Tuesday, January 7, 2014

Dark-eyed Juncos and Their Eyesight

I have long wondered if Dark-eyed Juncos can see better than other small passerines.  We have a spotlight that shines over our back deck and throw out seed each night so that birds have food at sunrise.

At 4:00 am on two recent mornings, I noticed a flock of 60+ Dark-eyed Juncos eating seeds for about 30 minutes on the lit porch.  The next morning, I kept the porch light off.  The Dark-eyed Juncos did not come to eat until about 6:30 am when civil twilight reflecting off the snow made it visible enough for me to watch them (for them to see?).

The next morning with porch light on, they returned at 4:11 am gobbled up the seed.

House Sparrows and House Finches do not come by until almost sunrise or well after on most mornings.

So do Dark-eyed Juncos have better eyesight?  They do live in darker habitats/woods and kick around for food under evergreen trees blocking sunlight.  Have they adapted for this?  It is worth doing some research when time permits.

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