Vespula germanica (Hymenoptera: Vespidae) for Protein-rich Baits

Food preferences displayed by foraging insects are important from a fundamental perspective and in pest control. We studied the preference of an invasive wasp, V. germanica, for protein foods in field conditions. Preferences were evaluated by placing baits in a paired design in different habitats and analyzing wasp visits, using a Bayesian approach to the Thurstone model. V. germanica workers display a clear rating of preferences, but were affected by the presence of competitors at the bait. These results contribute knowledge aimed at toxic baiting protocols for this wasp and suggest that food choice is a complex process subject to the influence of diverse factors. We emphasize the importance of on-site paired comparisons in preference studies to fully understand the drivers of food choice by insects.     

Food Color Preferences of Molting House Finches (Carpodacus mexicanus) in Relation to Sex and Plumage Coloration

Food color can be indicative of specific nutrients, and thus discrimination based on color can be a valuable foraging behavior. Several bird and fish species with carotenoid-based body ornamentation show color preferences for presumably carotenoid-rich red and orange foods. However, little is known within species about whether or not individuals with (or growing) more colorful ornaments show stronger food-color preferences than those with drabber coloration. Here, we examine food color preferences in house finches ( Carpodacus mexicanus ) – a species with sexually dichromatic and selected carotenoid coloration – as a function of sex and plumage coloration during molt. We captured wild, molting juvenile house finches over 4 wk in late summer/early fall, quantified the color and size of plumage ornaments being developed in males, and determined food color preference in captivity by presenting individuals with dyed sunflower chips (red, orange, yellow, and green). On average, finches showed an aversion to yellow-dyed chips and a preference for red- and green-colored chips. We found no significant difference between male and female preferences for specific food colors, and food color preference was not significantly related to male plumage ornamentation. However, we did find that redder birds demonstrated a higher degree of food selectivity, measured as the proportion of their preferred food color consumed. These results suggest that food color is not a major factor determining food choice in molting house finches, but that there still may be aspects of foraging behavior that are linked to the development of colorful plumage.     

Genetic correlations between nicotine reinforcement‐related behaviors and propensity toward high or low alcohol preference in two replicate mouse lines

Common genetic factors may contribute to the high comorbidity between tobacco smoking and alcohol use disorder. Here, we assessed behavioral and biological effects of nicotine in replicate mouse lines selectively bred for high (HAP2/3) or low alcohol preference (LAP2/3). In Experiment 1, free‐choice (FC) oral nicotine and quinine intake were assessed in HAP2/3 and LAP2/3 mice. Effects of nicotinic acetylcholine receptor blockade by mecamylamine on nicotine intake in HAP2 mice were also examined. In Experiment 2, HAP2/3 and LAP2/3 mice were tested for differences in sensitivity to nicotine‐induced taste conditioning. In Experiment 3, the effects of a single nicotine injection on nucleus accumbens (NAc) and dorsal striatum monoamine levels in HAP2/3 and LAP2/3 mice were tested. In Experiment 1, HAP2/3 mice showed greater nicotine intake and intake ratio than LAP2/3 mice. There were no line differences in quinine intake. Mecamylamine reduced nicotine intake and intake ratio in HAP2 mice. In Experiment 2, HAP2/3 mice showed weaker nicotine‐induced conditioned taste aversion (CTA) compared with LAP2/3 mice. In Experiment 3, nicotine treatment increased NAc dopamine turnover across both HAP2/3 and LAP2/3 mouse lines. These results show that there is a positive genetic correlation between oral alcohol intake (high alcohol intake/preference selection phenotype) and oral nicotine intake and a negative genetic correlation between oral alcohol intake and sensitivity to nicotine‐induced CTA.     

Temporal changes in food preferences of wood mice (Apodemus sylvaticus L.)

Diet choice was determined for wild-caught wood mice (Apodemus sylvaticus L.), temporarily confined to cages in the field and offered a choice of 24–26 types of seeds and fruits in 2-h sessions throughout the night. The mice showed an overall preference for some foods over others. The set-up minimized influences on food preferences of predation risk, hunger, food availability and competition. Variation in food preferences was not attributable to differences between individuals, but followed a temporal pattern. The variety of foods eaten showed a bimodal pattern with peaks corresponding to the two most active periods at the beginning and end of the night. Both the amount of food eaten and variation in the amount diminished from the first to the second active period. An expected selection for carbohydrates early in the night and proteins at the end of the night was not found, but sugars were selected for early in the night. These results are discussed in relation to the conflict between an animal's continuous energy requirements and the essentially periodic activity of foraging.     

Attitudinal reciprocity in food sharing among brown capuchin monkeys

Capuchin monkeys (Cebus apella) share food even if separated by a mesh restraint. Pairs of capuchins were moved into a test chamber in which one of them received apple pieces for 20 min, and the other received carrot pieces for the next 20 min. Previous research had shown a correlation between the rate of food transfer in both directions across female-female dyads. The present study confirmed this result. Reciprocity across dyads can be explained, however, by symmetry in affiliative and tolerant tendencies between two individuals, provided these tendencies determine food sharing. The present study was designed to exclude this symmetry-based explanation by testing each pair (N=16) of adult females on six separate occasions. There existed a significant covariation across tests of sharing in both dyadic directions, a result unexplained by relationship symmetry. Moreover, control procedures (i.e. testing of a food possessor without a partner, or testing of two individuals with the same food or two different foods at the same time) indicated that behaviour during food trials is not fully explained by mutual attraction or aversion. The monkeys take the quality of their own and the partner's food into account, and possessors limit transfers of high-quality foods. Instead of a symmetry-based reciprocity explanation, a mediating role of memory is suggested, and a mirroring of social attitude between partners. Copyright 2000 The Association for the Study of Animal Behaviour.     

Free mutual mate preferences in house mice affect reproductive success and offspring performance

When social constraints on the expression of mate preferences are absent, variation in offspring viability is predicted to favour females and males that display mate preferences. Earlier studies showed that female and male house mice, Mus domesticus, tested individually and mated with preferred (P) partners had higher reproductive success and better progeny performance than individuals mated with nonpreferred (NP) partners. Here we tested the effects of mutual mate preferences on reproductive success, offspring viability and performance. We conducted mate preference tests and created four types of reproductive pairings. One involved females and males that preferred each other (P-P); the second type had females that preferred the male but the male did not prefer the female (P-NP); the third had females that did not prefer the male but the male did prefer the female (NP-P). The last set consisted of females and males that did not prefer each other (NP-NP). We measured components of fitness for breeders (reproductive success) and offspring viability (birth-to-weaning viability and weight variation) as well as measures of offspring performance. There were no statistical differences in reproductive success of breeders or offspring viability and quality (weight variation) among the four types of pairings. There were, however, consistent differences between P-P versus NP-NP matings. The number of pups weaned, time to first litter, birth-to-weaning viability, pup body weight at birth and weaning, and the growth rates for pups of both sexes were consistently greater for progeny from P-P matings than NP-NP matings. Significant differences occurred among the four mating types in dominance of sons during aggression trials, nest construction and predator avoidance. Progeny from P-P matings displayed behaviour associated with higher fitness more often than progeny from NP-NP matings. These data show that breeders produce more highly competent progeny, most likely to survive, when social constraints on the expression of mate preferences in both sexes are relaxed.Copyright 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.      

Weitere Versuche zum Manipulier- und Werkzeug-verhalten junger Orang-Utans

Two young male orang-utans had to open lids of opaque boxes, each of which was closed by a number of bolt mechanisms. They received three trial series: In Series 1 the boxes contained no food-reward. In Series 2 the boxes were baited and the animals had to perform up to 25 manipulations to get the bait. In Series 3 the food-reward had been placed in a long box preventing the animals from reaching the bait by hand, even with their arms fully stretched. Having opened the box the animals still had to apply tool-using and tool-making behaviours in order to reach the bait. The exploratory manipulations during Series 1 seemed to be motivated intrinsically. The goal-directed behaviours during Series 2 and Series 3 evidently were oriented to the expected bait, so that a cognitive motivation could be inferred.     

Learned food aversion with and without an odour cue for protecting untreated baits from wild mammal foraging

Lethal methods of controlling wildlife foraging damage may present difficulties regarding conservation, ethics, welfare, and efficacy, providing an imperative to develop non-lethal alternatives. Learned food aversions offer a benign, targeted alternative to culling. However, food aversions are more readily associated with taste than with non-taste cues, and successful management applications have been limited primarily to reducing (bird) damage to treated items. To determine whether untreated foods might be protected without becoming damaged through sampling (tasting), we tested the role of an odour cue in learned food aversions with wild mammals using three conditioning treatments: (a) a combination of ziram (aversive agent) and clove oil (novel odour); (b) ziram; (c) clove oil. We tested two predictions: (1) ziram will produce learned aversion towards untreated foods; (2) training with the ziram–clove combination will produce enhanced aversion towards untreated foods in the presence of a clove odour cue. We collected detailed behavioural data from free-ranging animals using video surveillance. With European badgers Meles meles, both ziram treatments invoked innate aversion to baits. Ziram did not produce learned aversion to untreated foods, but conditioning badgers with the ziram–clove combination produced learned aversion towards untreated foods in the presence of the odour cue. The clove control did not affect badger behaviour. Our results support the second, but not the first, prediction with badgers. Red foxes Vulpes vulpes attended the ziram and the clove treatments only. Foxes displayed innate aversion to ziram, and subsequently developed learned aversions to untreated baits. Our results with foxes therefore support the first prediction, but we were unable to test the second. Learned food aversions using odour cues could potentially provide non-lethal protection for untreated foodstuffs, such as eggs, crops, and fruit, from mammalian pest species.