On Wednesday we as a class had the opportunity to learn from National Geographic Explorer Anusha Shankar by joining her livestream. During the stream, she explained a little bit about the work she had accomplished and what she was currently working on. Anusha explained how she had studied hummingbirds to learn more about animal energy conservation. Because of their size, hummingbirds are not able to store much energy. All the sugar they take in from nectar and sugar water is spent almost immediately. During the day, hummingbirds are constantly feeding, and therefore have no problems with their energy levels. However, if a hummingbird goes two or three hours without eating, it will die. How, then, is it possible for these birds to survive the nights? To investigate this phenomenon, Anusha moved to Ecuador to study the hummingbirds in the Andean mountains. After months of research, she and her team found that hummingbirds enter a state called torpor at night, which is deeper than sleep. Their temperatures drop to the temperature of their surroundings and their heartbeats slow significantly. Essentially, hummingbirds can switch from being warm to cold blooded.
After her work with hummingbirds, Anusha moved to Alaska to study grass rats. As it turns out, grass rats have much in common with humans, and Anusha wanted to study the effects of less light on human mental health. Seasonal affective disorder, or seasonal depression, is common in many people in the shorter days of the winter months. Less exposure to sunlight can make many people severely depressed, and is a widespread occurrence. There are currently not many treatments, although there is an experimental one called the Lightbox. The concept is to turn on a bright source of light that provides the same nutrients and energy that the sun usually would. In addition, there is research being done surrounding serotonin treatments, which would bolster the brains production of the chemical.
I was very interested by what Anusha had to say about seasonal affective disorder, because I had never thought seasonal depression was such a serious and widespread phenomenon. I had noticed it within myself, feeling more stressed and sad during shorter days and happier during the long days, but I had never thought it could be linked to science. Hearing that people like Anusha are studying how day length affects rats makes me want to learn more about how different abiotic factors can influence our behavior and feelings.
Hummingbird. Photography. Britannica ImageQuest, Encyclopædia Britannica, 25 May 2016.
quest.eb.com/search/149_2097292/1/149_2097292/cite. Accessed 9 Feb 2020.
NILE RAT. Photography. Britannica ImageQuest, Encyclopædia Britannica, 25 May 2016.
quest.eb.com/search/138_1081687/1/138_1081687/cite. Accessed 9 Feb 2020.