title: As the egg turns: monitoring egg attendance behavior in wild birds using novel data logging technology.
abstract: Egg turning is unique to birds and critical for embryonic development in most avian species. Technology that can measure changes in egg orientation and temperature at fine temporal scales (1 Hz) was neither readily available nor small enough to fit into artificial eggs until recently. Here we show the utility of novel miniature data loggers equipped with 3-axis (i.e., triaxial) accelerometers, magnetometers, and a temperature thermistor to study egg turning behavior in free-ranging birds. Artificial eggs containing egg loggers were deployed in the nests of three seabird species for 1-7 days of continuous monitoring. These species (1) turned their eggs more frequently (up to 6.5 turns h(-1)) than previously reported for other species, but angular changes were often small (1-10° most common), (2) displayed similar mean turning rates (ca. 2 turns h(-1)) despite major differences in reproductive ecology, and (3) demonstrated distinct diurnal cycling in egg temperatures that varied between 1.4 and 2.4 °C. These novel egg loggers revealed high-resolution, three-dimensional egg turning behavior heretofore never measured in wild birds. This new form of biotechnology has broad applicability for addressing fundamental questions in avian breeding ecology, life history, and development, and can be used as a tool to monitor birds that are sensitive to disturbance while breeding.
authors.affiliation: San José State University, Department of Biological Sciences, San Jose, California, United States of America.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Shaffer
authors.affiliation: San José State University, Department of Biological Sciences, San Jose, California, United States of America.
authors.forename: Corey A
authors.initials: CA
authors.lastname: Clatterbuck
authors.affiliation: San José State University, Department of Biological Sciences, San Jose, California, United States of America.
authors.forename: Emma C
authors.initials: EC
authors.lastname: Kelsey
authors.affiliation: Stanford University, Department of Aeronautics and Astronautics, Stanford, California, United States of America.
authors.forename: Alex D
authors.initials: AD
authors.lastname: Naiman
authors.affiliation: Pacific Rim Conservation, Honolulu, Hawaii, United States of America.
authors.forename: Lindsay C
authors.initials: LC
authors.lastname: Young
authors.affiliation: Pacific Rim Conservation, Honolulu, Hawaii, United States of America.
authors.forename: Eric A
authors.initials: EA
authors.lastname: VanderWerf
authors.affiliation: Point Blue Conservation Science, Petaluma, California, United States of America.
authors.forename: Pete
authors.initials: P
authors.lastname: Warzybok
authors.affiliation: Point Blue Conservation Science, Petaluma, California, United States of America.
authors.forename: Russell
authors.initials: R
authors.lastname: Bradley
authors.affiliation: Point Blue Conservation Science, Petaluma, California, United States of America.
authors.forename: Jaime
authors.initials: J
authors.lastname: Jahncke
authors.affiliation: Stanford University, Department of Aeronautics and Astronautics, Stanford, California, United States of America.
authors.forename: Geoff C
authors.initials: GC
authors.lastname: Bower
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000818:Animals; D000835:Animals, Wild / Q000502:physiology*; D001717:Birds / Q000502:physiology*; D002940:Circadian Rhythm; D060306:Magnetometry / Q000379:methods*; D009425:Nesting Behavior / Q000502:physiology*; D010063:Ovum / Q000502:physiology*; D013045:Species Specificity; D013696:Temperature; D013997:Time Factors