Transactions of the Illinois State Academy of Science [Volume 113 (2020)]
Distribution and Habitat Analyses of American Badgers (Taxidea taxus) and Plains Pocket Gophers (Geomys bursarius) in McLean County, Illinois
Authors: Alexander H. Palacios, Oscar A. Schmidt, Jack T. McKermitt, Noah T. Haskin, Angelo P. Capparella, R. Given Harper
Despite the loss of prairie habitat, fossorial species such as the American Badger (Taxidea taxus) and the Plains Pocket Gopher (Geomys bursarius) still persist in intensive agricultural landscapes in the Midwestern U.S. We determined the distribution of the two species in McLean County, Illinois via roadside automobile surveys in 2017 and 2018. We detected 88 badger burrows (0.09 burrows/km) in 18 of 30 townships, mostly in central, southern and eastern McLean County. Based on home range size from previous studies, we estimated a minimum of 5 and a maximum of 9 badgers inhabited the burrows. Likewise, we recorded 245 pocket gopher mounds in 16 mound clusters (15.31 mounds/cluster; 0.02 clusters/km) in 5 of 30 townships in central and eastern McLean County. There was no significant difference in the amount of hay/pasture within the home ranges of badgers versus in random locations, and for both species there were no significant effects of soil type, distance to railroad rights-of-way, and distance to habitat along streams. Populations and distributions of both species are likely limited by the lack of grassland habitat in the county and could be below minimum viable population size.
Short-term Effects of Silvicultural Treatments and White-tailed Deer Exclusion on Oak and Hickory Regeneration in Southern Illinois
Authors: Ryan E Leeson, Clayton K Nielsen, Devon C Oliver, Eric J Holzmueller, and Brianna M Winkel
Many forested regions in the U.S. are experiencing a lack of oak (Quercus spp.) and hickory (Carya spp.) regeneration, which may be partially due to high levels of white-tailed deer (Odocoileus virginianus) browsing. We assessed the impact of deer on oak and hickory regeneration in 5 forest management units in southern Illinois during 2015 and 2016. We established 30 paired plots (fenced exclosures and open reference plots) within each unit and quantified several habitat variables therein. We then compared presence, number, and height of oak and hickory seedlings, species richness, and competition from other species between enclosures and reference plots. Oak seedlings were present more often and in higher numbers within enclosed plots. White oak seedling numbers responded positively to deer exclusion while red oak seedling numbers responded positively to midstory thinning. Mean height of oak seedlings and the presence, number, and mean height of hickory seedlings did not differ in enclosed versus reference plots. Species richness was lower in reference plots while mid- story thinning positively affected both species richness and competition from less desirable species. Deer suppressed oak regeneration in reference plots after only 1 year, suggesting that managers must incorporate deer management into forest management plans to best encourage oak regeneration. Specifically, managers may have to consider implementing higher levels of deer harvest in areas lacking regeneration to decrease deer populations and mitigate damage.
Dirca palustris L. (leatherwood, Thymelaeaceae), Distribution and Abundance in Illinois
Authors: John E. Ebinger, Loy R. Phillippe, Paul B. Marcum, and William E. McClain
During the present study we searched for populations of Dirca palustris L. (eastern leatherwood) throughout Illinois. We started by searching for this species in most herbaria in Illinois, and a few outside the state, to determine potential population sites. More than 110 specimens of D. palustris were found representing 30 populations. Of these 30 populations identified from herbarium searches, we relocated 16. Nearly all populations were in good-quality mesic upland forests associated with ravines and mostly on N- to NW-facing slopes. During the field trips, extending throughout the growing seasons of 2011 to 2016, we found four previously unreported populations of this species, bringing the total to 20 known populations in Illinois.
Gap Crossing Event in the Southern Flying Squirrel (Glaucomys volans) in Fragmented Urbanized Forest Habitat
Authors: Jeremy M. Howard and Richard L. Essner Jr.
During a radio-telemetry study in 2018 in southern Illinois, an adult male southern flying squirrel (Glaucomys volans) was tracked between two forest patches on the campus of Southern Illinois University Edwardsville (SIUE), named the Western Corridor and Sweet William Woods. Based on GPS coordinates of the tracked squirrel, we determined that the squirrel most likely crossed a gap between forest patches via a gliding route. We identified putative launch and landing trees that would maximize glide distance while minimizing the ground needed to be covered. Based upon glide ratios from the literature, we estimated minimum, average, and maximum glide angles along with corresponding glide distances. Glide distances were calculated for each angle across a range of potential launch branch heights for the launch tree. From the calculations, it was determined that squirrels were able to cross the gap from branches that were at least 6 m in height, utilizing a minimum glide angle of 8.21°. While flying squirrels are highly agile gliders, gap crossing presents a significant problem moving between forest patches. Tree planting near forest edges may offer a feasible solution to reestablish connectivity and alleviate potential inbreeding depression.
Water Acidification and Pathogen Exposure Negatively Impact Innate Immunity in American Bullfrog (Lithobates catesbeianus) Tadpoles
Authors: Mackenzie R. Albin and Travis E. Wilcoxen
Freshwater acidification, an issue largely linked to industrialization and human activity, threatens freshwater environments and the organisms that inhabit them. The combination of acidification and pathogens already present in freshwater may increase the threat by altering immune defense in these organisms. We exposed American bullfrog (Lithobates catesbeianus) tadpoles to acidified water (pH 5.5), and 1.8 mL of a solution containing 100 colony forming units per 300 μL of Aeromonas hydrophila, a common water bacterium and amphibian pathogen. We monitored development, growth, and one parameter of immune defense, as measured by bacterial killing assays performed on whole blood samples from tadpoles among different treatment groups. Exposure to each acidic conditions and A. hydrophila significantly decreased A. hydrophila killing ability in L. catesbeianus. Our data suggest that L. catesbeianus is susceptible to decreased immune defense in the presence of stressors, both natural and those that result from anthropogenic activity.
Comparison of Soil Properties between Paired No-till and Conventional Tillage Systems in Central Illinois
Authors: Allison M. Lauria and Gregory L. Bruland
Various studies have shown that no-till agriculture has the potential to improve soil moisture retention, structure, quality, and carbon sequestration. The objective of this study was to compare paired conventional tillage (CT) and no-till (NT) agricultural systems 8 to 10 years after conversion from CT to estimate the effects of NT management on soil properties in Central Illinois. Samples were collected from the upper 20 cm of the soil profile from 8 paired sites in Cass and Morgan Counties, Illinois. No-till soils showed significantly greater mean SMC, 13.4% (1.4, SE)%, compared to paired CT soils, 11.9 (1.2)%, which represented a 13.2% increase in NT compared to CT. No-till soils also showed significantly greater mean SOM, 4.5 (0.5)%, compared to CT, 3.7 (0.6)%, which represented a 20.1% increase in paired NT soils. No significant differences in soil BD or temperature were observed across the paired sites, which may have been related to the relatively short time since conversion to NT. Given these results, NT systems in this region show the potential for increasing soil moisture and water availability to crops, improving soil quality, and enhancing soil carbon sequestration in decadal time scales or less. Site-specific soil, topographic, climatic, environmental, and agronomic conditions should continue to be considered in order to determine the suitability of NT versus CT systems for distinct locations in this region.
Rhamnus lanceolata Pursh (Lance-leaved Buckthorn, Rhamnaceae), Its Distribution and Abundance in Illinois
Authors: John E. Ebinger, Loy R. Phillippe, and Paul B. Marcum
During the present study we searched for populations of Rhamnus lanceolata Pursh (lance-leaved buckthorn) throughout its known range in Illinois. Considered a relatively common species based on herbarium records, the authors, with a combined total of more than 112 years of field work in Illinois, have rarely encountered this species. During part of a larger study involving 80 native Illinois species, we searched for all of these species in most herbaria in Illinois, and a few outside the state, to determine potential population sites. More than 240 specimens of R. lanceolata were found representing 103 populations. Of the 103 populations identified from the herbarium search, we relocated 13 populations from eight Illinois counties. We are not sure of the normal habitat for lance-leaved buckthorn in Illinois, but it is probably a species of hill prairies, hill prairie/forest interface, associated limestone glades of hill prairies, ravines and brushy areas of savannas, and in northeastern Illinois, calcareous fens.
Population Expansion of the State-threatened Eastern Sand Darter, Ammocrypta pellucida (Agassiz, 1863), within the Vermilion River Basin (Wabash River Drainage), Illinois
Authors: Jeremy S. Tiemann, Joshua L. Sherwood, Andrew J. Stites
The Eastern Sand Darter, Ammocrypta pellucida (Agassiz, 1863), has undergone range-wide population declines as a result of anthropogenic disturbances. Within Illinois, the fish historically occurred throughout the Wabash River drainage and Ohio River, but its range was reduced to only the Embarras and Vermilion river basins, including the Middle Fork Vermilion River and North Fork Vermilion River sub-basins. We report the first occurrences of A. pellucida in the Salt Fork Vermilion River sub-basin, thus expanding the known range of this imperiled fish by nearly 50 river-kilometers. The distribution expansion might indicate improved physicochemical conditions in the Vermilion River basin.