Any additional comments about
criteria, categories or the CREO project in general?
Comments by CREO Chairman,
Ian Harrison, have been added to some of the responses below -- in underlined
Birds Advisory Panel
Comment 1: (Thomas
Brooks should be credited for submitting these comments and devising
the following system.) MacPhee and Flemmings (1999) mammal
category II was too broad for birds because it included three very different
classes of unresolved extinctions:
--taxonomically invalid species;
--species that may have become extinct earlier than 1500;
--species that have not been recorded in the last 50 years but may survive.
Harrison and Stiassnys
(1999) fish category split these up but did not account for species
that may have become extinct prior to 1500.
MacPhee and Flemmings
mammal category IV also grouped two different classes: those definitely
lost within 50 years; and those that may survive. Brooks categorization
system for birds split these categories, following the protocol used
for fishes. Brooks agrees with the mammal survey protocol of keeping
taxonomically invalid and taxonomically undescribed species separate
(this was not done in the fish categories). (Similar comments have
been made in Mammal Panel Feasibility Surveys). Brooks found it
very difficult to separate the fish extinction categories B2/B3 and
D2/D3 for some birds, ie., the two possibilities (extinction not supported
by sampling or not supported by evidence of threat) can be difficult
to differentiate. (Another Bird Panelist has indicated that some
rigorous threat categories may overlap with the extinction categories).
Brooks' system recognizes
that species can first be broken down into three main groups:
-- I. Resolved AD
1500-50 years ago
Brooks states that these categories
can be modified by one or more additional pieces of information, as
-- II.Definite but possibly lost pre-AD 1500
-- III.Definite but possibly lost in last 50 years
b.Undescribed, otherwise resolved.
c.May survive (on the basis of unrepresentative sampling and/or apparent
environmental threat and population decline).
Hence a species is categorized
not according to a dichotomous key but according the three main categories
and any combination of the modifiers; eg. Gerygone hypoxantha
is categorized IIIac.
(This seems a sensible
and easy system to apply, probably easier than the fish key. It is
also more comparable to the revised IUCN system. But for fishes I
would still want to make the system more descriptive in the "may survive"
category, so that species that are thought to exist because sampling
has been unrepresentative are kept separate from other species where
there is simply no evidence of their decline (e.g., in the case of
enigmatic species that are known only from one or two specimens and
were never collected again). The reason Harrison and Stiassny (1999)
had steered away from a system of principal categories with modifiers
is that we thought we could possibly end up with a very complex set
of modifiers and submodifiers (eg. modifier c broken down into a series
of submodifiers which indicate why the extinction evidence is inconclusive)
- but perhaps this would be no more complex than an elaborate key?)
Coleoptera Advisory Panel
Comment 1: demonstrating
insect extinction is notoriously difficult except for certain well-known
groups (e.g. some lepidoptera, coleoptera) and some regions (e.g. parts
of Europe and North America). Exploring insects on an ordinal basis
will not be feasible, a family or tribal level is more realistic. Heritage
lists would be a very valuable starting point for CREO's assimilation
of insect data, and care should be taken not to duplicate effort of
Comment 2: in general
CREO is a worthwhile endeavour to undertake now. The Panelist is a
little skeptical that the same criteria for determining EEDs can be
applied to invertebrates and ephemeral plants as are used for vertebrates
and perrenial plants, but states that's no reason not to start.
Lepidoptera Advisory Panel
Comment 1: lepidoptera
are a good group to test. Also, we should think about just considering
particular regions and documenting regional extinctions (i.e. extirpations)
as a study of what processes are driving extinctions at a local level.
(This will provide very useful information for understanding the
processes of extinctions, and the CREO methodology could be easily applied
to local extinctions. However, this would mean that the project would
have to cover a much larger range of species, and could duplicate some
of the work of the more detailed work of SSC groups which are particularly
focused on threatened rather than extinct species).
Comment 2: The values
of particular Lepidoptera as 'umbrellas' may help us come to grips
with declines, but I suspect that the work of the CREO group will
be confined largely to a small subset of the order, butterflies, as
the only members for which even reasonably comprehensive historical
data will be available. Because this will be largely confined to the
temperate northern hemisphere, most progress will be made by concentrating
on that region as an initial thrust.
(Another entomologist has
stated that many suggested insect extinctions are too premature).