[Tweeters] Owls & Flying squirrels

J. Acker owler at sounddsl.com
Wed Dec 5 19:42:40 PST 2007

I respectfully disagree with your assessment that "the only
worthwhile data we have" is the Breeding Bird Survey, especially in the area
of monitoring owl populations for long term trends.

The Breeding Bird Survey does a poor job of assessing owl populations or
trends. It is designed to assess diurnal passerine populations, not
nocturnal owl populations. Yes, Barred, Screech, and Great Horned will call
during the very early hours of the survey, but they certainly aren't
uniformly represented by the survey. Additionally, by the survey's own
standards, these species are in a "category (that) reflects data with an
important deficiency." - namely, a lack of data. Saw-whet Owls, known
breeders in the state, are not represented by any data. Does this mean that
their populations are stable or decreasing?

The Audubon Christmas Bird Count data, though not as scientifically
collected, shows a steady decrease in Western Screech-owl populations, a
very slight decreasing trend for Great Horned Owls, and Barred Owl
populations are increasing exponentially. Additionally, many long time
monitors of Spotted Owls and other owlers are noting similar trends.

But most importantly, observers such as Tweeter members, are seeing and
reporting information that is being mirrored in the Christmas Bird Counts,
and to discount this information as "not worthwhile" is to ignore the truth.

J. Acker
Bainbridge Island, WA
Owler at sounddsl.com

A voice unspoken (or unwritten) is a voice unheard.
Be heard!

-----Original Message-----
From: tweeters-bounces at mailman1.u.washington.edu
[mailto:tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Richard
Sent: Tuesday, December 04, 2007 9:06 PM
To: Stewart Wechsler; tweeters
Subject: [Tweeters] Owls & Flying squirrels


It is risky to generalize form local observations.

Checking the Breeding Bird Survey data, the only
worthwhile data we have, there is good data only on
Great Horned Owls in Washington. GHOW are doing fine
4.6% increase. The tiny sample of Western Screech Owls
shows no change. Barred Owl numbers are increasing
pretty much everywhere.

As to Flying Squirrels, put a floodlight on your
peanut butter and suet feeders at night, and watch for
them. They are surprisingly common. I've had a
family living above our Tahoe home for decades. They
eat out of my hand. I even petted one. Amazing


--- Stewart Wechsler <ecostewart at quidnunc.net> wrote:

> Since the newer immigrant Barred Owl has become

> common in our

> state over the last 10 years in many areas where

> there once were more

> Western Screech

> Owls, Spotted Owls as well as many other species

> that are preyed on by the

> Barred Owls, I'm interested in people's observations

> and thoughts on where

> Barred Owl prey species will survive due to their

> adaptation to some

> habitats that are not preferred by Barred Owls.


> While Western Screech Owls were relatively frequent

> 7 years ago through the

> wooded parks of West Seattle (the area I know best)

> and elsewhere in our

> area, the ones that I am

> aware of are now largely restricted to the steep

> wooded slopes above the

> Puget Sound. In Lincoln Park with both flats a

> steep (mostly) wooded slope

> above the Puget Sound, it seems that the Barred Owls

> are pretty much

> restricted to the flat areas. The one Screech Owl I

> heard there 2 years ago

> (at about sunset on Christmas Day) was calling from

> a relatively shrubby

> wooded steep slope above the Sound. I'm also told

> that the Spotted Owls are

> still surviving tend to be on steep slopes in their

> remaining old growth

> forest habitats, while the Barred may have wiped

> them out in the flatter

> areas of the remaining old growth forest.


> It seems that Barred Owls are better adapted to

> relatively flat wooded

> areas. I think especially medium age or older

> second growth, especially

> near fresh water (They often hunt at the water's

> edge). They may prefer

> being near some forest edge (that would include all

> urban wooded areas). I

> suspect that Screech Owls will accept both all of

> the habitats that the

> Barred are now occupying (they too like to hunt by

> water) as well as

> accepting steeper slopes and possibly earlier

> successional shrubby and

> young, denser woods, but now have largely been wiped

> out in the preferred

> Barred Owl habitats.


> It may be that the steeper slopes are less desirable

> habitats for Barred

> Owls or both species, but that the Barred Owls have

> not yet colonized these

> less desirable habitats. I had hoped that the

> Screech would find that part

> of their niche was less acceptable to Barred and

> that this would allow them

> to survive. I imagine that the smaller owls may be

> able to ascend and

> descend more quickly, making it easier to hunt on

> steep slopes. Their

> smaller size would also allow them to fly through

> denser shrubbery and

> younger trees.


> Are other people finding the Western Screech Owls

> (or Spotted Owls)

> surviving on steeper slopes and that Barred are

> largely absent from these

> habitats. Do you have other observations of

> differences in habitat that

> each of these species are adapted to and surviving

> or colonizing / not

> colonizing?


> Camp Long in West Seattle, where I lead some of my

> nature programs also used

> to have flying squirrels, though I only rarely got

> reports of them and was

> never lucky enough to see one myself. I question

> whether they can persist

> in relatively small islands of habitat such as city

> parks with so many

> Barred Owls raising their young in these isolated

> habitats. Any other

> obvservations related to the survival of prey

> species of Barred Owls, as the

> Barreds move into new territory would be welcome.


> It also seems that Great Horned Owls are declining

> in areas now occupied by

> Barred Owls, do others have observations that relate

> to this possibility?

> They would at least compete for some food, but I

> don't know how much that

> would be a factor if the Barred is indeed to some

> degree displacing Great

> Horneds.


> Stewart Wechsler

> Ecological Consulting

> West Seattle

> 206 932-7225

> ecostewart at quidnunc.net


> -Advice on the most site-appropriate native plants

> and how to enhance habitat for the maximum

> diversity

> of plants and animals

> -Educational programs, nature walks and field trips

> -Botanical Surveys


> No virus found in this outgoing message.

> Checked by AVG Free Edition.

> Version: 7.5.503 / Virus Database: 269.16.10/1159 -

> Release Date: 11/29/2007

> 11:10 AM





> No virus found in this incoming message.

> Checked by AVG Free Edition.

> Version: 7.5.503 / Virus Database: 269.16.10/1159 -

> Release Date: 11/29/2007

> 11:10 AM


> No virus found in this outgoing message.

> Checked by AVG Free Edition.

> Version: 7.5.503 / Virus Database: 269.16.10/1159 -

> Release Date: 11/29/2007

> 11:10 AM


> _______________________________________________

> Tweeters mailing list

> Tweeters at u.washington.edu




Richard Carlson
Full-time Birder, Biker and Rotarian
Part-time Economist
Tucson, AZ, Lake Tahoe, CA, & Kirkland, WA
rccarl at pacbell.net
Tucson 520-760-4935
Tahoe 530-581-0624
Kirkland 425-828-3819
Cell 650-280-2965
Tweeters mailing list
Tweeters at u.washington.edu

More information about the Tweeters mailing list