Influence of interspecific competitors on behavioral thermoregulation: developmental or acute plasticity?
Many ectotherms reduce their exposure to changing thermal conditions using behavioral thermoregulation. The effectiveness of behavioral thermoregulation in maintaining ectotherm body temperatures within the target range is influenced not only by environmental (operative) temperatures but also by the presence of other con- and heterospecific individuals. How species’ interactions affect behavioral thermoregulation is largely unknown. Theory predicts that species’ interactions could affect the plasticity of behavioral thermoregulation in two ways, i.e., by developmental plasticity of a preferred temperature range or by an acute shift in body temperatures. Empirical tests of these predictions are scarce. We examined the developmental and acute effects of heterospecific social interactions on the accuracy and effectiveness of thermoregulation in the larvae of two competing species, Ichthyosaura alpestris and Lissotriton vulgaris. The presence of heterospecifics during larval development had no effect on preferred body temperatures but it modified later acute thermoregulatory responses to heterospecifics. Ichthyosaura alpestris larvae from heterospecific tanks increased their thermoregulatory accuracy and effectiveness, while L. vulgaris larvae from conspecific tanks relaxed their thermoregulatory efforts. The thermal dependence of somatic growth suggests that modified behavioral thermoregulation has the potential to accelerate growth in competitively dominant I. alpestris. Acute thermoregulatory responses are affected by heterospecific social interactions in newt larvae, but not conspecific. A developmental plastic response modified body temperatures not the target thermoregulatory range, which shows that the influence of heterospecific social interactions is more complex than predicted by theory. Species interactions complicate estimating an ectotherm’s vulnerability to ongoing climate change.
Many ectothermic animals control their body temperature through behavioral thermoregulation. Their thermoregulatory decisions are influenced not only by environmental temperatures, but also by the presence of other species. We show that the current thermoregulatory effort in interacting newt larvae is affected by previous experience with competing species. The influence of heterospecific social interactions is more complex than predicted by theory, which complicates estimating an ectotherm’s vulnerability to ongoing climate change.
KeywordsClimate change Species interactions Thermal niche Preferred temperatures Behavioral plasticity Newt
We thank C. R. Gabor and anonymous reviewers for their comments on the previous version of this paper; we would also thank P. Kristín for his help with the realization of seminatural experiment.
This research was supported by the Czech Science Foundation (grant numbers 15-07140S and 17-15480S to LG) and the Institute of Vertebrate Biology AS CR (RVO: 68081766 to LG).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national, and/or institutional guidelines for the use of animals were followed. All experimental procedures were approved by the Expert Committee for Animal Conservation of the Institute of Vertebrate Biology AS CR (research protocol no. 135/2016). The Agency for Nature Conservation and Landscape Protection of the Czech Republic issued permission to capture the newts (1154/ZV/2008).
- Braz E, Joly P (1994) Microhabitat use, resource partitioning and ecological succession in a size-structured guild of newt larvae (Triturus, Caudata, Amphibia). Arch Hydrobiol 131:129–139Google Scholar
- Canty A, Ripley B (2017) Boot: bootstrap R (S-plus) functions. R package version 1.3–19, https://cran.r-project.org/web/packages/boot/index.html
- Denny MW (1993) Air and water. The biology and physics of life’s media. Princeton University Press, Princeton, NYGoogle Scholar
- Dodd CK, Seigel RA (1991) Relocation, repatriation, and translocation of amphibians and reptiles: are they conservation strategies that work? Herpetologica 47:336–350Google Scholar
- Gvoždík L, Smolinský R (2015) Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae. BMC Evol Biol 15(238). https://doi.org/10.1186/s12862-015-0522-y
- Little A, Seebacher F (2016) Acclimation, acclimatization and seasonal variation in amphibians and reptiles. In: de Andrade DV, Bevier CR, de Carvalho JE (eds) Amphibian and reptile adaptations to the environment: interplay between physiology and behavior, 1st edn. CRC Press, Boca Raton, pp 41–62CrossRefGoogle Scholar
- Polis GA, Myers CA, Holt RD (1989) The ecology and evolution of intraguild predation: potential competitors that eat each other. Annu Rev Ecol Syst 20:297–330. https://doi.org/10.1146/annurev.es.20.110189.001501 CrossRefGoogle Scholar
- Sunday JM, Bates AE, Kearney MR, Colwell RK, Dulvy NK, Longino JT, Huey RB (2014) Thermal-safety margins and the necessity of thermoregulatory behavior across latitude and elevation. Proc Natl Acad Sci U S A 111:5610–5615. https://doi.org/10.1073/pnas.1316145111 CrossRefPubMedPubMedCentralGoogle Scholar
- Szymura JM (1974) Competitive situation in larvae of four sympatric species of newts (Triturus cristatus, T. alpestris, T. montandoni, and T. vulgaris) living in Poland. Acta Biol Cracov 17:235–262Google Scholar
- Thompson JN (2005) The geographic mosaic of coevolution. University of Chicago Press, ChicagoGoogle Scholar
- Werner EE, Gilliam JF (1984) The ontogenetic niche and species interactions in size-structured populations. Annu Rev Ecol Syst 15:393–425. https://doi.org/10.1146/annurev.es.15.110184.002141 CrossRefGoogle Scholar