U.S. Fish & Wildlife Service
Listing a Species as
Threatened or Endangered
Section 4 of the Endangered Species Act
The Endangered Species Act of 1973,
as amended, is one of the most far-reaching
wildlife conservation laws
ever enacted by any nation. Congress,
on behalf of the American people,
passed the ESA to prevent extinctions
facing many species of fish, wildlife and
plants. The purpose of the ESA is to
conserve endangered and threatened
species and the ecosystems on which
they depend as key components of
America’s heritage. To implement
the ESA, the U.S. Fish and Wildlife
Service works in cooperation with the
National Marine Fisheries Service
(NMFS), other Federal, State, and local
agencies, Tribes, non-governmental
organizations, and private citizens.
Before a plant or animal species can
receive the protection provided by
the ESA, it must first be added to
the Federal lists of threatened and
endangered wildlife and plants. The
List of Endangered and Threatened
Wildlife (50 CFR 17.11) and the List
of Endangered and Threatened Plants
(50 CFR 17.12) contain the names of
all species of mammals, birds, reptiles,
amphibians, fishes, insects, plants,
and other creatures that have been
determined by us and NMFS (for most
marine life) to be in the greatest need
of Federal protection.
What does “endangered” mean?
What does “threatened” mean?
A species is listed under one of
two categories, endangered or
threatened, depending on its status
and the degree of threat it faces. An
“endangered species” is one that is in
danger of extinction throughout all
or a significant portion of its range.
A “threatened species” is one that is
likely to become endangered in the
foreseeable future throughout all
or a significant portion of its range.
To help conserve genetic diversity,
the ESA defines “species” broadly
to include subspecies and (for
vertebrates) distinct populations.
What are the criteria for deciding whether
to add a species to the list?
A species is added to the list when
it is determined to be endangered
or threatened because of any of the
n the present or threatened
destruction, modification, or
curtailment of its habitat or range;
n overutilization for commercial,
recreational, scientific, or educational
n disease or predation;
n the inadequacy of existing regulatory
n other natural or manmade factors
affecting its survival.
What steps are involved in listing a
We follow a strict legal process known
as a rulemaking (or regulatory)
procedure. Federal agencies follow
this procedure to propose and adopt
regulations that have the effect of law
and apply to all persons and agencies
under U.S. jurisdiction.
As a first step in assessing the status
of species, we publish notices of review
that identify species that we believe
meet the definition of threatened
or endangered. We refer to these
species as “candidates” for listing.
Through notices of review, we seek
biological information that will help
us to complete the status reviews for
these candidate species. We publish
notices in the Federal Register, a daily
Federal Government publication.
Our latest Candidate Notice of
Review is also available on our Web
How do we decide which species to list?
Because of the number of candidates
and the time required to list a
species, we developed a priority
system designed to direct our efforts
toward the plants and animals in the
greatest need. In our priority system,
the degree or magnitude of threat
is the highest criterion, followed
by the immediacy of the threat and
the taxonomic distinctiveness of
the species (monotypic genus, then
species, then subspecies, variety, or
vertebrate population). The ESA gives
no preference to popular species or so-called
“higher life forms.”
We strive to conserve candidate
species to prevent the need for listing.
Candidate Conservation Agreements
are partnerships involving the Service
Susanne Miller, USFWS
Listed in 2008 as threatened because of the decline in sea ice habitat, the polar bear may
spend time on land during fall months, waiting for ice to return.
and States or U.S. Territories, Federal
agencies, private agencies, and you
or your neighbor to reduce or remove
the threats to species on the brink of
How can you comment on a listing
We or the NMFS (for most marine
species) publishes listing proposals in
the Federal Register. We sometimes
publish multi-species proposals when
several candidate species share a
common ecosystem. At this stage,
any interested person can comment
and provide additional information
on the proposal -- generally during a
60-day comment period -- and submit
statements at any public hearings that
may be held.
To promote awareness of a proposal,
we issue news releases, conduct special
mailings, and inform the scientific
community and other Federal and
State agencies. In addition, we publish
a summary of any proposal as a legal
notice in newspapers serving each area
in which the species is believed to occur.
We may hold public hearings in cases of
high public interest or if an interested
party asks us to do so within 45 days of
What do we do with comments and
In our final rulemaking, we analyze
information received in public
comments and testimony. Within one
year of a listing proposal, we may:
1) publish a final listing rule as
originally proposed or later revised
because the best available biological
data support it;
2) withdraw the proposal because the
biological information does not support
the listing; or
3) extend the proposal if there is
substantial disagreement within the
scientific community concerning the
biological appropriateness of the
listing. After a six-month extension, we
are required to make a decision on the
basis of the best scientific information
A final listing rule generally becomes
effective 30 days after publication in
the Federal Register.
Can you nominate a species for listing?
Although we may initiate listing
proposals, we also may start the
listing process with a petition
from any member of the public.
However, petitions need the support
of biological data. We consider any
information submitted on the biology,
distribution, or threats to the species
when making our decisions.
What are petitions for listing?
Petitions are formal requests to list
a species. The ESA requires that we
make and publish specific findings on
a petition. We or the NMFS (for most
marine species) is required to make
a finding within 90 days of receiving
a petition (to the extent practicable)
as to whether there is “substantial
information” indicating that the
petitioned action may be warranted.
If this preliminary finding is positive,
we conduct a status review. Within
one year of receipt of the petition,
we must make a finding whether the
listing is warranted. A positive 12-
month finding may be incorporated
into a proposed listing. However, if
a prompt proposal is precluded by
higher priority listing activities, we
may defer the proposal. Then the
species becomes a candidate for
listing and is added to our candidates
list. These “warranted but precluded”
findings require subsequent 12-
month findings on each succeeding
anniversary of the petition until we
either undertake a proposal or make
a “not warranted” finding.
What does “listing” mean for a species?
Once we add an animal or plant to
the List, protective measures apply.
These measures include protection
from adverse effects of Federal
activities (through consultations under
section 7 of the ESA); restrictions
on taking, transporting, or selling a
species; authority for us to develop
and carry out recovery plans;
authority to purchase important
habitat; and Federal aid to State and
Commonwealth wildlife agencies that
have cooperative agreements with us.
These efforts contribute to species’
survival and assist in achieving the
ultimate goals — conserving plants and
animals and maintaining their natural
diversity and the ecosystems upon
which they depend.
U. S. Fish and Wildlife Service
Endangered Species Program
4401 N. Fairfax Drive, Room 420
Arlington, VA 22203
Click tabs to swap between content that is broken into logical sections.