Wed Sep 4 09:41:38 CDT 2002

At 05:03 PM 9/3/02 -0700, Doug Yanega wrote:
>Steven Manning wrote:
>>Also, it seems likely that in some cases, when it is a race against time or
>>competing interests to save an endangered but poorly collected species or
>>ecosystem, the models can be used to predict and thus designate areas most
>>urgently needing protection at least temporarily until field work confirms
>>or refutes the predictions of the models, based on whatever climatic or
>>ecological data are available.  The models could also be used to prioritize
>>locations for fieldwork to be undertaken.
>That's actually the situation with this modeler I mentioned; the
>target species is endangered, and they are proposing to exclude
>certain areas from fieldwork (i.e., surveys) because the model
>predicts they won't be found there - even though some of the
>model-excluded areas contain known, confirmed sightings. The story
>I've heard is that the tolerances on the model "had to be narrowed"
>because if it was designed to include the habitat parameters of ALL
>known observations, the final predicted area would be essentially
>every piece of undeveloped land in the entire region, and that was
>considered unacceptable and unrealistic. No one seems to be objecting
>to this approach, to my knowledge, even though common sense would
>seem to dictate that one simply can't trust a model for this
>particular species, and that only survey work can tell us where it is
>or is not.
>Clearly, every organism has habitat preferences, but these
>preferences can be overridden in many cases. It seems to me that any
>model based solely on preferences is going to miss many marginal
>and/or suboptimal areas where a species could (or does) survive, and
>for endangered species, especially, that's a VERY risky approach to
>What does one do then?

How about including locality data of existing collections of the species as
part of the model?  The data entered into the model could then, if the
model is flexible enough, be modified each time a range extension is


>Doug Yanega        Dept. of Entomology         Entomology Research Museum
>Univ. of California - Riverside, Riverside, CA 92521
>phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
>   "There are some enterprises in which a careful disorderliness
>         is the true method" - Herman Melville, Moby Dick, Chap. 82

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