How do animals know when to start preparing for winter?
NPS / Jacob W. Frank
It’s not just from memory of years past—even young born that spring, who have never seen a winter, know to start readying. For many animals the answer lies in a part of the brain known as the pineal gland.
The pineal gland, which receives light information from the retina, produces melatonin only when it’s dark. As nights grow longer during the fall, melatonin will accumulate in the bloodstream. The increased melatonin levels trigger a series of changes, including the autumn molt.
Most animals have an autumn molt, replacing their fur or feathers before winter. The new coat will usually be thicker and warmer, some animals even double the thickness of their underfur when molting.
For birds the molt results in fresh flight feathers for migration. A few animals, like the short-tailed weasel (pictured above), even change color during the molt, exchanging their brown summer coat for a white winter one!
The molt happens in a set sequence, with side to side symmetry, even though it can appear quite random. Mink, for instance, always molt starting at the tail and ending at their head.
There’s an evolutionary advantage to looking mottled during the fall when the ground may be sparsely covered with snow. During this time, an animal would not want to be pure white or pure brown. Matching the ground, they’ll have a smattering of each.
Autumn is not simply a time of death and decay; look beneath the surface and resilient life is active as ever, undergoing impressive and fascinating changes!
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Leave No Trace Principle #3: Dispose of Waste Properly♻️
Pack it in, pack it out! This saying is common among backcountry hikers, but is good advice for everyone. Whether you’re hiking or relaxing, be sure to properly dispose of all trash and food scraps. (1/4)
While it may be tempting to toss apple cores, banana peels, and orange peels on the ground, they do not decompose well in many places.
They may get eaten by wildlife, and potentially cause harm to the animal or contribute to habituation. (2/4)
If you see trash where it shouldn't be, please pick it up!
It takes everyone to keep the 🌏 clean. (3/4)
What runs but never walks, murmurs, but never talks, has a bed but never sleeps, and has a mouth but never eats?
... a river! 💧
When you watch the crystal-clear rivers and creeks of Glacier, they seem to have a life of their own.
Thanks to melting snow, creeks and rivers flow fast in the spring—their water level rises, and they run brown with debris. As snowpack diminishes late in the summer, some creeks dry up entirely, and rivers shrink back to reveal their rocky shores.
At first glance, it may look like trees lined up against a vibrant sky. But hold on, is that a reflection?
This photo shows off a delightful phenomenon—rock flour—responsible for the color of many of Glacier's lakes and streams.
What is rock flour?
To answer that, you have to start with Glaciers. Glaciers are distinguished from other bodies of ice by the fact that they move. As they move, they grind and scrape the ground beneath them, pulverizing rock into particles so small they resemble flour.
When this flour-like substance finds its way to water, it gets suspended throughout and is very slow to sink.
How does rock flour turn a lake blue?
While rock flour is a terrible gluten-free alternative when baking, it excels at reflecting turquoise and blue light.