To the FWGNA group:
As most of you will recall, last month I
surveyed a set of 10
comprehensive wildlife conservation strategies recently published by
states of the southern U.S. I ranked each state by the number of
freshwater
gastropods on its list of species "prioritized for conservation,"
relative to its total number of priority species. The resulting
ratio, it seems to me, might give some measure of the importance of
freshwater gastropods to the overall conservation efforts of each
state, and hence (perhaps) the likelihood that grant funding might be
available.
This month I've done an identical survey for 12 states of The American
West. But before reading any further, I'd challenge
each of
you to make a prediction. Clearly there is more fresh water in
the South than in the West. In which region do you think
freshwater snails will attract greater conservation concern?
The answer is in the West, by far. The list below shows that two
of the 12 western states did not include any freshwater gastropods in
their conservation plans: Montana and Washington. This is
identical to the south, where two of 10 states excluded the freshwater
snails: Louisiana and Mississippi. But three western states
listed eye-poppingly large numbers of freshwater gastropods - 74 (28.1%
of all species!) in Nevada, 45 (16.1%) in Wyoming, and 23 (11.7%) in
Utah. Among southern states, only Alabama hit the double-digits
(11.1%). The average percent freshwater gastropod species on
state lists of special conservation concern was 0.070 in the West but
only 0.026 in the South.
The difference is largely attributable to endemic hydrobiids.
Nevada's 74 freshwater gastropod species of special priority included
61 Pyrgulopsis and 11 species of other hydrobiid genera, almost all
narrowly restricted to individual desert springs. Utah's 23
species included 14 hydrobiids, California's 35 included 21 hydrobiids,
and hydrobiids comprised all 14 of Arizona's freshwater gastropod
species of greatest conservation need.
Many of the lists of the western states also included pulmonate snails,
which are rarely mentioned in the south. Idaho and Oregon, for
example, were both about equally split between prosobranchs and
pulmonates.
A most interesting contrast emerged between the states of Wyoming and
Montana. According to the authors of Wyoming's Conservation
Strategy, only 44 of that state's 279 species (of all taxa) were listed
because of specific, known conservation needs. They stated, "The
remaining 235 have been included
primarily due to a lack of key data
necessary to assess their conservation status." That subgroup of
235 taxa included essentially the entire freshwater gastropod fauna of
Wyoming, 45 species in total. In striking contrast, Montana
listed only 60 species of all taxa, including no freshwater snails at
all. By way of explanation, the authors of the Montana Strategy
wrote, "Most invertebrates were not
included in the assessment due to
lack of data."
Below are the 12 states of the American West, ranked by the
conservation concern they directed toward their freshwater gastropod
faunas. As I mentioned last month, some states do appear to be
accepting outside proposals for grants to study their species of
greatest conservation need. Good luck to all of you!
And keep in touch,
Rob
------------------
Nevada Comprehensive Wildlife
Conservation Strategy
Species of Conservation Priority: 74 freshwater snails / 263 =
0.281
A
Comprehensive Wildlife Conservation Strategy for Wyoming
Species of Greatest Conservation Need: 45 freshwater snails
/ 279 = 0.161
Utah Comprehensive Wildlife
Conservation Strategy
Species of Greatest Conservation Need (all tiers): 23
freshwater snails / 196 = 0.117
The Oregon Conservation Strategy
Strategy Species: 18 freshwater snails / 286 = 0.063
Idaho Comprehensive
Wildlife Conservation Strategy
Species of Greatest Conservation Need: 13 freshwater snails /
229 = 0.057
Arizona's Comprehensive Wildlife
Conservation Strategy
Species of Greatest Conservation Need (Tiers 1a, 1b, 1c): 14
freshwater snails / 310 = 0.045
California Wildlife:
Conservation Challenges
Special Status Species: 35 freshwater snails / 824 = 0.042
Colorado's Comprehensive
Wildlife Conservation Strategy
Species of Greatest Conservation Need: 7 freshwater snails
/ 205 = 0.034
Comprehensive
Wildlife Conservation Strategy for New
Mexico
Species of Greatest Conservation Need: 14 freshwater snails /
452 = 0.031
The
Texas Comprehensive
Wildlife Conservation Strategy
Priority Species: 10 freshwater snails / 733 = 0.014
Montana's Comprehensive Fish and
Wildlife Conservation Strategy
Species of Greatest Conservation Need: 0 freshwater snails /
60 = 0.0
Washington's Comprehensive
Wildlife Conservation Strategy
Species of greatest conservation need: 0 freshwater snails /200
= 0.0
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