Midwest Fish & Wildlife Conference 2019

AUTHORS. Katherine Novak, Heather Waye – University of Minnesota Morris

ABSTRACT. Coloration is a crucial tool among amphibians for defense, for thermoregulation, and for mating. However, not much is known about how coloration is determined. One of the major pigments found in amphibian skin are carotenoids, which have two important uses. They largely make up the orange/yellow coloration in amphibian skin cells or can be metabolized into Vitamin A and other antioxidants. How amphibians either allocate these nutrients to become Vitamin A, or as part of their coloration, is a key tradeoff that potentially shows the individual’s status of health. If the individuals have access to excess food, they will have enough carotenoids to invest in brighter coloration. This leads to the question of whether increasing their access to carotenoids through diet would allow them to allocate more carotenoids into their pigmentation. Using twelve Eastern Tiger Salamanders (Ambystoma tigrinum) who have been individually housed at University of Minnesota Morris and six were offered a fish diet that they had been eating before the experiment as a control. The other six were offered a carotenoid enhanced krill for a total of eight weeks. Each salamander was photographed each week under the same light setup with a color standard. Before and after photographs for each salamander were compared with a color analysis R program. A significant increase in the yellow coloration of the experimental salamanders without a similar increase in control salamanders will indicate that the carotenoids obtained through diet were used for pigmentation.

AUTHORS. Arin Thacker, Jennifer Moore – Grand Valley State University

ABSTRACT. Complete knowledge of a species’ distribution and geographic extent are both critical variables in making informed and effective conservation and management decisions. A common source of error in delineating a species’ geographic extent is through false absences (not detecting the species when it is there), which commonly occur in species with low detection probabilities. Occupancy modeling is a technique that predicts the proportion of area a species of interest occupies, while accounting for species and survey-specific detectability, using repeated surveys and presence-absence data. We used this technique to estimate the occupancy and detection probabilities of the federally threatened Eastern Massasauga rattlesnake (Sistrurus catenatus). Due to low detection, the status of many eastern massasauga populations is uncertain. We surveyed 31 sites, each with a previous record of a massasauga occurrence, across Michigan’s lower peninsula from May-September 2018. At each site we measured several aspects of the vegetation community to estimate occupancy probabilities. We also measured survey-specific environmental variables to estimate detection probabilities. The results of this study will aid in the management of massasaugas, by providing information to improve survey and detection, clarifying the status of unknown populations, and identifying habitat features that are associated with massasauga occupancy. 

AUTHORS. Kaitlyn E. Seitz, Joshua C. Goble, Katrina M. Rosing, Richard S. Phillips – Wittenberg University

ABSTRACT. Eastern Box Turtles (Terrapene carolina carolina) have been the subject of much study given concerns over potential declines in population numbers.  Urban populations of box turtles are often at increased risk of illegal collection, vehicle collisions, and habitat fragmentation.  As part of an ongoing radio-telemetry study examining box turtle populations at two urban parks in southwest Ohio, we present data on both home range (11 box turtles) and movement on 19 box turtles.  Box turtles for home range analysis were located opportunistically for an average of 30 (range 17-52) locations per turtle, covering an average of 886 days (range 405 - 1,315 days).  Using the computer program Biotas, Samples sizes precluded comparisons of sex-specific home range data, but anecdotally our home range data support larger female home ranges using MCP (x¯_female= 9.93 hectares, x¯_male= 3.28 hectares).  However, interpretation of home range generated using alternative techniques suggest females exhibit more disjunct habitat usage compared to males.  Further, population monitoring show tremendous fidelity to both winter hibernacula and what appear to be nesting areas.  Given our data, it appears that populations in both urban parks allow access to both over-wintering and nesting sites.

AUTHORS. Brianna L. Finnegan, David E. Koch – University of Dubuque

ABSTRACT. The purpose of this study is to test the impact of bait on trap success for freshwater turtles. Trapping was done on the Upper Mississippi River system using hoop nets. The different types of bait used were chicken, fish, sardines in soybean oil and a control trap containing no bait. Trapping was done in lentic parts of the river system. The two types of freshwater turtles most commonly found here were Chrysemrys picta (northern painted turtle) and Chelydra serpentine (eastern snapping turtle). We found that C. picta were caught more often in sardine baited traps, while C. serpentine preferred fish. These findings will help improve trap success for future researchers in hopes of improving trap success rates for freshwater turtles.

AUTHORS. Katrina M. Rosing, Madison T. Nadler, Abigail Henson– Wittenberg University; Michelle Comer, ODNR Division of Natural Areas and Preserves; Richard S. Phillips, Wittenberg University

ABSTRACT. The spotted turtle is found in disjunct populations in the Great Lakes region of the United States and Canada.  Each state in the Midwest has afforded the species protection and, consequently, population monitoring is critical.  To monitor turtle population in a southwest Ohio fen, we used minnow traps with and without spotted turtle decoys as well as trail cameras.  During 2017, 12 spotted turtles were documented over 2,520 trap nights with a total of 51 spotted turtle captures and recaptures, with a single new turtle was identified by trail cam for a total of 13 documented animals.  In 2017, capture rates were highest in late March and April (4.6 and 5.4/100 trap nights respectively) with no captures in October.  In 2018, a total of 12 recaptures (no new animals) occurred during 1,033 trap nights with capture rates highest in May and June (1.6 and 2.9/100 trap nights respectively).  Overall capture rates were 2 turtles/100 trap nights in 2017 and 1 turtle/100 trap nights.  Although data from 2017 suggests the benefit of male decoys (27 captures over 1,106) over female decoys (18 captures over 1,099 nights), data from 2018 is contradictory regarding the influence of decoys on capture rates.  Trap nights with female decoys (386) resulted in 8 turtle captures, while male decoys (399) and traps without any decoys (248) resulted in 1 and 3 captures respectively.  Trapping efforts continue to determine the influence of decoys on spotted turtle captures rates in fen habitats.

AUTHORS. Andrew S. Hoffman, Annalee M. Tutterow, William E. Peterman – Ohio State University

ABSTRACT. Timber Rattlesnakes (Crotalus horridus) have declined dramatically throughout the northern periphery of their range, particularly in the Midwest. Here, remaining populations are concentrated on scattered Federal and State Forestry lands. Concerns regarding the potential for conflict between current forestry practices and resident timber rattlesnake populations prompted us to investigate rattlesnake home range size and habitat use using VHF telemetry on State Forestry lands in southeastern Ohio. From June 2016-October 2018, we located telemetered rattlesnakes 2-3 times per week. We assessed multi-scale habitat use at the individual and population level in relation to timber harvest and prescribed fire history. Our home range estimates were similar to those presented in previous studies from other states, but varied substantially within and among sex and age classes. We also observed substantial individual variation in habitat selection, though age class and sex strongly influenced selection among different management units. We found little evidence that snakes at our study site avoid previously burned or cut patches and observed some indication that snakes select for these disturbed habitats. Future studies will seek to link specific resource needs to different management approaches in order to determine why snakes are selecting for certain management units disproportionately.