Saddleback Journal of Biology - Saddleback College

Fall 2009 Biology 3A Abstracts
10. EFFECT OF SIMULATED SOLAR RADIATION ON EVAPORATIVE WATER LOSS IN
ZEBRA FINCH (Taeniopygia guttata). Casey R. Burgwald and Ronald T. Istrati. Department of
Biological Sciences, Saddleback College, Mission Viejo, CA, 92692, USA
Birds in xeric climates undergo extended exposure to direct solar radiation, which, among
other effects, was hypothesized to significantly increase evaporative water loss. Observations of
an American crow (Corvus brachyrhynchos) dehydrated and overheated from such prolonged
exposure spurred an interest in the water loss rate of avians subjected to solar radiation; it goes
without saying that water is crucial for survival, and that in the desert, a fresh supply is not likely
to be readily accessible. Due to legality, because of convenience of handling, and because of
their similarity to other birds, zebra finches (Taeniopygia guttata) were chosen to act as model
and specimen. T. guttata specimens subjected to standard in-door lighting conditions exhibited a
mean, mass-specific water loss rate of 6.51×10 -4 ± 7.11×10 -5 g H2O /g zebra finch /min (± se), n=10. T.
guttata specimens subjected to simulated solar radiation exhibited a mean, mass-specific water
loss rate of 7.54×10 -4 ± 7.49×10 -5 g H2O /g zebra finch /min (± se), n=10. No significant difference was
observed between the mean, mass-specific water loss rates under the two conditions (p=0.150,
paired one-tailed t-test).
11. THE EFFECT OF CAFFEINE ON FOOD CONSUMPTION IN MICE (Mus musculus).
Kathleen Kuechler and Lara Quintanar. Department of Biological Sciences, Saddleback College,
Mission Viejo, CA, 92692, USA
Many popular weight loss supplements, which claim to suppress appetite, feature caffeine as a
key ingredient. This study investigated the effects of caffeine directly on food consumption. It
was hypothesized that consuming caffeine would lead to a decrease in food consumption, based
on of a previous study, which found a decrease in food consumption of palatable foods in rats
chronically treated with caffeine (Pentenuzzo, et al. 2008). Eight mice, Mus musculus, were split
into two groups either receiving no caffeine or 0.6g/L of caffeine in their water, and their food
consumption was measured across ten days. The mice were also weighed daily so that the weight
adjusted food consumption could be calculated. Results for this study found that the mice
receiving no caffeine consumed an average of 0.175g food /g b.w. /day±0.008g food /g b.w. /day(±se). The
mice receiving 0.6g/L of caffeine consumed an average of
0.221g food /g b.w. /day±0.010g food /g b.w. /day (±s e). Contrary to the hypothesis, the mice on caffeine
consumed significantly more food than the mice without caffeine (p=0.00125, one-tailed t-test),
contradicting the findings of Pentenuzzo (2008). These results could be due to the fact that
caffeine acts as a stimulant of the sympathetic nervous system, which can induce hypoglycemia,
stimulating appetite and increasing food consumption. Using caffeine in weight loss supplements
may in fact be counter-productive
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Saddleback Journal of Biology
Spring 2010