Spring Peeper (Pseudacris crucifer) in Labrador, Canada: an update

Spring Peeper (Pseudacris crucifer) was first confirmed in Labrador in 1998, when vocalizations were recorded near Happy Valley-Goose Bay. Prior to this, only unsubstantiated reports of Spring Peepers in Labrador existed. In 2006, we visually documented nine Spring Peepers at six locations west of Happy Valley-Goose Bay, in the lower Churchill River valley. In 2014, using auditory surveys, we further documented 1–10 Spring Peepers calling at 13 additional locations in the same general area. These new records support earlier findings and provide additional information on the species at the extreme northeastern edge of its range.

Erythrism in Spring Peeper (Pseudacris crucifer) in Maritime Canada

We document three cases of erythrism in Spring Peeper (Pseudacris crucifer) in New Brunswick and Nova Scotia. Although the source of erythrism in Maritime P. crucifer remains uncertain, the occurrences reported here demonstrate this colour morph to be a widespread, although apparently rare, form in the Canadian Maritimes region.

Not just a peep: The evolution of calling in Pseudacris crucifer

Reproductive isolation is the hallmark of speciation as defined by the biological species concept. A species that is evolving towards reproductive isolation, but has not reached full isolation, is defined as an incipient species. One mechanism used by incipient species to further drive speciation is the use of mate recognition signals. The spring peeper, Pseudacris crucifer, is a North American frog that can be classified as an incipient species, as previous studies have found 6 distinct mitochondrial lineages within its range. Spring peepers use vocal signals for mate recognition and exhibit a female choice mating system where the males call to attract females. This study investigates the evolution of calling in spring peepers. Using calls from each lineage across the full range of spring peepers, I analyzed 11 different characteristics to determine whether the calls were different, and if so, which characteristics are being selected for. Preliminary evidence suggests that the calls between the lineages are distinct and that certain characteristics of the call are more heavily selected for than others. Full analysis on the data has not been completed at this time. This study will expand the understanding of the evolution of spring peepers, as well as offer insight into the role of mating systems on reproductive isolation.

Short-Term Exposure to Coal Combustion Waste Has Little Impact on the Skin Microbiome of Adult Spring Peepers (Pseudacris crucifer)

ABSTRACTDisruptions to the microbiome can impact host health as can exposure to environmental contaminants. However, few studies have addressed how environmental contaminants impact the microbiome. We explored this question for frogs that breed in wetlands contaminated with fly ash, a by-product of coal combustion that is enriched in trace elements. We found differences in the bacterial communities among a fly ash-contaminated site and several reference wetlands. We then experimentally assessed the impacts of fly ash on the skin microbiome of adult spring peepers (Pseudacris crucifer). Frogs were exposed to fly ash in the laboratory for 12 h, the duration of a typical breeding event, and the skin microbiome was assessed after 5 days (experiment 1) or after 5 and 15 days (experiment 2). We examined bacterial community structure using 16S rRNA gene amplicon sequencing and metabolite profiles using high-pressure liquid chromatography-mass spectrometry (HPLC-MS). We found little impact as the result of acute exposure to fly ash on the bacterial communities or metabolite profiles in either experiment, suggesting that the bacterial symbiont communities of adults may be relatively resistant to brief contaminant exposure. However, housing frogs in the laboratory altered bacterial community structure in the two experiments, which supports prior research suggesting that environmental source pools are important for maintaining the amphibian skin microbiome. Therefore, for contaminants like fly ash that may alter the potential source pool of symbionts, we think it may be important to explore how contaminants affect the initial assembly of the amphibian skin microbiome in larval amphibians that develop within contaminated sites.IMPORTANCEAnimals are hosts to many symbiotic microorganisms, collectively called the microbiome, that play critical roles in host health. Therefore, environmental contaminants that alter the microbiome may impact hosts. Some of the most widespread contaminants, produced worldwide, are derived from the mining, storage, and combustion of coal for energy. Fly ash, for example, is a by-product of coal combustion. It contains compounds such as arsenic, selenium, cadmium, and strontium and is a recognized source of ground and surface water contamination. Here, we experimentally investigated the impacts of short-term fly ash exposure on the skin microbiome of spring peepers, one of many species of amphibian that sometimes breed in open fly ash disposal ponds. This research provides a look into the potential impacts of fly ash on an animal's microbiome and suggests important future directions for research on the effects of environmental contaminants on the microbiome.