Re: Moths can see star patterns with their compound eyes

On 2025-06-19 6:19 p.m., RonO wrote:

On 6/19/2025 5:59 PM, Bob Casanova wrote:

On Thu, 19 Jun 2025 16:17:31 -0500, the following appeared
in talk.origins, posted by DB Cates <cates_db@hotmail.com>:
>

On 2025-06-19 2:47 p.m., RonO wrote:

On 6/18/2025 11:25 AM, RonO wrote:

https://www.nbcnews.com/science/science-news/moths-fly-600-miles-
particular-series-mountain-caves-scientists-think-rcna213703
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This is a sort of crazy science news article.  This one inch long moth
breeds in the hot lowlands of Australia, but the larva grow up and
become adults and then migrate 600 miles to caves in the Australian
alps.  They can sense the magnetic field of the earth, but it has been
discovered that they use star patterns to navigate to the caves.  They
can project star the southern star pattern in a flight chamber and the
moths will adjust their course dependent on how the star pattern is
oriented.  They don't know which direction to go if shown a random
pattern.
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They not only have to be able to interpret star patterns with their
compound eyes, but using the existing pattern has to be instinctive.
They may have only made the previous migration as sperm and egg cells.
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They have to figure out what the moths can see so that they can start
to figure out the genetics that resulted in flying in the right
direction based on that observed pattern.
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Moths have very small brains, but they obviously have very good visual
interpretive skills and can act on those interpretations.
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Ron Okimoto
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https://www.linkedin.com/pulse/fascinating-world-moth-vision-how-eyes-
help-them-navigate-gemmell
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Article on the low light sensitivity of moth eyes.  From other articles
compound eyes are good at detecting motion, and obtaining a broad
perspective (the night sky), but are not very good at fine details, but
they must be able to detect star patterns in a pretty crowded night sky.
   In Australia the milky way stretches across the night sky.
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Ron Okimoto
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My immediate thought (no evidence) is they may detect the orientation of
the milky way.
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Possibly; according to the article that's what at least some
of them suspect.

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It is the biggest structure in the sky besides the sun and moon that would be at different positions during a 24 hour day, but how do they translate that swath of brightness that would occur at a specific angle in the sky with what direction to go.  That visual cue has to trigger a desire to move in a certain direction when it becomes visible at night. I've seen timelapse pictures of the night sky in the Southern hemisphere and the movement is circular instead of from east to west like in the Northern hemisphere, but maybe you have to be further south to see the circular movement.  The angle of the milkyway should change during the night.
 Ron Okimoto
 

Umm, the relative amount of the sky that appears to move circularly vs east to west depends on your latitude. At the equator, *everything moves strictly east to west. At the north pole, face south (ha) and the whole sky rotates counterclockwise. At the south pole, face north (again ha) and the whole sky rotates clockwise.
The motion of the earth around the sun means that the position/orientation of the stellar objects are different at particular times of night at different times of the year. A combination of time and orientation can determine a direction. All of this would have to be able to change slowly over time to accommodate the procession of the earth's axis.
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Don Cates ("he's a cunning rascal" PN)