2 questions

[Dave Tucker]

Birders,  Have often wondered whilst watching hawks on Mt Agamenticus, how far away is that Kestrel that is at the limit of my 8 power binoculars.  Is it a mile, a half mile?  A goldfinch disappears a few hundred yards away.  An eagle, clearly, can be seen much farther away.  So is there a formula or a quotient or one of those math things that can give one an inkling into the distance at which an object of x size eludes viewing?

 

Secondly,  yesterday on Mt. A I watched a “kettle” of gulls roiling over the forest.  They weren’t over water, and they didn’t rise very high at all. But the kettle did sort of wander back and forth over a limited area, and they did so for a couple of hours.  I’m interested to know if anyone else has seen this kind of behavior?

 

Thanks,  Dave

 

Kittery Point

[Stan DeOrsey]

Good first question, I would like to know too.

As for kettles of gulls ... food ... I have seen such behavior over dumps, burns of various types (usually smoke is visible too), and some type of food processing plant with vented odors or actual dumped remnants, even just an active farm.

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[Bill Hancock]

Here’s a helpful reference to the distance question:

https://sora.unm.edu/sites/default/files/journals/auk/v054n01/p0096-p0097.pdf

Bill Hancock

On Mar 28, 2021, at 9:43 AM, Dave Tucker <dhtu...@comcast.net> wrote:



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[David Gulick]

Derek and/or Jeanette, Could your provide input on distance identification from your hawk watches? Thx David

Sent from my iphone with auto incorrect activated  :-)

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[AMF]

Good question.  I have thought about this as well.

I am not an expert in birding, but I observed that "kettle" of behavior over the Flood Farm in Clinton when the Golden Eagle was around.  The birds do not get freaked out by Bald Eagles.  They sure know they got freaked out by a Golden Eagle at the Flood Brothers Farm.  I wonder if a Golden Eagle was in the area. 

The gulls over a fire probably like to ride the updraft from the fire. 

Gulls doing this over open water are often an indicator that there is a school of fish like Blue Fish killing a lot of small fish.  The dead minnows attract the gulls. 

Allan

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[Boots.]

I have seen huge flocks of mixed gulls "kettling" over ant hatches. Usually once or twice a season in my area of Hancock County there will be a huge hatch of winged ants. The gulls go crazy for hours, feeding.

~Boots.