SEARCH · PubMed Health

Results for “Sedentary Behavior”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59Linked to original sources

PubMed1989

Exercise training increases the number of glucose transporters in rat adipose cells.

We studied the mechanism for the increase in glucose transport activity that occurs in adipose cells of exercise-trained rats. Glucose transport activity, glucose metabolism, and the subcellular distribution of glucose transporters were measured in adipose cells from rats raised in wheel cages for 6 wk (mean total exercise 350 km/rat), age-matched sedentary controls, and young sedentary controls matched for adipose cell size. Basal rates of glucose transport and metabolism were greater in cells from exercise-trained rats compared with young controls, and insulin-stimulated rates were greater in the exercise-trained rats compared with both age-matched and young controls. The numbers of plasma membrane glucose transporters were not different among groups in the basal state; however, with insulin stimulation, cells from exercise-trained animals had significantly more plasma membrane transporters than young controls or age-matched controls. Exercise-trained rats also had more low-density microsomal transporters than control rats in the basal state. When the total number of glucose transporters/cell was calculated, the exercise-trained rats had 42% more transporters than did either control group. These studies demonstrate that the increased glucose transport and metabolism observed in insulin-stimulated adipose cells from exercise-trained rats is due, primarily, to an increase in the number of plasma membrane glucose transporters translocated from an enlarged intracellular pool.

Adipose Tissue↗

PubMed2006

Reducing obesity indicators through brief physical activity counseling (PACE) in Italian primary care settings.

BACKGROUND: There is an alarming prevalence of obesity and sedentariness in Western countries. An ideal context for health promotion and preventive medicine seems to be the setting of primary care provided by the general practitioner (GP). PURPOSE: Therefore, this study evaluated the impact of GPs' brief physical activity counseling for overweight and obese patients. METHODS: Individuals recruited during routine physician visits were randomly split into an experimental (n = 48) group that received the Patient-centered Assessment and Counseling for Exercise (PACE) protocol, and a usual-care control (n = 48) group. Body mass index (BMI) and abdominal girth were assessed as objective biometrical parameters. Patients in the experimental group self-reported their readiness for physical activity and self-efficacy. RESULTS: The experimental group had significantly better BMI and abdominal girth compared with the control group after a 5- to 6-month follow-up. Furthermore, the experimental group progressed in their stage of physical activity readiness and increased their self-efficacy. CONCLUSIONS: The GPs' counseling for physical activity using the PACE protocol influenced mediators and biometrical outcomes in an Italian primary care context.

Adult↗

PubMed2006

Ethnicity and nutrition of adolescent girls in Hawaii.

OBJECTIVE: To describe the ethnicity and nutrition of adolescent girls in Hawaii. DESIGN: This was a cross-sectional survey. SUBJECTS: Girls, aged 9 to 14 years, were identified from the membership files of Kaiser Permanente Hawaii, a large Hawaii health maintenance organization. MAIN OUTCOME MEASURES: Nutrient and food group intakes were compared against recommended intakes, physical activity levels, and anthropometric measurements of height, weight, body mass index (BMI), and subscapular and iliac skinfold thicknesses. STATISTICAL ANALYSIS PERFORMED: Asian girls, girls of mixed ethnicity, and white girls were compared using analysis of variance. RESULTS: Although Asian girls weighed the least and were the most sedentary, white girls had the lowest BMIs. Mixed ethnicity girls had the highest weights, BMIs, and subscapular and iliac skinfold thicknesses. No significant differences were found in major macronutrient intake. However, mixed ethnicity and Asian girls had lower fiber, iron, folate, and calcium intake than white girls. All groups met recommendations for iron intake, whereas none met fiber and calcium recommendations. All girls met folate recommendations. No differences were found in intakes for tofu, soy, grains, vegetables, or fruit and nuts food groups. Mixed ethnicity girls had the highest sweetened carbonated beverage intake although overall sugar intake was highest in white girls. Asian and mixed ethnicity girls' meat intakes were higher than white girls'. Intakes of mixed ethnicity girls more closely resembled those of Asians, although they exhibited the highest BMIs. CONCLUSIONS: These data suggest grain, vegetable, fruit, and dairy intake should be encouraged as part of a balanced diet for adolescent girls in Hawaii.

Adolescent↗

PubMed1996

Family-based behavioural intervention for obese children.

The family environment can contribute to the development of obesity. Parenting styles may influence the development of food preferences and the ability of a child to regulate intake. Parents and other family members arrange a common, shared environment that may be conducive to overeating or a sedentary lifestyle. Family members serve as models, and reinforce and support the acquisition and maintenance of eating and exercise behaviours. Family-based interventions are needed to modify these variables in treating obese children. We have made significant progress in developing interventions that target obese 8-12 year-old children, completing four 10-year follow-up studies that provide support for two factors that are useful in childhood obesity treatment. First, our research suggests that the direct involvement of at least one parent as an active participant in the weight loss process improves short- and long-term weight regulation. Second, our research suggests that increasing activity is important for maintenance of long-term weight control. Correlational analyses on the 10-year database suggest that family and friend support for behaviour change are related to long-term outcome. Family-based obesity treatment provides interventions for both children and their parents, but children benefit more from treatment than their parents. These positive results provide an encouraging basis for optimism that further development of interventions, based on newer research on family processes and behaviour changes, can be useful in treating childhood obesity.

Adult↗

PubMed2005

Voluntary training in mice and submandibular lymphocyte response to acute exercise.

INTRODUCTION: Submandibular lymph nodes (SLN) are important for immune responses to antigens in the eye and oral mucosa. Athletes and exercise participants may be at increased risk of ocular, oral, and upper respiratory tract infections. PURPOSE: This study was conducted to examine the effects of voluntary training on the distribution, number, and apoptotic status of SLN lymphocytes in response to an acute bout of strenuous exercise. METHODS: Female C57BL/6 mice were assigned to voluntary wheel-running (WR) exercise (N=20) or were sedentary (N=10) for 16 wk. SLN lymphocytes were examined immediately (EX+Imm) or 24 h (EX+24 h) following strenuous treadmill exercise, or exposure to treadmill conditions without running (NonEX). Intracellular glutathione (GSH), mitochondrial membrane potential (MMP), cell viability (propidium iodide uptake, PI), surface phosphatidylserine (Annexin V), T-lymphocyte (CD3, CD4, CD8), and B-lymphocyte (CD19) phenotype distribution and number were assessed. RESULTS: The WR mice had a higher number and percent CD8 SLN lymphocytes, higher MMP, and lower Annexin V/PI SLN lymphocytes than controls. Regardless of training status, an acute bout of strenuous exercise decreased the total and phenotype specific (CD3, CD4, CD8) number of cells, MMP, and GSH levels immediately after exercise. CONCLUSION: WR in mice improved some aspects of cell viability in SLN lymphocytes compared with controls, but did not prevent the transient cell loss after acute treadmill exercise. Given the depletion in intracellular GSH levels, oxidative stress may account for the decline in SLN lymphocyte numbers following acute exercise. Loss of SLN lymphocytes may have consequences for ocular, oral, and upper respiratory tract health in some exercise participants and athletes during periods of overtraining.

Animals↗

PubMed1982

Commentary on the reduced urinary noradrenaline excretion following cold stress and exercise in physically trained rats.

Urinary catecholamine excretions of rats trained by swimming or running were compared with those of cold-acclimated rats and controls i.e. sedentary warm-acclimated rats. During cold stress the trained rats excreted less noradrenaline (NA) than did controls. In fact rats trained by swimming excreted less NA than did cold-acclimated rats, while rats trained by running excreted about the same amount as did cold-acclimated rats. 2 h of swimming increased the urinary catecholamine (CA) excretion of all groups but trained rats excreted less NA than did controls and cold-acclimated rats, which had excretions of similar magnitude. The NA excretions of the two trained groups never deviated statistically from each other. It is concluded that concerning NA requirement in order to maintain homeostasis, training produces "cross tolerance" to cold stress but cold-acclimation does not produce "cross tolerance" to acute exercise. Furthermore the positive effect of training on NA excretion during the stress of cold or that of acute exercise seems essentially to be an effect of increased locomotor activity as such regardless of the type of training. It is also suggested that increased levels of locomotor activity of the rat may be of importance for seasonal acclimation of the species by increasing its tolerance to cold.

Animals↗

PubMed1991

Exercise decreases fat selection in female rats during weight cycling.

Weight cycling (weight loss and regain) increases fat intake in rats allowed to self-select a diet from protein, carbohydrate, and fat sources. This study reports the effects of exercise on macronutrient self-selection. Female Sprague-Dawley rats (5 mo old) self-selected their diet. After 3 wk, rats were assigned to one of the following three groups: ad libitum fed sedentary (Con), sedentary food restricted to 40% Con intake (R-Sed), or treadmill exercised (20 m/min, 1 h/day, 6 day/wk) food restricted to 40% Con intake (R-Ex). Food restriction was for 3 wk followed by 5 wk of refeeding. This was repeated for a second cycle. During restriction, body weight decreased by 30% in R-Sed and by 33% in R-Ex than in R-Sed, fat regain was greater in R-Sed. By week 3 of refeeding, total caloric consumption did not differ. However, fat selection increased in R-Sed (56% kcal) vs. R-Ex (30%) and Con (35%). Fat selection in R-Sed increased further during cycle 2 (73% kcal). Resting oxygen consumption decreased during food restriction in R-Sed and R-Ex. After refeeding, resting metabolic rate in R-Ex was significantly greater than in R-Sed. In conclusion, weight cycling increases dietary fat selection and adiposity. Exercise mitigates this effect.

Adipose Tissue↗

PubMed2006

Control of energy balance in relation to energy intake and energy expenditure in animals and man: an ecological perspective.

In this paper, we consider the control of energy balance in animals and man. We argue that patterns of mammalian feeding have evolved to control energy balance in uncertain environments. It is, therefore, expected that, under sedentary conditions in which the diet is rich in nutrients and abundantly available, animals and man will overeat. This suggests that no physiological defects are needed to induce overweight and ultimately obesity in man. Several considerations arise from these observations. The time period over which energy balance is controlled is far longer than allowed by most experiments. Physiological models of energy balance control often treat excess energy intake as a defect of regulation; ecological models view the same behaviour as part of normal energy balance control in environments where resources are uncertain. We apply these considerations to common patterns of human and animal feeding. We believe that the ecological perspective gives a more accurate explanation for the functionality of excess fat and the need to defend nutrient balance and avoid gross imbalances, as well as explaining hyperphagia in the face of plenty. By emphasising the common features of energy balance control in different mammalian species, the importance of changes in behaviour to accommodate changes in the environment becomes apparent. This also opens up possibilities for the control of body weight and the treatment of obesity in man.

Animals↗

PubMed2001

A history of physical activity, cardiovascular health and longevity: the scientific contributions of Jeremy N Morris, DSc, DPH, FRCP.

Since Hippocrates first advised us more than 2000 years ago that exercise-though not too much of it--was good for health, the epidemiology of physical activity has developed apace with the epidemiological method itself. It was only in the mid-20th century that Professor Jeremy N Morris and his associates used quantitative analyses, which dealt with possible selection and confounding biases, to show that vigorous exercise protects against coronary heart disease (CHD). They began by demonstrating an apparent protection against CHD enjoyed by active conductors compared with sedentary drivers of London double-decker buses. In addition, postmen seemed to be protected against CHD like conductors, as opposed to less active government workers. The Morris group pursued the matter further, adapting classical infectious disease epidemiology to the new problems of chronic, non-communicable diseases. Realizing that if physical exercise were to be shown to contribute to the prevention of CHD, it would have to be accomplished through study of leisure-time activities, presumably because of a lack of variability in intensities of physical work. Accordingly, they chose typical sedentary middle-management grade men for study, obtained 5-minute logs of their activities over a 2-day period, and followed them for non-fatal and fatal diseases. In a subsequent study, Morris et al. queried such executive-grade civil servants by detailed mail-back questionnaires on their health habits and health status. They then followed these men for chronic disease occurrence, as in the earlier survey. By 1973 they had distinguished between 'moderately vigorous' and 'vigorous' exercise. In both of these civil service surveys, they demonstrated strong associations between moderately vigorous or vigorous exercise and CHD occurrence, independent of other associations, in age classes 35-64 years. In the last 30 years, with modern-day computers, a large number of epidemiological studies have been conducted in both sexes, in different ethnic groups, in broad age classes, in a variety of social groups, and on most continents of the world. These studies have extended and amplified those of the Morris group, thereby helping to solidify the cause-and-effect evidence that exercise protects against heart disease and averts premature mortality.

Cardiovascular Diseases↗

PubMed2002

Factors affecting levels of physical activity in adults.

A large proportion of adults in Western cultures are physically inactive, despite several decades of warnings about the potentially negative health consequences of a sedentary lifestyle. Efforts to promote physical activity have focused on identifying its determinants and designing interventions that might effectively promote regular physical activity. The multitude of factors that induce adults to initiate and maintain programmes of physical activity have been divided into those that are invariable (age, gender, race, ethnicity) and those that are presumed to be modifiable (behavioural and personality characteristics, environmental circumstances and community settings). The lack of consistency in the design, analysis and reporting of interventions in the lives of inactive or sedentary individuals has produced equivocal results. However, several social and environmental factors have systematically emerged as determinants of physical activity in adults. In ethnic minorities, the removal of barriers such as unaffordable facilities and unavailable childcare, high crime rates, fear for personal safety and culturally inappropriate activities are of primary importance. Social support from family, peers, communities and healthcare providers has resulted in modest improvements across cultures, ages and genders in selected settings, but the definition of specific interventions and their outcomes deserve additional attention. Longitudinal studies indicate that components of physical fitness are relatively transitory, with low to modest correlations between physical activity and measures of physical fitness in childhood and adolescence and in adulthood. Attempts to explain the activity behaviour of adults by applying various theories in programmes of intervention have also produced mixed results. Successful interventions tailor programmes to individual needs, account for personal levels of fitness, allow for personal control of the activity and its outcomes, and provide for social support by family, peers and communities. The initiation and maintenance of regular physical activity in adults depends on a multitude of biological and sociocultural variables that demand attention across the lifespan.

Adult↗

PubMed2000

Evaluating the cardiovascular tolerance for sex.

The cardiovascular tolerance for sex has largely been equated with physical activity, yet sexual arousal plays a major role. Exercise testing is useful, primarily for evaluating functional capacity, which reflects the extent of physical conditioning and the limitation imposed by symptoms of angina, dyspnea, and fatigue. Exercise testing, which is useful for evaluating functional capacity in sedentary patients, is generally unnecessary in physically active patients. Exercise testing, with or without radionuclide imaging, is of limited value in assessing the risk of future cardiovascular events-a limitation shared by all diagnostic tests, including coronary angiography. The absolute risks of coition-induced myocardial infarction (MI) or death are extremely low-on the order of 2 chances per million per hour in healthy middle-aged individuals or 20 chances per million per hour in "high-risk" patients with ischemic heart disease. This is equivalent to an annual risk of 1. 01% and 1.2%, respectively. Sex is a comparatively weak precipitant of acute coronary events, accounting for only 0.5-1.0% of all such events. The cardiovascular tolerance for sex in an individual can be characterized by the "functional reserve," that is, the extent to which the cardiovascular response to sex-measured by the heart rate, blood pressure, and oxygen consumption-encroaches on the peak response to exercise. Cardiovascular symptoms during sex rarely occur in patients who do not experience similar symptoms during exercise testing at a level equivalent to 6 METS.

Coitus↗

PubMed2006

Consequences of nitrogen and phosphorus limitation for the performance of two planthoppers with divergent life-history strategies.

Phytophagous insects have a much higher nitrogen and phosphorus content than their host plants, an elemental mismatch that places inherent constraints on meeting nutritional requirements. Although nitrogen limitation is well documented in insect herbivores, phosphorus limitation is poorly studied. Using factorial experiments in the laboratory and field, in which levels of soil nitrogen and phosphorus were manipulated, we studied the relative consequences of macronutrient limitation for two herbivores, namely the phloem-feeding planthoppers Prokelisia dolus and P. marginata. These planthoppers inhabit the salt marshes of North America where large stands of their Spartina host plant are found. Notably, these congeners differ in their dispersal abilities; P. marginata is dispersive whereas P. dolus is sedentary. Both nitrogen and phosphorus subsidies enhanced the nitrogen and phosphorus content of Spartina. When P. dolus and P. marginata were raised on plants with an enriched nitrogen signature, they exhibited greater survival, grew to a larger size, developed more rapidly, and achieved higher densities than on nitrogen-deficient plants. However, P. marginata experienced greater fitness penalties than P. dolus on nitrogen-deficient plants. Phosphorus limitation and associated fitness penalties were not as severe as nitrogen limitation for P. marginata, and were not detected in P. dolus. The tempered response of P. dolus to N- and P-deficient Spartina is probably due to its greater investment in feeding musculature and hence ability to compensate for nutrient deficiencies with increased ingestion. To cope with deteriorating plant quality, P. dolus employs compensatory feeding, whereas P. marginata disperses to higher quality Spartina. When its option of dispersal is eliminated and P. marginata is confined on nutrient-deficient plants, its performance is drastically reduced compared with P. dolus. This research highlights the importance of interfacing herbivore life-history strategies with ecological stoichiometry in order to interpret the consequences of macronutrient limitation on herbivore performance and population dynamics.

Animals↗

PubMed2006

Prevalence of leisure-time physical activity in Taiwanese adults: results of four national surveys, 2000-2004.

OBJECTIVES: Literature on the prevalence of physical activity in Asian countries is limited, despite evidence of increasing rates of sedentary-related disease such as obesity and diabetes. It is important to establish nationally representative data in countries such as Taiwan to set up levels and patterns of activity and to inform health policy. METHODS: Unpublished data from four cross-sectional nationally representative surveys comprising 29,226 people aged 20 and older were analyzed. We explored the population prevalence of meeting national recommendations for health, examined temporal change across a 4-year period, and attempted comparisons with neighboring Asian and selected westernized countries. Logistic regression analysis provided adjusted odds ratios of physical activity engagement for several demographic variables. RESULTS: Around 14% of Taiwanese adults met national recommendations. Similar to other Asian countries, but in contrast to declines with age seen in western populations, people aged 45 and older were more likely to be active than younger people. High-risk groups for inactivity were those aged 20-44 with limited formal education and in paid employment. CONCLUSIONS: Overall prevalence in leisure-time physical activity was low. There is scope to increase active leisure for improving health, particularly among younger adults.

Adult↗

PubMed2005

Exercise activates the phosphatidylinositol 3-kinase pathway.

Physical exercise is known to enhance psychological well-being and coping capacity. Voluntary physical exercise in rats also robustly and rapidly up-regulates hippocampal brain-derived neurotrophic factor (BDNF) mRNA levels, which are potentiated following a regimen of chronic antidepressant treatment. Increased BDNF levels are associated with enhanced activity of cyclic AMP response element binding protein (CREB). So far, relatively little is known about the intracellular signaling mechanisms mediating this effect of exercise. We wished to explore the possibility that exercise and/or antidepressant treatment activate the hippocampal phosphatidylinositol-3 (PI-3) kinase pathway, which mediates cellular survival. In young male Sprague-Dawley rats, we examined the effects of 2 weeks of daily voluntary wheel-running activity and/or tranylcypromine (n = 7 per group) on the levels of the active forms of protein-dependent kinase-1 (PDK-1), PI-3 kinase, phospho-thr308-Akt, phospho-ser473-Akt, and phospho-glycogen synthase kinase-3beta (GSK3beta; inactive form), as well as BDNF, activated CREB, and the phospho-Trk receptor, in the rat hippocampus, and compared these with sedentary saline-treated controls. Immunoblotting analyses revealed that in exercising rats, there was a significant increase in PI-3 kinase expression (4.61 times that of controls, P = 0.0161) and phosphorylation of PDK-1 (2.73 times that of controls, P = 0.0454), thr308-Akt (2.857 times that of controls, P = 0.0082), CREB (60.27 times that of controls, P = 0.05), and Trk (35.3 times that of controls, P < 0.0001) in the hippocampi of exercising animals; BDNF was also increased (3.2 times that of controls), but this was not statistically significant. In rats receiving both exercise and tranylcypromine, BDNF (4.51 times that of controls, P = 0.0068) and PI-3 kinase (4.88 times that of controls, P = 0.0103), and the phospho- forms of Trk (13.67 times that of controls, P = 0.0278), thr308-Akt (3.644 times that of controls, P = 0.0004), GSK-3beta (2.93 times that of controls, P = 0.026), and CREB (88.97 times that of controls, P = 0.0053) were significantly increased. These results suggest that the exercise-induced expression of BDNF is associated with the increased expression of several key intermediates of the PI-3 kinase/Akt pathway, which is known for its role in enhancing neuronal survival.

Analysis of Variance↗

PubMedDate not supplied

[Dietary habits, life styles and respiratory symptoms in childhood].

Asthma and obesity in children are common chronic conditions and both disorders have been increasing in the last 2 to 3 decades. The changes of dietary habits and a sedentary life style could have played a role in increasing the prevalence of both conditions. The aim of this report is to analyse the relation between some respiratory conditions (current wheezing, asthma and chronic cough) with dietary habits, body mass index (BMI), the physical activity and the habit to watch television. A total of 19,995 children (10,294 males and 9701 females) were investigated. Current wheezing is associated with increased BMI (V quintile OR=1.65), TV watching (more than 5 h/day OR=1.53), adding salt to the foods (OR=2.45), and fizzy drink (5 times or more per week OR=1.31). Children who often eat tomatoes, fruits, cooked vegetables and citrus fruits have a lower risk of current wheeze. The pattern of association is similar for asthma. High BMI, TV watching, adding salt to foods, and fizzy drink are risk factors for chronic cough. An increased BMI and TV watching are strongly related to respiratory symptoms. Our data confirm that dietary factors such as salt, vegetables and fruits are associated with the prevalence of respiratory symptoms in children.

Asthma↗

PubMed1981

Feeding patterns of endurance athletes.

Feeding pattern was studied in 13 long distance runners, eight cyclists and eight sedentary men. The timing of the food and fluid intakes, the kind and the amount of food and fluids taken, the body weight (BW), and the exercise schedules were recorded on 3 or 4 successive days under ad libitum conditions of feeding and drinking. The subjects remained in energy and water balance, since the BW measured in the morning during the observation periods did not change significantly. The total caloric intake was 13 876 kJ per day in the runners and 26 282 kJ per day in the cyclists, exceeding the estimated basic metabolic rate by 103% and 250% respectively. The total water intakes were 33 and 36 ml . kg-1 . 24 h-1. The athletes consistently showed a nibbling pattern, characterized by frequent eating and drinking (average 8-10 per day). In the runners 63% of eating and drinking were synchronized, in the cyclists only 49% (p less than 0.01). In both groups drinking occurred most frequently in the morning, at noontime and in the evening. After 8 p.m. 45% of the total daily fluid intake occurred. In all likelihood the fluid intake followed an underlying circadian rhythm. The total intake frequency was determined by the total caloric needs.

Adolescent↗

PubMed1990

Exercise during rat pregnancy and lactation: maternal effects and offspring growth.

Eighty Sprague-Dawley rats were divided into exercised (E) and sedentary (S) groups. E rats were trained to run on a treadmill (30 m/min, 2 hr/day). Within each group, two subgroups were mated and three served as virgin time controls. Of the mated subgroups, one was terminated within 24 hours of delivery and the other on day 14 of lactation. Subgroups of virgin S and E controls were terminated at times corresponding to the mating, delivery and lactation day 14 of mated rats. MANOVA revealed that exercise significantly affected food intake, body weight and body composition in both virgin and mated animals: generally, E rats ate more, gained more weight, and had less carcass fat than S controls. E rats did not store fat during pregnancy. At parturition, they were 7.0% fat, similar to both E (6.6%) and S (7.6%) controls prior to mating, and less than S rats at parturition (11.9%). Despite diminished fat stores at parturition in E rats, litter size and pup birthweight were similar in E and S rats, as was offspring growth during lactation (mean weights on day 14 of 28.9 g and 29.3 g, respectively). Remaining body fat and increased food intake were adequate to support normal pup growth.

Animals↗

PubMed1999

The impact of predation on burrow use by arctic ground squirrels in the boreal forest.

In sedentary animals, the choice of a suitable home site is critical to survival and reproductive fitness. However, habitat suitability may vary with predation risk. We compared habitat use of Arctic ground squirrels (Spermophilus parryii plesius) living in the boreal forest under conditions of fluctuating predation pressure. In our study area, predators show ten-year cycles in numbers that track that of their primary prey, the snowshoe hare (Lepus americanus). In 1993, we compared burrows that continued to be occupied following the period of intense predation during the hare decline of 1990-1992 with those that became vacant, and with random locations. We contrasted these sites to those in a predator exclosure where predation pressure was minimized. Burrows on control sites were located on sloped sites with high visibility. Burrows that remained occupied during the period of intense predation were more likely to be in open areas with fewer fallen trees than burrows that became vacant. We used discriminant functions derived from the control sites and found that 89% of the burrows on the predator exclosure were classified as being similar to the random locations on control sites. We conclude that the distribution of Arctic ground squirrels in the boreal forest is a direct function of predator presence.

Animals↗