Date: 7/31/20 7:52 am
From: Brian Tennessen <brian.tennessen...>
Subject: Re: [mou-net] Peregrine aggression on North Shore
Some follow up on the Falcon post I submitted last night after we did some
more digging online..

The falcons we observed were both juveniles, so we think this is a case of
sibling rivalry.

Or it could also be a case of something we read where they will do ‘mock
combat’ with one another as a form of practicing.

But what we observed seemed more aggressive and one sided, where the one
was always the instigator...

We read that sibling rivalry can get more intense when food is scarce, but
we observed some consistent successful hunting and the birds all appear
well fed and healthy to our untrained eyes..

I will have to see if I can find a way online to read reports on the
Tettegouche area Falcons...


On Thu, Jul 30, 2020 at 8:31 PM Brian Tennessen <brian.tennessen...>

> Hi, we are nearing the end of a week up on the North Shore, staying near
> Tettegouche. We walked out to Shovel Point hoping to see the Peregrines and
> on the way back were not disappointed. Up at the high point, where people
> rock climb, two Peregrines were involved in some aggressive behavior, or
> should I say it seems one was the instigator and the other was in a
> defensive posture. We’ve been observing this as an ongoing drama in the
> week we’ve been up here. We looked online a bit, and see that there can be
> aggressive behavior between Peregrine’s, but usually in the spring, when
> there may be competition for a nesting site, if a currently established
> bird is perceived to be weak, or aging.
> Or maybe this is a case of an adult telling a fledged youngster it’s time
> to move on and leave the area?
> I got some good photos of this drama which I cannot post right now since
> we do not have wireless where we are staying, but I can post when I have
> opportunity (I believe Tettegouche visitor center has access so could
> utilize that).
> I see that both of these birds are banded.
> I’m sure these Peregrines are monitored closely, just curious if anyone
> can tell us whether this is typical behavior for this time of year or is
> unusual?
> FYI, we were out to shore of Lake Superior predawn yesterday morning, to
> take in a sunrise, and as an added bonus got to observe the Peregrines
> hunting offshore. We watched one take a bat very nearby, so close you could
> hear the impact at the point of success. It took the bird several attempts,
> but it would circle around and come back for another attempt. Took about
> 4-5 tries in this case.
> Thanks for any educating knowledge any can pass on..
> Brian T.

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