Date: 9/8/17 1:34 pm
From: Matt Lau <mjaylau707...> [northbaybirds] <northbaybirds-noreply...>
Subject: Re: [NBB] Bodega Bay - Raving with Ravens
I just wanted to chime in about Raven numbers...

Here in Point Reyes it is not uncommon to observe anywhere between 40-70
Common Ravens on the beach or in the dunes, particularly between North
Beach and the Kehoe trail. And yes, they are a HUGE problem for nesting
Snowy Plovers. I'd venture to say they're one of the top reasons why SNPL
reproductive success is fairly low here and elsewhere up and down the
coast. I once counted 200 Common Ravens in the agricultural fields behind
Kehoe Beach!

CORA numbers have dramatically increased in the West in the last half
century, so I'm not terribly surprised by these observed numbers.

------------
*Matt Lau*
Snowy Plover Ecologist
Point Reyes Seashore Association/National Park Service
(e) <mjaylau707...> <mjaylau707...>
(c) 707-478-6264
https://www.linkedin.com/in/mattlau707



On Fri, Sep 8, 2017 at 9:08 AM, Steve Hutchcraft
<steve.hutchcraft...> [northbaybirds] <
<northbaybirds-noreply...> wrote:

>
>
> Hmmm. Unprecedented numbers of ravens staging near Bodega Bay. Didn't
> something like this happen 54 years ago? If I lived there, I might start
> thinking about boarding up the windows and closing the chimney flues. . . .
>
> Happy *Birds*!
>
> Steve
> Alamo, CA
>
> On Sep 8, 2017, at 7:32 AM, Dan Nelson <birdsurf64...>
> [northbaybirds] wrote:
>
>
>
>
>
> On Friday, September 8, 2017 7:29 AM, Dan Nelson <birdsurf64...>
> wrote:
>
>
> Hi Birders,
> On Wednesday Sept. 6 there were unprecedented numbers of Common Ravens
> staging on the coast near Bodega Bay. At one point, I counted 45 circling
> in the air at one time, over Bodega Head near Owl Canyon and Campbell Cove.
> At hour later, another large group was just W. of Valley Ford.
>
> While not a rare species, I thought this might be worthy enough to report
> NBBer's. Or maybe not.
>
> At any rate, I wanted to discuss the well-known "knocker" call, which is
> part of the regularly-heard repertoire given by CORAs - but slightly less
> frequent. This is a louder, very percussive version of a normal raven
> call, and transmits much further distances through open space,. This call
> is a very important component of Raven communication, and is often heard at
> places such as Bay Hill Rd., Jenner Headlands, or Marin Headlands. It is
> usually uttered aerially, in flight, and virtually always DOUBLED.
>
> CAUTION : A few of the CORAs I reported were youngsters, and have
> been heard giving their doubled, youngster version of the "knocker" call.
> These calls can be heard daily at Campbell Cove, Owl Canyon and vicinity if
> one puts in time to listen. DO NOT CONFUSE this call with the pre-song
> clucking of Yellow-billed Cuckoo. The large influx of CORAs may be
> associated with the explosion of Voles / Microtis #s on the coast, also
> attracting Barn Owls and others.... which keep the ravens squawking .
>
> Fun times, good birding
> - Dan Nelson, Sonoma County
>
>
>
>
>
>
>
>
>

 
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