Case of the shrinking salamanders

Congratulations to Patrick Moldowan for our publication in Global Change Biology on “Climate associated decline of body condition in a fossorial salamander”.

Abstract of the study below:

Temperate ectotherms have responded to recent environmental change, likely due to the direct and indirect effects of temperature on key life cycle events. Yet, a substantial number of ectotherms are fossorial, spending the vast majority of their lives in subterranean microhabitats that are assumed to be buffered against environmental change.

Here, we examine whether seasonal climatic conditions influence body condition (a measure of general health and vigor), reproductive output, and breeding phenology in a northern population of fossorial salamander (Spotted Salamander, Ambystoma maculatum). We found that breeding body condition declined over a 12-year monitoring period (2008–2019) with warmer summer and autumn temperatures at least partly responsible for the observed decline in body condition.

Our findings are consistent with the hypothesis that elevated metabolism drives the negative associa- tion between temperature and condition. Population-level reproduction, assessed via egg mass counts, showed high interannual variation and was weakly influenced by autumn temperatures. Salamander breeding phenology was strongly correlated with lake ice melt but showed no long-term temporal trend (1986–2019).

Climatic warming in the region, which has been and is forecasted to be strongest in the summer and autumn, is predicted to lead to a 5%–27% decline in salamander body condition under realistic near-future climate scenarios. Although the subterranean environment offers a thermal buffer, the observed decline in condition and relatively strong effect of summer temperature on body condition suggest that fossorial salamanders are sensitive to the effects of a warming climate.

Given the diversity of fossorial taxa, heightened attention to the vulnerability of subterranean microhabitat refugia and their inhabitants is warranted amid global climatic change.

This study resulted from the PhD research of Patrick Moldowan, working with Dr. Njal Rollinson (U of Toronto) and myself. The research emanated from a long-term monitoring project called BLISS (https://tattersalllab.com/bliss/) that was initiated at various times in the past, with an objective to monitor mole salamanders (Spotted Salamanders, Ambystoma maculatum) in a pristine environment, for potential changes over time in population, phenology, reproductive output, and morphology.

I first met the Bat Lake salamanders in 1993, being introduced to the field site by a generous Dr. James Bogart who trusted me enough to leave me alone for 4 months to conduct research on an NSERC USRA project. I really want to thank Jim for sending me to this place where the field site captured the imagination, was a retreat from the urban life, and a crash course in wildlife ecology.

Here is a link to the paper http://doi.org/10.1111/gcb.15766 or request access from researchgate

Citation

Moldowan, PD, Tattersall, GJ, and Rollinson, N. 2021. “Climate associated decline of body condition in a fossorial salamander”. Global Change Biology. http://doi.org/10.1111/gcb.15766 

Acknowledgements

Many thanks to all the folks at the Algonquin Wildlife Research Station for support over the years and to all the Salamanderers who took part in BLISS: DL LeGros, SP Boyle, O Butty, JWD Connoy, D Crawford, EA Francis, G H-Y Gao, N Hrynko, JA Leivesley, DI Mullin, S Paiva, D Ravenhearst, C Rouleau, M Terebiznik, H Vleck, L Warma, SJ Kell and T Wynia. There are so many others who have helped out over the years, and we hope we have acknowledged all their assistance in the paper acknowledgements!

Shape-shifting animals

Congratulations to Sara Ryding, Deakin University for the first chapter of her PhD thesis being published in Trends in Ecology & Evolution on “Shape-shifting: changing animal morphologies as a response to climatic warming”. Link to the paper here or here.

In this review, Sara writes about how animal appendages (ears, feet, limbs, bills, etc) are important morphological indicators of temperature and therefore potential signatures of changing climate.

Appendages have an important, but often undervalued, role in animal thermoregulation as sites of heat exchange.

This thermoregulatory role leads to geographic clines in animal morphology where animals at lower latitudes, in warmer climates, have larger appendages (a pattern known as ‘Allen’s rule’).

In this review, we discuss evidence for animals (mostly evidence in birds and mammals, although the field does extend to other animal taxa) that are shifting their morphologies to have proportionately larger appendages in response to climate change and its associated temperature increases.

A thermal image of a Galapagos sea lion, showing distinctly warm front flippers. Appendages tend to be variable in size and have capacity to vary peripheral blood flow, and thus may serve as sensitive indicators of changing climate.

It has been a real pleasure to work with Sara Ryding on this project. Full credit and thanks go to Sara for all her hard work on this paper. I helped out only a small bit, but she reviewed the field within which my lab has been conducting collaborative research since 2010. Hopefully more research will follow as she navigates the rest of the project us (Drs. Matthew Symonds and Marcel Klaassen and myself). Many late nights and early morning zoom meetings await us all. Many thanks to Deakin University and the Australian Research Council for supporting this project.

Citation

Ryding, S, Klaassen, M, Tattersall, GJ, Gardner, JL, and Symonds, MRE. 2021. Shape-shifting: changing animal morphologies as a response to climatic warming. Trends in Ecology & Evolution. DOI: https://doi.org/10.1016/j.tree.2021.07.006

News articles

https://www.vice.com/en_us/article/wx59p4/climate-change-is-forcing-animals-to-quickly-shape-shift-study-suggests

https://www.cnn.com/2021/09/07/world/animals-climate-change-shape-shift-scn/index.html

https://www.brisbanetimes.com.au/environment/climate-change/climate-change-means-bigger-bills-and-ears-and-tails-as-well-20210907-p58pg6.html