Specific Food Preferences Research Articles

Is eating science or common sense? Knowledge about “natural foods” among self-identified “natural food” consumers, vendors and producers in rural and urban Mexico

Objective: To explore the common sense knowledge that consumers, vendors and producers hold of “natural foods”. The focus was on common knowledge because this is infrequently explored in social psychology where most studies focus on the implementation of scientific knowledge. The focus was on natural foods because the naturalness of foods seems to be one of the particular concerns that current consumers have about today's food market and because a specific natural food preference was observed in the contexts of study. Method: Fifty-seven informants in a rural context and 58 informants in an urban context participated in either a free association study or an interview study. Data content were analyzed. Results: In the urban context natural foods obtain their significance in the relationship between food and the self-concept; eating natural (or good) food is a task that requires effort and attitude, and foods obtain a moral value. In the rural context natural foods obtain their significance as an expression of a social and cultural system of interdependence that establishes practices and customs that have a long history in the community. Conclusions: It is suggested that these common knowledge systems are related to practical challenges that are particular to the informants’ context and that the structure of their common sense knowledge systems depend on the mediation of the flow of scientific knowledge and technological knowledge in each context.

Consumer preferences concerning potentially unsafe food


 BACKGROUND: Recent studies have shown that the reasons behind consumers’ preferences towards certain food products are extremely dynamic. Organic foods, raw milk products and bottled water are a few products discussed in this paper that have gone under debate regarding their safety versus their perceived health benefits. METHODS: Over 100 people participated in an exclusively online self-administered questionnaire. The questionnaire was publicized through both email and social media. Participants responded to questions regarding their food preferences of a variety of food types. RESULTS: It was found that there was a statistically significant association between education and preferences towards both milk products and organic/non-organic food products. No other demographic (setting, gender, age) were found to be associated with food preferences. It was also found that all food preferences were associated with the reasoning for that specific food preference, with the exception of cut/whole fruit. CONCLUSION: The association between food preferences and its reasoning concludes that consumers who prefer opposing products do so for extremely different reasons. Consumers that prefer the more risky food products mainly do so for taste and potential health benefits. Public health officials need to ensure that consumers that prefer riskier products thoroughly understand the risks, so that they themselves can then truly compare the benefits of taste or perceived “healthiness” with the consequences of potential contamination and illness.

Effects of in utero conditions on adult feeding preferences.

The fetal or early origins of adult disease hypothesis states that environmental factors, particularly nutrition, act in early life to program the risks for chronic diseases in adult life. As eating habits can be linked to the development of several diseases including obesity, diabetes and cardiovascular disease, it could be proposed that persistent food preferences across the life-span in people who were exposed to an adverse fetal environment may partially explain their increased risk to develop metabolic disease later in life. In this paper, we grouped the clinical and experimental evidence demonstrating that the fetal environment may impact the individual's food preferences. In addition, we review the feeding preferences development and regulation (homeostatic and hedonic pathways, the role of taste/olfaction and the reward/pleasure), as well as propose mechanisms linking early life conditions to food preferences later in life. We review the evidence suggesting that in utero conditions are associated with the development of specific food preferences, which may be involved in the risk for later disease. This may have implications in terms of public health and primary prevention during early ages.

Spatial and temporal diversity of the diet of the tawny owl (Strix aluco)

Spatial and temporal diversity of the diet of the tawny owl (Strix aluco) The author compared diet of eight owl species in Slovakia, out of which four species prey in the non-forest environment (Bubo bubo, Tyto alba, Asio otus and Athene noctua), while the other four species prey mostly in the forest (Glaucidium passerinum, Aegolius funereus, Strix uralensis and Strix aluco). Tawny owl (Strix aluco) has shown the highest degree of adaptability when it comes to various types of environment and broad diversity of prey. Appendix 1 presents material of total 225,441 pieces of diet, which contains 69 species of mammals and at least 147 species of birds. While B. bubo diet is typical especially for high presence of bigger prey species within mammals and birds (66 diagnostic taxa), diet of S. aluco is characterized by as many as 89 taxa with higher share than the average of all eight compared owls (taxa with values 1+ and 2+ in blocks as marked by full line). Based on the analysis of 68,070 pieces of S. aluco diet collected in Slovakia, it is possible to differentiate seven basic diet types: A - from lower mountains, B - from middle montane locations, C - from colder and more humid parts of mountains, D - characterized by high share of bats (Chiroptera), E - characterized by high share of slugs (Limacidae), F - from floodplain forests, and finally G - from environment strongly influenced by humans. Diagnostic species for one or several diet types are characterized by markedly higher share than Slovak average. By the large amount of analyzed samples of S. aluco diet it is possible to gain the knowledge about structure of several animal groups from relatively little disrupted forest ecosystems and those from environment to some degree influenced by humans. Diet types represent simplified models, which are understood in a different sense than plant communities. Individual disposition for specific food preference (e. g. Chiroptera) also plays an important role by some tawny owl's specimens. Some types of prey can be further divided into undertypes (e. g. undertypes G1 and G2 in Table 1). Diet of S. aluco has been examined more in detail and over a longer period of time especially in following national parks: Slovenský kras, Muránska planina and Veľká Fatra Mts. Samples from other parts of Slovakia are also presented here according to their relevance to particular diet types. Pellets of S. aluco were collected over a longer period of time (up to 30 years) in several sites and it is chronological periodicity in presentence of diagnostic species, which stands in focus. Long-term changes in S. aluco diet during Holocene were examined in two parts of Veľká Fatra Mts, which are influenced by climatic changes as well as human activity (deforestation and pasture). The author has occasionally collected pellets of S. aluco in several mountains of Europe between Western Alps and Caucasus and from northern border in S. aluco areal, from Trondheim area in Norway. Furthermore, the author presents hereby his own material from pellets of S. aluco from the Middle East to Himalaya (in particular countries of Jordan, Israel, Lebanon, Syria, Turkey, Iran, Kyrgyzstan and Nepal).

Genotype × nutrient association of common polymorphisms in obesity-related genes with food preferences and time structure of energy intake

Personal food preferences can either enhance or suppress the development of obesity and the selection and proportion of macronutrients in the diet seem to have a heritable component. In the present study, we therefore focused on dietary composition as a specific trait related to obesity and we determined whether genetic variations in leptin (LEP), LEP receptor (LEPR), adiponectin (ADIPOQ), IL-6 and pro-opiomelanocortin (POMC) underlie specific native food preferences and obesity-related anthropometric parameters. The total of 409 individuals of Czech Caucasian origin were enrolled into the present study and 7 d food records were obtained from the study subjects along with selected anthropometric measurements. In a subset of study subjects, plasma levels of ADIPOQ, LEP and soluble LEPR were measured. Independently of the BMI of the individuals, common variations in LEP and LEPR genes were associated with specific eating patterns, mainly with respect to timing of eating. The LEP + 19A/G polymorphism served as an independent predictor for BMI, percentage of body fat and skinfold thickness and significantly affected the time structure of the daily energy intake. The POMC RsaI polymorphism was associated with percentage of body fat. The ADIPOQ 45 T/G polymorphism was associated with the thickness of the subscapular skinfold. The LEPR Gln223Arg polymorphism was associated with multiple parameters, including diastolic blood pressure, meal sizes during the day and plasma ADIPOQ levels. In a separate analysis, soluble leptin receptor (sObR) plasma levels and LEP:sObR ratio were significantly correlated with systolic blood pressure (beta = - 0.66, P = 0.002; beta = - 1.23, P = 0.02) and sObR plasma levels also served as an independent predictor for diastolic blood pressure (beta = - 0.50; P = 0.04). To conclude, we report common allelic variants associated with specific feeding behaviour and obesity-related anthropometric traits. Moreover, we identified allelic variants that significantly influence the time structure of food intake during the day.

Role of cannabinoid CB1 receptors on macronutrient selection and satiety in rats

It has been shown that endogenous and exogenous cannabinoids substantially increase feeding. Despite evidence for a role of endocannabinoids in mediating food ingestion, the mechanisms by which CB1 receptor agonists and antagonists have an effect on motivational processes (hunger, satiety) as well as on specific food preference are not entirely understood. The purpose of this study was to investigate the effects of systemic injection of the CB1 receptor agonist, ACEA, on protein, carbohydrates and fat intake as well as on the behavioural satiety sequence (BSS) in pre-satiated rats. Following a 120-min access to a three pure nutrient diet (protein, carbohydrates and fat) at dark onset, male Wistar rats were injected intraperitoneally with ACEA (0.1, 0.25, 0.5 and 1.0 mg/kg). Immediately after the injection, animals were placed into separate experimental cages with free access to food and a single 60-min period was video recorded to evaluate the BSS; protein, carbohydrates and fat intake (g) was measured at the same period of time. Intake of carbohydrates was significantly increased and this effect was prevented by the pre-treatment with AM 251. Analysis of BSS showed that administration of 0.5 mg/kg of ACEA reversed the satiation induced by food ingestion by increasing the time spent eating and decreasing the time resting without altering the overall activity. The present results suggest that the stimulation of food intake induced by activation of CB1 receptors involves a specific dietary component and behavioural selective mechanisms (stimulating hunger and inhibiting satiety).

The relationship between stress, dietary restraint, and food preferences in women

The relationship between stress, restraint, and eating has been studied using various methods, including retrospective self-reports of stress and eating that are open to inaccuracies. Additionally, laboratory research has not systematically varied the fat content and sweetness of food items to assess how stress relates to specific food preferences. In this study of 40 women we examined the role of restraint and experimentally induced stress on the amount of sweet, salty, high-fat, and low-fat food consumed. High-restraint women ate more high-fat food than did low-restraint women, regardless of stress level. High-stressed women preferred sweet, high-fat food more than did low-stressed women, whereas low-stressed women ate more low-fat than high-fat food. There was no interaction between restraint and stress level. Social influence effects of small-group testing may have increased the ego-threat of the stressor or disinhibited high-restraint women in both stress groups. Future laboratory research is needed to assess the role of the presence of others in both stress induction and eating behaviors.

Genetic and environmental determinants of children's food preferences

Omnivores have the advantage of a variety of food options but face a challenge in identifying foods that are safe to eat. Not surprisingly, therefore, children show a relative aversion to new foods (neophobia) and a relative preference for familiar, bland, sweet foods. While this may in the past have promoted survival, in the modern food environment it could have an adverse effect on dietary quality. This review examines the evidence for genetic and environmental factors underlying individual differences in children's food preferences and neophobia. Twin studies indicate that neophobia is a strongly heritable characteristic, while specific food preferences show some genetic influence and are also influenced by the family environment. The advantage of the malleability of human food preferences is that dislike of a food can be reduced or even reversed by a combination of modelling and taste exposure. The need for effective guidance for parents who may be seeking to improve the range or nutritional value of foods accepted by their children is highlighted.

How Do Toddler Eating Problems Relate to Their Eating Behavior, Food Preferences, and Growth?

Eating problems are a common cause of concern for the parents of toddlers, but few studies have examined the correlates of eating problems or the growth patterns associated with them in a large population-based sample. Our goal was to examine the distribution of eating behaviors in a large representative sample of toddlers and their mothers' approach to feeding. In addition, we describe the prevalence of parentally perceived eating problems and how they relate to specific behaviors, food preferences, and growth in the child. We conducted a cross-sectional analysis of data from a United Kingdom population-based birth cohort, the Gateshead Millennium Baby Study, which included 455 questionnaires completed by parents when their children were aged 30 months. Eating was perceived to be a problem by 89 (20%) parents. Eating a limited variety (79 [17%]) and preferring drinks to food (57 [13%]) were the most prevalent problem behaviors. Thirty-seven children (8%) were described by parents as definitely "faddy" (picky), and these children liked fewer foods and had higher eating restriction scores than those described as not faddy. Children who were described as having an eating problem gained less weight over the first 2 years; 11.1% had weight faltering compared with 3.5% in children not described as having an eating problem. Being faddy was only weakly associated with poor growth, and simply eating a limited variety was unrelated to growth. High milk consumption was associated with lower appetite but not with poor growth. Eating problems are common in toddlers and in the majority are associated with normal growth, although weight faltering is more common in such children. Excessive milk-drinking may be a cause of low appetite at meal times.

Magnetic resonance spectroscopy in a patient with Kleine-Levin syndrome

Sirs: Kleine-Levin syndrome (KLS) is a rare recurrent hypersomnia associated with behavioural, cognitive, eating and sexual disturbances [1, 2]. A recent SPECT study in 7 patients with (KLS) showed decreased thalamic perfusion during the hypersomnolent attacks [3]. These findings were later confirmed in a case report by Hong et al. [4]. Proton magnetic resonance spectroscopy (1H MRS) is a noninvasive method of obtaining metabolic information. By means of MRS, different compounds can be measured including N-acetylaspartate (NAA), a marker of neuronal integrity and glutamate-glutamine (Glu-Gln), which plays an important role in excitatory neurotransmission and mitochondrial metabolism [5]. We present a 19-year-old patient with idiopathic, classical KLS. Over a 4-year period he suffered 19 stereotypical hypersomnolent episodes. The attacks were always preceded or accompanied by fever up to 39 °C, sore throat or stomach pain. At the beginning of the episodes mood depression was observed, the patient was melancholic, sad and withdrew socially. Sleep behaviour reached 20 hours/day, interrupted by compulsive eating, 7–8/days without any specific food preference resulting in a weight gain of approximately 5 kg/attack. Sexual disinhibition with masturbation, irritability, aggressiveness, cognitive and concentration disturbances were frequent. The attacks usually ended with insomnia lasting 2–3 days and a subsequent gradual improvement of emotional state and cognition. The patient described this phase as awakening from a dream and had difficulty recalling the events that had occurred during the attack. In the first year before treatment 12 attacks were observed. Under therapy with lithium 30 mg/day and valproic acid 2000 mg/day a remarkable reduction in frequency and severity of the episodes (7 attacks over a period of 2.5 years) was noted. The duration of the hypersomnolent episodes remained unchanged, 10 days on average. Hypocretin-1 in the cerebrospinal fluid during an attack was in the normal range, 530 pg/ ml. The patient underwent 1H MRS in an asymptomatic period and a month later during a typical episode. Because of presumed hypothalamic [6] or thalamic [3, 4] dysfunction in KLS we chose three regions of interest: hypothalamus and both thalami. MRS was performed on a Philips Achieva 3.0 T scanner. Single-voxel proton MR spectra, voxels of 17 x 14 x 15 mm in both thalami (3.57 cm3) and of 10 10 10 mm (1 cm3) in the hypothalamus, were acquired and processed to determine metabolite concentration ratios. A remarkable change between the two examinations was observed in the concentration ratios of NAA-NAAG, (total NAA)/Cr and Glu-Gln/Cr (Fig. 1). During the attack lower (total NAA)/Cr ratios in the right (–25.7 %) and left (–13.2 %) thalami were observed. In the hypothalamus the (total NAA)/Cr ratio was slightly higher in the second scan during the hypersomnolent attack. The Glu-Gln/Cr ratio was higher during the attack – in both the right (59.8 %) and left (52.3 %) thalamus. In hypothalamus a reliable value for Glu-Gln/Cr ratio was obtained only during the second scan and it was similar to the values in both thalami. Different values for intraindividual metabolite ratio, variability and reproducibility of the results are reported in the literature, depending on the technical parameters of the acquisition and on the region of interest. For example an intraindividual temporal cortical variation up to 12 % was observed for (total NAA)/Cr and up to 29 % for Glu-Gln/Cr on a 3T scanner [7]. The decrease in the (total NAA)/Cr concentration ratio in both thalami during the hypersomnolent episode in our patient exceeds the normal range of the intraindividual variability at 3T. Our finding supports the hypothesis of a thalamic dysfunction in KLS, recently suggested by other authors [3, 4]. This hypothesis is indirectly supported also by the observation of KLS-similar symptoms (reduced alertness, impaired sleep and behavioural changes) following paramedian thalamic strokes [8]. The observed high Glu-Gln/Cr concentration ratio in all regions of interest during the episode points to additional, global metabolic changes in the brain. Glutamate is a primary excitatory neurotransmitter. Decreased NAA/Cr and increased LETTER TO THE EDITORS

Food-associated calls in chimpanzees: responses to food types or food preferences?

Chimpanzees produce specific vocalizations, ‘rough grunts’, when encountering food, and it has been suggested that these calls vary acoustically depending on the food type discovered by the caller. Nearby listeners often behave as if the calls are meaningful to them, indicating that the calls may function as referential labels for particular foods. We investigated whether rough grunt variants are the result of callers responding to specific food types or relative food preferences. We recorded calls from captive individuals in response to nine different food items, which could be ranked as high, medium or low preference. Individuals consistently produced three acoustically distinct grunt variants to the three food preference classes. There was no evidence that chimpanzees produced individual labels for food types of low and medium preference. However, calls to high-preference food types differed significantly in their acoustic structure. These acoustic patterns remained stable over trials, suggesting that rough grunts have the potential to serve as semantic labels for individual high-preference food types. We were unable to replicate these findings with a set of recordings from the wild, although most other aspects of calling behaviour remained identical. We discuss these discrepancies between the wild and captivity and suggest that the emergence of referential labels for food items may be a by-product of the special circumstances found in captive settings.

Contextual Factors Influencing the Eating Behaviours of African American Women: A Focus Group Investigation

Objectives: African American women suffer disproportionately from many chronic diseases, and it is well acknowledged that eating patterns and habits are important contributory factors. Our goal was to describe and understand how personal and contextual factors among African American women contribute to food choices that increase the risk for chronic disease. Design: Focus groups were conducted with 40 African American women. Two experimenters abstracted and categorized statements about eating attitudes, beliefs and behaviours from the focus group transcripts. Results: A total of 139 statements were sorted into 10 major categories: (1) specific meals, (2) planning, (3) family/social, (4) snacking, (5) food preferences, (6) health awareness, (7) shopping, (8) food preparation, (9) eating out and (10) emotional. These categories were subdivided into 49 sub-categories to reveal more specific patterns of behaviour. Conclusion: African American women showed considerable variability in how they approached planning, choosing, preparing and eating food. A plethora of habits and food meanings--influenced by the personal, cultural, and environmental context--place these women at high risk for chronic disease. There were attempts to eat 'healthy', but these were overcome by traditions, social influences, habits and price. Individualized assessments to determine how each woman uses contextual information to make her food choices should be conducted in order to facilitate permanent eating behaviour change.

Patterns of ecological segregation among forest and woodland birds in south-eastern Australia

Much information has been gathered on birds of eucalypt forests and woodlands in south-eastern Australia. This was examined to assess some of the mechanisms of ecological segregation that may apply. A database was constructed of 209 species pairs (148 species from 48 genera). Most patterns resemble those reported overseas, with habitat and range featuring as major segregating mechanisms. Use of different strata and substrates was the dominant primary mechanism allowing use of identical space by congeners. Mechanisms such as specific food preferences, migration and choice of nest sites contributed but rarely as primary factors. One species pair appears to show no ecological segregation, despite co-existence in varying proportions over a large geographical range. Indiscriminate interspecific aggression is used by some species to maintain high levels of resources for themselves, in environments that can sustain such resources throughout the year. Communal breeding is a feature of those species. Implications for conservation are discussed.

Taphonomy and paleobiological implications ofTenontosaurus-Deinonychusassociations

ABSTRACT The discovery of a nearly complete skeleton of Tenontosaurus tilletti and closely associated multiple shed teeth of the dromaeosaur Deinonychus antirrhopus provides evidence that may support the often repeated suggestion that Deinonychus was a pack-hunting predator. The taphonomy of the specimen adds weight to the additional conclusion that Tenontosaurus was the specific food preference of the Deinonychus predator population. Among theropods, the only other specific animals that have been found as unmistakable food objects are Bavarisaurus in Compsognathus and Coelophysis in Coelophysis. These two could have been examples of opportunistic incidental predation or scavenging, but it appears that Deinonychus actively preyed on a deliberate food choice, Tenontosaurus.

Mechanisms of Appetite Control and their Abnormalities in Obese Patients

Human appetite is a complex mixture of physiological and psychological phenomena which include feelings of hunger, total energy intake, ingestion of particular nutrients, distribution and sizes of meals and snacks, specific cravings and food preferences. These phenomena can be assembled into a profile of motivation and a pattern of eating which represents the way in which appetite fluctuates over time. The satiety cascade shows the processes through which nutrition exerts effects on the biological system and, therefore, on feelings and behaviour. Within the biological system, the control of appetite involves post-ingestive mechanisms, including signals arising from the gastrointestinal tract and the release of hormones when food is processed. Post-absorptive mechanisms include the detection of important products of digestion, such as glucose and amino acids, together with the nature of the fuel mix oxidized and other metabolic variables. In obese patients, evidence points to a defect in the control of fat intake. In these people, dietary fat exerts only a weak action on satiation and satiety; it fails to generate strong responses in the mechanisms of the satiety cascade. An imbalance between fat intake and oxidation favours weight gain. A consideration of the psychobiological system (interactions between behaviour, peripheral physiology and neurochemical profiles) suggests strategies for treating or preventing the development of weight gain in vulnerable individuals.

Bait additives as a means of improving acceptance by rodents1

There is a general desire by those formulating rodent baits to improve them to achieve better rodent control. Various bait additives are currently in use while others have been evaluated without significant benefit. Some food or taste preferences are innate while other specific food preferences of rodents are learned during early experiences in life. Sugar (sweet items) and vegetable oils and animal fats are the most universally effective additives for cereal baits to improve acceptance and palatability for the three major species of commensal rodents. Salt, monosodium glutamate, and a wide array of natural, semi‐natural, and synthetic flavors/aromas as bait enhancers have been explored as gustatory (taste) and olfactory (odor) additives. Their influence on rodents seeking out the bait and on bait acceptance are varied and inconsistent. Flavor additives to baits have often decreased rather than increased consumption.

A study of the life history of Blue Magpie (10)

1. Behavior of Blue Magpie Cyanopica cyana against other bird species was studied during April 1962 and December 1973 in Nagano City area.2. The Kitatobe population of Blue Magpie was kept under observation of reactions against other birds of 53 species (27 families) which intruded or trespassed the home range. Of these birds, the Blue Magpie's reaction was observed against the following species: Calonectris leucomelas (a strayed individual), Nycticorax, nycticorax, Egretta garzetta, Anser albifrons, Milvus migrans, Buteo buteo, Falco tinnunculus, Sterna albifrons, Streptopelia orientalis, Cuculus canorus, Hypsipetes amaurotis, Lanius cristatus, Passer montanus, Sturnus cineraceus, Sturnus sturnina, Garrulus glandarius and Corvus corone.3. The behavior against these intruders was described in each case and the reaction patterns could be classified into: 1) harmful (or predatory) relation, 2) food relation, 3) roost relation.4. The harmful relation was seen against 13 species and consisted of: A. Emission of alarm notes B. Attacking, C. Mobbing, D. Chasing flight, E. Fleeing, and A. was most usual.5. Sensitive reaction was observed against some large water birds. such as Night Heron or egrets, etc., the meaning of which however was not clear.6. Against buzzard and kestrel, the Blue Magpie reacted when they were flying and not reacted or mobbed when they were perched. Against kite, it behaved differently, only reacting when the kite was flying low and straight.7. The frequency of reaction against cuckoo was low and the effect of its plumage of raptor pattern was not evident.8. Against Carrion Crow, alarm note reaction was usual throughout the year and in breeding season strong attacking and chasing behaviors were added. No reaction was shown against young crows or flocks in roosting flight.9. The dominance relation for food of Grey Starling>Blue Magpie>Brown-eared Bulbul was confirmed. Such specific ranks in food competition are correlated not only with amount or distribution pattern of the food but also with specific food preference.10. The roost relation was seen between the Grey Starlings. The Blue Magpie moved off from its settled roosting position by social pressure of increasing number of arriving starlings.

Comparative Analysis of the Feeding Habits of Two Species of Arizona Blind Snakes, Leptotyphlops h. humilis and Leptotyphlops d. dulcis

Stomach content analyses of 28 Leptotyphlops humilis humilis and 17 L. dulcis dulcis indicate that these snakes feed extensively on ants and termites which compromise 54-64 per cent of the total diet. L. d. dulcis appears to be more fossorial in its feeding activity than L. h. humilis which preys on a greater percentage of surface-dwelling arthropods. Presumably, this serves to reduce competition for the available food supply in geographical areas of sympatry. Both species show a definite preference for soft-bodied prey-types. In addition, several insect species which live as commensals in ant and termite nests are readily consumed along with their hosts. INTRODUCTION Most of the existing literature on the blind snakes of the genus Leptotyphlops deals specifically with the systematics of the group (Klauber, 1940) and their general ecology and geographical distribution (Banks and Farmer, 1963; Banta, 1965; Brattstrom, 1953; Turner and Wauer, 1963). Previous investigations on the feeding behavior of the Western Blind Snake, Leptotyphlops humilis humilis, and the Texas Blind Snake, L. dulcis dulcis, have demonstrated that these fossorial species feed extensively on ants and termites (Brattstrom and Schwenkmeyer, 1951; Reid and Lott, 1963; Stebbins, 1966). It has been further shown that L. d. dulcis frequently utilizes the pheremone trails of some ant species to locate its prey (Watkins, Gehlbach and Baldridge, 1967). Although it has been suggested that additional softbodied arthropods are also consumed (Stebbins, 1954), quantitative and qualitative information concerning the specific food preferences of these snakes is lacking. The purpose of the present study was to accurately analyze the feeding habits of these two species in an area of sympatry as well as to determine what differences, if any, exist in their food preferences. MATERIALS AND METHODS Twenty-eight L. h. humilis and 17 L. d. dulcis were collected 5 km ESE of Chiricahua, Cochise Co., Arizona during May through August 1971. The area was characterized by sand flats and intermittent boulder-strewn hillsides. Several rocky canyons with dry creek beds were present. There were no apparent micro-habitat differences between the two species. The prevalent vegetation included mesquite (Prosopis juliflora), incense bush (Symphoricarpos sp.), creosote (Covillea) and ocotillo (Fouquieria splendens). Most specimens were collected along paved and dirt roads at night. Several individuals were found within rocky crevices during the day. L. h. humilis specimens ranged in length from 21.4-33.8 mm; L. d. dulcis individuals from *Current Address: Dept. of Zoology & Entomology, Iowa State University, Ames, Iowa 50010, USA.

Studies of the Spider Prey of Several Mud-Dauber Wasps1

This study of the spiders provisioned by common mud-dauber wasps occurring in Maryland was initiated in 1937. At that time some material was collected from several nests with the intention of identifying the various species of spiders concerned. Later, 1942, in the course of a survey of the spiders of the state this material was identified and the following trends were observed; one, the predominance of certain species of spiders and two, the occurrence of rare or uncommon species. The predominance of several spiders suggested the possibility of specific food preferences of the different wasps, while the occurrence of uncommon forms indicated accidental collection. The study was begun with these problems as aims.