This week I spent a little time seeing how species protected under the Endangered Species Act in Colorado, Wyoming, and Utah tracked with species included on the international Red List.

Since August I've been attending a conservation genetics discussion group, and our reading for next week includes de Grammont and Cuarón (2006):  "An Evaluation of Threatened Species Categorization Systems Used on the American Continent".  It was intriguing to view some endangered species issues through the eyes of conservation biologists from Mexico, and to see just how many other countries in the Americas have adopted some kind of method of identifying species most at risk of extinction.

Building on Mace and Lande (1991), the authors suggested 15 "desirable characteristics of threatened species categorization systems" (p. 19) and then evaluated systems in use in 20 countries in the Americas, including the Endangered Species Act.  They concluded that "the most adequate system" (p. 21) was the one used by the World Conservation Union (IUCN) because of its emphasis on defining extinction risk quantitatively, but they also conceded that "much of the information required by this system may not be available" (p. 23).

I decided to check the IUCN Red List to see how their categorization of species status matched up (or didn't) with species listed under the Endangered Species Act that occur in Colorado, Wyoming, and Utah, and I especially was on the lookout for species that the IUCN considered to be Critically Endangered or Endangered that are not protected under the Act.

There didn't seem to be a way to search by state distribution, so I skimmed through the Critically Endangered and the Endangered lists for U.S. species to see what jumped out at me (which isn't terribly helpful for finding species slipping through the cracks).  I also checked Natureserve (the Natural Heritage Program's database) to see whether I could search by IUCN status there, but no luck.  Then I searched the IUCN database for the Endangered Species Act-listed and Candidate species in Colorado/Wyoming/Utah to see which they consider to be the most endangered. 

IUCN coverage is spotty - taxonomic groups show up on the list only if there's an expert who is actively involved with IUCN, it seems.  Keeping tabs on the world's biodiversity is a gigantic job, so this is a caveat rather than a criticism.  For example, plants are almost totally missing from the 2006 list because they have not been reevaluated since the IUCN changed criteria after 1994, as the FAQ page explains.

It was still a worthwhile excercise.  In those three states, the most endangered of the species protected under the Endangered Species Act that are included in the 2006 Red List are the black-footed ferret and the Wyoming toad, both of which IUCN lists as Extinct in the Wild.  I was surprised to see them placed in that category, because they both do occur in the wild now, but it's true that's because of captive breeding programs that continue to prop up existing populations. 

There were two Critically Endangered species from our region:  Eskimo curlew (listed Endangered, possibly extinct, no confirmed sightings since mid 1980's, former migrant through CO/WY/UT) and Kanab ambersnail (listed Endangered, three sites in SW UT and one in the Grand Canyon area of AZ).

Among the currently listed and Candidate species in CO/UT/WY, IUCN categorizes the following as Endangered:  bonytail chub, whooping crane, Preble's meadow jumping mouse, razorback sucker, relict leopard frog, and - get this - Gunnison sage-grouse.  I noticed the grouse when I was scanning the list; it has no federal status now.  The U.S. Fish and Wildlife Service made a politically motivated decision to remove the Gunnison sage-grouse from the Candidate list in April, and the IUCN's assessment is further testament to the fact that there was no biological basis for doing so.

The last of the three threatened or red-listed categories that IUCN uses is Vulnerable, which they still characterize as a "high risk of extinction in the wild".  Uncompahgre fritillary, humpback chub, Colorado pikeminnow, desert tortoise, woundfin, lesser prairie chicken, and Bonneville pondsnail fell into that category.  I also noticed Utah physa (a snail that I don't know much about - Natureserve says Utah Lake, Boulder County, CO, and possibly WY; Utah Division of Wildlife Resources says Utah Lake plus the Paradox/Dolores River drainage area in CO), and Dakota skipper (we joined Biodiversity Conservation Alliance's petition for this species) on the Vulnerable list.

Since many of our listed/Candidate/petitioned species do not seem to have been evaluated by the IUCN yet, the Red List can't stand alone as a prioritization tool, but it does reinforce that we are making good choices by focusing some of our efforts on the ferret, jumping mouse, sage-grouse, and skipper.  We need to be thinking more about what can be done for the Wyoming toad (chytrid fungus is the main threat), and I need to learn more about the Utah physa.

The Summary Statistics page was a bit of a shock, although again it could be a matter of uneven reporting.  The IUCN indicates that 236 animal species in the U.S. have gone extinct or are considered Extinct in the Wild.  This is by far the largest of any country - the second highest is French Polynesia, with 79.  The plant stats tell a similar story:  30 U.S. species extinct or Extinct in the Wild - runners up are Brazil and French Polynesia, both with 6.

Are there other species we should be paying more attention to, or other ways we can benefit from the IUCN's expertise?  Please let us know!