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Fatty-acid composition of fat stores affects exercise performance in a variety of vertebrates although few such studies focus on flying vertebrates such as migratory birds, which are exceptional exercisers. We first discuss the natural variation in quality of fat available in natural foods eaten by migratory birds and their behavioral preferences for specific fatty acids in these foods. We then outline three proposed hypotheses for how dietary fatty acids can affect exercise performance, and some of the evidence to date that pertains to these hypotheses with special emphasis on the exercise performance of migratory birds. In theory, selectively feeding on certain long-chain unsaturated fatty acids may be advantageous because (1) such fatty acids may be metabolized more quickly and may stimulate key facets of aerobic metabolism (fuel hypothesis); (2) such fatty acids may affect composition and key functions of lipid-rich cell membranes (membrane hypothesis); and (3) such fatty acids may directly act as signaling molecules (signal hypothesis). Testing these hypotheses requires cleverly designed experiments that can distinguish between them by demonstrating that certain fatty acids stimulate oxidative capacity, including gene expression and activity of key oxidative enzymes, and that this stimulation changes during exercise. [ABSTRACT FROM AUTHOR]

ABSTRACT Regional and intraseasonal patterns of food use influence populations through impacts on breeding success, survival, and distribution of individuals. We used both traditional foregut content analysis and stable carbon and nitrogen isotopes in liver and leg muscle to determine intraseasonal patterns in the diet of Atlantic brant geese ( Branta bernicla hrota) from early winter through spring staging (1 Dec-31 May 2007-2008) along the mid-Atlantic coast of the United States. Overall, brant diet consisted of macroalgae (52%), salt marsh cordgrass (22%), eelgrass (18%), and terrestrial grass and clover (8%). Mean δ13C and δ15N values differed among these 4 food sources. Therefore, we used an isotope mixing-model (SIAR) to estimate the relative contributions of each source to brant diet among regions and months. Wintering brant in northern and southern regions ate mostly macroalgae throughout the wintering period and ate more salt marsh and terrestrial grasses in spring. Brant in central regions had a more stable diet from December to May. Regional and intraseasonal patterns in brant diet are likely affected by several factors including variation in food source availability and quality due to synergistic effects of long-term annual and intraseasonal changes in abundance of submerged aquatic vegetation. Our estimates of diet combined with information on brant daily energy requirements and forage quality can be used to more accurately determine carrying capacity of wintering brant geese given established population objectives. © 2014 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Hosts can manage parasitic infections using an array of tactics, which are likely to vary contingent on coevolutionary history between the host and the parasite. Here we asked whether coping ability of congeners that differ in host-parasite coevolutionary history differed in response to experimental infections with a coccidian parasite. House sparrows (Passer domesticus) and gray-headed sparrows (Passer griseus) are sympatric and ecologically similar, but house sparrows are recent colonizers of Kenya, the site of our comparison, whereas gray-headed sparrows are native. We evaluated three variables as barometers of infection coping ability: vertical flight, pectoral muscle size, and fat score. We also measured routing of a dose of 13C-labeled leucine, an essential amino acid, among tissues to compare resource allocation strategies in response to infection. We found that burden effects on performance were minimal in both species, but house sparrows maintained considerably higher burdens than gray-headed sparrows regardless of exposure. House sparrows also had more exogeneous leucine tracer in all tissues after 24 h, demonstrating a difference in the way the two species allocate or distribute resources. We argue that house sparrows may be maintaining larger resource reserves to mitigate costs associated with exposure and infection. Additionally, in response to increased parasite exposure, gray-headed sparrows had less leucine tracer in their spleens and more in their gonads, whereas house sparrows did not change allocation, perhaps indicating a trade-off that is not experienced by the introduced species. [ABSTRACT FROM AUTHOR]

Flexible phenotypes enable animals to live in environments that change over space and time, and knowing the limits to and the required time scale for this flexibility provides insights into constraints on energy and nutrient intake, diet diversity and niche width. We quantified the level of immediate and ultimate spare capacity, and thus the extent of phenotypic flexibility, in the digestive system of a migratory bird in response to increased energy demand, and identified the digestive constraints responsible for the limits on sustained energy intake. Immediate spare capacity decreased from approximately 50% for birds acclimated to relatively benign temperatures to less than 20% as birds approached their maximum sustainable energy intake. Ultimate spare capacity enabled an increase in feeding rate of approximately 126% as measured in birds acclimated for weeks at −29°C compared with +21°C. Increased gut size and not tissue-specific differences in nutrient uptake or changes in digestive efficiency or retention time were primarily responsible for this increase in capacity with energy demand, and this change required more than 1-2 days. Thus, the pace of change in digestive organ size may often constrain energy intake and, for birds, retard the pace of their migration. [ABSTRACT FROM AUTHOR]

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ABSTRACT The southern New England continental shelf is an important region for black scoters ( Melanitta americana) during winter and migratory staging periods and a priority area for developing offshore wind energy facilities. However, little is known about the migration phenology and habitat use of black scoters in this portion of their range and this information is necessary to assess potential risks to black scoters during the marine spatial planning process. In this regional black scoter study over 2 winters, we used satellite telemetry and spatial modeling techniques to estimate migratory timing and length of stay, quantify winter home range size and site fidelity between winters, examine key habitat characteristics associated with core-use areas, and map relative probabilities of use across a 3,800-km2 marine spatial planning area for 2 proposed offshore renewable energy facilities. Black scoters spent nearly 5 months in southern New England, with wide variation among individuals in the size of winter utilization distributions (range 16-12,367 km2). Approximately 50% of the tagged birds returned to southern New England during the subsequent winter and had variable fidelity to core-use areas occupied the previous winter. During both winters, black scoter core-use areas were located closer to shore, at shallower water depths, with coarser sediment grain size and higher probability of hard-bottom occurrence relative to available areas. Resource selection functions classified the majority of a nearshore 5-turbine, 34-km2 renewable energy zone off Block Island as high probability of use by black scoters, whereas an offshore 200-turbine, 667-km2 federal lease block zone was classified as low to medium-low probability of selection. Wind energy facilities, such as the Block Island site, constructed in relatively shallow (<20 m deep), nearshore habitats (<5 km) over hard-bottomed or coarse-sand substrate could displace some foraging black scoters wintering in this region, whereas the larger federal lease block zone located farther offshore is more likely to affect scoters dispersing among core-use areas and during migration between wintering and breeding grounds. © 2014 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Fleshy-fruited plants depend fundamentally on interactions with frugivores for effective seed dispersal. Recent models of frugivory within spatially explicit networks make two general predictions regarding these interactions: rate of fruit removal increases (i.e., is facilitated) as densities of conspecific neighborhood fruits increase, and fruit removal rate varies positively with frugivore abundance. We conducted a field experiment that constitutes the first empirical and simultaneous test of these two primary predictions. We manipulated neighborhood abundances of arrowwood ( Viburnum recognitum and Viburnum dentatum) fruits in southern New England's maritime shrub community and monitored removal rates by autumn-migrating birds. Focal arrowwood plants in neighborhoods with high conspecific fruit density sustained moderately decreased fruit removal rates (i.e., competition) relative to those in low-density neighborhoods, a result that agrees with most field research to date but contrasts with theoretical expectation. We suggest the spatial contexts that favor competition (i.e., high-abundance neighborhoods and highly aggregated landscapes) are considerably more common than the relatively uniform, low-aggregation fruiting landscapes that promote facilitation. Patterns of arrowwood removal by avian frugivores generally varied positively with, and apparently in response to, seasonal changes in migratory frugivore abundance. However, we suggest that dense stands of arrowwood concentrated frugivore activity at the neighborhood scale, thus counteracting geographic patterns of frugivore abundance. Our results underscore the importance of considering spatial context (e.g., fruit distribution and aggregation, frugivory hubs) in plant-avian frugivore interactions. [ABSTRACT FROM AUTHOR]

All vertebrates must contend with an increase in oxidative stress during intense exercise. Birds, in particular, may be exposed to increased oxidative stress during long-distance migration, and dietary antioxidants are likely important in alleviating the deleterious effects associated with such a stressor. We evaluated whether fruit selection by birds at a migratory stopover site in southern New England was related to the antioxidant and macronutrient content of fruits from seven commonly consumed fall-fruiting shrub species. Our objectives were to: (1) quantify, for the first time, total hydrophilic and lipophilic antioxidants, as well as two types of lipophilic antioxidants (i.e., carotenoids, and tocopherols) in wild fruits consumed by migrating birds, (2) test the hypothesis that antioxidant content of wild fruits is related to macronutrient composition, and (3) relate patterns of avian frugivory to antioxidant availability and macronutrient content of wild fruits during autumn migration. We found significant differences between fruits in total lipophilic antioxidants, carotenoids, and tocopherols, but not total hydrophilic antioxidants. Viburnum spp. and Myrica pennsylvanica had the most lipophilic antioxidants and tocopherols, whereas Celastrus orbiculatus and Rosa multifiora contained the most carotenoids. Carotenoid content was positively correlated with protein content but no significant relationships were evident between the other antioxidants and macronutrients. Fruit consumption was negatively correlated with carotenoid content and was not related to any other antioxidant measure. Interestingly, the most consumed fruit species, arrowwood, was among the highest in fat, total lipophilic antioxidants, and locopherols. These data indicate that antioxidant content differs significantly between fruit species and suggest that (1) birds can acquire different types of antioxidants depending on the fruits they select and (2) lipophilic antioxidants, especially tocopherols, may be important antioxidants for birds during autumn migration. [ABSTRACT FROM AUTHOR]

The article discusses a study on the densities of wintering scoters relative to benthic prey assemblage in Narragansett Bay, Rhode Island, an urbanized North Atlantic estuary. The study involves sea duck surveys during the winter of 2010 to 2011. It showed that lower densities of scoters were related to mixed-sand-gravel-mud substrates that supported patchily distributed infauna and epifaunal assemblages.

Species associated with early successional habitats have experienced dramatic declines in the eastern United States as a result of land use changes and human disruption of natural disturbance regimes. Consequently, active management is required to create early successional habitat and promote plant and animal communities that depend on periodic forest disturbance. Ruffed grouse ( Bonasa umbellus) depend on recently disturbed forest habitat, and have experienced dramatic declines over the last half-century. Although ruffed grouse are extensively studied, little effort has been made to link population dynamics with habitat management at landscape scales. We used stochastic, spatially explicit population models that combined landscape conditions derived from a Geographic Information System with demographic data, and applied the model to a declining ruffed grouse population in Rhode Island, USA. We identified vital rates that influence ruffed grouse population dynamics using baseline models constructed with current demographic rates and landscape conditions, and assessed the effect of landscape-scale forest management alternatives on population persistence by running multiple management simulations. Baseline models typically predicted population decline, and we concluded that vital rates (survival and recruitment) had a greater influence on population persistence than did dispersal capability, carrying capacity, or initial population size. Management simulations predicted greater population persistence under a scenario where high-quality habitat was provided in fewer large blocks as opposed to many small blocks, and the rate at which we allowed ruffed grouse to colonize newly created habitat had a substantial impact on management success. Populations of ruffed grouse in the eastern United States are likely to continue to decline given current disturbance regimes, and our work provides a link between ruffed grouse demography and landscape-scale habitat conditions to support management decisions. © 2011 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Migrating blackcaps (Sylvia atricapilla) were used to test the predictions that (1) the rebuilding of the digestive tract, as reflected by mass-specific consumption of food on the first 2–3 days of a stopover, is faster in birds with access to drinking water than in birds without, and (2) that adipose tissue and pectoral muscles grow faster and to a greater extent in birds with unlimited access to water. We simulated migratory stopover in two experiments. In Experiment I, each of 31 birds was randomly assigned to one of three experimental groups for 6 days. Along with mealworms (∼64% water) ad libitum, Group 1 received drinking water ad libitum; Group 2 had 0.5 h/day access to water; and Group 3 had no access to water. In Experiment II, 30 birds were offered a mixed diet for insectivorous birds (∼33% water) ad libitum for 6 days, while randomly assigned to two groups: (1) Water ad libitum—control; and (2) 30 min access to water twice a day. We measured lean mass and fat mass using dual energy X-ray absorptiometry, as well as body mass (mb), pectoral muscle index (PMI), and daily intake of food and water. Mean daily water intake was significantly different among the groups in both experiments. However, the availability of drinking water positively affected the rates of gain of lean and fat mass only in birds fed with the mixed, relatively dry diet. Furthermore, mass-specific daily food intake was affected by the availability of drinking water only in the mixed diet experiment, in which birds with unlimited access to drinking water reached an asymptote, 1 day earlier than birds in the water-restricted group. We suggest that in birds consuming diets with low water content, the lack of sufficient drinking water may result in slower rebuilding of the digestive tract, or may influence biochemical processes in the gut that result in slower growth of tissue. Although blackcaps obtained sufficient water from preformed and metabolic water to renew lost tissues when eating mealworms, given access to water, the birds drank prodigiously. Our results also suggest that if drinking water is unavailable to migrating blackcaps, their choices are restricted to water-rich foods, which may constrain their rate of feeding and thus the rate at which they deposit fat. Consequently, drinking water may have an important influence on birds’ migratory strategies with respect to habitat selection, use of energy, and the saving of time. [ABSTRACT FROM AUTHOR]

During migration, birds undergo alternating periods of fasting and re-feeding that are associated with dynamic changes in body mass (mb) and in organ size, including that of the digestive tract. After arrival at a migratory stopover site, following a long flight, a bird must restore the tissues of its digestive tract before it can refuel. In the present study we examined how the availability of dietary protein influences refueling of migrating blackcaps (Sylvia atricapilla) during a migratory stopover. We tested the following predictions in blackcaps deprived of food and water for 1–2 days to induce stopover behavior: (1) birds provided with a low-protein diet will gain mb, lean mass and fat mass, and increase in pectoral muscle size slower than do birds fed a high-protein diet; (2) since stopover time is shorter in spring, birds will gain mb and build up fat tissue and lean tissue faster than in autumn; and (3) if low dietary protein limits a bird’s ability to gain mb and fat reserves, then birds that do not obtain enough protein will initiate migratory restlessness (Zugunruhe) earlier than will birds with adequate dietary protein. These predictions were tested by providing captured migrating blackcaps with semisynthetic isocaloric diets differing only in their protein content. Each day, we measured mb, and food intake; also lean mass and fat mass were measured using dual energy X-ray absorptiometry. In addition, we monitored nocturnal activity with a video recording system. In both spring and autumn, birds fed diets containing either 3 or 20% protein increased in mb, lean mass and fat mass at similar rates during the experiment. However, the group receiving 3% protein ate more than did the group receiving 20% protein. In support of our predictions, mb, lean mass, fat mass, and intake of food all were higher in spring than in autumn. We also found that in spring all birds had higher levels of migratory restlessness, but birds fed 3% protein were less active at night than were birds fed 20% protein, possibly an adaptation conserving energy and protein. We conclude that protein requirements of migrating blackcaps during stopover are lower than expected, and that birds can compensate for low dietary protein by behavioral responses, i.e. hyperphagia and decreased migratory restlessness, that ensure rapid refueling. [ABSTRACT FROM AUTHOR]

All animals route assimilated nutrients to their tissues where they are used to support growth or are oxidized for energy. These nutrients are probably not allocated homogeneously among the various tissue and are more likely to be preferentially routed toward some tissues and away from others. Here we introduce an approach that allows researchers to identify and compare nutrient routing among different organs and tissues. We tested this approach by examining nutrient routing in birds. House sparrows Passer domesticus were fed a meal supplemented with one of seven 13C-labeled metabolic tracers representing three major classes of macronutrients, namely, carbohydrates, amino acids, and fatty acids. While these birds became postabsorptive (2 h after feeding), we quantified the isotopic enrichment of the lean and lipid fractions of several organs and tissues. We then compared the actual 13C enrichment of various tissue fractions with the predictions of our model to identify instances where nutrients were differentially routed and found that different classes of macronutrients are uniquely routed throughout the body. Recently ingested amino acids were preferentially routed to the lean fraction of the liver, whereas exogenous carbohydrates were routed to the brain and the lipid fraction of the liver. Fatty acids were definitively routed to the heart and the liver, although high levels of palmitic acid were also recovered in the adipose tissue. Tracers belonging to the same class of molecules were not always routed identically, illustrating how this technique is also suited to examine differences in nonoxidative fates of closely related molecules. Overall, this general approach allows researchers to test heretofore unexamined predictions about how animals allocate the nutrients they ingest. [ABSTRACT FROM AUTHOR]

We conducted extensive behavioral and food sampling of Atlantic brant (Branta bernicla hrota) across their winter range and used time-activity budgets for brant to determine daily energy expenditure (DEE). Sampling occurred 1 December-31 May 2006-2008 in 11,225-km2 sites between Rhode Island and Virginia containing important estuarine and upland habitat. To calculate DEE we used instantaneous scan sampling to estimate time-activity budgets. We also determined foods eaten by brant and energy density of food plants. Last, we quantified body condition of brant, which differed among years, months, regions, and ages, and sexes. Overall DEE for brant was 1,530 ± 64 kJ/day. There was considerable variation in time- activity budgets among years, months, regions, habitat, tide, temperature, and time-of-day, but we detected no significant difference in DEE of brant between years or among regions. However, DEE in January (2,018 ± 173 kJ/day) was nearly double the DEE of brant in May (1,048 ± 137 kJ/day). Brant spent their time feeding (32.3%), swimming (26.2%), resting (16.2%), and flying (14.5%). The percent of brant foreguts sampled contained macroalgae (53%) eelgrass (Zostera marina; 18%), salt marsh cordgrass (Spartina alterniflora; 17%), and terrestrial grass (Poa. sp.) and clover (Trifollium sp.; 9%). Energy density differed by vegetation type: macroalgae (12.6 ± 0.1 kJ/g), eelgrass (14.1 ± 0.1 kJ/g), new-growth salt marsh cordgrass (16.9 ± 0.2 kJ/g), and terrestrial grass and clover (17.7 ± 0.1 kJ/g). Atlantic brant exhibited behavioral plasticity thereby allowing modification of daily activity budgets to meet seasonally varying energetic requirements associated with wintering and spring staging. Recognizing a variable DEE can be used along with eventual estimates of food biomass and total metabolizable energy on the landscape to calculate carrying capacity (goose use days) on state, region, or range-wide scales. [ABSTRACT FROM AUTHOR]

Phenotypic flexibility in organ size of migratory birds is typically explained in functional terms in accordance with the principal of economic design. However, proposed functional hypotheses do not adequately explain differences in phenotypic flexibility between organs during fasting and in-flight starvation. We show that the extent of phenotypic flexibility in organ mass in five species of migratory birds during actual migration or simulated in-flight starvation consistently ranked as follows from highest to lowest mass change: small intestine, liver, kidney, gizzard, heart, flight and leg muscle. This pattern of phenotypic flexibility in organ mass was not consistent with proposed functional hypotheses, and was almost completely explained by differences in tissue-specific turnover rate measured in vivo using nutrients differing in their isotopic values. Thus, the fundamental process of tissue-specific protein turnover determines extent of organ mass changes for birds during migration, this likely applies to other organisms during fasting, and no further functional explanation(s) for differences in the magnitude of phenotypic flexibility between organs is required. [ABSTRACT FROM AUTHOR]

This article discusses a study which examined whether interspecific differences in protein requirements of birds are related to their foraging strategy and whether protein requirements of birds increase with demand, for example during migratory periods. Researchers measured protein requirements of the omnivorous Hermit Thrush (Catharus guttatus) and the granivorous White-throated Sparrow (Zonothrichia albicollus) during nonmigratory and migratory stages of the annual cycle. They compared the findings with published estimates for other songbird species.

Food abundance can affect a species' distribution. In many studies of potential food limitation, researchers focus on carrying capacity estimates during the nonbreeding season for temperate species consuming a fixed food source. Estimates of energetic carrying capacity for year-round breeders feeding on a replenishing resource would be more difficult and require much data. To determine whether gathering detailed information on year-round carrying capacity would be an important investment, we conducted an assessment to determine whether there was evidence that energy or protein might limit numbers of the tropical, endangered Hawaiian moorhen (Gallinula chloropus sandvicensis). We compared observed numbers of moorhen at 15 Oahu, Hawaii, USA, wetlands with predicted numbers based on measured energy and protein in food plants and abundance of these food plants in each wetland and on estimates of energy expenditure of moorhen. We made comparisons assuming moorhen are limited by their ability to metabolize food plants, by competition for food, and by estimated costs associated with reproduction. We also compared ranked moorhen abundance and density with ranked energy and protein under different wetland management regimes. Energy values consistently overestimated expected numbers of Hawaiian moorhen at wetlands except for one wetland location (predicted, 3803 ± 4856; observed, 6.2 ± 10.8). In addition, we detected no significant relationship between moorhen abundance and measures of energy (all r² = 0.02-0.73, all P > 0.1) or protein abundance (all r² = 0.08-0.50, all P > 0.3). This lack of relationship held once we controlled for wetland area or when we considered whether wetlands were managed for waterbirds. Hawaiian moorhen on Oahu did not appear to be limited by energy, nor did they appear to select sites based on energy or protein, in contrast to many studies relating animal numbers to energy in nonbreeding situations. Consequently, we suggest that researchers and managers explore other potentially limiting factors for Hawaiian moorhen. [ABSTRACT FROM AUTHOR]

The article discusses a study on fuel use and storage in passerine migration and its correlation to fruit resources at autumn stopover sites. The study procedure included the measurement of concentrations of uric acid, B-hydroxybutyrate, and triglyceride. The site differences in plasma metabolites is also noted.

The article focuses on the importance of essential nutrients particularly long-chain omega-3 polyunsaturated fatty acids (LCPUFA) for wild vertebrates like tree swallows. It discusses how LCPUFA can develop the growing swallow chick's immune competence, and physiological needs. It also talks about LCPUFA's effect on mammals in hibernation, on human reproduction and growth.

The article focuses on a study that aims to predict the distribution of potential grouse habitat in a landscape of management concern in order to inform management authorities and support future research, conducted in the Arcadia Management Area and surrounding private lands in Washington County, Rhode Island. A relatively new ecological modeling technique that has been used to predict habitat distribution for rare wildlife species was adopted by the researchers for the study. No more than one location was collected per day to ensure independent observations.

Stable isotopes are an important tool for physiological and behavioral ecologists, although their usefulness depends on a thorough understanding of the dynamics of isotope incorporation into tissue(s) over time. In contrast to hair, claws, and feathers, most animal tissues continuously incorporate carbon (and other elements), and so carbon isotope values may change over time, depending on resource use and tissue-specific metabolic rates. Here we report the carbon turnover rate for 12 tissues from a passerine bird, the zebra finch (Taeniopygia guttata). We measured average carbon retention time (τ) for 8 d for small intestine; 10-13 d for gizzard, kidney, liver, pancreas, and proventriculus; 17-21 d for heart, brain, blood, and flight muscle; and 26-28 d for leg muscle and skin. We used these data, along with the few other published estimates, to confirm that the fractional rate of isotopic turnover for red blood cells, whole blood, liver, and leg muscle scales with body mass to approximately the 1/4 power. Our data also support several key assumptions of the "isotopic-clock" model, which uses differences in isotope value between tissues, along with estimates of turnover rate of these tissues, to predict time elapsed since a diet shift. Finally, we show that between-tissues differences in turnover rate largely, but not entirely, explain the extent of phenotypic flexibility in organs of garden warblers during their long-distance flight across the Sahara Desert during spring. More studies that measure tissue-specific protein synthesis, metabolic rate, and elemental turnover in many tissues from a variety of animals are needed. [ABSTRACT FROM AUTHOR]

Plasma lipid metabolites can provide information about fat metabolism and storage in migrating birds, yet little is known about the influence of diet and nutrition or how they relate to intraindividual differences in body composition of songbirds. We investigated how dietary macronutrient composition affects plasma lipid concentrations and subsequent changes in fat accumulation in white-throated sparrows (Zonotrichia albicollis). Birds fed a low-protein diet with more glucose had higher plasma triglyceride levels and higher average fat mass compared with levels and mass in birds fed diets with less glucose, and birds fed diets with less glucose and more fat had the highest plasma B-hydroxybutyrate concentrations, regardless of protein content. Birds fed the low-protein, high-fat diet also had the highest plasma nonesterified fatty acids. Diet-related changes in plasma triglyceride and B-hydroxybutyrate were more strongly related to fat mass than to lean mass of birds. Nevertheless, diet-related changes in lipid metabolites were more strongly influenced by the intake of certain macronutrients than by body fatness. Thus, plasma lipid metabolites may reliably indicate fat mass and fattening rates of birds, although our results suggest that diet composition must be considered given that certain macronutrients, namely, dietary glucose, may enhance fat deposition in songbirds. [ABSTRACT FROM AUTHOR]