Fig 1.
Location of field surveys (A), and iNaturalist observations (B) of Eastern Red-backed Salamanders (Plethodon cinereus) in New Brunswick.
Each hollow circle with a cross represents the location of a field survey in New Brunswick (n = 23), each red circle represents iNaturalist reports of a striped colour morph (n = 263), and each black circle represents iNaturalist reports of an unstriped colour morph (n = 21). A small inset map in the top-left corner highlights the study area, New Brunswick, Canada, using a dark blue outline. The scale bar represents 100 km. The basemap was created using the ‘ne_states’ function from the R package ‘rnaturalearth’, and plotted using the “geom_sf” function from the R package ‘ggplot2’ [25]. The scale bar and north arrow were added to plots using the ‘ggsn’ R package [26].
Fig 2.
The colour variation in the Eastern Red-backed Salamander (Plethodon cinereus) in New Brunswick.
All photos were reported on iNaturalist (http://www.inaturalist.org/) and included in this study. The top left individual is a leucistic morph (photo credit: Bradley Doiron), the top middle (photo credit: Alexis Godin) and top right individuals (photo credit: Sébastien Benoit) are red-backed or striped morphs, the bottom left individual is an amelanistic morph (photo credit: Damien Mullin), the bottom middle individual is a lead-backed or unstriped morph (photo credit: David Robichaud), and the bottom-right salamander is an erythristic morph (photo credit: Dani Landry).
Fig 3.
The percentage of Eastern Red-backed Salamanders (Plethodon cinereus) colour morphs reported on iNaturalist (blue bars) and observed during field surveys (orange bars).
Data is presented by colour morph, which includes the striped or red-backed morph, the unstriped or lead-backed morph, and any other colour morphs observed (including erythristic, albino, amelanistic, or leucistic). In the graph, sample size is denoted above each column. Significance (p < 0.05) is denoted by asterisk’s (***).
Table 1.
The aggregative behavior of P. cinereus across its active season (May to October 2022) encountered during our field surveys.
Fig 4.
The percentage of Eastern Red-backed Salamanders (Plethodon cinereus) found aggregated under the same shelter object (grouped) versus found solitary under shelter reported on iNaturalist (blue bars) and during field surveys (orange bars).
The sample size is denoted above each column. Significance (p < 0.05) is denoted by asterisk’s (***).
Table 2.
A summary of environmental variables (average ± standard deviation) of adult unstriped and striped colour morphs of P. cinereus found during field surveys.
Table 3.
Outcomes of generalised linear mixed-effect models (GLMMs) testing if microclimate variables (i.e., soil moisture, canopy coverage, and soil temperature) and cover object volume differ between field locations where solitary and mating pairs/aggregations of Eastern Red-backed Salamanders (Plethodon cinereus) occur.