Thursday, September 15, 2022

Let's Talk About . . . Nature and the Night Sky

Note:
What follows is informational material that Sue has developed for the North Central Arkansas Master's Naturalist's "Let's Talk" table at Arkansas' First Dark Sky Party on the Buffalo National River, Oct. 21 - 22, 2022.
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Let’s LEARN about Human Health and the Dark Sky!

  • Circadian rhythms are physiological changes affected by the 24 hour cycle of light and darkness.
  • “Night owls” and “Early birds” experience slight shifts in their genetic adaptation to their circadian rhythms.
  • Our hypothalamus is a small area in the brain behind the eyes that regulates our genetic “biological clock” in response to the circadian rhythms of night and day.
  • Dusk signals the production of melatonin via the hypothalamus signalling the pineal gland; it encourages drowsiness for the sleep cycle. The morning light activates the hormone cortisol, which alerts us to activity for the day ahead.
  • Humans can experience depression, sleep disorders, and changes in eating habits when artificial lighting at night disrupts our genetically controlled biological clocks.
  • Scientists are exploring evidence that even sleeping in a room exposed to light pollution may increase body fat and the risk of diabetes.
  • LED lighting emits high temperature “blue” spectrum light, which interferes with the production of melatonin. To avoid sleep disruption, avoid bright lighting after dusk and use electronic devices with a “night shade” setting.
The Pineal Gland and Melatonin


Let’s WATCH VIDEOS about Human Health and the Dark Sky!


A Study of the Human Response to our Biological Clocks.
https://www.youtube.com/watch?v=BKQH6T1DZvI
How Circadian Rhythms Can Affect Your Weight and Health
https://www.youtube.com/watch?v=ho4sNQPBXMc&list=PL5TLzNi5fYd9_fKTUsJAannC63hLGmOpX&index=5
Chromosome 10 - What regulates our body clock?

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Let’s LEARN about Birds and the Night Sky!

  • 70% of North American birds are migratory—and 80% of those fly at night.
  • Most depend on the dark sky to navigate with the moon and stars.
  • Birds can be disoriented by artificial light beacons, and can circle until worn out, or vulnerable to predators.
  • Night light pollution increases bird collisions with other birds, buildings, and signs.
  • The four North-South migratory flyways in the U.S. are the Pacific, the Central, the Mississippi, and the Atlantic—----and each have different urban dark sky obstacles.
  • The “Lights Out Program” during the spring and fall migratory seasons is gaining public awareness in more American cities.


Let’s READ more about Birds and the Night Sky!


“What you should know about Bird Migration and Light Pollution”
https://www.darksky.org/what-you-should-know-about-bird-migration-and-light-pollution/
Lights Out Programs for Cities in North America
https://www.audubon.org/conservation/existing-lights-out-programs


Let’s WATCH VIDEOS about Birds and the Night Sky!


Lights Out for Migratory Birds in Texas
https://www.youtube.com/watch?v=_FEzCj5npiI&list=PLI3sHpSFmf1UrG0quQxcZZATADMeabhR3&index=1
University of Delaware Explores how Light Pollution Affects Migrating Birds
https://www.youtube.com/watch?v=9pJlMqCFHj8
Birds and Artificial Light At Night: An Overview
https://www.youtube.com/watch?v=kdMnztQSDvg
CornellLabs Live Birdcast Migration


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Let’s LEARN about Insects and the Dark Sky!


  • Insect populations are threatened by habitat loss, pesticides, water quality . . . and light pollution.
  • 50% of flying insects are nocturnal, exhibiting a “flight to light” response to outdoor lighting sources.
  • Moths, butterflies, and bees can lose their navigational cues and become exhausted while orbiting exterior lights and bright windows. . . .and they are also spotlighted for predators.
  • Fireflies use their flashing luminescence to attract mates and outdoor lighting disrupts their courtship signals.
  • Some insects (mosquitoes, bed bugs, and some beetles) can see infrared light giving them an advantage over their prey at night!

Let’s READ more about Insects and the Dark Sky!


“The Devastating Role of Light Pollution in the “Insect Apocalypse”
https://www.smithsonianmag.com/smart-news/light-pollution-contributes-insect-apocalypse-180973642/
“Light Pollution from Street Lights Linked to Insect Loss”
https://www.bbc.com/news/science-environment-58333233
“When Fireflies Await a Night that Never Comes”
https://www.nytimes.com/2022/08/11/science/firefly-light-mating.html
"Infrared Vision"
https://education.nationalgeographic.org/resource/infrared-vision

Let’s WATCH VIDEOS about Insects and the Dark Sky!


“Light Pollution is One of the World’s Biggest Buzzkills”
https://www.youtube.com/watch?v=BGg0Wz671Z8
“Reducing Light Pollution at Night is a Simple Way to Help Insects”
https://www.youtube.com/watch?v=q7M77BSEwP0

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Let’s LEARN about PLANTS and the Night Sky!

  • Plants rely on a 24 hour circadian cycle, using daylight hours for photosynthesis, and nighttime hours to signal the metabolic changes needed for seasonal survival.
  • Artificial Light At Night (ALAN) can range from the low intensity sky glow of distant cities to the high intensity of urban and suburban all night lighting.
  • High intensity night light (i.e. street lights) can trigger longer periods of photosynthesis. In some species of grasses this can accelerate growth, but in other grasses it stunts growth.
  • Artificial lighting at night can disrupt the life cycles of insects with their host plants, resulting in a mismatch of the timing necessary for pollination.
  • Nocturnal plants need darkness to activate blooming. Artificial night lighting can prevent blooming and thus the necessary pollination for reproduction.
  • Artificial night lighting can delay the onset of deciduous fall leaves, thus weakening the protection that dormancy provides for the winter season ahead.
  • ALAN can also disrupt the photoperiod signals for spring budding, risking early growth that endangers the plant’s growth and survival.

Let’s READ more about PLANTS and the Night Sky!


“Ecological Effects of Artificial Light at Night on Wild Plants”
https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.12551
“Light Pollution is Disrupting the Seasonal Rhythms of Plants and Trees
https://arstechnica.com/science/2022/07/light-pollution-is-disrupting-the-seasonal-rhythms-of-plants-and-trees/

Let’s WATCH VIDEOS about PLANTS and the Night Sky!


“Sunlight vs. Artificial Light in Plant Growth
https://www.youtube.com/watch?v=Xz4XfheXZc8



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Let’s LEARN about Wildlife and the Night Sky!

  • Many animals, such as birds, sea turtles and even dung beetles, use the moon and the stars to navigate at night.
  • Artificial night lighting can disrupt mating signals for frogs and insects, and increase the exposure of all nocturnal wildlife to predators.
  • Birds can be disoriented by artificial light beacons, circling endlessly until exhausted, and increasing bird collisions with other birds, buildings, and signs.
  • The four North-South migratory flyways in the U.S. are the Pacific, the Central, the Mississippi, and the Atlantic—-and each have different urban dark sky obstacles.
  • The “Lights Out” program during the spring and fall migratory seasons is gaining public awareness in more American cities.
  • Pit Vipers and Vampire Bats see the infrared light emitted by their prey.

Let’s READ more about Wildlife and the Night Sky!


“Light Pollution Effects on Wildlife and Ecosystems”
https://www.darksky.org/light-pollution/wildlife/
“The Moon and the Stars are a Compass for Nocturnal Animals. . . “
https://theconversation.com/the-moon-and-stars-are-a-compass-for-nocturnal-animals-but-light-pollution-is-leading-them-astray-142301
“What You Should Know about Bird Migration and Light Pollution”
https://www.darksky.org/what-you-should-know-about-bird-migration-and-light-pollution/
"Moonlight Guides Dung Beetle Activity at Night"
"They Can See the Blood Running Through You"


Let’s WATCH VIDEOS about Wildlife and the Night Sky!


“Light Pollution and its Impact on Birds and Wildlife”
https://www.youtube.com/watch?v=ooLYWwA43SE&t=19s
“Birds and Artificial Light at Night: An Overview”
https://www.youtube.com/watch?v=kdMnztQSDvg
"Heat Seekers: Harnessing the Infrared Senses of Animals"
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