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Letter
to the editors
I wish to praise you
on a fine Special Issue No. 4 to CAT NEWS titled The
Jaguar in Brazil. I also wish to thank the contributors
for some excellent work that adds to our knowledge about
jaguars in Brazil. Brazil is indeed a very important
country for the future of jaguar conservation and as
well as that of many other wildlife species. However,
I would also like to raise the warning that some people
might consider using CAT NEWS in lieu of writing up
data for peer reviewed publications. I hope this is
not the case for most felid biologists and that the
editors of CAT NEWS encourage their contributors to
publish significant findings in peer-reviewed journals.
I found several statements and conclusions in The Jaguar
in Brazil that I believe would have been questioned
and modified had the papers gone through peer review.
One set of data in particular really stands out in this
special issue and I need to bring it up with your readers.
In the paper titled Jaguar Conservation in Brazil: The
Role of Protected Areas, the authors Sollmann, Torres
and Silveira produce an estimate of nearly 52,000 jaguars
in the Amazon biome of Brazil with a total figure of
more than 55,000 jaguars in the entire country. These
are, quite frankly, unbelievable figures. I would be
surprised if there were 55,000 jaguars surviving at
present throughout the entire range of the jaguar from
Mexico to Argentina. In a book soon to be published
on jaguars by Yale University Press, Brazilian jaguar
biologist Peter Crawshaw, a friend and colleague, is
quoted as saying: “I wouldn’t dare give numbers for
estimates of jaguars remaining in Brazil.” He then states
that while the ja-guar might be more threatened outside
the Amazon and Pantanal, it is still very threa-tened
within these biomes as well.
The problem with the
figures put forth in this special issue of CAT NEWS
is that they come from a completely erroneous analysis
in which jaguar density estimates, which are based on
good camera-trapping methodology, are extrapolated over
large areas. Unfortunately, this erroneous kind of analysis
has been done elsewhere and has even been published
in at least one peer-reviewed journal. But such wide
ranging extrapolation, producing completely unrealistic
numbers for biomes throughout Brazil in this Special
Issue No. 4 of CAT NEWS is incorrect and dangerous.
This kind of analysis and extrapolation goes completely
against the assumptions and the rigorous methodo-logy
as described in the seminal work done on camera-trapping
for tiger density estimates by Ullas Karanth. If an
entire study area cannot be camera-trapped, then the
density estimates obtained with selective, non-random
placing of camera traps can be used reliably ONLY for
those areas that were part of the camera trap study.
Does this mean that field biologists can never do reliable
estimates or “guesstimates” of jaguar numbers over large
areas? No it does not. But in order to do so, scientists
must show that they are carefully and systematically
taking into account factors that affect jaguar numbers
and densities throughout existing habitats. Optimal
densities must then be adjusted in a standardized manner
if any kind of ballpark estimate is to be believed and
accepted.
I believe that our field
has a serious issue with the use of camera traps and
that many field scientists are using camera traps incorrectly
in the first place. But in this case, the greater error
was to extrapolate optimal densities over large landscapes
producing numbers that any big cat biologist would find
simply impossible to believe. Worse still, such figures
could be used by those wanting to show that jaguars
are really doing better than they are in the wild. We
cannot have erroneous figures and erroneous analyses
such as these getting out to the public in the guise
of acceptable and peer-reviewed data.
Alan
Rabinowitz
President
and CEO, PANTHERA
www.panthera.org
Response
We appreciate the concern
of Mr. Rabinowitz regarding the results presented in
“Jaguar Conservation in Brazil: The role of protected
areas” (Sollmann et al. 2008) and their meaning for
jaguar conservation. However, we feel his critique misses
several key points of the paper.
First, although Cat News
is not a peer-reviewed journal, it is edited by renowned
cat biologists. Additionally, the cited article went
through external review by some of today’s leading conservationists
prior to publication.
Second, Mr. Rabinowitz
contradicts himself in stating that reliable jaguar
abundance estimates can be obtained “systematically
taking into account factors that affect jaguar numbers
and densities throughout existing habitats” and at the
same time calling our analysis “completely erroneous”.
By estimating jaguar abundance only for protected areas
of a minimum size and using biome-specific densities,
we take into account two major factors influencing jaguar
numbers and build a simple yet systematic model. In
contrast, during the 1999 Jaguar in the New Millennium
workshop organized by WCS, which led to the classic
paper by Sanderson et al. (2002), assessment of jaguar
population status was entirely based on expert opinion
– Jaguar Conservation Units could be defined as areas
researchers “believed to contain” a resident jaguar
population.
Third, extrapolating
local information to larger spatial scales is a common
practice (see Ranganathan et al. 2008 for just one recent
example) and often the only option for species with
limited available information. In exposing all steps
taken to obtain abundance estimates, we unambiguously
inform the reader about all associated uncertainties
(although we agree that we did not quantify them). While
any extrapolation has to be treated with caution, this
approach is very different from simply guessing a number.
Just like Mr. Crawshaw, as cited by Mr. Rabinowitz,
we, too, would not dare to guess, neither would any
serious scientist. To further avoid misinterpretation
we state in our paper that “results should be understood
comparatively”. Indeed, the objective of the paper was
not to estimate jaguar abundance in Brazil, but instead
to compare how protected areas contribute to jaguar
conservation in the different Brazi-lian biomes. While
jaguar numbers for Brazil may well be different from
our estimates, the conclusions derived from them continue
to hold true: For Brazil, only in the Amazon do existing
protected areas cover enough land to be the centerpiece
for regional long-term jaguar conservation.
Fourth, when the Jaguar
in the New Millennium data set was updated in 2006,
the species was estimated to currently occupy 61% of
its original range – an increase compared to the 46%
estimated in 1999. Following Mr. Rabinowitz’s line of
reasoning, these numbers also support “those wanting
to show that jaguars are really doing better than they
are in the wild”. The true interpretation is obvious
- we simply know more today than we did 10 years ago
and we should be happy that the jaguar has actually
disappeared from less of its range than previously assumed.
Instead of branding such information counterproductive
to conservation, positive findings should be acknowledged
as what they stand for - a better chance of saving the
jaguar in a world where habitat loss and direct persecution
continue to threaten it.
Finally, we would like
to know based on what data Mr. Rabinowitz renders our
estimates “impossible to believe”. Our extrapolation
is not absurd in light of previously published regional
estimates (e.g. Maffei et al. 2004). While there is
a growing number of jaguar studies, data on abundance
patterns are still sparse. In 1985, Soulé called conservation
biology a “crisis discipline”, where “one must act before
knowing all the facts”. The 2008 update of the IUCN
Red List clearly shows that this crisis is not over.
Listed as “Near Threatened” with decreasing population
trends, the jaguar is part of this crisis. Hopefully,
in 10 years, more data on jaguar abundance will allow
a more reliable assessment of jaguar population status.
Hopefully, these data will bear a positive surprise,
as did the update of the Jaguar in the New Millennium
data. Until then, point estimates are the best we have
in hand to outline large scale jaguar conservation strategies.
For most of Brazil, and probably for most of the species’
range, the conclusion derived from these estimates is
that protected areas are not enough to guarantee the
jaguar’s long-term survival. To show that was our main
purpose. We believe that no big cat biologist would
disagree with that.
For
the authors: Rahel Sollmann
Scientific
Manager, Jaguar Conservation Fund/Instituto Onça-Pintada
References
Maffei
L., Cuéllar E. & Noss A. 2004. One thousand jaguars
(Panthera onca) in Bolivia’s Chaco? Camera trapping
in the Kaa-Iya National Park. Journal of Zoology 262,
295-304.
Ranganathan
J., Chan K. M.A., Karanth K. U. & Smith J. L. D.
2008. Where can tigers persist in the future? A landscape-scale,
density-based population model for the Indian subcontinent.
Biological Conservation 141, 67-77.
Sanderson
E. W., Redford K. H., Chetkiewitz C. B., Medellin R.
A., Rabinowitz A. R., Robinson J. G. & Taber A.
B. 2002. Planning to Save a Species: the Jaguar as a
Model. Conservation Biology 16, 58-72.
Sollmann
R., Tôrres N. M. & Silveira L. 2008. Jaguar Conservation
in Brazil: The Role of Protected Areas. Cat News. Special
Issue 4 – The Jaguar in Brazil, 15-20.
Soulé
M. 1985. What is Conservation Biology? BioScience 35,
727-734
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