Veery (Catharus fuscescens), a woodland thrush (Turdidae), were studied at the Alma College Ecological Station, in Vestaburg, Michigan (43 23 26.98 Long, and--84 53 40.01 Lar). The purpose was to describe the population of Veery located at the Ecological Station, over a 12-year period. From 1999 to 2010, a total of 169 Veery, 126 adult birds and 43 juveniles, were captured in mist nets, banded, and measured. A Telemetry study of breeding adults was also performed using GPS data from 24 Veery, from 2007 to 2010. Analysis of age, sex, recaptures, and foraging areas created a demographic snapshot of this population.
A Preliminary Study of the Behavioral Effects of the Endocrine Disruptor Diisononyl Phthalate on Neonatal Rats (Rattus norvegicus). Brenton Petting, Delia Blaschka, Kaitlin DuCharme, Ryan Phillips, Toribiong Uchel, Elizabeth Wall, and Gary M. Lange, Saginaw Valley State University
Diisononyl Phthalate (DINP), a known endocrine disruptor, is widely used as a plasticizer in paints, dyes, adhesives, coatings on electrical wires and cables, plastic tubing and plastic food containers. Previous research suggests that exposure to DINP can increase weight gain and insulin resistance in human males and act as an antiandrogen in the body of mammals. Previous research conducted in the Behavioral Neuroendocrinology Laboratory (BNEL) at Saginaw Valley State University suggests that DINP also plays a role in altering an array of behaviors of organisms. This study assesses the effects of DINP exposure at the neonatal level in the Norway rat (Rattus norvegicus). Neonatal exposure could potentially induce far different effects on growth, development and behavior than has been seen in our previous experiments using this compound when exposure was at the prenatal or adult level alone. Anogenital statistics and righting responses are recorded at parturition for all pups. Anxiety, as tested using the elevated plus maze, neuromuscular development, balance and coordination are all tested and recorded. These data are compared to control populations.
Assessing Ecosystem Health and Pollution in Saginaw County, Michigan Using Parasite-Host Relationships in Two Species of Ranid Frogs. Brenton J. Fetting, Saginaw Valley State University
Evaluating the health of our environment is extremely important for scientists, state and federal agencies, and conservationists who are concerned with improving our environment and maintaining biodiversity. Research which has studied the use of parasites as biological markers of pollutants has increased in recent years, giving rise to a field referred to as environmental parasitology. The information presented is preliminary data providing a brief survey of parasites present in two species of ranid frogs found in Saginaw County, MI. Green frogs (Rana clamitans) and bullfrogs (Rana catesbeiana) were collected from three separate bodies of water: a stream near the campus of Saginaw Valley State University in Kochville Township; a pond in Wickes Recreational Park in Saginaw Township; and the Kimberly Bayou near the Shiawassee River State Game Area. A large number of lung flukes (Trematoda: Haematoloechidae) were collected, as were few adult tapeworms (Cestoda: Proteocephalidae) and few nematodes. The preliminary work proposes what pollutants may be present based on the parasites found. Further investigation will elaborate on the roles parasites play in our environment, and how their sensitivity to certain pollutants may indicate the presence of pollutants as well as the overall health of their environment.
Behavioral and Reproductive Effects of Exposure to the Endocrine Disruptor Atrazine. Tyler Beyett, Nancy Q. Lackey, Alisha Kuhtic, and Gary M. Lange, Saginaw Valley State University
Today, a serious problem facing the Great Lakes region is pollution. One of the most toxic classes of pollutants are herbicides, which accumulate from the large volume of agricultural runoff present in the Midwest. The herbicide atrazine has drawn significant attention for its observed adverse ecological and physiological effects. Atrazine is a chlorinated, general purpose broadleaf herbicide which is a known estrogen mimic with strong endocrine disrupting capabilities. Recent studies have shown low-level chronic exposure to atrazine to be capable of reversing sexual development in male frogs. We report on reproductive, developmental, and behavioral effects of chronic atrazine exposure in Long-Evans rats. Rats received a daily subcutaneous injection of 1 atrazine suspended in 0.5% methylcellulose. Various behavioral and reproductive tests are performed on pups that were exposed to atrazine in utero. Behavioral tests implemented include elevated-plus mazes, grip strength, and righting response. Reproductive success, litter size, and mating behaviors are also used to assess reproductive related effects. The combination of reproductive and behavioral data can be used to assess the effects of atrazine on organisms in contaminated environments.
Comparing the Effects of Temperature on the Calling Song of Males, the Phonotaxis of Females, and the L3 Auditory Neuron in Crickets (Acheta domesticus). (Poster) Tori Steely, Esther Cha, John Stout, Helen Hasegawa, Gordon Atkins, Andrews University; Benjamin Navia, Kettering College, and Christina Burden, Arizona State University
This study evaluates how temperature contributes to the variability described in the calling songs of males and phonotaxis of female crickets. Ground temperatures vary as much as 20 [degrees]C along 10-m transects in habitats frequented by crickets. The body temperature of a cricket changes by 7 [degrees]C in the first minute following a transition from sun to shade or vice versa and 12 [degrees]C over a 5 min period. The syllable periods of singing males range from 30-110 ms and decrease linearly by approximately 2.5 ms/[degrees]C. The syllable period, that is most attractive to females and elicits the best phonotaxis, is significantly correlated with temperature; and decreases by 2.2 ms/[degrees]C. The syllable periods causing the greatest decrement in the L3 interneuron range from 30-90 ms and decreases linearly by approximately 2.7 ms/[degrees]C. There is more variation in the females' phonotactic response and the L3 neuron compared to the variation in the male's calling song. This difference may be an adaptation to account for temperature differences between senders and receivers in the different microhabitats.
Effects of Nanoinjecting Three Inhibitory Neurotransmitters into the Prothoracic Ganglion on the Selectivity of Phonotaxis in Female Crickets (Acheta domesticus). (Poster) James Yoon, John Stout, Gordon Atkins, Andrews University and Kristin Lee, Loma Linda University
Female crickets respond phonotactically to the calling songs of conspecific males. The females' response to the syllable period of the calling song ranges from very selective to rather unselective. Phonotactic selectivity is promoted by increased levels of juvenile hormone III. A neuronal model has been proposed to explain how syllable period is encoded by auditory neurons in the prothoracic ganglion and how neuronal selectivity to syllable period increases with increased hormonal levels. The model proposes that reduced levels of inhibition by the omega neuron result from increased levels of juvenile hormone, and that reduced inhibition of the L3 auditory interneuron causes phonotaxis to become more selective. This study tests this model by nanoinjecting three inhibitory neurotransmitters (histamine, glycine and GABA) into the prothoracic ganglion and then testing for changes in phonotactic selectivity. Since histamine is reported to be the neurotransmitter of the omega neuron, histamine should decrease phonotactic selectivity whereas glycine and GABA (or their analogues) should not. Nanoinjection of histamine significantly decreased phonotactic selectivity. Preliminary evidence indicates that glycine and GABA do not influence selectivity, which supports our working model.
Estimating Body Mass of Ground Squirrels from Skeletal and Dental Variables with Application to an Extinct Giant Ground Squirrel, Paenemarmota. Kelsey M. Bullock and Thomas H. Goodwin, Andrews University
By examining the relationships between extant ground squirrel body mass and various skeletal and dental measurements, we developed regression models for estimating body mass of extinct ground squirrel species. Cross-sectional area of the femur was the skeletal variable that best predicted body mass, while length of the lower fourth premolar was the most predictive dental variable. Regression models were then utilized to estimate body mass of the extinct giant ground squirrel, Paenemarmota, from the late Miocene and Pliocene. Femoral cross-sectional area was available for one fossil species, P. barbouri, whereas lower fourth premolar was available for P. barbouri, P. mexicana, and P. sawrockensis. In P. barbouri, regression based on cross-sectional area produced a lower estimated body mass (9.4 kg) than did regression based on length of lower fourth premolar (16.1 kg); estimated body mass for other species (based solely on dental evidence) ranged from 9.7 kg (P. sawrockensis) to 20.8 kg (P. mexicana). Based on these estimates, species of Paenemarmota were probably 3-7 times larger than the modern woodchuck (Marmota monax). Availability of body mass estimates for Paenemarmota will provide insights into this intriguing animal's ecology and physiology.
Histological Analysis of Thermally Regulated Melanization of Young Chrysemys picta and Trachemys scripta Turtles. Carolyn Commissaris, Lawrence Wittle, and John Rowe, Alma College
Relatively dark skin color can facilitate radiant heat absorption. Thus, cold environments favor darker organisms. Skin color may also be involved with background matching such that predator detection can be avoided. In our study, we tested whether skin color varies as a function of temperature, substrate color, and their interaction in two species of freshwater turtles. Hatchling Chrysemys picta marginata and Trachemys scripta elegans were randomly assigned to experimental groups: white-substrate warm water, white-substrate cool water, black-substrate warm water, or black substrate-cool water. Hatchlings were reared for 160 days in white or black-bottomed tubs and in water temperatures of 25[degrees] or 30[degrees] C. At 160 days, 5 mm tail samples were taken from turtles in each experimental group. Tail samples were blocked in paraffin, cross-sectioned, and photographed at 400x magnification. We converted each image to a binary format and tallied pixels in each of six 50x50 pixel boxes within the outer keratinized layer. ANOVA indicated that turtles reared on black substrates were darker than those reared on white substrates and that those reared in cool water were slightly darker than turtles reared in warm water. Therefore, turtles match background color but a thermal effect on skin color was weak.
Second Report of a Big-Headed Fly Genus (Diptera: Pipunculidae) Parasitic upon Crane Flies (Diptera: Tipulidae) and First Michigan Record of the Parasite. Stephen W. Taber, Saginaw Valley State University
A recently discovered parasite of crane flies is reported for the first time from Michigan. The single previous report of such a natural enemy was the original discovery in Pennsylvania as published in 2007. A larva of a big-headed fly of the genus Nephrocerus Zetterstedt exited the abdomen of an adult female Tipula tephrocephala Loew that was caught while in flight. The host species and the state are new records for this parasitoid genus.
Substrate-Induced Melanization in Four Freshwater Turtle Species. Brittany Miller, Mark Stuart, and Brianna Huyck, Alma College
Background matching, which may reduce predation rates, has been shown to he induced by substrate color (dark and light turtles develop on dark and light substrates respectively) occur in a few turtle species. We tested for substrate induced melanization in four turtle families (Chelydridae, Emydidae, Kinostemidae, and Trionychidae) by rearing turtles on black or white substrates. Within the Emydidae, melanization could be induced by dark substrates in Sliders, two Map Turtle Species, but not in the terrestrial Eastern Box Turtle. The Chelydrid Common Snapping and the Trinoychid Spiny and Smooth Softshells also showed strong substrate color effects on pigmentation levels. The Kinosternid Stinkpot Turtle showed a weak substrate color effect. Our results indicated that substrate color-induced melanization may be phylogenetically widespread in freshwater turtle species. The ability to match backgrounds may not be well-developed or even lost in terrestrial species and in the typically dark-bodied, bottom dwelling Stinkpot Turtle.
The Role of Chloride Channel Inhibition in the Brain on the Phonotactic Selectivity of Female Crickets. (Poster) Brent Sherwin, John Stout and Gordon Atkins, Andrews University
Phonotaxis of female crickets toward the calling songs of males is controlled by a number of neurotransmitters and modulalators. Pictiotoxin, a non-selective blocker of chloride channels, causes unselective females to become selective to the syllable period of the calling song when nanoinjected into the prothoracic ganglion (the location of the primary auditory intemeurons). The goal of this project is to determine if picrotoxin has an effect in the supraesophageal ganglion (the location of the secondary and tertiary auditory interneurons) of female Acheta domesticus. Females are pretested for phonotaxis on a non-compensating treadmill over a range of syllable periods. Following exposure of the prothoracic ganglion, 9.2 n1 of either saline (control) or 10-5 M picrotoxin is nanoinjectied into the supraesophageal ganglion of unselective females. Posttests following saline injection (10 min later) are identical to the pretests and these control crickets remain unselective for male calling songs. Preliminary experiments demonstrate that females similarly treated with pictrotoxin become more phonotactically selective. This indicates that inhibitory inputs in the supraesophageal ganglion that are dependent on chloride channel inhibition may he involved in the modulation of selective phonotaxis.
The Role of Melanocyte Stimulating Hormone (MSH) in Controlling Melaninization of Red-Eared Slider Turtles (Trachemys scripta elegans) Reared on Light and Dark Substrates. Darren Shaw, Alma College
Previous studies have shown changes in melaninization in turtles reared on light and dark substrates. The mechanism of color change may involve increased or decreased melanocyte release of melanosomes resulting from changes in MSH levels. In our study, the role of MSH in melaninization was investigated. Four groups of light-colored red-eared slider turtles reared on light substrates received: 1) Initial injections of propranolol, a beta-adrenergic blocker, followed by injections of synthetic human [varies] or [proportional]MSH, 2) Injections of [varies] or [proportional]MSH, 3) Injections of saline and 4) Injections of propranolol. Two similar groups of light-colored turtles received injections of propranolol or injections of saline and were reared on dark substrates. Propranolol was used to test whether it is an antagonist to the MSH binding site on the melanocytes. Thus, endogenous MSH in turtles reared on dark backgrounds would be blocked and the turtles' skin would remain light, while skin of the saline injected turtles would darken. The turtles injected with propranolol and mMSH or just propranolol were expected to remain light; turtles injected with [varies] or [proportional]MSH were expected to become darker; controls would remain light. Our results indicated that [varies] or [proportional]MSH does increase melaninization. Propranolol did not block the injected [varies] or [proportional]MSH, but it blocked endogenous MSH.
The Taber-Keller Trap: A Modification of the Berlese Funnel to Entrap Flying Insects. Oliver Keller and Stephen W. Taber, Saginaw Valley State University
The Berlese funnel is an apparatus developed by Antonio Berlese to extract small arthropods from leaf litter, soil, and other organic materials. The basic apparatus is a funnel that contains medium sized wire mesh upon which organic material is placed. Beneath the funnel a vial containing alcohol is attached to catch and preserve the specimens that try to escape the drying leaf litter for later examination. A modification is called the Tullgren funnel, which includes a light bulb above the funnel to accelerate the drying of the material and to force the specimens towards the vial at the bottom. To prevent the escape of flying insects from the Berlese funnel, an extension (called the Taber-Keller trap) was developed and tested. The extension consists of a tent-like pyramidal-shaped structure with a collecting container on top, to capture flying insects that would otherwise escape. A first experimental run was conducted, several problems were discovered and improvements were developed. Currently, a second run is being conducted and a second set of data will be collected. A third experimental run using an improved and simpler version is planned and research for possible marketability and wider applications is being conducted.
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|Date:||Mar 22, 2013|
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