A Façade of Science: An analysis of the Jack Ward Thomas
report, based on sworn testimony of members of the Thomas Committee.
A report for the Association of O & C Counties & the Northwest
Forest Resource Council.
(Note: The reading of this report is tedious. Please endure it; if
you want to know the truth, this is your opportunity. The Forest Service
and the U.S. Department of Fish & Wildlife, at all levels of decision
making about the policy of our forest management in regard to the
spotted owls, have quoted the Thomas report. After the release of
this report, which we print with the permission of Northwest Forest
Resource Council, (all such agencies) should become null and void.)
By Preston, Thorgrimson, Shindler, Gates and Ellis
In May of 1991 the Interagency Scientific Committee to Address the
Conservation of the Northern Spotted Owl (commonly called the "Thomas
Committee" or "ISC") issued its report recommending
a conservation strategy to maintain a viable population of spotted
owls in Washington, Oregon and California. The report recommended
that seven million acres of federal land in the three states be set
aside as habitat conservation areas (HCA's) for spotted owls, most
of which are to be large enough to provide habitat for at least 20
pairs of owls and are to be no more than 12 miles apart from each
other. No timber harvesting is permitted within the HCAs. Intervening
federal timber lands are to be managed under a "50-11-40"
rule in which 50% of each quarter township of federal land must at
all times contain trees averaging 11 inches in diameter at breast
height and 40% canopy closure.
Between February and May, 1991 five of the six members of the ISC
gave sworn testimony in the spotted owl lawsuit known as Portland
Audubon Society v. Lujuan (The head of the Agricultural Department
at that time) and Seattle Audubon Society v. Robertson (the US Forest
Service Chief at the time). Committee members Jack Ward Thomas, Jared
Verner, Eric Forsman, Barry Noon and Joseph Lint each testified under
oath in depositions and Portland Audubon v. Lujuan. Drs. Thomas, Verner,
Forsman and Noon also testified under oath in depositions in Seattle
Audubon v. Robertson. Dr. Thomas, Verner and Forsman testified in
person before Judge Dwyer in Seattle Audubon Society v. Robertson.
The sworn testimony of these scientists reveals that the ISC Strategy
is primarily the product of subjective personal judgment of the members
of the Committee rather than an objective scientific product based
on verifiable facts, reliable data or recognizable scientific theory.
In large measure the ISC Report presents a facade of science to create
the appearance that the ISC Strategy is firmly grounded in objective,
verifiable science when in fact it is not. Every component of the
ISC Strategy is primarily the product of the "professional judgment"
of the members of the Committee. This judgment is untested, unexplained
and represents, in the words of one committee member, a "management
exercise" rather than a scientific effort.
This does not mean that the ISC Strategy is necessarily wrong or fatally
flawed. It means simply that the aura of an objective science which
has been cast over the ISC Report in not justified, and should not
inhibit close scrutiny of every component of the ISC Strategy by policymakers,
administrative officials and legislators who must make the ultimate
legal decision as to whether the ISC Strategy should be adopted and
implemented by the Forest Service, the Bureau of Land Management,
or the Fish and Wildlife Service.
II. HOW THE ISC OPERATED
The ISC did not keep any minutes, notes or other documentation of
its discussion in the period of October 1989 - March 1990 during which
it prepared its conservation strategy. (Noon, p. 64) Thus, it is impossible
to recreate the actual analytical process, which led to the ISC Strategy.
Further, the Committee did not retain the raw data, which it analyzed
in developing the strategy. Rather, each Committee member that supplied
data simply retained that data in his own office. (Noon p. 29) The
Committee members made no effort to verify whether each other's data
was correct, but simply accepted it as true. (Noon p. 25) However,
when Dr. Forsman, who supplied large quantities of data to the Committee
was asked in his deposition to verify his own calculations, which
were used by the Committee, he was unable to do so. (Forsman p. 13,
p. 213) He explained that he would have to return to his lab to attempt
to verify the data, and even then was not sure he would be able to
do so. (Forsman p. 14, p. 109)
In the absence of documentation of the ISC deliberations, the only
available source of information is the recollections of the Committee
members describing the process followed by the Committee. The ISC
members who testified uniformly identified four sources of information
which were relied on in the development of the strategy empirical
data, scientific theory, computer models and professional judgment.
(Verner p. 45, Thomas p. 97, Noon p. 57) All four sources were equally
important to the Committee. (Verner p. 46)
The Committee did not look to any of these sources of information
to prove the validity of a particular conservation strategy. Rather,
it viewed its proposed conservation strategy as a hypothesis, and
it used each of the four sources of information to attempt to disprove
the conservation strategy would succeed. (Thomas p. 97, Verner p.
97) This approach reflects the common scientific view that scientists
can never prove anything; they can simply disprove on hypothesis by
showing that it is contradicted by existing fact. (Thomas p. 202)
This approach had enormous impact on the process followed by the Committee.
The Committee acknowledged that there is virtually no statistically
reliable, relevant, demographic data on any of the vital behaviors
of the spotted owl (birthrates, reproduction rates, longevity, mortality
rates). (Verner p. 179) This lack of data should have made it difficult
for the Committee to come up with a reliable plan. However, by using
the empirical data merely to attempt to disprove the validity of its
hypothesis, the Committee minimized the absence of data by finding
that the lack of data simply failed to disprove its hypothesized conservation
The importance of this process is that the Committee could have developed
a much different conservation strategy and the empirical data would
equally have failed to disprove the validity of that strategy. It
could have proposed considerably smaller HCAs considerably farther
apart and the empirical data would no more have disproved the validity
of that approach than of the approach ultimately recommended by the
ISC. The absence of reliable data became significant to the Committee,
although it should have been central to recognizing the limits of
the Committee's ability to develop a valid spotted owl plan.
Likewise, the absence of recognized scientific theory (a "theory
is a hypothesis which has been sufficiently tested and validated over
time to become generally recognized as true) also should have inhibited
the ISC from developing long-term conservation plans. Instead, the
absence of relevant scientific theory merely failed to disprove the
particular conservation strategy the Committee developed.
Equally, the highly questionable nature of the population simulation
models developed by the Committee should have been a further reason
for it to hesitate to develop a long-term conservation plan, but instead
the weakness of the models merely resulted in failing to disprove
the proposal developed by the Committee.
III. HOW THE COMPONENTS OF THE ISC STRATEGY WERE DEVELOPED
A. Size of HCAs. The single most important component of the ISC Strategy
is the requirement for the creation of so-called "Category 1
HCAs" large enough to hold at least 20 pairs of spotted owls.
The vast majority of the seven million acres of federal land included
within protected areas under the ISC Strategy is within Category 1
HCAs. No valid empirical data.
The Committee "had no studies of owls" to indicate how large
each HCA should be in a system composed of many HCAs in order to minimize
the risk that every HCA will lose its owl population and the species
will go extinct. (Verner p. 179)
Lacking such direct empirical data, the ISC instead looked at studies
of other large-bodied birds like ravens (The spotted owl is considered
a large-bodied bird). (Verner p. 66-67) The data relied on by the
Committee came from studies of birds living off the coast of England
and California. (Verner p. 67). None of the studies were of birds
living in forests like those of the Northwest.
The Committee judged the English island studies to be more relevant
to the forests of the Northwest. (ISC Report at 289)
These English studies revealed that no population of birds larger
than 11 pairs in size had ever gone extinct in any of the studies,
which had lasted as long as 30-40 years. (ISC Report 289) Dr. Noon,
the mathematician on the Committee, took the empirical data from these
English island studies and turned them into a linear regression model
to predict how long populations of different sizes would survive on
an island. This model projected that a population of 20 pairs of birds
would live on an island for 50 years. Report at 289. Table 0-3; (Verner
The Committee relied primarily on this 50-year linear regression projection
for a population of 20 pairs on an island to justify the 20-pair HCA
size specified in the ISC Strategy. (Verner p. 83-84) However, the
Committee's anticipation was that if an individual cluster went extinct
(i.e., all the birds died within the cluster) it would be recolonized
quickly by birds from other clusters. (Noon p. S. 94). Thus, the average
time between local extinctions in a cluster is of very little relevance
to the long-term viability of the species.
At the hearing before Judge Dwyer, Dr. Mark L. Boyce testified that
this linear regression projection probably severely underestimated
the length of time that a 20-pair population would continue to live
on an island. (ST 950). He believes that as the size of the population
increases the length of time the population would remain present on
an island would increase exponentially rather than linearly as the
Committee believed. (ST 95)
2. No support from models
The only other source of information cited by the Committee to support
the 20-pair HCA size was the computer model developed by Dr. Noon,
together with Dr. Rollie Lamberson at the Forest Service Redwood Sciences
Lab in Arcata, California. (Noon S 28) The model actually showed that
cluster with 15 pairs of birds remained stable over long periods of
time. (ISC Report @ 257)
Dr. Noon testified that the computer models were not the basis of
the ISC Strategy and were simply used to test general concepts of
reserve design rather than the specific details of the ISC Strategy.
(Noon p. 114) He strongly objected to the suggestion that the ISC
had relied on the models as the basis for the 20-pair HCA requirement.
(Noon S 29) Nonetheless, Drs. Verner and Forsman testified that they
did in fact rely on the models. (Verner S p 84, Forsman S p 24)
3. HCAs larger than necessary
Dr. Verner testified that the Committee's actual goal was to have
15 live pairs of owls in each HCA at any one time, and that because
they anticipated that only three-fourths of the spotted owl sites
would be occupied at any one time, it was necessary to provide habitat
for 20 pairs of owls so that there would be 15 pairs present on a
regular basis. (Verner S 83-86) Thus, the 20-pair size was actually
an exercise in caution aimed at assuring that 15 pairs of birds would
be present in each HCA.
However, having expanded the size of the HCAs to account for less
than 100% occupancy of pair sites, the Committee made a second, duplicate
expansion of HCA size to adjust for the very same concern all over
again. Table Q-3 ISC Report at 3220 contains an adjustment factor
for HCAs of different sizes depending upon the percentage of pair
sites that are suitable. For 20-pair HCAs the adjustment percentage
was 54%-93% depending upon how much suitable habitat is present. Thus,
the number of pairs projected in the future for each HCA was adjusted
downward based on Table Q-3. These adjustments are shown in the right-hand
column of Tables Q-4, Q-5 and Q-6 showing the number of "adjusted
future expected pairs" in each HCA in the three states.
A total of 57 of the Category 1 HCAs were made large enough so that
20 or more pairs of owls were predicted to be present in the future
after applying the adjustment. (Table Q-3) Yet, according to Dr. Verner,
the goal of the 20-pair size was to provide 15 pairs at any one time.
The result of this double adjustment was that all of the HCAs are
at least one-third larger than the Committee judged to be necessary.
While their goal was to have 15 pairs of owls present at any one time,
they provided that 57 of the HCAs would have at least 20 pairs present
at one time, and 15 of the HCAs will have at least 25 pairs of owls
present at one time. This far exceeds the level the Committee thought
Dr. Verner confirmed that table Q-3 was intended to reflect the occupancy
adjustment in the number of pairs of owls that would be present in
HCAs at any one time. (Verner S. 113)
B. Distance between HCAs.
The ISC admitted in its report that it had no objective scientific
bases to determine how far apart the HCAs should be. Lacking such
data, the Committee used the "Delphi Method" to determine
that HCAs should be no more than 12 miles apart. The Delphi Method
is nothing more than a process in which a group of individuals talks
about an issue until they reach a consensus on the answer to the issue.
(Noon S 94)
Although the Delphi process resulted in selecting a separation between
HCAs equal to the distance traveled by 67% of the dispersing juveniles,
no member of the Committee could recall why 67% was selected or how
that decision was reached. (Noon P 143-144)
In fact, when the HCAs were drawn on maps the average distance between
HCAs was on eight miles rather than the 12-mile maximum allowed in
the standards and guidelines. (Verner S 18, Noon S 101)
Committee member Joseph Lint was largely responsible for drawing the
HCAs on the maps for the state of Oregon. (Lint P 15) He testified
that drawing the HCAs on the maps was not a scientific exercise but
a "management exercise". (Lint P 38) He testified that he
could have made the HCAs farther apart and would have been within
the standards and guidelines as long as they were no more than 12
miles apart. (Lint P 40-41)
C. The 50-11-40 rule.
1. Origin of the 50-11-40 rule.
Dr. Jared Verner wrote the chapter of the ISC Report, which discusses
the 50-11-40 rule. (Verner P 9) When asked precisely where the biological
justification for the 50-11-40 rule as explained in the report, he
said, "it's not as well spelled out as we might have done."
(Verner P 43) He further stated "I would agree that its' not
an adequate explanation." (Verner P 150) In fact, nowhere in
the ISC Report is there any explanation for the basis of the 50-11-40
rule. The 50-11-40 rule apparently received very little analysis by
the ISC. The Committee was informed by unnamed "silviculturists"
working for the Forest Service that current Forest Service management
practices would generally produce a condition similar to 50-11-40
over a large management area (Not on a quarter township basis) (Verner
P 143) Armed with that knowledge Dr. Verner testified "And so,
we didn't pursue it any further. We rather assumed that this was not
going to be a source of consternation." (Verner P 141)
The basic intent of the 50-11-40 rule was to lock current management
practices into place in order to make it impossible for the federal
land management agencies "To intensify commercial forestry in
the matrix". (Thomas P 102, Forsman P 164) (The matrix is the
biologist's term for the forestlands in between HCAs)
The ISC report states that the general purpose of the 50-11-40 rule
is to provide "dispersal habitat" for juvenile owls as they
fly from one area where they are hatched to the area which they will
occupy as an adult. (ISC Report at 27) However, all of the members
of the Committee candidly admit that they do not know what "Dispersal
habitat" is for spotted owls. (Thomas P 104, Verner P 138, Noon
P 108) Dr. Thomas said the best the Committee could do was to "make
some fairly decent guesses at what dispersal habitat is". (Thomas
P 104) Dr. Thomas also concede that the dispersal habitat requirement
"is the weakest part, without any doubt" of the strategy.
(Thomas P 124)
Dr. Thomas acknowledged that the 50-11-40 rule is not the minimum
for dispersal habitat. He stated; "No, it's not the minimum guideline...I
don't know what the absolute minimum is". (Thomas P 178)
Dr. Verner admits that there is not data indicating that dispersal
of juvenile owls is a problem at the present time on BLM land. (Verner
Lint could draw no biological conclusion from the failure to satisfy
the 50-11-40 rule one every quarter township. (Lint P 86-87) Lint
testified that it was inappropriate to base a biological impact analysis
on whether or not the agency was complying with the 50-11-40 rule.
(Lint P 8) He testified "what you're dealing with is a recommendation...to
cross over and say that recommendation is now a biological fact has
biological implications of cause and effect, I would not do that"
(Lint P 87) The Committee "presumed" that studies would
be done to determine if the 50-11-40 standard was appropriate. (Lint
Dr. Thomas also firmly testified that he would not impose the 50-11-40
rule on private lands, even if he had the power to do so, because
it is unnecessary. (Thomas P 141)
2. Lack of scientific basis for the 50-11-40 rule.
Since the ISC Report does not contain "an adequate explanation"
of the basis for the 50-11-40 rule, the members of the Committee were
asked to explain the basis for the rule. The explanation, uniformly,
was that the rule was based almost entirely on "professional
judgment" rather than on any scientific data.
a. No ecological theory supports the 50-11-40 rule. Dr. Thomas was
asked, "is there any ecological theory that identifies 50-11-40
as the proper measure of dispersal habitat for spotted owls?"
he replied "No". (Thomas P 117)
b. The Committee's models do not support the 50-11-40 rule.
Dr. Noon, who was in charge of computer modeling for the Committee,
categorically denied that his models provided any support for the
50-11-40 rule. (Noon P 107, P 116, P 150). Dr. Noon testified that
any application of his models "to real landscapes is an inappropriate
use of the models". (Noon P 102-103)
c. No empirical data supports the 50-11-40 rule.
(1) No basis for 50% rule.
Dr. Thomas, the chairman of the Committee, testified that the 50%
rule came from "our collective judgment " that there was
"no data to support" that judgment. (Thomas P 88) Dr. Forsman
said the 50% figure was "our best professional judgment - of
a figure we could live with". (Forsman P 183) Lint stated it
was arrived at "through consensus discussion" based on "professional
judgment"/ (Lint P 79) Dr. Verner, who authored the chapter on
the 50-11-40 rule, was asked what facts he relied on to select the
50% figure and replied "I guess main professional judgment at
that point". (Verner P 153) Remarkably, Dr. Verner didn't seem
to think it necessary to have any data to support the 50% figure,
stating "I don't think the - the challenge is on us to prove
that 50% is adequate." (Id at 152)
(2) No basis for 11 inch rule.
Dr. Thomas testified that the selection of 11-inch diameter trees
as the minimum requirement was based on "professional judgment"
rather than any particular empirical evidence. (Thomas P 204-205)
Dr. Thomas stated; "That was the median that looked like a good
number and we took it. That was the gist of our professional judgment"
(Id at 204) Both Dr. Thomas and Dr. Verner thought that there was
some support for the 11-inch rule in Table F-1 in the ISC Report,
which was prepared by Dr. Forsman. However, Dr. Forsman admitted that
the studies listed in Table F-1 were not studies of dispersal habitat
for spotted owls. (Forsman P 148-149, P 151) Further, none of the
studies mentioned in the table identify 11 inches as a minimum size
for any spotted owl habitat. When asked, "Do these studies support
the use of an 11-inch DBH minimum as opposed to a 10-inch minimum?"
Dr. Thomas replied, "No". (Thomas P 77)
Dr. Forsman said the different studies in the report involved trees
five to 20 inches in diameter and that "we made a professional
judgment about what we thought was reasonable". (Forsman P 151)
He agreed that none of the studies in the report specifically points
to 11 inches as the proper definition of dispersal habitat. "No,
in terms of picking 11 inches as a reasonable or average number from
all those stands, no, not - its - 11 is not mentioned in any particular
one of them as being the number, no" Id at 152-153)
Lint stated; "we settled on 11 inches as something that we felt
was comfortable... it could have been 10, it could have been 12; 12
being better than 11, 10 being slightly less than 11". (Lint
P 72-77) Dr. Thomas also revealed that the ISC had recently concluded
that hardwood stands would provide dispersal habitat for spotted owls
with no minimum tree size at all. (Thomas P 181-182) He could not
explain why no minimum size was required for hardwood stands but is
required for conifer stands. Id.
(3) No basis for 40% canopy rule
Dr. Thomas admitted that the 40% canopy closure figure "was largely
professional judgment". (Thomas P 118, P 205) Dr. Forsman agreed
that the 40% figure "was a professional judgment" (Forsman
P 11) He stated that there were no studies supporting the 40% rule.
Id @ 162) Dr. Verner could not remember where the 40% figure came
from even though he had written the section of the report on the 50-11-40
Rule. (Verner P 155)
Lint testified that the 40 percent rule was based on "the personal
experience of a lot of people in the room that had dealt with the
owls". (Lint P 78) The personal experience was based on observation
of adult territorial bird habitat rather than juvenile dispersal,
although facilitation of the latter was the aim of the 50-1-40 rule.
(4) No basis for quarter township rule
The ISC requires that the 50-11-40 rule must be met on federal land
in each quarter township (nine square miles). If some of the area
in the quarter township is owned privately, the 50-11-40 rule must
be met on the federal portion of the area. (ISC Report @ 327) Further,
if an HCA is located on part of a quarter township, the area within
the HCA may not be counted in determining compliance with the 50-11-40
rule. Id. Dr. Forsman testified that there were no reports or studies,
which support the requirement for 50-11-40 rule to be applied on a
quarter township basis. (ForsmanP 190-191)
Dr, Verner conceded that the intent of the 50-11-40 rule is met if
the quarter township as a whole satisfies the 50-11-40 rule even if
the federal ownership within the quarter township does not meet the
rule. (Verner P 148) Neither Dr. Verner nor Dr. Thomas knows how much
dispersal habitat exists today on the intermingled private lands.
(Verner P 145, Thomas P 138) Dr. Thomas admitted that he doesn't know
how many quarter townships of intermingled BLM and private lands meet
the 50-11-40 rule today, and that no member of the Committee had ever
looked into the question. (Thomas P 139) Dr. Noon was not real knowledgeable"
on quarter township issue. (Noon P 167-168)
IV. THE COMPUTER MODELS DO NOT DIRECTLY SUPPORT THE ISC STRATEGY,
AND WOULD EQUALLY SUPPORT A WIDE RANGE OF OTHER PROPOSALS.
The two computer models developed for the ISC were heavily relied
on by the Committee in selecting the 20-pair minimum HCA size and
to support the entire conservation strategy. Yet the creators of the
model never intended them to be directly used to develop strategy,
and the models fail to provide any direct support for the ISC Strategy.
In fact, the models could equally support a conservation strategy
with one-quarter as much land set aside for spotted owl habitat.
Dr. Barry Noon was the committee member responsible for the models.
However, he denied authorship of the models, attributing them to Dr.
Rollie Lamberson and claiming only a secondary role for himself. (Noon
P 45, P 51) Work on the "cluster" model, which is cited
to support the HCA concept began after the ESC began its deliberations,
an there was never any written description of the model other than
in the ISC Report. (Noon P 46-47) No one on the Committee or outside
the Committee ever evaluated the structure of the model. (Noon P 48)
Dr. Noon testified that model should only be used to test general
principles of reserve design, and that it would be "inappropriate"
to apply the models to the real world, (Noon P 102-103) He has come
to doubt the assumptions in the cluster model and has been revising
the model using different assumptions. (Noon P 68) He has no data
to support the assumption in the model. (Noon P 69) The cluster model
does not reflect any real landscape that Dr. Noon is aware of. (Noon
P 55) and the model cannot determine the minimum population size required
for viability. (Noon P 87)
The key assumption in the cluster model is that a juvenile spotted
owl is more likely to successfully disperse to a new home within a
cluster of habitat sites than between clusters. It is this assumption
which justifies the entire concept of an HCA and many sites clustered
together as opposed to the SQHA system of scattered individual sites.
However the HCA had no data to support this assumption. (Noon P 67,
Further a key variable in determining how large a cluster must be
and how far apart it should be from other clusters is the "search
efficiency" of a dispersing Janesville owl (the number of sites
a dispersing owl can visit in search of a home before dying) However,
the actual search efficiency of juvenile owls is unknown. (Noon P
88) Thus, the model cannot predict how many owls are required to maintain
viability. (Noon P 89)
The cluster model also assumes that a juvenile spotted owl cannot
settle as a "floater" in a territory that is already occupied
by a pair of owls, even though biologists know that this commonly
occurs. (Noon P 92) If the model had been adjusted to reflect this
reality, it would have resulted in a higher survival rate for juveniles.
(Noon P 93) and this measure would be key to evaluating any proposed
conservation strategy. (Noon P 94) This adjustment would have supported
smaller HCAs farther apart.
The model also assumes that there are no breeding pairs of spotted
owls outside the HCAs which Dr. Noon recognized as "unrealistic'>
(Noon P 113. P116) The model further assumes that only 80% of the
spotted owl's sites are occupied at the beginning of the model run.
A species is normally assumed to be present in numbers sufficient
to occupy all of its available habitat (known as "carrying capacity".
If the model had assumed that owls were at 100% of their carrying
capacity, smaller HCAs farther apart would have produced the same
level of viability as larger HCAs at 80% of carrying capacity.
The model does not assume that every acre of spotted owl territory
is suitable spotted owl habitat, it merely assumes that there is enough
suitable habitat within a territory so that a pair of owls can successfully
occupy it. (Noon P 111) Thus, the model provides no support for the
ISC Strategy's prohibition on all timber harvesting within HCAs. (the
empirical data also fails to show a need to prohibit all harvesting
within HCAs Forsman P 145)
The model also does not support the proposition that every territory
within the HCA must be viable for spotted owls. To the contrary, the
model showing that an HCA in which 60% of the sites were suitable
for owls was just as effective in maintaining a viable population
of owls as an HCA in which 100% of the sites were suitable. (Noon
The ISC Report itself found that a site with 40% suitable habitat
is just as effective in supporting a reproducing pair of spotted owls
as a site with 100% suitable habitat. ISC Report at 183 (relying on
Bart and Forsman unpublished 1990) Thus, the cluster model would provide
just as much support for a conservation strategy proposing HCAs in
which 12 sites out of 20 were suitable habitat. Under this alternative
strategy only 24% as much habitat would have to be preserved to provide
as many spotted owls as under the ISC strategy.
V. CHECKERBOARD HCAS ARE AS EFFECTIVE AS 100% SUITABLE HCAS.
Some of the HCAs in Oregon are placed in areas of checkerboard ownership
of 50% BLM and 50% private land. Other nearby HCAs are 100% Forest
Service land. The ISC Report projects the same number of owls per
acre on checkerboard HCAs as on the 100% federal HCAs, even though
the report specifically states that timber harvesting on the private
lands within the HCAs is not constrained in any way.
Eric Forsman endorses the judgment that an HCA with 50% checkerboard
federal land is just as effective in providing habitat for spotted
owls as nearby HCA composed of 100% federal land. (Forsman P 276-78)
Barry Noon confirms that the cluster model projects that a cluster
with 50% suitable sites is just as effective as a cluster with 100%
suitable sites as long as there is a capacity of 25 pairs of owls.
(Noon P 188)
A. The ISC Report contains contradictory analysis of population trends.
Far more spotted owls have been observed in the past five years than
were know to exist previously on the highly fragmented checkerboard
BLM timberlands in western Oregon. In 1985 only 100 pairs of owls
were known to be present on those BLM lands, while in 1990, 500-700
pairs were observed.
However, the ISC discounted these population reports completely. The
ISC Report states that the spotted owl population in the Roseburg
BLM district, which is the only heavily studied BLM area, was declining
at 14% a year, and the reason that more owls were observed year after
year was due to timber harvesting. ISC Report at 235-237 points to
packing as the explanation for the increased number of observed owls.
At the same time, the report also places great reliance on the habitat
study prepared by Jonathan Bar and Eric Forsman, which compares densities
of owl populations in different proportions of older forest. It relies
heavily on this study in finding that a large proportion of older
forest is required for spotted owls. ISC Report, Appendix G. The US
Fish and Wildlife Service listing decision also relies heavily on
the Bart and Forsman paper.
The Bart and Forsman paper however, is based on the assumption that
packing is not occurring at the present time. (Forsman P 24) It assumes
that the relative density of owls in different types of habitat is
a reflection of the suitability of those types of habitat. Thus, the
Committee assumed at the same time that packing is and is not occurring.
Both cannot be true.
If packing is occurring, it should be evidenced by declines in reproduction
and survival rates where packing is occurring. (Thomas P 60) Dr. Jack
Ward Thomas who has never conducted any on -the-ground spotted owl
research believed that the reproductive rates are declining on the
Roseburg BLM district. (Thomas P 62) However, Dr. Forsman, who is
conducting the research on the Roseburg BLM district testified that
the reproductive rates and the survival rates are not declining on
the Roseburg district. (Forsman P 245). He has no evidence that the
reproductive rate or survival rates of the spotted owl are declining
anywhere in its range at the present time. (Forsman P 246)
2. Population trends on the Roseburg BLM district.
The ISC Report presents a demographic analysis which suggests that
the spotted owl population on the Roseburg BLM district is declining
at the rate of 14% per year. (ISC Report at 234) The Committee appeared
to place great significance on this presumed rapid decline in population.
(Noon S 80-81) However, both the Committee members who conduct the
on-the-ground research on the Roseburg district disbelieve that projection.
Dr. Eric Forsman does not believe that a 14% per year decline is occurring,
but thinks that the rate of decline is closer to 2% per year. (Forsman
P 236-237) He discussed his concerns with Dr. Noon, who prepared the
14% analysis, and pointed out that the 14% figure might be too high
because the last year of data banding study is always less reliable
than data from previous years. (Forsman P 215-216, P 238-239) He doesn't
know why this problem was not disclosed in the ISC Report. (Forsman
P 239) Dr. Forsman himself had reported ' an insignificant change"
in the population on the Roseburg district between 1988 and 1989 in
his own research report, a finding that is not consistent with the
14% annual decline. (Forsman P 240-241) (His findings could be consistent
if packing were occurring but Dr. Forsman along with Dr. Bart does
not believe that packing is occurring at the present time)
In 1990 there were 151 confirmed pairs of owls on the Roseburg district
plus 46 single owls, for a total of 348 owls. If there were a 14%
decline per year occurring on the Roseburg district between 1985 and
1990, there would have been over 670 owls on the Roseburg district
in 1985. Dr. Forsman does not believe that there were over 670 spotted
owls on the Roseburg district in 1985. (Forsman P 244) This number
"doesn't fit with my experience". ld.
Joseph Lint, who has worked on the Roseburg district for almost a
decade, confirms that he supervised a survey of Roseburg district
BLM data which indicated an annual decline of 2% per year rather than
the 14% suggested in the ISC Report. (Lint P 154)
The ISC Strategy is based on the Committee's belief that habitat fragmentation
causes serious harm to spotted owls. (ISC Report P 22-23 Thomas P
53) However, none of the members of the Committee knew of any studies,
which showed that fragmentation of habitat harms spotted owls. While
Dr. Thomas was sure that the Committee's analysis of fragmentation
studies was "very carefully worked out in the report" (Thomas
P 53) Dr., Verner hedged his answer with the statement that "Fragmentation
is exceedingly difficult to study". (Verner P 105) He believes
that the best study on fragmentation has been done by Mark Boyce and
Joe Meyer. (Verner P 106) Dr. Noon agrees that this is the best study
of fragmentation, (Noon P 79) Dr. Boyce testified at the Seattle Audubon
Society hearing that his study had not shown that fragmentation of
habitat has any harmful impact on spotted owls (ST 941-942)
No study has ever shown that fragmentation of habitat has any harmful
impact on spotted owls.
The ISC Strategy is not the objective, verifiable scientific product
its proponents have held it to be. The Committee ignored the huge
gaps in empirical data, the lack of relevant scientific theory and
the unreliability of the population simulation models, and based the
Strategy largely on the collective professional judgment of its members.
Each of the three key components of the ISC Strategy - the size of
HCAs, the distance between HCAs and the 50-11-40 rule is primarily
the professional judgment rather than data, theory or model. (Joseph
Lint, who was the only Committee member to do any of the actual map
drawing denied that the map drawing process was a scientific exercise,
labeling it "a management exercise".
The Committee evidenced confusion or misunderstanding on such key
issues as fragmentation, packing and population trends. It left behind
no record of its deliberations to allow subsequent researcher to recompute
and verify its calculations or to resolve the contradictions and inconsistencies,
which now appear in the report. The ISC Strategy should not and cannot
be viewed as the last word on the spotted owl. Policy makers, administrative
officials and legislators who are charged with the legal responsibility
to make final management decision on the spotted owl should view the
ISC Report as nothing more than a tool to assist them - a tool which
must be used properly and with full understanding of its limitations.