Migration: Birds, amongst other animals, are dependent on the sun for regulating biological rhythms such as the chemical changes in the brain responsible for rest, a process known as Zeitgeber. One of these chemicals is melatonin which is responsible for sleep. This is why moving to areas with different solar times results in fatigue or jet lag. The Lapland longspur however, encounters an issue every year during migration. Each spring they head to the Arctic to breed, during this time of year, the sun is out roughly twenty four hours a day. To adapt to this, Lapland longspur, amongst other arctic breeding birds use different cues when up north. Instead of relying on the sun’s position in the sky, the chemical processes are instead dependent on the amount of available light and temperature change. This switch in cues only happen when they are in the Arctic however.
Sources:
Ashley, Noah T., et al. "Revealing a Circadian Clock in Captive Arctic-Breeding Songbirds, Lapland Longspur (Calcarius lapponicus), under Constant Illumination." Sage Journals, Journal of Biological Rhythms, Dec. 2014, journals.sagepub.com/toc/jbra/29/6. Accessed 20 Jan. 2023. "Lapland Longspur." All About Birds, The Cornell Lab, 2023, www.allaboutbirds.org/guide/Lapland_Longspur/maps-range. Accessed 20 Jan. 2023. |