Erin Hewett - The effect of Brown-headed Cowbird removal on the demography of the Dickcissel: a declining grassland bird (Mentor: Brett Sandercock).
The Dickcissel (Spiza americana) is a familiar grassland bird that is a common host to a generalist brood parasite, the Brown-headed Cowbird.  The objectives of this study were to evaluate the impact of cowbird removal on the demography of the Dickcissel, as well as the consequences of parasitism on a common grassland host.  A total of 346 Brown-headed Cowbirds (75 female) were captured using wooden walk-in traps on two watersheds with similar habitat and size components.  Fifty Dickcissel nests were monitored from both removal sites along with twenty-five nests from control sites across Konza Prairie.  The results show that cowbird removal significantly reduced the frequency of parasitic events as well as the rate of multiple parasitism.  Treatment effect had little effect on the four major aspects of Dickcissel reproduction (clutch size, daily survival rates for laying/incubation and brooding stages (DSR), hatching success and fledging success).  The same analysis was performed for cowbird reproduction, and the number of cowbird eggs per Dickcissel nest was significantly lower in removal nests.  The other three reproductive components of cowbird reproduction showed no significant difference between removal and control sites.  Productivity values for all nests showed little difference between Dickcissels in removal or control sites, with both treatments fledging about 0.45 offspring per nest, while cowbird productivity was 0.315 for control nests and 0.140 for removal sites.  Next, the effect of parasitism on the reproduction of Dickcissels was analysed, and a significant difference was found in clutch size, with parasitized nests maintaining much lower average clutch sizes than unparasitized nests.  The other aspects of Dickcissel reproduction were not significantly different between parasitized and unparasitized nests.  These results along with the results of productivity levels between parasitized and unparasitized nests suggests that the reduction of Dickcissel clutch size caused by the host egg removal activity of female Brown-headed Cowbirds may be the largest impact of parasitism on Dickcissel demography.   

Brian Holloway - Factors affecting the establishment of a native tallgrass species in areas dominated by the invasive grass Bothriolchola bladhii (Mentor: John Blair).
Bothriolchola bladhii (Caucasian Bluestem or Old World Bluestem) was introduced in the Southern Great Plains as a forage plant with a high degree of drought resistance.  As with many introduced species, however, B. bladhii became invasive, out-competing and eliminating native prairie species in the grassland communities into which it was introduced.  B. bladhii has a caespitose, or bunchgrass, growth form, which is different than most native tallgrass prairie species, and it often grows in dense, nearly monospecific stands, with relatively large patches of bare soil between the individual grass bunches. While other studies have assessed some basic physiological traits and environmental effects of B. bladhii, there is an acute lack of information concerning the factors underlying the competitive success of B. bladhii and the apparent inability of other species to grow in the bare soil patches in areas dominated by this species.  I conducted an experiment to assess the potential inhibitory effects of shading and low soil nutrient levels on the germination and short-term seedling survival of the native grass Andropogon gerardii in areas dominated by B. bladhii.  Twenty-four square plots, 20 x 20 cm, were delineated in patches of bare soil within an area of established B. bladhii; these plots were surrounded on all sides by only B. bladhii.  Four treatments were applied to the plots, with 6 repetitions of each; a control treatment (no change in resource levels), an increased light treatment (clipping an additional 10 cm around each plot), a fertilizer treatment (adding 1.06 g N and .16 g P per plot), and a light + fertilizer treatment (clipping and fertilizing).  Twenty-four plots of the same size and treatments were established in an adjacent area of native tallgrass prairie grasses.  Each of the 48 plots was then planted with 49 Andropogon gerardii seeds, with the short term focus being on germination rates and seedling success within the different treatments.  Contrary to our initial hypothesis, germination and survivorship of A. gerardii seedlings was highest under intact B. bladhii canopies.  Fertilization had little affect on germination rates or survivorship.  These results suggest that the establishment of the dominant native grass species (A. gerardii) is not inhibited by the presence of the invasive grass B. bladhii, and that other factors or longer-term competitive interactions may underlie the success of B. bladhii in these grasslands.

Rebecca Lohnes - Nest defense behavior of female Common Nighthawks (Chordeiles minor) (Mentor: Brett K. Sandercock).  
The Common Nighthawk (Chordeiles minor) is a member of the poorly understood Caprimulgidae family. Nighthawks are a semiprecocial ground nesting bird that prefer very open habitat such as the rocky hilltops on Konza Prairie. The semiprecocial growth form is intermediary between altricial and precocial. Chicks are hatched eyes open, with down, but are unable to move great distances until fledging. The females are the only incubator and the primary caretaker of the young. Female nighthawks have developed extensive nest defense displays that are performed when they are disturbed off the nesting area. By using the nest defense intensity models for altricial (peaking at fledge) and precocial (peaking at hatch) birds, we predicted that the peak in intensity of nest defense behavior for the semiprecocial nighthawk would occur sometime between the two peaks, between hatching and fledging. We monitored 30 nests over the course of the summer. In order to observe the nest defense behavior we flushed the birds off the nest site, recorded distance from observer to nest site at time of flush, and observed and categorized the different behaviors of the females. We observed females throughout the incubation period and visited every two days after hatch. We found that females were consistently present at the nest until the very end of the chicks' growth period (the final ten days). This could be due to the development of self-defense displays by the almost fully feathered chicks. We also found that the frequency of the four riskiest behaviors (tail dragging, broken wing display, drop with outstretched wings, and drop with hiss) all steadily increased until fledging. This does not fit our predictions for semiprecocial birds; however it does fit the model for altricial birds. This could be due to the relative immobility of the chicks until their legs and wings develop fully enough to allow them to move freely.

Kristen Pitts - Effects of flooding on the fish distribution on Kings Creek, Kansas (Mentor: Craig Paukert). 
Hydrologic disturbances are quite common in prairie streams, sometimes resulting in extremes such as complete loss of surface water during dry periods and reconfiguration of stream geomorphology during intense rains. Such variability affects the fish species that inhabit the stream, especially their distribution through increased connectivity and flow. We sampled Kings Creek, using a backpack electrofishing unit, to determine fish distribution on three separate occasions throughout a late spring-early summer flood series. We looked specifically at the relations between flood stage and reach on catch rates. Stream reaches were determined as the stretch of the creek between road culverts. Emphasis was placed on the general trends of the three minnow species that make up the majority of the fish population; Semotilus atromaculatus, Campostoma anomalum, and Phoxinus erythrogaster. We also marked 405 fish prior to the first flood by making subcutaneous injections of acrylic paint that were site-specifically colored. We had 8 recaptures following the first flood and one following the larger floods, showing a variety of movement. Analysis of variance tests show that before and after the floods tend to have higher abundances than in between the floods, suggesting fish get washed downstream following a flood and make their way back upstream soon after. Due to high standard error, no concrete conclusions were determined from the barrier study. However, floods were found to have a significant affect on fish distribution in the short term.

Laura Sellens - Insect visitation of introduced versus native plant species at Konza Prairie (Mentor: Carolyn Ferguson).
The purpose of this project was to begin collecting baseline data of the pollination habits of several forb species on Konza Prairie, and to compare insect visitation of introduced and native plants. Eleven plant species were studied: the natives Verbena stricta, Ratibida columnifera, Erigeron strigosus, Teucrium canadense, Linum sulcatum, Dalea candida, Dalea purpurea, and Lythrum alatum, and the introduced species Coronilla varia, Hypericum perforatum, and Dianthus armeria. For each species insect visitation observations were carried out during five different time intervals on each of four days: early morning (6-8 am), late morning (9-11 am), early afternoon (1-3 pm), late afternoon (4-6 pm) and evening (8-10 pm). Visitation rates were calculated for each species. When all species were compared, the visitation rate of Hypericum perforatum was significantly higher than all the others, and those of Teucrium canadense, Lythrum alatum, Coronilla varia, and Dianthus armeria were significantly lower than the rest. Comparisons of native versus introduced plants' visitation rates were not significant due to high variability between species. This study was the first of its kind on Konza Prairie, and rare in general due to its breadth and its inclusion of time intervals throughout the day. It provides some superficial information on the pollination habits of these species and a wealth of baseline data that should aid future research in pollination biology on Konza Prairie and elsewhere.

Jeremy Thornbrugh - Carnivore community distribution in tallgrass prairie (Mentor: Samantha Wisely). 
Carnivore communities are affected by a variety of ecosystem processes, from primary productivity, to insect abundance, to small mammal populations. Because of this, they can be used as an indication of ecosystem health. This project looked at the effects on the carnivore community by different grazing schemes and burn regiments. I conducted a spotlight survey within Konza Biological Station. My route included bison grazed, cattle grazed, and ungrazed watersheds. I searched for Canis latrans, Mephitis mephitis, Didelphis virginiana, Taxidea taxus, Lynx rufus, and Procyon lotor. I also included identified scat in my data. I found a overall diversity (Shannon Diversity Index) of 1.04 in the cattle grazed watersheds, 1.17 in the bison grazed watersheds, and 1.36 in the ungrazed watersheds. Also, many of the species were found in higher concentrations within one grazing scheme, compared to the other two. Effects of burning regiment were not able to be analyzed due to most of the sightings occurring on a road. While the data suggests that some species might be affected by grazing, more research is needed to be conclusive.

Andrew Tilker - Interaction of small-stream fish with natural and artificial barriers (Mentor: Keith Gido).
Both natural and artificial barriers inhibit the movement of small-stream fish. To adequately construct a the movement patterns of these fish we must understand how they deal with these barriers. In an attempt to reconstruct fish movements we marked two species, Campostoma anomalum and Phoxinus erythrogaster, with acrylic paint above and below selected stream barriers. Approximately two weeks later we sampled the entire reach of King's Creek to re-capture marked fish. By then noting their location we could see how these fish moved in response to barriers in the stream. of nine re-captured fish, none traversed a barrier of any kind. We also build an experimental stream setup to test whether or not these fish were physically able to overcome a typical artificial barrier. By placing individuals of both species "downstream" and then running a current through a culvert barrier, we found that both species were able to traverse the barrier. Both of these experiments have shed light on the physical abilities and behavioral attributes of small-stream fish.

Melinda Williamson - Dominance and territoriality in the Great Plains Skink, Eumeces obsoletus (Mentor: Eva Horne).
The Great Plains Skink, Eumeces obsoletus, is a lizard found primarily in south-central North America about which little is known in regards to behavioral interactions.  This study looked at aggressive behavior in male-male and female-female interactions.  The objectives of the study included determining if: 1) the skinks are territorial, 2) if they exhibit dominance and 3) if so, whether or not size plays a role.  Animals were collected on Konza Prairie Biological Station and surrounding areas between the months of April and July 2004.  Measurements (snout-vent length, total length, mass) were taken and the animals were housed in separate containers.  Nineteen animals were captured and we set up an experiment as follows: one animal was placed in a 200 liter tub for 48 hours to establish “residency.”  Water, shelter, and a rock were provided in the new home.  Artificial light in the observation room simulated natural day and nighttime conditions (14L:10D).  After 48 hours an intruder was introduced and the behaviors of both animals were recorded for 30 minutes in 30 second intervals.  The individual behaviors were categorized into 5 general behavioral groups: aggressive, submissive, assertive, exploratory, and escape.  Aggressive behavior was focused on and when the data were analyzed we found no significant difference in aggressive behaviors between residents and nonresidents. However, nonresidents did exhibit significantly more exploratory behavior than did residents.  We also found no significant differences in dominance or aggression between large and small animals.  We conclude that the Great Plains Skink, like other Eumeces species studied, are not territorial, but, unlike others, they do display aggressive behaviors outside of the breeding season.

Last updated: January 2005