Editorial Type:
Article Category: Research Article
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Online Publication Date: Feb 27, 2023

Salamander Movement Propensity Resists Effects of Supraseasonal Drought

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Page Range: 109 – 118
DOI: 10.1643/h2022051
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Movement can act as an effective strategy used by amphibians to avoid detrimental environmental conditions, particularly drought. However, due to the unpredictable nature of droughts, evaluating the patterns and consequences of movement has rarely been investigated. In 2007–2008, the southeastern United States experienced a supraseasonal drought that resulted in 110 yr low flow levels among the first-order streams. In this study, 61 months of mark–recapture data collected from one first-order stream were used to examine the effects of drought on the movement frequency distribution, survival, and growth rates of adult Desmognathus fuscus (Northern Dusky Salamander). We hypothesized that salamanders would demonstrate a higher propensity to move during supraseasonal drought conditions and that moving salamanders would experience higher survival and growth rates. We found that salamanders were more likely to move immediately after the drought compared to the pre-drought and drought conditions. Although movement frequency was low during the drought, survival was higher for individuals who moved during drought conditions in comparison to individuals who remained in their original capture location. Although our model did not detect a trend, salamanders experienced slightly higher growth in the post-drought conditions compared to drought and pre-drought conditions. In addition, during the post-drought, salamanders that moved had slightly higher growth rates compared to salamanders who remained in their original capture location. Our results suggest that adult salamanders were potentially displaying an adaptive movement strategy to resist drought conditions by moving away from affected (i.e., dry) areas within the study stream. In addition, movement was likely utilized to access replenished resources in other areas after the severe effects of the drought ended. Therefore, both in-stream and riparian barriers that impede movement may inhibit resilience of stream amphibians during severe droughts.

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Copyright: © 2023 by the American Society of Ichthyologists and Herpetologists
Fig. 1.
Fig. 1.

Movement frequency distribution of the distance traveled in meters (m) by adult Desmognathus fuscus from (A) entire sampling period (i.e., November 2005 to November 2010), (B) pre-drought period (i.e., November 2005 to July 2007), (C) drought period (i.e., August 2007 to August 2008), and (D) post-drought period (i.e., September 2008 to November 2010) either upstream or downstream in a Piedmont stream in North Carolina.


Fig. 2.
Fig. 2.

Monthly number of movements of adult Desmognathus fuscus from November 2005 to November 2010 in a Piedmont stream in North Carolina. The vertical lines represent the beginning and end of the supraseasonal drought that occurred from August 2007 to August 2008.


Fig. 3.
Fig. 3.

Estimates of survival of Desmognathus fuscus between movers (black bars) and stayers (white bars) sampled from November 2005 to November 2010 in a first-order stream in Mecklenburg County, North Carolina. Pre-drought conditions included samples from November 2005 to July 2007, drought conditions occurred from August 2007 to August 2008, while post-drought occurred from September 2008 to November 2010. Error bars are ±1 SE.


Fig. 4.
Fig. 4.

Estimates of mean growth rate of Desmognathus fuscus before, during, and after the supraseasonal drought, sampled from November 2005 to November 2010 in a first-order stream in Mecklenburg County, North Carolina. Pre-drought conditions included samples from November 2005 to July 2007, drought conditions occurred from August 2007 to August 2008, while post-drought occurred from September 2008 to November 2010. Error bars are ±1 SE.


Contributor Notes

Department of Forestry and Natural Resources, University of Kentucky, Lexington, Kentucky 40546; ORCID: (KMG) 0000-0003-0227-1982; and (SJP) 0000-0002-2388-0579; Email: (KMG) kathryn.greene@uky.edu; and (SJP) steven.price@uky.edu. Send correspondence to KMG.
Department of Biology, University of Kentucky, 101 TH Morgan Building, 675 Rose Street, Lexington, Kentucky 40506; ORCID: (JVC) 0000-0003-3656-4257; Email: (JVC) jvancleve@uky.edu.

Associate Editor: J. Lamb.

Received: May 19, 2022
Accepted: Dec 08, 2022