Can you think of other sub-criteria
that would be helpful for your group for analyzing absence after the EED?
Comments by CREO Chairman,
Ian Harrison, have been added to some of the responses below -- in underlined
Amphibians Advisory Panel
Comment 1: for
some amphibians our best information is often 'has not bred since date
x', because many species are only visible when they breed and we do
not know how long they can live between breeding episodes.
Comment 2: sampling
must not only include expected range, but also expected habitats.
Most amphibians have a complex life history meaning that both aquatic
and terrestrial habitats must be sampled.
Comment 3: failure
to hear advertisment calls would be just as significant as absence
of a sighting.
Birds Advisory Panel
Comment 1: some
work has been done with indirect evidence; eg. woodpecker holes. But
this is unacceptably tenuous.
Comment 2: states
that the history of rediscoveries is built around long absences (or
even not so long absences but people have not looked at the evidence)
during which it is "feared" that extinction has occurred, almost always
by office-workers (rather than fieldworkers) who are charged with
documenting these things. So, apart from actually looking at the right
time and in all the possible places, it is actually really
important to assemble all the data available, the better to establish
what those times and places are.
Comment 3: the environmental
threat criterion used for fish could profitably be added for birds.
In New Zealand, areas of suitable habitat lack taxa solely because
of presence of introduced species.
Coleoptera Advisory Panel
Comment 1: plant
distribution might be called into play for herbivorous species.
Comment 2: cannot think
of other sub-criteria to help refine this other than the capture and
dissemination of a whole lot more primary data about many more taxa.
Fishes Advisory Panel
Comment 1: a
missing criteria could be complete eradication of the habitat; eg. drying
a desert spring, clearing an oasis, transforming a karst tower into
Mammals Advisory Panel
Comment 1: Criteria
relating to EED need to be adaptable to the organisms being considered.
Criteria for birds and mammals would be different to those for cryptic
taxa. A threatened species listing committee on which I work has used
the following definition for adequacy of survey:
ADEQUACY OF SURVEY
1. Surveys should encompass
the range of available techniques and sampling should have been conducted
throughout the possible (as distinct from the known) geographic range
of the taxon.
2. Surveys should be conducted
in a range of seasonal and environmental conditions consistent with
the biology of the taxon.
3. Taxa confined to geographically
restricted or specialised habitats may require less time or effort
to survey than those occurring in more widespread habitat.
4. In the case of taxa
known from very few specimens, a fact pertinent to the nomination,
the nominator should demonstrate that all available collections have
been examined. (This is very good point; MacPhee and Flemming (1999)
also drew attention to hypodigms in their paper).
Comment 2: Sometimes
archaeological and ethnographical data can be useful - ancient art,
tools, etc. People of the past usually reflect their interactions
especially with hunting mammals."
Reptiles Advisory Panel
Comment 1: these
two criteria, broadly construed, appear sufficient.
Comment 2: whether
there are no reliable opportunistic observations, or sampling, despite
such records prior to the EED. (This seems to be a statement of
the level of attempted sampling conducted before and after the EED)
Comment 3: in some
special cases it is necessary to apply a more detailed analysis
of absence especially for secret and rare species of snakes. There
should be long-term monitoring in typical habitats made by special
methods; also special questionnaires among the local people with the
distribution of pictures and posters.