Assessing nest attentiveness of Common Terns via video cameras and temperature loggers

• Published in: Avian Research
• Main Authors: Sullivan, Jeffery D., Marbán, Paul R., Mullinax, Jennifer M., Brinker, David F., McGowan, Peter C., Callahan, Carl R., Prosser, Diann J.
• Other Authors: U.S. Army Corps of Engineers, U.S. Geological Survey, University of Maryland, Maryland Department of Natural Resources, Maryland Environmental Service, Maryland Coastal Bays Program
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier BV 2020
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Common tern; Sterna hirundo
• Online Access: http://dx.doi.org/10.1186/s40657-020-00208-7; https://link.springer.com/content/pdf/10.1186/s40657-020-00208-7.pdf; https://link.springer.com/article/10.1186/s40657-020-00208-7/fulltext.html

Abstract Background While nest attentiveness plays a critical role in the reproductive success of avian species, nest attentiveness data with high temporal resolution is not available for many species. However, improvements in both video monitoring and temperature logging devices present an opportunity to increase our understanding of this aspect of avian behavior. Methods To investigate nest attentiveness behaviors and evaluate these technologies, we monitored 13 nests across two Common Tern ( Sterna hirundo ) breeding colonies with a paired video camera - temperature logger approach, while monitoring 63 additional nests with temperature loggers alone. Observations occurred from May to August of 2017 on Poplar (Chesapeake Bay, Maryland, USA) and Skimmer Islands (Isle of Wight Bay, Maryland, USA). We examined data respective to four times of day: Morning (civil dawn‒11:59), Peak (12:00‒16:00), Cooling (16:01‒civil dusk), and Night (civil dusk‒civil dawn). Results While successful nests had mostly short duration off-bouts and maintained consistent nest attentiveness throughout the day, failed nests had dramatic reductions in nest attentiveness during the Cooling and Night periods ( p < 0.05) with one colony experiencing repeated nocturnal abandonment due to predation pressure from a Great Horned Owl ( Bubo virginianus ). Incubation appeared to ameliorate ambient temperatures during Night, as nests were significantly warmer during Night when birds were on versus off the nest ( p < 0.05). Meanwhile, off-bouts during the Peak period occurred during higher ambient temperatures, perhaps due to adults leaving the nest during the hottest periods to perform belly soaking. Unfortunately, temperature logger data alone had limited ability to predict nest attentiveness status during shorter bouts, with results highly dependent on time of day and bout duration. While our methods did not affect hatching success ( p > 0.05), video-monitored nests did have significantly lower clutch sizes ( p < 0.05). ...