Tasker et al. 2022

Effects of elevated temperature, reduced hydroperiod, 

and invasive bullfrog larvae on Pacific chorus frog larvae

Tasker, B. R., Honebein, K. N., Erickson, A. M., Misslin, J. E., Hurst, P., Cooney, S., ... & Bancroft, B. A. (2022). Effects of elevated temperature, reduced hydroperiod, and invasive bullfrog larvae on Pacific chorus frog larvae. Plos one, 17(3), e0265345. 

Keywords:

Aquatic, amphibian larvae, experiment, species fitness

Summary: 

This paper investigated the potential impacts of climate change and the invasive American bullfrog (Lithobates catesbieanus) on the development and survival of Pacific chorus frogs (Psuedacris regilla). The authors used eight different treatment groups (see Figure 1) that allowed them to explore the impacts of historic versus future climates, bullfrog presence versus absence, and direct (physical) versus indirect (visual/chemical) bullfrog impacts. The results indicated that, overall, bullfrogs had a larger negative impact on Pacific chorus frogs than climate conditions. However, future warming may allow Pacific chorus frogs to partially compensate for some of the negative effects of bullfrogs by allocating additional energy toward mass.

Take Home Points:

• Bullfrogs have clear negative effects on Pacific chorus frog growth (i.e., reduced body length and mass at metamorphosis). 

• Pacific chorus frogs developed faster in future climate conditions and emerged at heavier weights compared to the historic climate treatments. In this study, Pacific chorus frog tadpoles allocated energy to rapid development without a reduction in mass or body length.

• The presence of bullfrogs had less of an effect on Pacific chorus frogs, in terms of their final mass, under future climate conditions as compared to the effects of the invasive frog under current climate conditions; though notably, impacts on length at metamorphosis in the presence of bullfrogs was significant under future climate conditions. This suggests that climate change could mitigate invasive bullfrog impacts on native chorus frog tadpole development by creating physical conditions allowing for faster growth (though not length) in the presence of this additional stressor.  

Management Implications:

• Size at metamorphosis can impact frog survival1, physical performance2-5, and fitness6. Bullfrogs reduced the size of Pacific chorus frogs both in mass and body length, suggesting that the presence of bullfrogs in the larval habitat may negatively affect frogs in the terrestrial stage.

• The Pacific chorus frogs displayed strong plasticity which may help them meet the demands of new environments, including future climate change.

Suggested Pairing:

• Urban MC, Richardson JL, Freidenfelds NA. Plasticity and genetic adaptation mediate amphibian and reptile responses to climate change. Evol Appl. 2013; 7: 88-103. https://doi.org/10.1111/eva.12114 PMID: 24454550

Works Cited:

The information in this summary is attributed to Tasker et al. 2022 unless otherwise noted.

1. Székely D, Cogălniceanu D, Székely P, Armijos-Ojeda D, Espinosa-Mogrovejo V, Denoël M. How to recover from a bad start: size at metamorphosis affects growth and survival in a tropical amphibian. BMC Ecol. 2020;20: 24. Pmid:32316956 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175581/ 

2. Watkins TB. A quantitative genetic test of adaptive decoupling across metamorphosis for locomotor and life-history traits in the Pacific tree frog, Hyla regilla. Evolution. 2001;55: 1668–1677. Pmid:11580026 https://pubmed.ncbi.nlm.nih.gov/11580026/ 

3. John-Alder HB, Morin PJ. Effects of larval density on jumping ability and stamina in newly metamorphosed Bufo woodhousii fowleri. Copeia. 1990;1990: 856–860.

4. Goater CP, Semlitsch RD, Bernasconi MV. Effects of body size and parasite infection on the locomotory performance of juvenile toads, Bufo bufo. Oikos. 1993;66: 129–136. https://www.jstor.org/stable/3545205 

5. Beck CW, Congdon JD. Effects of age and size at metamorphosis on performance and metabolic rates of Southern Toad, Bufo terrestris, metamorphs. Funct Ecol. 2000;14: 32–38. https://besjournals.onlinelibrary.wiley.com/doi/full/10.1046/j.1365-2435.2000.00386.x 

6. Semlitsch RD, Scott DE, Pechmann JHK. Time and size at metamorphosis related to adult fitness in Ambystoma talpoideum. Ecology. 1988;69: 184–192. https://esajournals.onlinelibrary.wiley.com/doi/abs/10.2307/1943173 

Summary Authors: Carey Schafer, Deb Rudnick