Biological Sciences

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Research from the Department of Biological Sciences. The department website may be found at https://www.ndsu.edu/biology/

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Growth and Development of Native Range Plants in the Mixed Grass Prairie of Western North Dakota
(North Dakota State University, 1963) Goetz, Harold
This study was initiated to secure quantitative data on growth characteristics of the major species in the mixed grass prairie of western North Dakota; to determine the extent and range in yearly variations in growth patterns of the species and of the type as a whole; to assess the general influence of climate as a cause for seasonal and yearly variations in growth patterns; and to interpret the data obtained in terms of their possible application to the practical grazing management of these grasslands.
Effects of nest site environment and timing of breeding on reproductive success in Franklin's gulls (Larus pipixcan)
(North Dakota State University, 2009) Berg, Emily Anne
Offspring performance and phenotype are affected by genotype and environment, which in birds includes yolk resources (part of the embryonic environment). Female colony nesting birds may influence offspring competitive ability in the post-hatching nest site environment by differentially allocating yolk resources to eggs based on nest site characteristics. Offspring performance may also be linked to prenatal allocation of resources, as well as post-natal parental care. Nest site characteristics, including nest size, density, and timing of breeding, influence the behavior (e.g., aggressive, social) and resource acquisition of the parents, as well as provide measureable variation in the postnatal environment. I used an experimental approach to quantify relationships among nest site characteristics, nest success, and offspring performance (growth and survival) in a nesting colony of Franklin's gull (Larus pipixcan). I also used a cross-foster experiment to examine tbe effects of parental care and provisioning on growth and survival of neonates. Timing of breeding, egg quality, chick quality, nest success and chick survival varied between the 2006 and 2007 cohorts. Nests in 2006 were initiated later than nests in 2007 and experienced lower nest survival rates but produced chicks in better condition. Chicks in 2006 also experienced higher survival than chicks in 2007; however, chicks in 2006 experienced slower growth. Timing of breeding may have influenced measures of nest and chick success examined in this study. In Franklin's gull, a trade-off between offspring quality and offspring quantity may be a consequence of migratory delays or unusual weather patterns in this long-distance migratory species.
Plant Phenological Responses to Climate Change in the Northern Great Plains
(North Dakota State University, 2010) Dunnell, Kelsey Liann
Climate change has been associated with shifts in phenological events which could be disrupting evolved species relationships. The current first flowering times of plants were compared to historical data in the Red River Valley. This gave insight as to what effects climate change is currently having on species in this area. By merging climate variable data from the same time period it was possible to correlate first flowering dates with climate variables for that specific year. Variation in plant flowering times was analyzed over the century to better understand potential ecological consequences of climate change. First flowering times were found to have shifted since previously recorded. The lengthening growing season in the Red River Valley as a result of climate change has resulted in significant shifts in the timing of plant life cycles. The second study used an experimental approach to test the effects of warming on plant species in the tallgrass prairie. Measuring phenological and species composition responses to the temperature changes showed evidence that increasing air temperatures are leading to earlier flowering. There was also a significant increase in species richness. The results of both studies conclude that climate change has the potential to impact the plant community by shifting phenological responses in the tallgrass prairie in the Northern Great Plains.
Investigation of the Nature of Science Views of Undergraduate Natural Science and Nonscience Majors in Biology Courses
(North Dakota State University, 2010) Miller, Marie Christine Desaulniers
Science educators have the common goal of helping students develop scientific literacy, including understanding of the nature of science (NOS). University faculties are challenged with the need to develop informed NOS views in several major student subpopulations, including science majors and nonscience majors. Research into NOS views of undergraduates, particularly science majors, has been limited. In this study, NOS views of undergraduates in introductory environmental science and upper-level animal behavior courses were measured using Likert items and open-ended prompts. Analysis revealed similarities in students' views between the two courses; both populations held a mix of naYve, transitional, and moderately informed views. Comparison of pre- and postcourse mean scores revealed significant changes in NOS viev .. 's only in select aspects of NOS. Student scores on sections addressing six aspects of NOS were significantly different in most cases, showing notably uninformed views of the distinctions between scientific theories and laws. Evidence-based insight into student NOS views can aid in reforming undergraduate science courses and will add to faculty and researcher understanding of the impressions of science held by undergraduates, helping educators improve scientific literacy in future scientists and diverse college graduates.
Effects of Processing on Health-Promoting Attributes of Soymilk Phenolics
(North Dakota State University, 2010) Tan, Yingying
This study was designed to investigate the effects of different processing methods on the antioxidant and anti-cancer properties of soymilk crude phenolic extract (CPE) using the human prostate cancer cell line DU 145 as a model system. Four grinding methods and two ultra-high temperature (UHT) processing methods were investigated. Briefly, the four grinding methods included grinding with tap water (Method 1), okara-washed water (Method 2), soaked water (Method 3), as well as both okara-washed water and soaked water (Method 4); the two UHT processing conditions included one-phase UHT (143 °c, 60 s) and two-phase UHT (120 °C, 80 s + 140 °C, 4 s) methods. The antioxidant capability of CPE was measured by oxygen radical absorbance capacity (ORAC) and/or ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH) assays. The DU 145 human prostate cancer cell line was sub-cultured in the presence of CPE at various concentrations (0, 1, 2, 4, 8 mg/ml) for 48 h and the percentage of cell viability was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and/or flow cytometric analysis with carboxyfluorescein succinimidyl ester (CFSE) staining. An induction of apoptosis was detected by flow cytometric analysis with annexin V/ propidium iodide (Pl) double staining, morphological change observation with acridine orange/ethidium bromide (AO/EB) double staining, and Western blot assay of apoptotic proteins. The results showed that grinding Method 4 and the two-phase UHT method exhibited greater total phenolic content and antioxidant capability than the other three grinding methods and one-phase UHT, respectively. In addition, soymilk CPE inhibited cell proliferation in a dose-dependent manner and upon purification. The anti-proliferation effects observed in soymilk CPE were associated with the apoptosis induction in DU 145 cell line as evidenced by morphological changes and the expression of apoptotic proteins. These results suggest that the soymilk CPE plays an important role in anti-proliferation, and apoptotic properties of soy in DU 145 cells. Furthermore, these health-promoting properties were affected by processing conditions, such as grinding and thermal conditions. The results of this study benefit the soy product industry to select appropriate processing conditions to retain more health-promotion phytochemicals during soy food's processing.
Influence of Adjacent Uplands and Groundwater on the Hydrology and Invertebrate Community Composition of Seasonal Forest Ponds in North Central Minnesota
(North Dakota State University, 2010) Bischof, Matthew Markus
Seasonal ponds are common throughout northern Minnesota's forested areas. Seasonal ponds typically flood due to snow-melt and high precipitation rates in early spring, then dry by mid-late summer. The dynamic hydroperiods of seasonal ponds create a unique fishless habitat hosting an abundance of many endemic aquatic species. Hydroperiod has long been considered a major controller of biological communities in seasonal ponds, but few data are available for testing hydrological linkages among seasonal ponds, their surrounding watersheds and their resident invertebrate communities. To identify hydrological pond function, I placed peizometers and monitoring wells in 8 sites in the Buena Vista State Forest in Beltrami County, MN, and 8 sites in the Paul Bunyan State Forest in Hubbard County, MN (16 sites total). Water levels were monitored weekly (2006-2009) from spring melt until ponds dried and water tables fell below readable depths. Invertebrate communities were also sampled weekly during 2008 and 2009. Results indicate that high but variable water exchange occurs between seasonal ponds and ground water. Hydrological patterns of seasonal ponds were related to several physical parameters including hydrological function, maximum depth, and canopy cover. Most relationships appear to be consistent between the 2 forest areas; however, some differences are notable, such as soil characteristics and influence of pond surface area on hydroperiod. Patterns in pond invertebrate communities were also related to hydrological function and hydroperiod, and these patterns appear consistent between the 2 forest areas, suggesting that many invertebrates are generalist users of these areas.
Matrix Metalloproteinase Expression Varies Throughout Development and During the Innate Immune Response of Tobacco Hornworm. Manduca sexta
(North Dakota State University, 2010) Vishnuvardhan, Smitha
Matrix metalloproteinases (MI'v1Ps) are a family of conserved, proteolytic enzymes. MMPs can degrade most extracellular matrix proteins. As such, they are key enzymes in tissue remodeling processes. such as molting and metamorphosis in insects. The presence of MMP in tracheae of 4th and 5th instar Manduca scxra (M sexta) larvae was investigated using zymograms and Western blots, and the expression was found to decrease at the end of the instar. Failure to completely inhibit gelatinolytic activity in a zymogram indicates the existence of various other proteases that arc involved in the molting process. However, delay in the appearance of the dorsal blood vessel along with a reduction in the body mass upon inhibition of MMP supports our hypothesis that MMPs are required for molting. MMPs are also known to be up-regulated in many disease states, where they may cause tissue damage. Their presence may be beneficial, as their inhibition may result in worsening of symptoms or increased mortality. We tested the hypothesis that MMPs play a role in innate immunity in the tobacco hornworm caterpillar. Jf. sex/a. Larvae infected with E. coli DH5a had significantly more circulating hemocytes (insect blood cells) when compared to the larvae v,:hich received an MMP inhibitor. suggesting that MMPs may be important for hernocyte recruitment from the hematopoietic organs such as the lymph gland and hematopoictic cells present near the v.'ing imaginal discs. The expression of MMP was increased by 50% in larvae that had been infected with E. coli DH5a. However, this response was abrogated upon inhibition of MMPs. reducing expression tocontrol levels. The majority of the circulating hemocytes were granulocytes. a cell type that phagocytoses foreign bodies. including pathogens. We used flow cytometry to assess phagocytic ability. Hemocytes in the presence of the MMP inhibitor were less abk to phagocytose sephadex beads. supporting the hypothesis that this MMP contributes to the cellular innate immune response. Our results suggest that MMP expression is high at the beginning of the in star while it reduces as the caterpillar reaches molting. during which other proteases like chitinases and molting fluid proteinases play a more prominent role. Our results also suggest that M. sex/a larvae have a reduced immunity to bacterial infections when MMPs are inhibited. Collectively, inhibition of MMPs during the molting process indicates that the larvae. by down regulating the expression of MMPs. prevent the elicitation of immune responses that is generally seen during the larval pupal metamorphosis.
Assessment of Blackbird Damage to Sunflower and Corn Fields in the Prairie Pothole Region of North Dakota
(North Dakota State University, 2011) Klosterman, Megan Elise
North Dakota is the top sunflower producing state in the United States, annually harvesting about 405,000 ha (1 million acres). Up to 63% of this crop is grown in central North Dakota in an area known as the Prairie Pothole Region (PPR). Since the early 2000s, com also has become a major crop in the PPR due to the development of hybrids for northern crop areas and increases in com prices. Blackbirds (Icteridae) can cause significant damage to both ripening com and sunflower. It has been three decades since a comprehensive sunflower damage survey was conducted in the PPR. I assessed blackbird damage to ripening sunflower and com in 120 randomly-selected plots during three growing seasons, 2008-2010. Damage was analyzed across four strata (Northeast Drift Plains, Northwest Drift Plains, Southern Drift Plains and Missouri Coteau) within the PPR. Landcover was analyzed to determine possible variables (pasture, com, sunflower, open water, wetland, small grains, developed, wooded, beans and other) related to blackbird damage. Stepwise logistic regressions were performed along with AIC model selection to determine significant (p<0.1) independent variables related to sunflower and com damage. Average damage to sunflower (2.14%) was higher than damage to com (0.33%), with sunflower in the Southern Drift Plains having the greatest levels of damage (11.11 %). Beans and wetland showed the greatest significance in relation to sunflower damage (p=<0.001, p=0.035), according to the selected AIC model. The most significant landcover variables surrounding damaged corn fields was open water (p=0.022), showing an increase in damage, and pasture (p=0.056), showing a decrease in damage. The results of this study provide data to help producers make informed decisions about crop selection and location.
The Evaluation of Christmas Bird Counts as an Indicator of Population Trends and Habitat Selection in Blackbirds and Starlings
(North Dakota State University, 2011) Strassburg, Matthew D.
Agelaius phoeniceus (red-winged blackbird), Quiscalus quiscula (common grackle), and Sturnus vulgaris (European starling) are three of the most abundant bird species found in North America, and along with Euphagus carolinus (rusty blackbird) and Euphagus cyanocephalus (Brewer’s blackbird), make up a significant proportion of the avian population. Population trends of these four blackbird species and European starlings (EUST)were analyzed from the Christmas Bird Count (CBC) data collected between 1988 and 2008. Population analyses were conducted using linear mixed-effect regressions from the Lmer package of Program R. This approach was effective in modeling the population trends of widespread species with large populations. However, it was not as effective in modeling species with smaller populations and distributions. Only RWBL had significant change in population during the study period, showing a positive increase in mean count number of approximately 2.4% each year. Habitat selection showed some parallels among species.
Quantifying Seasonal Variation in Physiological Condition of Adult Franklin's Gull (Luecophaeus Pipixcan) during Nesting
(North Dakota State University, 2011) Weissenfluh, Shawn Edward
Understanding seasonal variation in adult physiological condition is important for developing hypotheses on how nest initiation, adult condition, chick development and recruitment are related in Franklin's gull and other migratory species of the northern plains. The purpose of this study was to profile physiological condition during the breeding season in nesting Franklin's gull (Luecophaeus pipixcan) adults. Physiological condition was quantified in nesting adults through four metrics: body measurements recorded from live-trapped birds, the corticosterone stress response measured from blood samples collected serially from live-trapped birds, and two measures of immune function (antimicrobial capacity of plasma from blood samples and heterophil/lymphocyte ratios based on blood smears, both taken from live-trapped birds). Physiological condition declined across the breeding season, as shown by a decline in body condition, stress tolerance and immune performance. Specifically, residual body mass decreased and exposure of the sternum keel increased with the progression of the breeding season. Additionally, birds nesting later in the season showed greater maximum corticosterone concentrations in the stress profile along with lower antimicrobial capacity. These results suggest two hypotheses: 1) that timing of nesting has a significant impact on the physiological condition of Franklin's gull and 2) that birds in poorer condition initiate breeding later in the season. Seasonal variation in condition may be related to time constraints observed in temperate latitudes and whether these birds are capital (i.e., acquiring resources outside the breeding area) or income (i.e., acquiring resources locally) breeders. Thus, determining physiological condition during the breeding season is an important step in elucidating how nest initiation, adult condition, chick development and recruitment are related in Franklin's gull.
Development of the Stress Response in Fast (Coturnix Japonica) Versus Slow (Callipepla Gambelii) Growing Species
(North Dakota State University, 2012) Gastecki, Michelle Lynn
In this study, we evaluated the development of stress response in (1) two different species of quail, one species that is relatively fast-growing (Japanese quail, Coturnix japonica) and one that is relatively slow-growing (Gambel’s quail, Callipepla gambelii) and (2) two strains of a single species, the Japanese quail (wild-type and domesticated), that differ considerably in final size. Our data indicate that wild-type Japanese quail and Gambel’s quail have experienced trade-offs between growth and the stress response (e.g. Gambel’s quail have slower growth rates, but greater levels of CORT). However, the domesticated strain of Japanese quail used in this study seem to violate some predictions based on the life history theory (e.g. the domestic strain has faster growth rates and greater levels of CORT). The data in this study contribute to the understanding of differences in the stress response between species that exhibit different life history strategies.
Characterization of Variation in Growth Performance in Inbred Strains of Zebrafish (Danio Rerio)
(North Dakota State University, 2012) Meyer, Ben Michael
Although zebrafish have been a widely utilized model organism for several decades, there is little information available on physiological variation underlying genetic variation among the commonly used inbred strains. This study evaluated growth performance in response to fasting in six zebrafish strains [AB, TU, TL, SJA, WIK, and petstore (PET) zebrafish]. Fasting resulted in a decrease in whole blood glucose levels in PET, TL, and TU strains and did not affect glucose levels in AB, SJA, and WIK strains. Similarly, fasting had no effect on myostatin mRNA levels in AB, PET, TU, and WIK strains, but decreased myostatin-1 and -2 mRNA levels in SJA zebrafish. Fasting increased myostatin-2 mRNA levels in TL zebrafish. These data demonstrate that growth performance variation is present between commonly used zebrafish strains and can help future research endeavors by highlighting the attributes of each strain so that the most fitting strain may be utilized.
Student Interpretations of Phylogenetic Trees in an Introductory Biology Course
(North Dakota State University, 2013) Dees, Jonathan Andrew
Phylogenetic trees are a common visual representation in biology, and the most important visual representation used in evolutionary biology. Thus, phylogenetic trees have also become an important component of biology education. We sought to determine what forms of reasoning are utilized by introductory biology students to interpret taxa relatedness on phylogenetic trees, what percentage of students correctly interpret taxa relatedness, and how these results alter in response to instruction and over time. Our students demonstrated a tendency for counting synapomorphies and nodes, rather than more common misinterpretations found in current literature. Students also struggled mightily with correctly interpreting phylogenetic trees, including many who exhibited memorization of correct reasoning. Broad initial instruction achieved little for phylogenetic tree understanding. More targeted instruction on evolutionary relationships improved understanding, but to a still unacceptable level. It appears these visual representations, which can directly affect student understanding of evolution, represent a formidable challenge for instructors.
Online Student Resource Use and the Effect on Student Course Performance
(North Dakota State University, 2013) Greywind, Tonya
The purpose of this study was to identify potential factors of student resource use that could indicate student success in an online course. This would allow instructors to look for in patterns of use to identify students that may not be successful. Statistical components of the course management system, Blackboard, and online lecture resource, Tegrity, were used to collect student resource use (clicks). Duration of access was also available exclusive to the Tegrity resource. The findings of the study indicate students that used online resources more often were more successful. Successful students used online resources nearly twice as often as their counterparts. Additionally, they spent nearly twice the amount of time engaged in lecture resources watching, on average, 59% of the lecture resources available. Furthermore, there appeared to be a critical window where those who accessed the resources in the first five weeks had a greater likelihood of course success.
Stereotype Threat in the Introductory Science Classroom: Investigating Its Existence and Triggers
(North Dakota State University, 2013) Lauer, Shanda Deleen
Research in undergraduate education has documented achievement gaps between men and women in math and physics that may reflect, in part, a response to perceived stereotype threat. My research efforts aimed to reduce achievement gaps by mediating the impact of stereotype threat in introductory science classrooms with a short, values-affirmation writing exercise. The purpose of this research was to (1) investigate and compare the performance of women and men across introductory science sequences (biology, biochemistry, physics), (2) document endorsement of stereotype threat, (3) investigate the utility of a values-affirmation writing task in reducing achievement gaps, (4) provide a meta-analysis of triggers causing stereotype threat, and (5) advise classroom practices to avoid stereotype threat. In this study, analysis of final grades and normalized learning gains on concept inventories revealed no achievement gap in the courses sampled, little stereotype threat endorsement, and no impact of the values-affirmation writing task on student performance.
Diet and Effects of Environmental Stressors on the Altricial Nestlings of Double-Crested Cormorants (Phalacrocorax Auritus)
(North Dakota State University, 2014) Randa, Jacob G.
Double-crested cormorants (Phalacrocorax auritus) are a common species of altricial waterbird found across much of North America. As a piscivorous colonial waterbird, cormorants are often persecuted due to perceived impacts on fisheries. In this study I examined the diet of cormorant nestlings at five cormorant colonies in central North America to answer two questions: 1) Is nestling diet reflective of opportunistic feeding behavior, thus diminishing the likelihood of negative impacts to the fishery? and 2) How do diet and environmental stressors effect the development of cormorant nestlings? By analyzing the caloric content of nestling diet and quantifying environmental stressors such as endoparasite and ectoparasite loads, I found diet was a significant contributor to structural long bone growth in both the wing and tarsus. Diet analysis also corroborated the long held belief that cormorants have highly variable diets reflective of local fish communities and may vary annually as fish assemblages change.
Growth Hormone Mediated Regulation of Osmoregulation in Euryhaline Teleosts
(North Dakota State University, 2014) Martin, Lincoln
Within the multitude of fish species that exist on our planet, there are a certain number that possess the unique ability to live in both freshwater (FW) and seawater (SW) environments. This ability, known as euryhalinity, is limited to a relatively small number of species, thus making it a prime target for scientific research into osmoregulation, due to the uniqueness of this ability. It has been shown previously that growth hormone (GH) plays an important role in regulating this ability, and in this work, Atlantic salmon (Salmo salar) and Rainbow trout (Oncorhynchus mykiss) were used as models to examine the expression of specific osmoregulatory genes in response to SW transfer and GH exposure, and to examine the signaling mechanisms used by GH to facilitate any changes. We found that GH utilizes specific cell signaling pathways to facilitate the transition between FW and SW in both Rainbow trout and Atlantic salmon.
Evolution of the Growth Hormone Receptor: Insights Into the Molecular Basis of the Physiologically Pleiotropic Nature of the Growth Hormone Receptor
(North Dakota State University, 2014) Ellens, Elizabeth Rose
One of the oldest, extant, lineages of vertebrates, the sea lamprey, was used to clarify the evolutionary origin and divergence of the growth hormone receptor (GHR) family. A single, full-length, cDNA, and a second, partial, cDNA were identified and shown to encode proteins that share amino acid identity with GHRs and prolactin receptors (PRLR s) previously identified. The complexity of the dynamic signaling system, with special emphasis on this system in fish and in the context of the evolution of this system, is discussed in the first chapter. The second chapter integrates the new insights gained by these studies. Included is a newly proposed phylogenetic analysis and revised nomenclature-system for vertebrate GHRs that better represents the evolutionary history of the receptor family. The molecular evolution of the receptors is, furthermore, highlighted as the backdrop for the continued discussion regarding how the GH-family of hormones exhibit such coordinated and pleiotropic actions.
The Distribution and Habitat Use of North Dakota Bats
(North Dakota State University, 2014) Barnhart, Paul Roy
Prior to 2009, a comprehensive statewide survey of occurrence and distribution of bats in North Dakota had not been conducted. From 2009 to 2012, mist netting, radio telemetry, and acoustic monitoring were conducted to document species presence and habitat associations across North Dakota. We surveyed multiple sites at 17 locations, captured a total of 309 bats, documented habitat associations, and identified roosting sites. Data was then used to: 1) build habitat suitability maps (also called species distribution maps or SDMs) for each species in the state, 2) examine the environmental and climatic variables that influence bat habitat use along the periphery of their distribution, 3) assess the effect of sampling technique on habitat suitability models, and 4) determine if North Dakota's badlands region contains overwintering bat populations that may be susceptible to white nose syndrome, an emerging fungal disease of hibernating bats. We confirmed the presence of 11 species in the state and found that five species were present in areas outside their ND IUCN distribution. Maximum-entropy modeling showed that temperature was the most important variable for SDM production. We found that sampling technique (physical capture vs. acoustic detection) led to pronounced differences in habitat suitability maps for some species (33.9% overlap; Myotis septentrionalis) while models from other species were highly similar (80.4% overlap; Myotis lucifugus). Our findings show that acoustic detection results in better SDMs for Myotis spp. while physical capture was best for Eptesicus fuscus and Lasionycteris noctivagans. During the winter, we positively identified four species based on both acoustic detection and physical capture: E. fuscus, Myotis evotis, Myotis ciliolabrum, and Corynorhinus townsendii. Based on known and potential hibernacula locations, we produced a habitat suitability map that was successfully used to locate additional potential hibernacula. We also recorded temperature in confirmed and potential hibernacula, finding that temperatures were within the optimum range of fungal growth. The information gathered from these studies will be used to develop the first statewide conservation action plan for North Dakota bats. Also, the habitat suitability maps produced will be used by managers to target areas of high priority for conservation of bat communities.
The Effectiveness of 9, 10 Anthraquinone as a Repellent to Protect Oilseed Sunflower from Blackbird Depredation
(North Dakota State University, 2014) Niner, Megan Denise
Across the Prairie Pothole Region of North America, blackbirds (Icteridae) cause millions of dollars in damage to sunflower crops annually, but effective methods to prevent or limit blackbird damage to sunflower crops are lacking. I tested two repellents (Avipel and AV2022, both with active ingredient 9, 10 anthraquinone) under application conditions that would be appropriate for large-scale, sunflower farming in two consecutive years. In 2012, I conducted daily avian point counts and weekly crop damage surveys to assess blackbird use of, and damage to, plots of sunflowers were sprayed with Avipel or left unsprayed (i.e., control). In 2013, I placed six netted enclosures (each containing three male red-winged blackbirds, Agelaius phoeniceus, approximately 40 mature sunflowers and trays with cracked corn and water) in a plot of sunflower treated with AV2022 applied by a ground sprayer, and six netted enclosures (each containing three male red-winged blackbirds approximately 40 mature sunflowers and trays with cracked corn and water) in an adjacent plot of sunflower left untreated (i.e., control). Results from 2012 indicate that blackbird use of, and damage to, sunflower plots did not vary with treatment of Avipel. Results from 2013 indicate that enclosures in the AV2022 treated plot had sunflower plants with significantly more seed loss and significantly less cracked corn consumed from food trays than enclosures in the untreated (i.e., control) plot. I conclude that 9, 10 anthraquinone does not significantly reduce blackbird damage to sunflower crops when applied using typical methods for pesticides in large-scale, commercial agriculture.

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