{"id":10713,"date":"2023-11-27T13:13:24","date_gmt":"2023-11-27T19:13:24","guid":{"rendered":"https:\/\/www.elfruler.com\/?page_id=10713"},"modified":"2024-10-04T10:17:45","modified_gmt":"2024-10-04T15:17:45","slug":"photoperiodism-and-life-history","status":"publish","type":"page","link":"https:\/\/www.elfruler.com\/?page_id=10713","title":{"rendered":"

PHOTOPERIODISM and REPRODUCTION TIMING<\/strong><\/p>"},"content":{"rendered":"

\u00a9 elfruler 2023<\/p>\n

PHOTOPERIOD, CIRCADIAN RHYTHMS, and CIRCANNUAL RHYTHMS<\/strong><\/h4>\n

Most viewers of Bald Eagle nest cams are aware of how important photoperiod<\/a><\/span>, circadian<\/a><\/span> rhythms, and circannual<\/a><\/span> rhythms are in the lives of birds. They are fundamental to how eagles\u2019 behaviors and physiological processes engage with the environment around them. This article provides information about what these systems are and how they work, and it explores some of the complexities of how they govern the processes of the Life History of Bald Eagles<\/a>.<\/p>\n

The photoperiod<\/a><\/span><\/strong> is the timespan of sunlight within a 24-hour day, usually called daytime or daylight. Its counterpart is the scotoperiod<\/a><\/span><\/strong>, the timespan of darkness, or nighttime. As everyone knows, the photoperiod<\/a><\/span> and scotoperiod<\/a><\/span> change from one day to the next following an annual cycle<\/a><\/span>, and they also vary by latitude (location on the earth north or south of the equator). Changes in photoperiod<\/a><\/span> and the seasons of the year are caused by the Earth\u2019s tilt on its axis<\/strong> by about 23.5\u00b0and its revolution around the sun<\/strong> every 365.4 days. In the Northern Hemisphere<\/strong> during the winter months<\/strong> the North Pole tilts away from the sun, making the sun lower in the sky and the daytimes short. During summer<\/strong> the North Pole tilts toward the sun, which thus is higher in the sky and the daytimes are long.<\/p>\n