Date: 9/8/17 3:01 pm From: 'Denise Hamilton' <napabirders...> [northbaybirds] <northbaybirds-noreply...> Subject: Re: [NBB] Bodega Bay - Raving with Ravens
Glad you wrote about the Ravens at Pt. Reyes. We have seen that many, too. Sometimes at the water troughs at the dairy farms. I figured that it was NOT good to have so many around.
I’m curious as to why their population has exploded (on-going destruction of habitat?). We’ve been going to Pt. Reyes for years and certainly do not remember seeing so many of them in years past.
Denise & David Hamilton
From: Matt Lau <mjaylau707...> [northbaybirds]
Sent: Friday, September 8, 2017 1:05 PM
To: Steve Hutchcraft
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.
Snowy Plover Ecologist
Point Reyes Seashore Association/National Park Service
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. . . .
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:
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