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ABSTRACT Environmental challenges early in development can result in complex phenotypic trade-offs and long-term effects on individual physiology, performance and behavior, with implications for disease and predation risk. We examined the effects of simulated pond drying and elevated water temperatures on development, growth, thermal physiology and behavior in a North American amphibian, Rana sphenocephala. Tadpoles were raised in outdoor mesocosms under warming and drying regimes based on projected climatic conditions in 2070. We predicted that amphibians experiencing the rapid pond drying and elevated pond temperatures associated with climate change would accelerate development, be smaller at metamorphosis and demonstrate long-term differences in physiology and exploratory behavior post-metamorphosis. Although both drying and warming accelerated development and reduced survival to metamorphosis, only drying resulted in smaller animals at metamorphosis. Around 1 month post-metamorphosis, animals from the control treatment jumped relatively farther at high temperatures in jumping trials. In addition, across all treatments, frogs with shorter larval periods had lower critical thermal minima and maxima. We also found that developing under warming and drying resulted in a less exploratory behavioral phenotype, and that drying resulted in higher selected temperatures in a thermal gradient. Furthermore, behavior predicted thermal preference, with less exploratory animals selecting higher temperatures. Our results underscore the multi-faceted effects of early developmental environments on behavioral and physiological phenotypes later in life. Thermal preference can influence disease risk through behavioral thermoregulation, and exploratory behavior may increase risk of predation or pathogen encounter. Thus, climatic stressors during development may mediate amphibian exposure and susceptibility to predators and pathogens into later life stages.
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A large, infrequent ecosystem subsidy (cicada carcasses) and warming additively accelerate development and increase growth of larval amphibians
Abstract Many ecosystems receive resource subsidies that affect productivity and food webs. Ecosystem subsidies vary in quantity, quality, and timing, and effects are often mediated by environmental factors, including temperature. Deposition of periodical cicada carcasses into ponds represents a large, high‐quality, infrequent subsidy. Cicadas emerge in massive numbers every 17 yr, and many individuals die and fall into aquatic ecosystems. As climate warms, future cicada subsidies may enter warmer ponds. We conducted a mesocosm experiment with a factorial design to examine the effects of cicada carcasses and elevated (~ 2.6°C) temperature on the growth and development of tadpoles of a common frog,Hyla chrysoscelis. Carcasses and warming each increased frog size at metamorphosis and shortened the time to metamorphosis, and the effects of cicadas and warming were additive for both traits. Mass at metamorphosis was largest and time to metamorphosis shortest with carcass addition and warmed temperature, whereas mass at metamorphosis was smallest and time to metamorphosis longest under ambient temperature without carcasses. Carcasses greatly increased algae biomass (periphyton and phytoplankton), possibly accounting for faster development and larger size of frogs. Warming did not increase standing algal biomass, but increased primary production, possibly increasing food supply for, and growth rates of, tadpoles. Our results show that a large, high‐quality, infrequent subsidy strongly affects pond amphibians, and effects are additively enhanced by warming. Because adult frogs migrate to land, live for several years, and return to their natal pond to breed, a cicada carcass subsidy may mediate reciprocal resource fluxes between land and ponds for several years.
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- PAR ID:
- 10656704
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Limnology and Oceanography
- Volume:
- 70
- Issue:
- S2
- ISSN:
- 0024-3590
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/lno.70191
