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Full-Text Articles in Life Sciences

Effects Of Methylmercury And Unpredictable Food Stress Exposure On Songbirds’ Physiology And Seasonal Transition, Claire L.J. Bottini Dec 2022

Effects Of Methylmercury And Unpredictable Food Stress Exposure On Songbirds’ Physiology And Seasonal Transition, Claire L.J. Bottini

Electronic Thesis and Dissertation Repository

Organisms regularly adjust their physiology to respond to predictable seasonal or environmental variation. However, annual cycle transitions could be disrupted by contaminants or stressors. For example, methylmercury and stress exposure can independently disrupt birds’ neural and endocrine systems, energy balance, metabolism, or behaviour, all necessary for seasonal transitions. Although, the effects of combined exposure to stressors and methylmercury (MeHg), and how long they last after exposure ends, are poorly understood. The objective of my PhD was to evaluate the impact of MeHg exposure on songbirds’ physiology and its potential carry-over effects on seasonal transitions. I exposed song sparrows (Melospiza …


Effects Of Temperature On Growth, Metabolic Rate, And Lower Dissolved Oxygen Tolerance Of Speckled Peacock Bass Cichla Temensis, Manuel E. Coffill-Rivera Aug 2022

Effects Of Temperature On Growth, Metabolic Rate, And Lower Dissolved Oxygen Tolerance Of Speckled Peacock Bass Cichla Temensis, Manuel E. Coffill-Rivera

Theses and Dissertations

I examined the effects of temperature (25, 30, and 35°C) on growth, standard metabolic rate (SMR), and lower dissolved oxygen tolerance (LDOT) of juvenile Speckled Peacock Bass Cichla temensis. Fish were acclimated to 150-L aquaria for 7 weeks before the growth, SMR, and LDOT experiments. The growth study lasted 58 days and fish acclimated to 25 and 30°C displayed similar growth rates, while fish acclimated to 35°C had very poor growth rates. The SMR and LDOT experiments were performed using intermittent respirometers. Fish acclimated to 25°C had the lowest SMR, followed by 30°C, and finally 35°C. The highest LDOT …


The Influence Of Temperature And Body Size On Food Consumption In Prairie Lizards (Sceloporus Consobrinus), Morgan Pelley May 2022

The Influence Of Temperature And Body Size On Food Consumption In Prairie Lizards (Sceloporus Consobrinus), Morgan Pelley

Biological Sciences Undergraduate Honors Theses

Understanding the effect of temperature on physiological and digestive processes, such as voluntary consumption rate, is critical for assessing the impact of climate change. Food consumption is required for lizard survival and reproduction and its rate is dependent on temperature. For ectotherms, as temperatures increase, the amount of food consumed to meet the energy requirements related to survival and reproduction must also increase. Information on the amount of food voluntarily consumed may aid in determining if lizards can meet energy requirements. Such information could also aid in predicting survival of lizard populations, through construction of predictive climate change models. In …


Drivers And Direct Impacts Of Lean Mass Dynamics On The Stopover Ecology And Migratory Pace Of Nearctic-Neotropical Migrant Songbirds In Spring, Mariamar Gutierrez Ramirez Mar 2022

Drivers And Direct Impacts Of Lean Mass Dynamics On The Stopover Ecology And Migratory Pace Of Nearctic-Neotropical Migrant Songbirds In Spring, Mariamar Gutierrez Ramirez

Doctoral Dissertations

Annual migration in songbirds is one of the most demanding life-history stages. It represents a period of high mortality, yet there is still much unknown about the ecological correlates that influence its successful completion. After long non-stop migratory flights, birds require a stopover period to rest and replenish depleted energy reserves. Birds use fat as the primary fuel to power long-distance flights. However, birds also burn lean tissue, which results in significant reductions in muscle and organ masses. The discovery and quantification of lean mass catabolism represented a paradigm shift in migration ecology because non-fat components were thought to remain …