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Full-Text Articles in Nutrition

American Bullfrog (Lithobates Catesbeianus) Diet In Uruguay Compared With Other Invasive Populations In Southern South America, Gabriel Laufer, Noelia Gobel, Mauro Berazategui, Matías Zarucki, Sofía Cortizas, Alvaro Soutullo, Claudio Martinez Debat, Rafael O. De Sá Dec 2021

American Bullfrog (Lithobates Catesbeianus) Diet In Uruguay Compared With Other Invasive Populations In Southern South America, Gabriel Laufer, Noelia Gobel, Mauro Berazategui, Matías Zarucki, Sofía Cortizas, Alvaro Soutullo, Claudio Martinez Debat, Rafael O. De Sá

Biology Faculty Publications

Between 2000-2020, more than ten new populations of the invasive American bullfrog (Lithobates catesbeianus) have been reported in the southern cone of South America. We studied the stomach contents of 126 bullfrogs from a population at an early invasion stage in Uruguay (Acegua, Cerro Largo Department). We observed a rich diet, with extensive prey volume range (1 mm3 to more than 7 000 mm(3)); the most frequent items were Hymenoptera (19.6%), Coleoptera (16.4%), Amphipoda (13.3%), Anura (8.9%) and Heteroptera (8.7%). Despite some overlap, differences were observed in volume (chi(2) = 54.6, p <0.001, d.f. = 2) and prey quantity (F = 8.1, p <0.001, d.f. = 79) between males, females, and juveniles. Juveniles showed significantly higher consumption of terrestrial prey by count (82% of their total ingestion) than adults (29% for males and 32% for females) (chi(2) = 28.5, p <0.001, d.f. = 2). Adults, especially females, showed a high frequency of cannibalism (33% of their total ingestion; chi(2) = 20.9, p <0.001, d.f. = 2). Comparing our data with other bullfrog regional studies, we found great plasticity in trophic habits and differences in the incidence of cannibalism (higher incidence in the populations of Acegua, Uruguay, and Buenos Aires, Argentina). These differences could be related to local biodiversity, but also could be affected by the invasion phase. Cannibalism frequency was higher in small bullfrog populations, where it could be favoring the establishment success. This shift in foraging strategies during the invasion process had been insufficiently evaluated in amphibians. Knowing the ecological determinants for the invasion by bullfrogs can be useful to the development of management strategies.


The Energy Savings-Oxidative Cost Trade-Off For Migratory Birds During Endurance Flight, Scott R. Mcwilliams, Barbara J. Pierce, Andrea Wittenzellner, Lillie A. Langlois, Sophia Engel, John R. Speakman, Olivia Fatica, Kristen J. Demoranville, Wolfgang Goymann, Lisa Trost, Amadeusz Bryla, Maciej Dzialo, Edyta T. Sadowska, Ulf Bauchinger Dec 2020

The Energy Savings-Oxidative Cost Trade-Off For Migratory Birds During Endurance Flight, Scott R. Mcwilliams, Barbara J. Pierce, Andrea Wittenzellner, Lillie A. Langlois, Sophia Engel, John R. Speakman, Olivia Fatica, Kristen J. Demoranville, Wolfgang Goymann, Lisa Trost, Amadeusz Bryla, Maciej Dzialo, Edyta T. Sadowska, Ulf Bauchinger

Biology Faculty Publications

Elite human and animal athletes must acquire the fuels necessary for extreme feats, but also contend with the oxidative damage associated with peak metabolic performance. Here, we show that a migratory bird with fuel stores composed of more omega-6 polyunsaturated fats (PUFA) expended 11% less energy during long-duration (6 hr) flights with no change in oxidative costs; however, this short-term energy savings came at the long-term cost of higher oxidative damage in the omega-6 PUFA-fed birds. Given that fatty acids are primary fuels, key signaling molecules, the building blocks of cell membranes, and that oxidative damage has long-term consequences for …


The Effects Of Dietary Linoleic Acid And Hydrophilic Antioxidants On Basal, Peak, And Sustained Metabolism In Flight‐Trained European Starlings, Wales A. Carter, Kristen J. Demoranville, Barbara J. Pierce, Scott R. Mcwilliams Feb 2020

The Effects Of Dietary Linoleic Acid And Hydrophilic Antioxidants On Basal, Peak, And Sustained Metabolism In Flight‐Trained European Starlings, Wales A. Carter, Kristen J. Demoranville, Barbara J. Pierce, Scott R. Mcwilliams

Biology Faculty Publications

Dietary micronutrients have the ability to strongly influence animal physiology and ecology. For songbirds, dietary polyunsaturated fatty acids (PUFAs) and antioxidants are hypothesized to be particularly important micronutrients because of their influence on an individual's capacity for aerobic metabolism and recovery from extended bouts of exercise. However, the influence of specific fatty acids and hydrophilic antioxidants on whole‐animal performance remains largely untested. We used diet manipulations to directly test the effects of dietary PUFA, specifically linoleic acid (18:2n6), and anthocyanins, a hydrophilic antioxidant, on basal metabolic rate (BMR), peak metabolic rate (PMR), and rates of fat catabolism, lean catabolism, and …


The Fat Of The Matter: How Dietary Fatty Acids Can Affect Exercise Performance, Barbara J. Pierce, Scott R. Mcwilliams Nov 2014

The Fat Of The Matter: How Dietary Fatty Acids Can Affect Exercise Performance, Barbara J. Pierce, Scott R. Mcwilliams

Biology Faculty Publications

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 …