Lafayette Reservoir birds
Tue, 10 Apr 2001 10:53:56 -0700
From: Maury Stern
Today there was a White-throated Sparrow in a flock of White-crowned and Golden-crowned Sparrows at the first rim trail access road between the parking lot and the office. There was a singing Cassin's Vireo just up the rim trail as well.
More exciting was the juvenile Bald Eagle that circled the reservoir for about an hour and swooped down once to try to catch a fish. The last report of the adult Bald Eagle was in mid-March.
Good birding,
Maury Stern
Redwood Regional Park, etc.
Thu, 12 Apr 2001 11:34:20 PDT
From: Anthony Fisher
Redwood Regional Park, Oakland Hills, April 11, 2001
When I left the house at 5:25 AM (dark) American Robins were singing. When I got to the park robins were not singing. I assume the street lights, etc., trigger their morning song early. Are the robins getting enough sleep?
Songs in the park:
Song Sparrow, 5:45 AM
Pacific-slope Flycatcher, Mourning Dove, Winter Wren, 5:50 AM
Spotted Towhee, 6:00 AM
Of course, Great Horned Owls (male and female) were going the whole time. At
one point, a Great Horned Owl was making a terrific coughing sound, like a large
dog with a foxtail in its throat mixed with a single hoot. It took me a while
to figure out what it was. Perhaps the owl was trying to pass a large pellet.
A lot of Warbling Vireos were singing. There were 3 Varied Thrush including
one on top of a pine tree singing its strange song for all to hear. This was
not the typical flighty, shy behavior you'd expect from a Varied Thrush, but
some fit of pre-breeding, gonad-induced machismo.
Pileated Woodpecker (Alameda County) was heard only today. A Red-breasted Nuthatch was clearing debris from an oblong, pileated-type hole in preparation for nesting. An Orange-crowned Warbler was collecting little strips of bark from the trunk of a toyon bush.
The others:
Canada Goose 2
Double-crested Cormorant 5
Turkey Vulture
Red-tailed Hawk
California Quail
Band-tailed Pigeon
Anna's Hummingbird
Allen's Hummingbird (nest)
Northern Flicker
Steller's Jay
Western Scrub-Jay
Common Raven
Chestnut-backed Chickadee
Oak Titmouse
Bewick's Wren
Ruby-crowned Kinglet (singing their necks out)
Wrentit
California Thrasher
Hutton's Vireo
Yellow-rumped Warbler
Wilson's Warbler
California Towhee
Golden-crowned Sparrow
Purple Finch
American Goldfinch
At Garin Regional Park in Hayward on Saturday April 7, I saw my first Black-headed Grosbeak of the season. Also, the Loggerhead Shrikes have young in the nest in their regular spot in the parking lot.
Anthony Fisher
Reply #1 Reply #2 Reply #3 Reply #4 Reply #5 Subject Index
Re: Great Horned Owl calls
Fri, 13 Apr 2001 08:41:34 PDT
From: Phil Gordon
Greetings Anthony,
Thanks for your nice account of some neat bird finding. The Great Horned Owl "coughing" was most likely the beginnings of a bird of the season = young Great Horned Owl getting its new voice. As a kid, when it was still legal, we raised a nestling Great Horned Owl and our owl went through this gruff period. It would often shake its head after calling as if this new vibration was some kind of irritation - which it was!
For the last three years we hear a "third" owl hooting (it's been a female from the higher pitch of the call) from the successful nesting of a pair down our canyon. But we're too far away from the branching site to hear the early "cough" calls.
Happy Birding, especially Owling!
Phil Gordon
Original Message Next Reply Subject Index
Re: Great Horned Owl calls
Fri, 13 Apr 2001 12:29:11 -0700
From: Don Lewis
Three years ago, I was trying to ascertain how to tell my backyard male from the female Great Horned Owls. Don't believe everything you read. For instance:
- Peterson's Western Birds says that the female's hoots are higher pitch and in a shorter sequence
- Peterson's Eastern Birds says that the female's hoots are lower pitch and in a longer sequence
- The Suttons, in How to Spot an Owl, say that the female's hoots are lower and briefer
- Stokes Bird Behavior Guide III says the female is higher
- Sibley says that the female is higher
- Tyler and Phillips say in Owls by Day and Night that the female is higher and briefer
- Armstrong, in Birds of Alaska says that the male is briefer
- In response to a BirdChat question, Sheri Williamson of the SE Arizona Bird Observatory said that from personal observation, the female has the lower pitch
- Also in response, Joe Morlan said that the primary literature says that the female is higher
- Another response said that in a book by Santa Barbara birder Margaret Miller, of the pair living in her yard, the male has the higher pitch
- Meg Pauletich, in her monthly bird column in the Contra Costa Sun, said that the male has the higher pitch
- Now, Phil Gordon on EBbird says the female is higher.
Whew! That adds up to 6 votes for the female being higher and 5 for the male, although the more expert opinion tends to higher but you have to ignore Williamson and the Suttons among others, not to mention RTPeterson in Eastern. Actually, I had another vote from a biology professor who said that the Suttons are right. If I counted that, it would be a tie.
Of the five sources mentioning length of call, the vote is three for the female being shorter and two for longer. Of the four which mention both pitch and length, there are three different combinations.
Everyone knows that the female is bigger. However, a friend in Colorado was awakened one night by a racket and watched a Great Horned Owl copulation on his back deck. He swears that the male was bigger. The pros, of course, will dismiss that sort of report. I suspect that the majority of the sex identifications are based on size. If there is any possibility that the conventional knowledge on size can sometimes be wrong, we might have an explanation for the varying correlations with pitch and sequence length.
Don Lewis
Lafayette, CA
Original Message Next Reply Subject Index
Re: Great Horned Owl calls
Fri, 13 Apr 2001 15:13:44 -0700
From: Tom Condit
The "baby" Great Horned Owl sounds like a cat of some sort growling and howling its defiance. I know that's not very precise. I've heard it twice. Once was at Big Sur in early July at night. We thought it was a bobcat. The second time was at the Kern River Preserve, also on a July night. The Nature Conservancy biologist there very kindly chummed it in for all of us to look at. It waddled up to the back porch to be fed, looking about as ungainly as could be, while continuing the growling and howling.
Original Message Next Reply Subject Index
Re: Great Horned Owl calls
Fri, 13 Apr 2001 17:05:15 PDT
From: Jim Tietz
Hi-
I have no idea which sex calls higher, but from listening to duets, the bird that calls higher typically has a longer call. The high caller usually has 6 notes and the low caller usually 4. The numbers can vary, but I have always found during a duet that the higher caller has more notes. There's probably exceptions though that I haven't heard yet.
One Great Horned Owl barking call that I am familiar with is the one that sounds more mammalian than avian. I tracked one bird down that was making these calls and watched it until it switched to the high six-note call. I think it was the 6-note call as I thought at the time that it was a female.
A juvenile call that I am familiar with has the quality of a Barn Owl screech, but is patterned more like a Short-eared Owl call "eee-er-eee" (no pauses) with the middle part lower than the ends.
It's hard to believe that nobody has watched color-banded birds hooting, and don't rehabilitated and crippled owls still call in captivity?
Jim Tietz
Original Message Next Reply Subject Index