SWFL Eagles ~ M15 STARTLES Harriet Awake!! Alert Vocals! She Thinks The Owl Has Returned! 10.29.19

10/29/2019 1:19:27 PM

Lady Hawk - Harriet was sleeping on the nest again tonight and M had flown over to the west pasture to sleep. He returns at 12:29 AM and Harriet awakens suddenly in a defensive posture sounding alert vocals! She continues to vocalize & remains alert for three minutes before she retracts her wing and starts to relax. She is on high alert with her unihemispheric slow wave half brain sleeping and the other half awake watching for danger from the owl. Usually birds are ‘half-asleep’ – and birds choose which half dozes. Birds that are literally half-asleep - with one brain hemisphere alert & the other snoozing - control which side of the brain remains awake. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere shuts, while the wakeful hemisphere's eye stays open and vigilant. This has only been found in birds and some aquatic mammals such as dolphins, whales, seals, and manatees. Ornithology author Frank B. Gill: Birds exhibit three stages of sleep: slow-wave sleep, or SWF; intermediate sleep; and rapid-eye-movement sleep, or REM (as in mammals). Slow-wave sleeping requires the use of only one side of the brain at a time, a primary feature of bird sleep (Kavanau 1996; Rattenborg et al. 1999). This so-called unihemispheric sleep has been observed in 29 bird species belonging to 13 orders. Birds typically close their eyes when they sleep, but just one eye at a time for unihemispheric sleep. Unihemispheric sleep enables continued vigilance. Thus, an apparently sleeping duck watches for predators with one eye open and sleeps with the other eye closed. REM sleep takes place with both eyes closed. Very short and frequent bouts of REM sleep are a feature of sleep in the birds. Quick bouts of REM sleep combined with (one-eyed) unihemispheric sleep enable birds such as Scooty Terns and swifts to sleep on the wing. Thank you for watching! Video captured & edited by Lady Hawk Thank you SWFEC , hosted by Dick Pritchett Real Estate, for allowing us the opportunity to view these amazing eagles. Watch live: https://www.dickpritchettrealestate.com/eagle-feed.html