Transactions of the Illinois State Academy of Science [Volume 114 (2021)]
Vegetation of Hitts Siding Prairie Nature Preserve, Will County, Illinois
Authors: Paul B. Marcum, Loy R. Phillippe, and John E. Ebinger
Hitts Siding Prairie Nature Preserve, 3 km northeast of Braidwood, Will County, Illinois, is dominated by an extensive mesic prairie on sandy loam. The trailing shrub Rubus flagellaris was the dominant species of the dry-mesic to mesic prairie with a mean cover of 14.18 and an importance value (I.V.) of 11.9 (possible 200). Schizachyrium scoparium was the dominant grass (I.V. of 11.2) followed by Sorghastrum nutans (I.V. of 9.2) and Andropogon gerardii (I.V. of 6.8). Dominant forbs included Euth- amia gymnospermoides (I.V. of 10.8), Helianthus mollis (I.V. of 10.7), Solidago missouriensis (I.V. of 8.6), and Coreopsis tripteris (I.V. of 7.6). A total of 106 species were recorded for the survey plots of the prairie. Of the species recorded in the plots 72 had an I.V. of 1.4 or less while six exotic species were recorded. A small sedge meadow dominated by Carex haydenii/stricta (I.V. of 51.2) forming small tussocks was surveyed in the Preserve as well as a marsh dominated by Onoclea sensibilis (I.V. of 43.3) and Thelypters palustris (I.V. of 30.9). We recorded 360 vascular plant species from the Preserve. The study was conducted to determine vascular plant species composition, and vegetation structure of the least disturbed plant communities of the Preserve.
New Records of Bird-voiced Treefrogs, Hyla avivoca, in Southern Illinois
Author: John G. Palis
Since European settlement, southern Illinois has lost an estimated 95.9% of its bald cypress and mixed bald cypress-hardwood swamps. Bird-voiced Treefrogs (Hyla avivoca)—thought to be swamp obligates—were detected at only 24 southern Illinois remnant swamps in the 1990s and were subsequently listed as state-threatened. I conducted systematic acoustic surveys for vocalizing male Bird-voiced Treefrogs during May and June of 2019 and 2020, and accrued supplementary observations from 2008–2017. My efforts yielded 32 new detections of Bird-voiced Treefrogs in three southern Illinois watersheds, including 14 swamp remnants, a stream channel, and 17 human-made water bodies. As a result of habitat restoration, Bird-voiced Treefrogs appear to be recolonizing portions of their former Illinois range from which they were previously extirpated by forest clearing and wetland drainage
Mortality of Turtles and Snakes on Rural Roads in Southern Illinois
Author: John G. Palis
Roads are a significant source of wildlife mortality as a result of vehicle-wildlife collisions. Vehicular mortality may have negative consequences for reptiles such as skewed sex ratios, population isolation, and population reduction. I examined road mortality of turtles and snakes on 30.5-km of hard-surfaced, rural roads in Johnson and Union counties, Illinois, every spring from 2002–2004. I detected 198 road-killed reptiles composed of 84 turtles (five species) and 114 snakes (11 species). Using the observed mortality rate (0.032 road-killed reptiles/km), I estimate that 3097 turtles and snakes are killed each spring on roads in Johnson and Union counties and 9071 turtles and snakes are killed each spring on roads in the 7-county region of southernmost Illinois. Given an adult bias in road-kills observed during the spring breeding season, the observed rate of mortality may be having negative consequences for turtle and snake populations in southernmost Illinois.
Embryonic Vesicle Depth using Transabdominal Ultrasound Early in Gestation as a Predicter of Gestational Age in Sheep
Authors: Valentine Georgel, Julissa Navarrete, Michelle Kibler, Justin Rickard, Jennifer Earing, and Drew Lugar
Ultrasonography is commonly used by producers to determine pregnancy in their flocks (Scott 2012; Jones et al., 2016). Transabdominal ultrasonography is a simple, non-invasive method; however, it is not frequently used for early pregnancy detection in sheep. The aims of the current study were to determine whether pregnancy detection through transabdominal ultrasound is viable as early as day 25 of gestation and if a single measure of the embryonic vesicle could predict gestational age. Transabdominal ultrasound was performed on a total of 11 ewes at days 25, 27, 29, 31, 33 and 60 of gestation. Pregnancy diagnosis and accuracy of pregnancy detection were determined, and ultrasonic measurement of embryonic vesicle depth (EVD) was recorded for each ultrasound time period. Pregnancy may be determined at day 25 (accuracy = 45%); however, accuracy of pregnancy detection increased until day 31 (100%). A significant correlation between gestational age and EVD was identified (P < 0.001; r = 0.791). A regression analysis of gestational age (days since conception) on EVD resulted in a significant correlation of determination of 0.675 (P ≤ 0.001). This resulted in a quadratic predictive equation to estimate gestational age using EVD (y = 9.32 + 9.10 * EVD – 0.38 * EVD2). The results of the present study show that early pregnancy detection is possible in sheep; however, accuracy of pregnancy detection is reduced prior to day 31. Embryonic vesicle depth was able to predict gestational age with a simple quadratic equation. The number of fetuses present during ultrasonography was not counted in the present pilot study and may impact EVD and thus the estimation of gestational age. Future work in this area is warranted to investigate embryonic vesicle depth and the number of fetuses present during ultrasonography to predict gestational age.
Survival of Fishes in a Stormwater Retention Pond at the Watershed Nature Center, Edwardsville, Illinois
Authors: Manuel Gomez, Richard Brugam, and Sharon Locke
A study of the Upper Pond at the Edwardsville Watershed Nature Center (WNC) was conducted to discover the potential cause of fish kills in the small stormwater retention pond and to determine how the current populations of bluegill (Lepomis macrochirus), redear sunfish (Lepomis microlophus), common carp (Cyprinus carpio) and largemouth bass (Micropterus salmoides) can survive in the pond based on prevailing environmental conditions. Dissolved oxygen (DO) was measured from June 19 to December 5, 2019 at a site in the center of the open lake (4 m deep) and from a dock near the shore (1.1 m deep). Water temperature was measured intermittently at both sites from June 19 to November 4. In the open lake, oxygen levels reached a peak of 11.6 mg/L at the surface on July 2. Below 2.5 m DO remained less than 1.5 mg/L until Oct. 8 when it slowly began to rise reaching a high of 10.8 on Nov. 20. The dock station had similar oxygen levels. Temperature varied from a high of 31.2 °C on July 21 to a low of 6.5° C on November 3. The low DO in the pond results from a nearly continuous cover of duckweed (Lemna sps) which prevents interchange of oxygen with the atmosphere. It is likely that the low oxygen levels select for fish species that are physiologically and behaviorally capable of surviving hypoxia.
Do Freshwater Macroinvertebrates Select for Different Substrates Used in Fisheries Habitat Enhancement?
Authors: Jacob D. McArtor, Thomas M. Detmer, Anthony P. Porreca, Joseph J. Parkos III, and David H. Wahl
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 Habitat enhancement projects are commonly used for augmenting fisheries in lakes and reservoirs, but a dearth of research exists regarding how habitat enhancements influence lower trophic levels. Structures used for habitat enhancement may be comprised of a range of natural and artificial materials and thus present different substrates for macroinvertebrates. We examined whether motile, grazing macroinvertebrates from the genera Baetis, Ischnura, Pachydiplax, and Trichocorixa exhibited different selection for substrates commonly used in fisheries habitat enhancement projects. Substrates evaluated included natural pine wood with bark, polyvinyl chloride plastic (PVC; a common frame material for artificial fish cribs), and the composite plastic of a commercial fish attractor. Counts of individuals on each substrate were recorded at one-min- ute intervals for 30 minutes in a common garden style aquarium experiment where all substrate types were equally avail- able. Substrate selection differed among the macroinvertebrate taxa tested. Natural wood was not selected more often than artificial substrates. Trichocorixa rarely selected for the wood substrate over artificial substrates. Ischnura selected the light colored PVC substrate most often and Pachydiplax selected the darker artificial composite most often. Our results suggest that selection of different substrates may be taxon specific and not heavily influenced by material composition.