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Declining and At-Risk Species

An ounce of prevention is worth a pound of cure. Once a species becomes threatened or endangered, recovery can be biologically difficult, as well as expensive and controversial. There have are many efforts to voluntary prevent species from declining to the point of needing protection under law. The Oregon Conservation Strategy is designed to maintain healthy habitats for fish, wildlife and people, hopefully preventing and reversing species declines. There are many other valuable assessments that serve as watch lists for focused, preventative action. Here are the most commonly-used lists of at-risk species.

Sensitive Species (Oregon Department of Fish and Wildlife)

Many of Oregon's wildlife species are declining, but people can help slow or even reverse these declines. One tool to help focus wildlife management, research and conservation actions is the Sensitive Species List, a non-regulatory approach to conservation. The Sensitive Species List serves as an early warning system for biologists, land managers, policy makers, and the public. It helps ensure that conservation actions are prioritized, cost-efficient, and effective.
Sensitive species are naturally-reproducing native animals which are considered at-risk in all or any significant portion of their range in Oregon. They face one or more threats to their populations and/or habitats. Implementation of appropriate conservation measures to address the threats may prevent them from qualifying for listing. The list is divided into 4 categories as defined below:

CRITICAL (SC) - "Critical" sensitive species are those for which listing as threatened or endangered would be appropriate if immediate conservation actions were not taken. Some peripheral species which are at risk throughout their range and some disjunct populations (those that are geographically isolated from other populations) are also considered
VULNERABLE (SV) - "Vulnerable" sensitive species are not in imminent danger of being listing as threatened or endangered, but could become "sensitive-critical," "threatened," or "endangered," with changes in populations, habitat or threats.
PERIPHERAL OR NATURALLY RARE (SP) -"Peripheral" species are on the edge of their range. "Naturally Rare" species are those with historically low population numbers in Oregon due to naturally limiting factors. The management objective is to maintain existing populations within their current range.
UNDETERMINED STATUS (SU) -"Undetermined" species are those for which status is unclear. They may be susceptible to population declines that may result in a listing as endangered, threatened, critical or vulnerable in the future, but additional research is needed before a decision can be made regarding their status.

Species of Concern (U.S. Fish and Wildlife Service)

Species of Concern are taxa whose conservation status is of concern to the U.S. Fish and Wildlife Service (many previously known as Category 2 candidates), but for which further information is still needed. These species receive no legal protection and the use of this term does not necessarily imply that a species will eventually be proposed for listing.

State and Global Status Ranks (Oregon Biodiversity Information Center and NatureServe)

The Oregon Biodiversity Information Center (ORBIC) is part of the Institute for Natural Resources - Portland. ORBIC and NatureServe have developed state and global conservation status ranks, to objectively evaluate the status of all wildlife species without any legal or political considerations. These global and state ranks are used by the U.S. Forest Service, the Bureau of Land Management, the Sustainable Forestry Initiative and others to help make management decisions, but have no relationship to threatened and endangered species status under either the federal or state Endangered Species Acts. There are 5 basic ranks, which are defined below. State ranks are applied to species based on their distribution and status in Oregon only, using the same definitions.

G1 Critically Imperiled -- At very high risk of extinction due to extreme rarity (often 5 or fewer populations), very steep declines, or other factors.
G2 Imperiled -- At high risk of extinction due to very restricted range, very few populations (often 20 or fewer), steep declines, or other factors.
G3 Vulnerable -- At moderate risk of extinction due to a restricted range, relatively few populations (often 80 or fewer), recent and widespread declines, or other factors.
G4 Apparently Secure -- Uncommon but not rare; some cause for long-term concern due to declines or other factors.
G5 Secure -- Common; widespread and abundant.

The state and federal ranks of all species in North American can be found on NatureServe Explorer. The status of all species considered to be at-risk in Oregon, including any with a global or state rank of 1-3, is included in the booklet, Rare, Threatened and Endangered Species of Oregon.

Authored by the Oregon Department of Fish and Wildlife (2008)

Image source: Oregon Department of Fish and Wildlife