TY - JOUR
T1 - Headwater-stream salamander movements and home-range size increased under drought
AU - Cochrane, Madaline M.
AU - Lowe, Winsor H.
N1 - Publisher Copyright:
© 2025 The Society for Freshwater Science. All rights reserved.
PY - 2025/6
Y1 - 2025/6
N2 - Climate change is increasing the frequency and intensity of droughts and floods, which will likely have disproportionate effects on freshwater organisms. Stream salamanders are often top predators in small, fishless headwater streams that are highly responsive to hydrologic changes. Although these salamanders persist in dynamic stream environments, we lack the empirical understanding of how they respond to variable drought and flooding intensity that would allow us to predict future responses to climate-related changes in hydrology. We used 3 y (2019–2021) of data from passive integrated transponder (PIT)-tag surveys to characterize how movement distance, movement direction, and home-range size of the Northern Spring Salamander Gyrinophilus porphyriticus (Green, 1827) vary across a range of hydrologic conditions. Most notably, this PIT-tag data included a period of severe drought in the late summer of 2020. We found that total distance moved and home-range size increased with drought intensity. Total distance moved was not related to peak discharge at the range of flooding experienced across this study (<5-y flood recurrence intervals). Larval movements were skewed downstream after large floods but were skewed upstream across all other conditions. The direction of adult movements did not differ across extreme flood or drought conditions. Overall, adults moved greater distances and had larger home ranges than larvae (median movement = 1.9 m vs 1.6 m; median home range = 5 m2 vs 4 m2). We also found adults using moist terrestrial microhabitats for up to 14 consecutive days, even during moderate drought. Our results suggest that headwater salamanders will move more as drought intensity increases in the future. We interpret these movements as behavior used to find habitable, moist environments as stream reaches dry. These results suggest that adequate instream and riparian refuges will become more important for stream salamander survival as climate change progresses.
AB - Climate change is increasing the frequency and intensity of droughts and floods, which will likely have disproportionate effects on freshwater organisms. Stream salamanders are often top predators in small, fishless headwater streams that are highly responsive to hydrologic changes. Although these salamanders persist in dynamic stream environments, we lack the empirical understanding of how they respond to variable drought and flooding intensity that would allow us to predict future responses to climate-related changes in hydrology. We used 3 y (2019–2021) of data from passive integrated transponder (PIT)-tag surveys to characterize how movement distance, movement direction, and home-range size of the Northern Spring Salamander Gyrinophilus porphyriticus (Green, 1827) vary across a range of hydrologic conditions. Most notably, this PIT-tag data included a period of severe drought in the late summer of 2020. We found that total distance moved and home-range size increased with drought intensity. Total distance moved was not related to peak discharge at the range of flooding experienced across this study (<5-y flood recurrence intervals). Larval movements were skewed downstream after large floods but were skewed upstream across all other conditions. The direction of adult movements did not differ across extreme flood or drought conditions. Overall, adults moved greater distances and had larger home ranges than larvae (median movement = 1.9 m vs 1.6 m; median home range = 5 m2 vs 4 m2). We also found adults using moist terrestrial microhabitats for up to 14 consecutive days, even during moderate drought. Our results suggest that headwater salamanders will move more as drought intensity increases in the future. We interpret these movements as behavior used to find habitable, moist environments as stream reaches dry. These results suggest that adequate instream and riparian refuges will become more important for stream salamander survival as climate change progresses.
UR - https://www.scopus.com/pages/publications/105013549806
U2 - 10.1086/735624
DO - 10.1086/735624
M3 - Article
AN - SCOPUS:105013549806
SN - 2161-9549
VL - 44
SP - 159
EP - 169
JO - Freshwater Science
JF - Freshwater Science
IS - 2
ER -
