Title: Weather, hydroregime, and breeding effort influence juvenile recruitment of anurans: implications for climate change

Abstract

Amphibians that primarily breed in ephemeral wetlands are especially vulnerable to climate change because they rely on rainfall or temperature to initiate breeding and create suitable hydroregimes (water duration, timing, frequency, depth) for reproductive success. Hydroregime effects on reproductive success are likely to differ among species because of differences in reproductive strategies: the length and timing of breeding period, rate of larval development, and timing of metamorphosis. We applied an information-theoretic approach to 22 consecutive years of continuous amphibian trapping data at eight ephemeral wetlands to test hypotheses regarding environmental (hydroregime, weather) and biological (adult breeding effort) factors affecting juvenile recruitment (JR) by six focal species representing four reproductive strategies. We hypothesized that (1) JR by species with similar reproductive strategies would be influenced by similar variables; (2) JR would be higher for all species when models encompassed the maximum time span of potential tadpole occurrence and development; and (3) JR rates within individual wetlands and breeding cycles would correlate most closely between species with similar breeding strategies. The best model for all focal species (except Scaphiopus holbrookii) encompassed the maximum time span and indicated that ≥1 hydroregime variable, total precipitation, or both were important drivers of reproductive success; averagemore » air temperature was not. Continuous hydroperiod through peak juvenile emigration was an important predictor of JR for species with prolonged breeding periods, slow larval development, and a “fixed” late spring start date for juvenile emigration (regardless of when oviposition occurred, or cohort age; Lithobates capito, Lithobates sphenocephalus), but not for species with rapid larval development and continual emigration as cohorts complete metamorphosis (Anaxyrus terrestris, Anaxyrus quercicus, Gastrophryne carolinensis, S. holbrookii). Total rainfall was positively associated with recruitment for most species; depth characteristics affected species differently. Annual JR was positively correlated among species with similar reproductive strategies. Our results indicate that weather and hydroregime characteristics interact with reproductive strategies that differ among amphibian species and influence reproductive plasticity, opportunity, and success. In conclusion, effects of altered weather patterns associated with climate change on amphibian reproductive success may correspond more closely among species having similar reproductive strategies, with critical implications for population trends and assemblages.« less

Authors:

Greenberg, C. H. ^[1]; Zarnoch, S. J. ^[2]; Austin, J. D. ^[3]

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+ Show Author Affiliations

1. USDA Forest Service, Asheville, NC (United States)
2. USDA, Forest Service, Moore, SC (United States)
3. Univ. of Florida, Gainesville, FL (United States)

Publication Date:

Wed May 03 00:00:00 EDT 2017

Research Org.:

Univ. of Florida, Gainesville, FL (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1393502

Grant/Contract Number:  

AI09-76SR00056

Resource Type:

Accepted Manuscript

Journal Name:

Ecosphere

Additional Journal Information:

Journal Volume: 8; Journal Issue: 5; Journal ID: ISSN 2150-8925

Publisher:

Ecological Society of America

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; amphibian recruitment; Anaxyrus quercicus; Anaxyrus terrestris; anuran reproduction; breeding strategy; climate and amphibians; ephemeral wetland; Gastrophryne carolinensis; hydroregime; Lithobates capito; Lithobates sphenocephalus; Scaphiopus holbrookii