3rd Ohio Amphibian Research & Conservation Conference
March 12, 2016. Columbus, Ohio
Presenters are in bold
(Draft: Check back for updates)
Ralph A. Pfingsten
Rob Denton1 (Denton.66[at]osu.edu), Katherine Greenwald2 , and H. Lisle Gibbs11Department of Evolution, Ecology, and Organismal Biology, Ohio State University, 368 Aronoff Laboratory, 318 West 12th Avenue, Columbus, Ohio 43210
2Department of Biology, Eastern Michigan University, 401N Mark Jefferson Science Complex, Ypsilanti, Michigan 48197
Unisexual Ambystoma salamanders are unique among vertebrates for their strange reproductive mode. These all-female salamanders have retained an independent mitochondrial genome for five million years, but their nuclear genomes have instead been shuffled in and out of the lineage after being “stolen” from males of sexual Ambystoma species. This reproductive mode, termed kleptogenesis, is especially interesting in Ohio because the ranges of all five sexual species that donate genomes to unisexual Ambystoma intersect. One of these sexual species (A. laterale) is endangered in Ohio, but those unisexuals with genomes derived from A. laterale are ecologically successful across the majority of the state. In this presentation, we highlight our research on the mechanism of kleptogenesis, the factors that dictate the paradoxical coexistence between these groups, and the characterization of ecological niches for unisexuals with differing genome combinations. We provide new data that supports kleptogenesis as a valid reproductive mode, show differential dispersal ability between unisexual and sexual salamanders, and suggest that different combinations of nuclear genomes produce large differences in ecological niche.
Jeffrey G. Davis (OhioFrogs[at]gmail.com)
Cincinnati Museum Center, Frederick and Amye Geier Research and Collections Center, 1301 Western Ave. Cincinnati, Ohio 45203-1130
The Cave Salamander (Eurycea lucifuga) has been documented in only three Ohio counties, Adams, Butler, and Hamilton. In all three, it is at the northern edge of its range. Because it spends the majority of its time in subterranean habitats, we only get occasional glimpses of this species in habitats at the surface. There are no caves in southwest Ohio. Consequently, what we know about the Cave Salamander’s life history in Ohio is limited. To see this species living underground in our state, access to unique manmade habitats is required. This discussion shares the preliminary findings of the first half of a one year study of the Cave Salamander resulting from more than 1,500 sightings during biweekly visits to a 167 year old springhouse in southwest Ohio.
Nicholas Smeenk (Smeenk.6[at]osu.edu) and Gregory Lipps
Ohio Biodiversity Conservation Partnership, Ohio State University, Columbus, Ohio 43210
Katherine Krynak1,2 (kkrynak[at]gmail.com), Michael F. Bernard1, and David J. Burke3
1Department of Biology, Case Western Reserve University, 10900 Euclid Ave, Cleveland, Ohio 44106-7080
2Cleveland Metroparks Zoo, 3900 Wildlife Way, Cleveland, Ohio 44109
3Research Department, The Holden Arboretum, 9500 Sperry Road, Kirtland, Ohio 44094
The ease of global transportation has created a “small world” and therefore, a high probability of unintentional pathogen translocations. Pathogens like ranavirus, amphibian chytrid (Bd), and the eater of salamanders (Bsal) have had devastating effects on amphibian populations across the globe, and there will undoubtedly be others – so what do we do to protect amphibians from these threats? One way is to determine how anthropogenic changes to the environment influence the ability of amphibians to resist diseases, and change our practices to promote resistance. Amphibians have evolved traits which provide broad pathogen protection including antimicrobial peptides produced in the skin and symbiotic relationships with microbial organisms which inhabit the skin. However, environmental changes may reduce the efficacy of these defenses, increasing amphibians’ vulnerability to pathogens. Using experimental and observational studies, our team has found that 1) within species, amphibian populations differ in their skin-associated microbiomes and antimicrobial peptides, 2) water and landscape characteristics can predict interpopulation variation in these traits, 3) amphibian populations can respond differently to the same habitat alteration, and 4) changes to the larval habitat can alter the larval skin microbiome, and can carry-over to alter immune defenses post-metamorphosis. There is much more to learn, but by improving our understanding of what aspects of the environment may alter these immune defense traits, we have impetus to modify land management practices to better protect amphibian health.
Phenology, Fecundity, and Dispersal: Predicting the Effects of Climate Change on Amphibian Metapopulations
Michael F. Benard (mfb38[at]case.edu)
Department of Biology, Case Western Reserve University, 10900 Euclid Ave, Cleveland, Ohio 44106-7080
Two of the most widely studied amphibian responses to climate change are shifts in breeding phenology and larval development. Long-term surveys have demonstrated that many amphibians are now breeding earlier in the year compared to several decades ago. Experiments have shown that amphibian larvae raised at warmer temperatures have a shorter larval period. However, it is not clear whether shifts in breeding phenology and larval development will have a significant effect on amphibian population dynamics. To investigate this problem, I conducted a seven-year capture-mark-recapture study of wood frogs (Rana sylvatica) across six wetlands and tested for associations between weather and frog ecology. Warmer winters were associated with earlier breeding but reduced female fecundity. Surprisingly, earlier breeding was associated with delayed larval development, explained through a counterintuitive correlation between breeding date and temperature during larval development. Warmer winters led to earlier breeding, which in turn was associated with cooler post-breeding temperatures that slowed larval development. The delay in larval development did not fully compensate for the earlier breeding, such that for every 2 days earlier that breeding took place, the average date of metamorphosis was 1 day earlier. Earlier metamorphosis also led to increased rates of movement between populations. These results suggest climate change may reduce local population sizes of wood frogs through reduced fecundity, but increase gene flow and metapopulation persistence through increased dispersal. These results also caution against the common assumption that short-term climate change will lead to larvae experiencing warmer temperatures.
Examining How Land Use Changes, Contaminants, and Natural Factors Influence Blanchard’s Cricket Frog Distribution in the Midwestern US
Michelle D. Boone (boonemd[at]miamioh.edu)
Department of Biology, Miami University, 212 Pearson Hall, Oxford, OH 45056
Julie Ziemba (jziemba09[at]jcu.edu), Cari Hickerson, and Carl Anthony
John Carrol University, 1 John Carroll Blvd, University Heights, Ohio 44118
Asian pheretimoid earthworms (e.g. Amynthas and Metaphire spp.) are invading North American forests and consuming the vital detrital layer that forest floor biota [including the keystone species Plethodon cinereus (Eastern Red-backed Salamander)], rely on for protection, food, and habitat. Plethodon cinereus population declines have been associated with leaf litter loss following the invasion of several exotic earthworm species, but there have been few studies on the specific interactions between pheretimoid earthworms and P. cinereus. Since some large and active pheretimoids spatially overlap with salamanders beneath natural cover objects and in detritus, they may distinctively compound the negative consequences of earthworm-mediated resource degradation by physically disturbing important salamander activities (foraging, mating, and egg brooding). We predicted that earthworms would exclude salamanders from high quality microhabitat, reduce foraging efficiency, and negatively affect salamander fitness. In laboratory trials, salamanders used lower quality microhabitat and consumed fewer flies in the presence of earthworms. In a natural field experiment, salamanders and earthworms shared cover objects ~60% less than expected. Earthworm abundance was negatively associated with juvenile and male salamander abundance, but had no relationship with female salamander abundance. Juvenile and non-resident male salamanders do not hold stable territories centered beneath cover objects such as rocks or logs, which results in reduced access to prey, greater risk of desiccation, and dispersal pressure. Habitat degradation and physical exclusion of salamanders from cover objects may hinder juvenile and male salamander performance, ultimately reducing recruitment and salamander abundance following Asian earthworm invasion.
A Captive Head-Starting and Stream Conservation Program to Recover Eastern Hellbender Populations in Ohio
Gregory Lipps (Lipps.37[at]osu.edu) and Nicholas Smeenk
Ohio Biodiversity Conservation Partnership, Ohio State University, Columbus, Ohio 43210
The Eastern Hellbender (Cryptobranchus a. alleganiensis) is Ohio’s largest amphibian species, originally ranging throughout the streams and rivers in the two-thirds of the state draining to the Ohio River. After statewide surveys showed a dramatic decline in populations, a diverse partnership was formed to reverse the declines and recover this state endangered salamander. Our goal, laid out in a conservation plan, is being pursued through the implementation of two objectives. First, a consortium of zoos is head-starting young from wild-collected eggs hatched and reared in biosecure facilities. From 2012 – 2015 a total of 249 individuals have been released at 8 sites in 4 watersheds, with an additional 1,100 individuals currently being reared for release. Our second objective relates to the protection and restoration of Hellbender habitat to ensure viability of populations in the wild. As siltation is regarded to be the greatest impairment of Hellbender habitat, much of our habitat work focuses on identifying current and potential future sources of sediment and working to stabilize streambanks and protect riparian areas. Having locally-based partners in soil and water conservation districts and land trusts has proved to be a critical component for success. With 95% of Ohio’s land in private ownership, conservation at a watershed scale requires building relationships and trust with local landowners to effectively implement conservation actions.
Amphibians on the Road: Potential Impacts of Roadway Mortality and Ecopassage Utilization on Amphibian Populations Along a Two-lane Highway
Charlene Hopkins (ch183014[at]ohio.edu), Shawn R. Kutcha, and Willem M. Roosenburg
Department of Biological Sciences, Ohio University, 107 Irvine Hall, Athens, Ohio 45701
As roadways depress amphibian population sizes, disrupt connectivity, and degrade habitat mitigation measures are increasingly being implemented. Barriers and ecopassages are a common strategy used to mitigate roadway impacts. Barriers limit access to roadways and may direct animals toward ecopassages, which are corridors designed to conduct animals safely over or under the roadway. The effectiveness of these mitigation measures for small animals remains poorly studied. The Nelsonville bypass, completed in 2013, bisected the largest tract of continuous forest in Ohio, including wetlands and associated amphibian migration routes. The Ohio Department of Transportation installed mitigation measures and views this as their flagship effort, upon which future projects will be based. Thus it is essential that these mitigation efforts be assessed and, if necessary, improved. We quantified levels of roadway mortality, ecopassage use, and amphibian populations, in order to assess the effectiveness of a barrier-ecopassage system. We monitored wildlife deaths along a 2.6km stretch of two-lane highway, used camera traps in ecopassages, examined drift fence effectiveness, and surveyed surrounding habitat to obtain population estimates. We will be presenting our preliminary findings and directions for future research.