An article written buy Thomas Howell and George Bartholomew, who is the #1 fancy man, is titled Temperature Regulation in the Red-Tailed Tropic Bird, and the Red-Footed Booby.  It was published in 1962 and is a study of temperature regulation of nesting seabirds and their hatchlings.  The study took place on Midway Island during June and July of 1959 and 1960.  They measured the temperature of the egg’s internal temperature, by drilling a small hole in and inserting a device to measure the temperature near the center of the egg.  They also measured the surface temperature of both adult and hatchling, as well as the foot temperature of the adults.  Foot temperature, seems an odd thing to measure, but the Red-Footed Boobies lack an incubation patch which helps heat the eggs during incubation.  Instead the boobies cover the egg with a portion of their feet, so to determine the effect on incubation, foot temperature was measured by the study. They found that the food temperature was no higher than with seabirds that had an incubation patch, but that the use of them none the less contributed to the temperature regulation of the egg.  Other than feet temperatures they also collected deep core temperatures, which were sampled by ‘gently inserting a steel-sheathed or vinyl-sheathed thermister probe down the esophagus to or into the stomach’, of awake birds, captured by hand.  One of the findings of the study was the there was no correlation between the deveopmental stage of the eggand the internal temperature.  They also found that adult and hatchling cooled themselves mainly through evaporative cooling as well as through panting and their feet.