CREO Feasibility Survey Responses
The purpose of this Feasibility Survey is to guide Advisory Panelists in assessing CREO prototype criteria and how these criteria would need to be refined and adapted to be applicable to their taxonomic group.
The most important thing to determine from this survey, then, is how we can formulate criteria that can be broadly applicable across many taxa. If the method of determining extinctions is handled differently for different taxa, then the meaning of "extinct" is ambiguous, and drawing reliable conclusions about the processes that underlie extinctions becomes impossible.
--QUESTIONS RELATING TO BASIC CRITERIA
Our first criterion is that the species name and status must be systematically valid.
Our second criterion is that the effective extinction date (EED) must be confirmed as falling within recent times. The studies on recently extinct fish and mammals defined this time as covering from AD 1500 to the present. We felt that AD 1500 represented a justifiable start date for surveying recent extinctions for two reasons: following this date, human exploration of the globe became more prevalent, and reliable evidence for the loss of other species in association with human movement and activities began to be recorded widely. Do you agree that this is a sensible date from which to start a survey such as this? If not, how much further back in time do you think the survey should go?
What is your opinion about how we determined the effective extinction date (EED)? Specifically, for your group, can an EED be adequately assigned to a species solely based on observational evidence, or would collected material be the only satisfactory evidence?
In reference to establishing the EED, we have stated that evidence of observation, identification, and date of collection of the specimen should be "reliable." We defined "reliable source" as someone with an intimate knowledge of the taxon in question. Do you consider this to be sufficiently precise and, if not, how would you change it?
How should the EED criteria be changed if it was decided that these surveys should begin significantly earlier than AD 1500?
Our third criterion involves using a 50-year rule as an insurance policy (albeit arbitrary) against prematurely declaring a species "extinct;" in other words, unless at least 50 years have passed since the species was last located in the wild, its extinction cannot be declared "resolved." We adopted this protocol because it provides a lengthy time period during which the species, if still extant, might be seen or collected, purely by chance. This can be particularly important when it is difficult to judge whether sufficient sampling has been conducted to confirm the species absence.
--QUESTIONS RELATING TO SUB CRITERIA
For some taxa it may be necessary to apply a more detailed analysis of absence after the species reported EED in order to accurately account for its status. In our survey of freshwater fish, for example, it was determined that because they are so elusive, extant species could easily be overlooked and wrongly considered extinct unless these additional criteria were applied:
We did not stipulate quantitative measures for defining when significant attempts had been made to relocate the species, or for defining when there had been a species decline or environmental threat (see above), because quantitative measures proved difficult to develop and apply. Do you think it is necessary to develop a more quantitative system? If so, do you have any suggestions for how it could be developed?
Can you think of other sub-criteria that would be helpful for your group for analyzing absence after the EED?
In general, can you think of any other criteria or sub-criteria that would be helpful for assessing extinctions in your group?
Any additional comments about criteria, categories, or the CREO project in general?