TY - JOUR
T1 - Obtaining plasma to measure baseline corticosterone concentrations in reptiles
T2 - How quick is quick enough?
AU - Tylan, Catherine
AU - Camacho, Kiara
AU - French, Susannah
AU - Graham, Sean P.
AU - Herr, Mark W.
AU - Jones, Jermayne
AU - McCormick, Gail L.
AU - O'Brien, Melissa A.
AU - Tennessen, Jennifer B.
AU - Thawley, Christopher J.
AU - Webb, Alison
AU - Langkilde, Tracy
N1 - Funding Information:
We thank the Solon Dixon Forestry Education Center, the United States Air Force, and J. Matter and the Raystown Field Station for access to land and logistical support; L. Van Der Sluys and the staff of Penn State’s Summer Experience in the Eberly College of Science (SEECoS) and Upward Bound Math and Science (UBMS) programs for logistical support regarding the involvement of high school students in this research; and the Cavener lab for access to their plate reader. M. DeLea, D. Ensminger, M. Goldy-Brown and J. Penzelik provided valuable assistance in the field, and R. Clark and E. Taylor provided valuable advice on the rattlesnake study. C. Knapp, J. Iverson, and D. DeNardo provided valuable assistance with field and lab work on the rock iguana study. The John G. Shedd Aquarium provided field research support, and the Bahamas National Trust assisted with permitting. This work was supported by the National Science Foundation ( IOS1456655 and IOS1051367 awarded to T.L.), the Pennsylvania State University (Erickson Discovery Grant, awarded to M.H.), Utah State University (RGS RC Seed grant awarded to S.S.F.) and the Utah Agricultural Experiment Station (project number 1347 awarded to S.S.F.). Funding sources had no influence on the design of this study. The authors have no conflict of interest to declare. Appendix A
Funding Information:
We thank the Solon Dixon Forestry Education Center, the United States Air Force, and J. Matter and the Raystown Field Station for access to land and logistical support; L. Van Der Sluys and the staff of Penn State's Summer Experience in the Eberly College of Science (SEECoS) and Upward Bound Math and Science (UBMS) programs for logistical support regarding the involvement of high school students in this research; and the Cavener lab for access to their plate reader. M. DeLea, D. Ensminger, M. Goldy-Brown and J. Penzelik provided valuable assistance in the field, and R. Clark and E. Taylor provided valuable advice on the rattlesnake study. C. Knapp, J. Iverson, and D. DeNardo provided valuable assistance with field and lab work on the rock iguana study. The John G. Shedd Aquarium provided field research support, and the Bahamas National Trust assisted with permitting. This work was supported by the National Science Foundation (IOS1456655 and IOS1051367 awarded to T.L.), the Pennsylvania State University (Erickson Discovery Grant, awarded to M.H.), Utah State University (RGS RC Seed grant awarded to S.S.F.) and the Utah Agricultural Experiment Station (project number 1347 awarded to S.S.F.). Funding sources had no influence on the design of this study. The authors have no conflict of interest to declare.
Publisher Copyright:
© 2019
PY - 2020/2/1
Y1 - 2020/2/1
N2 - There is growing interest in the use of glucocorticoid (GC) hormones to understand how wild animals respond to environmental challenges. Blood is the best medium for obtaining information about recent GC levels; however, obtaining blood requires restraint and can therefore be stressful and affect GC levels. There is a delay in GCs entering blood, and it is assumed that blood obtained within 3 min of first disturbing an animal reflects a baseline level of GCs, based largely on studies of birds and mammals. Here we present data on the timing of changes in the principle reptile GC, corticosterone (CORT), in four reptile species for which blood was taken within a range of times 11 min or less after first disturbance. Changes in CORT were observed in cottonmouths (Agkistrodon piscivorus; 4 min after first disturbance), rattlesnakes (Crotalus oreganus; 2 min 30 s), and rock iguanas (Cyclura cychlura; 2 min 44 s), but fence lizards (Sceloporus undulatus) did not exhibit a change within their 10-min sampling period. In both snake species, samples taken up to 3–7 min after CORT began to increase still had lower CORT concentrations than after exposure to a standard restraint stressor. The “3-min rule” appears broadly applicable as a guide for avoiding increases in plasma CORT due to handling and sampling in reptiles, but the time period in which to obtain true baseline CORT may need to be shorter in some species (rattlesnakes, rock iguanas), and may be unnecessarily limiting for others (cottonmouths, fence lizards).
AB - There is growing interest in the use of glucocorticoid (GC) hormones to understand how wild animals respond to environmental challenges. Blood is the best medium for obtaining information about recent GC levels; however, obtaining blood requires restraint and can therefore be stressful and affect GC levels. There is a delay in GCs entering blood, and it is assumed that blood obtained within 3 min of first disturbing an animal reflects a baseline level of GCs, based largely on studies of birds and mammals. Here we present data on the timing of changes in the principle reptile GC, corticosterone (CORT), in four reptile species for which blood was taken within a range of times 11 min or less after first disturbance. Changes in CORT were observed in cottonmouths (Agkistrodon piscivorus; 4 min after first disturbance), rattlesnakes (Crotalus oreganus; 2 min 30 s), and rock iguanas (Cyclura cychlura; 2 min 44 s), but fence lizards (Sceloporus undulatus) did not exhibit a change within their 10-min sampling period. In both snake species, samples taken up to 3–7 min after CORT began to increase still had lower CORT concentrations than after exposure to a standard restraint stressor. The “3-min rule” appears broadly applicable as a guide for avoiding increases in plasma CORT due to handling and sampling in reptiles, but the time period in which to obtain true baseline CORT may need to be shorter in some species (rattlesnakes, rock iguanas), and may be unnecessarily limiting for others (cottonmouths, fence lizards).
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UR - http://www.scopus.com/inward/citedby.url?scp=85075195521&partnerID=8YFLogxK
U2 - 10.1016/j.ygcen.2019.113324
DO - 10.1016/j.ygcen.2019.113324
M3 - Article
C2 - 31733208
AN - SCOPUS:85075195521
VL - 287
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
SN - 0016-6480
M1 - 113324
ER -