TY - JOUR
T1 - Nocturnal Sleep Behavior and Vigilance of Incubating Common Terns (Sterna hirundo) at Two Inland Breeding Colonies
AU - Diehl, Jenna
AU - Korpi, Zoe O.
AU - Oswald, Stephen A.
AU - Curtis, Paul D.
AU - Arnold, Jennifer M.
N1 - Funding Information:
All work was carried out under the appropriate permits, including Canadian Wildlife Service Migratory Bird Conservation Act Scientific Permits CA 0242 and CA 0308, banding permits 10431V, 10431W, and 10901 and using methods approved by Penn State Universitys Institutional Animal Care and Use Committee (protocols #28103 and #45332). Research at Oneida Lake was conducted under U.S. Department of the Interior Federal Bird Banding Permit Number 2402, and Cornell University's Institutional Animal Care and Use Committee approval (protocol #2001-0091). We thank staff from the Cornell Biological Field Station for logistic support at Oneida Lake. We also thank all Penn State Undergraduate Interns who assisted with data collection in the field. We are indebted to all the Presqu'ile staff, especially D. Tyerman, S. Smith, M. Barker, J. Belliveau, R. Cunningham, and A. Parker for logistic support. Research at Gull Island was supported in part by grants from the Friends of Presqu'ile and Adopt-a-tern donors. The New York State Department of Environmental Conservation provided funding for a student intern and tern research at Oneida Lake. All applicable ethical guidelines for the use of birds in research have been followed, including those presented in the Ornithological Council's Guidelines to the Use of Wild Birds in Research (Fair et al. 2010).
Publisher Copyright:
© 2020 The Waterbird Society. All rights reserved.
PY - 2020/3
Y1 - 2020/3
N2 - Although sleep is necessary for maintaining physiological and cognitive function in birds, nocturnal sleep behavior has yet to be documented for terns. Nocturnal sleep behavior and vigilance of incubating Common Terns (Sterna hirundo) were explored at two colonies, Gull Island (Ontario, Canada) for six years, and Little Island (New York, USA) throughout one breeding season, using 1-min interval, time-lapse images from infrared trail cameras. Behavioral posture and vigilance (eye[s] open) of visible study birds were recorded from the images to determine if these differed between the two colonies. Terns utilized two sleeping postures, Back Sleep and Front Sleep, nearly identical to those used by gulls. Differences in the proportion of time spent sleeping between the two colonies were surprisingly large. Terns at Gull Island spent 75% less time in Back Sleep (deep-sleep posture, 7% of the night) than those at Little Island, and 64% of night with their eyes open (vs. <20% at Little Island). Differences between the study sites that may have caused this disparity include predation risk, colony size, vegetation cover and the presence of other nesting waterbirds. Apparent, long-term sleep deprivation at Gull Island may have physiological impacts. Further research is needed to establish causes and effects of differences in nocturnal sleep behavior in Common Terns.
AB - Although sleep is necessary for maintaining physiological and cognitive function in birds, nocturnal sleep behavior has yet to be documented for terns. Nocturnal sleep behavior and vigilance of incubating Common Terns (Sterna hirundo) were explored at two colonies, Gull Island (Ontario, Canada) for six years, and Little Island (New York, USA) throughout one breeding season, using 1-min interval, time-lapse images from infrared trail cameras. Behavioral posture and vigilance (eye[s] open) of visible study birds were recorded from the images to determine if these differed between the two colonies. Terns utilized two sleeping postures, Back Sleep and Front Sleep, nearly identical to those used by gulls. Differences in the proportion of time spent sleeping between the two colonies were surprisingly large. Terns at Gull Island spent 75% less time in Back Sleep (deep-sleep posture, 7% of the night) than those at Little Island, and 64% of night with their eyes open (vs. <20% at Little Island). Differences between the study sites that may have caused this disparity include predation risk, colony size, vegetation cover and the presence of other nesting waterbirds. Apparent, long-term sleep deprivation at Gull Island may have physiological impacts. Further research is needed to establish causes and effects of differences in nocturnal sleep behavior in Common Terns.
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U2 - 10.1675/063.043.0103
DO - 10.1675/063.043.0103
M3 - Article
AN - SCOPUS:85085911243
SN - 1524-4695
VL - 43
SP - 28
EP - 35
JO - Waterbirds
JF - Waterbirds
IS - 1
ER -