From the description, Great Horned Owl sounds more than possible.
(GHOs aren't gray and don't have white spots, per se, but it certainly
could have looked like that in a somewhat frenzied moment to someone who
isn't a birder.) GHOs are largely crepuscular hunters (ie, the hours
around dawn and dusk) and can easily take a chicken.
They're also slightly crazy in their intense lust to take prey, which
could explain the peculiar behavior refusing to be chased off. Most
raptors only expend the energy to go after prey when they need a meal,
but GHOs can't seem to resist doing it when they see an opportunity even
if they're stuffed to the gills with a recent kill and their crops are
bulging. If they're too full to eat it, they'll sometimes just rip the
head off the prey and fling it somewhere, then leave the corpse.
Yes, if it's a local bird and not one just passing through for some
reason, it could well come back after the chickens. Can't do much to
prevent that, but she might want to not have her chickens out
unsupervised too much, especially as dusk approaches.
On 11/6/2014 1:54 PM, Frances Delwiche wrote:
> Last week, I received an email from a friend asking about a strange
> bird encounter she recently had. She lives in rural Georgia/Milton,
> on a dairy farm where she raises a small flock of chickens. At about
> 5 pm on the last weekend of October, the chickens were out in the
> yard when she suddenly heard a huge ruckus among the flock. She ran
> over and saw a huge bird flying low trying to grab the chickens. It
> was light grey with white spots and large (probably 5ft?) wingspan.
> She thought it was a hawk, but another observer said it may have been
> an owl. She ran around screaming and chasing it away, but it kept
> coming back until she finally ran right up to it (probably about 10ft
> away); it was coming straight at her, head on, till finally it veered
> off and flew off toward the pasture. Her question is what could it
> have been, and will it continue to haunt her flock? It was seemingly
> prepared to carry off a full sized chicken.
> Any suggestions?
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