Climatic and geographic predictors of life history variation in Eastern Massasauga (Sistrurus catenatus): A range-wide synthesis

Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size-fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus) is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions. To address Eastern Massasauga life history data gaps, we compiled data from 47 study sites representing 38 counties across the range. We used multimodel inference and general linear models with geographic coordinates and annual climate normals as explanatory variables to clarify patterns of variation in life history traits. We found strong evidence for geographic variation in six of nine life history variables. Adult female snout-vent length and neonate mass increased with increasing mean annual precipitation. Litter size decreased with increasing mean temperature, and the size-fecundity relationship and growth prior to first hibernation both increased with increasing latitude. The proportion of gravid females also increased with increasing latitude, but this relationship may be the result of geographically varying detection bias. Our results provide insights into ectotherm life history variation and fill critical data gaps, which will inform Eastern Massasauga conservation efforts by improving biological realism for models of population viability and climate change

Assessment of Darkling Beetle Fauna after Implementation of an Environmental Restoration Program in the Southern Iberian Peninsula Affected by the Aznalcóllar Toxic Spill

This study is part of the Follow up Restoration Program of animal communities that colonize the Guadiamar River Basin. In 1998, the area was affected by a release of toxic sludge after the retention walls of the Aznalcóllar Mines (southern Iberian Peninsula) broke. The main objective of this study was to assess the current state of the population of Tenebrionidae, one of the most representative groups of edaphic Coleoptera inhabiting the Guadiamar River Basin. This paper analyses the progress made by the darkling beetle community six years after the disaster occurred and the Restoration Program was implemented. The study is based on faunistic data from systematic sampling carried out for six years to monitor plots distributed across the damaged area. To make an overall assessment of the tenebrionid fauna in relation to adjacent areas qualitative and quantitative ecological indices were applied, and temporal follow up and biogeographical comparisons were also made. The results indicate that, on the whole, tenebrionid fauna was somewhat affected by the Aznalcóllar Mine spill, and that a greater loss of fauna was detected closer to the accident site. The analysis of the temporal population dynamic suggests that the most affected zones are undergoing a process of re-colonization. However, this process varies widely by species and has not yet reached the expected levels of a non-affected river basin in the southern Iberian Peninsula

First record of Paintedhand Mudbug (Lacunicambarus polychromatus) in Ontario and Canada and the significance of iNaturalist in making new discoveries

Paintedhand Mudbug (Lacunicambarus polychromatus (Thoma, Jezerinac & Simon 2005)) (Decapoda: Cambaridae) was recently discovered at three locations in Windsor, Ontario. These represent the first reports of this burrowing crayfish in Canada. iNaturalist, a nature app and website designed to record photo-based observations of plants and animals, was instrumental in facilitating this discovery. We discuss the importance of collaborative platforms, such as iNaturalist, for linking naturalists and citizen scientists to taxonomic experts around the globe

Climatic and geographic predictors of life history variation in Eastern Massasauga (Sistrurus catenatus): A range-wide synthesis

Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size-fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus) is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions. To address Eastern Massasauga life history data gaps, we compiled data from 47 study sites representing 38 counties across the range. We used multimodel inference and general linear models with geographic coordinates and annual climate normals as explanatory variables to clarify patterns of variation in life history traits. We found strong evidence for geographic variation in six of nine life history variables. Adult female snout-vent length and neonate mass increased with increasing mean annual precipitation. Litter size decreased with increasing mean temperature, and the size-fecundity relationship and growth prior to first hibernation both increased with increasing latitude. The proportion of gravid females also increased with increasing latitude, but this relationship may be the result of geographically varying detection bias. Our results provide insights into ectotherm life history variation and fill critical data gaps, which will inform Eastern Massasauga conservation efforts by improving biological realism for models of population viability and climate change

Relationship between latitude (untransformed) and size–fecundity (natural log back-transformed) as explained by the top-ranked model using AIC_c (Table 3).

<p>Female size was held constant at 55.2 cm SVL based on the average size of adult females in Cass County, Michigan. The shaded area represents the smoothed 95% CI using t-based approximations. County and district abbreviations are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172011#pone.0172011.g001" target="_blank">Fig 1</a>. The image of dam and offspring was taken within minutes of parturition in Cass County, Michigan (Photograph credit, E. T. Hileman).</p

Relationship between latitude (untransformed) and age-zero annual growth as explained by the top-ranked model using AIC_c (Table 3).

<p>The shaded area represents the smoothed 95% CI using t-based approximations. County and district abbreviations are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172011#pone.0172011.g001" target="_blank">Fig 1</a>.</p

Relationship between mean annual precipitation (untransformed) and neonate mass as explained by the top-ranked model using AIC_c (Table 3).

<p>The shaded area represents the smoothed 95% CI using t-based approximations. County and district abbreviations are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172011#pone.0172011.g001" target="_blank">Fig 1</a>.</p

Candidate model sets for life history variables.

<p>Bolded 95% confidence intervals exclude zero and therefore indicate the standardized effect size for a given explanatory variable is informative. For models with two predictor variables, the standardized effect size and 95% CI for the first and second variable are in the first and second row associated with that model. Model abbreviations are the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172011#pone.0172011.t002" target="_blank">Table 2</a>.</p

Locations of Eastern Massasauga study sites (counties/districts shaded black) and the approximate historic range of the Eastern Massasauga (gray shading, from http://www.iucnredlist.org/).

<p>County and district codes: IA = Bremer, IA; IL.1 = Clinton, IL; IL.2 = DuPage, IL; IL.3 = Cook/ Lake, IL; IL.4 = Piatt, IL; IL.5 = Warren, IL, IL.6 = Will, IL; IN.1 = Hendricks, IN; IN.2 = LaGrange, IN; IN.3 = Marshall, IN; MI.1 = Barry, MI; MI.2 = Cass, MI; MI.3 = Kalkaska, MI; MI.4 = Lenawee, MI; MI.5 = Oakland, MI; MI.6 = Van Buren, MI; MI.7 = Washtenaw, MI; NY.1 = Genesee, NY; NY.2 = Onondaga, NY; OH.1 = Ashtabula, OH; OH.2 = Champaign, OH; OH.3 = Clark, OH; OH.4 = Greene, OH; OH.5 = Greene/ Warren, OH; OH.6 = Hardin, OH; OH.7 = Trumball, OH; OH.8 = Wyandot, OH; ONT.1 = Bruce, ONT; ONT.2 = Essex, ONT; ONT.3 = Muskoka, ONT; ONT.4 = Beausoliel Island, ONT; ONT.5 = Parry Sound District (1995–1996), ONT; ONT.6 = Parry Sound District (1992–2009), ONT; ONT.7 = Regional Municipality of Niagara, ONT; PA = Butler/ Venango, PA; WI.1 = Buffalo, WI; WI.2 = Juneau/ Monroe, WI. Reprinted and modified from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172011#pone.0172011.ref150" target="_blank">150</a>] under a CC BY license, with permission from [Collin P. Jaeger], original copyright [2016] (See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172011#pone.0172011.s003" target="_blank">S3 File</a>).</p

Snout‐vent length plotted against capture day‐of‐year of Eastern Massasaugas captured during 2006–2014 in Cass County, Michigan.

<p>Seven distinct age classes are evident: age 0 (blue) includes recently born animals prior to their first hibernation; age 1 (gray) includes animals captured following their first hibernation, but prior to their second hibernation; age 2 (black) includes animals captured following their second hibernation, but prior to their third hibernation, and so on; age 3 (white); age 4 (orange); age 5 (red); age 6 (yellow). Age 1 begins to overlap with age 2 in August (~ DOY 225).</p