Lecture 6/7: Gray Wolf Trophic Cascade and an Endangered Status & Finishing up on Wolf Conservation

Was there actually a reversal of a trophic cascade following wolf reintroduction?

Some studies indicate very large affects, but such studies have been criticized for methodological flaws

What do most studies conclude about the trophic cascade of wolves in Yellowstone?

a modest and spatially variable reversal of trophic cascade or none at all

What were lots of the confounding factors?

• Spotty pattern and often modest vegetation recovery

• Cougar recovery

  • kill more elk than wolves

• Slow beaver recovery

  • ecological engineers - alternative stable state

• Changes in fire regime

  • seedling establishment

• Lack of strong evidence for the operating mechanisms

  • are wolves a keystone species?

How 'endangered' was the Gray Wolf? U.S. Endangered Species Act (ESA)?

Legislation that affords federal legal protections to threatened and endangered species (signed in 1973)

Regulations implemented by USFWS

have the right to identify such species as endangered/threatened

What is an Endangered species?

Species that are "in danger of extinction within the foreseeable future throughout all or a significant portion of its range"

What is a Threatened species?

"Those animals and plants likely to become endangered within the foreseeable future throughout all or a significant portion of their ranges."

Is endangered species a federal or formal status?

federal status

Is threatened species a federal or formal status?

formal status - federally regulated

What is a Distinct population segment (DPS)? - UNDER THE ENVIRONMENTAL PROTECTION ACT (1973)

vertebrate population or group of populations that is discrete from other populations of the species and significant in relation to the entire species

How can protections under the ESA (1973) be applied to a population that is not the entire species?

applied to a particular area

How were Wolves listed in 1978 across the lower 48 states?

endangered; but threatened in Minnesota

What was the numbers of wolves in 1995 (when wolves were released in Yellowstone)

2450 wolves in the lower 48 states

5k to 7k in Alaska

50k to 60k in Canada

200k to 250k worldwide

What are stakeholders, in the specific context of Endangered Species Act (ESA) recovery teams and working groups?

representatives of conflicting human interests who must agree on a management plan for species survival

What are some examples of stakeholders?

Legal Authority

Bearers of economic cost

Public trust

1967-1974: Initial Protections - Before the ESA:

several wolf "subspecies" (including eastern timber wolf and northern Rocky Mountain gray wolf) were protected under early pieces of conservation legislation

What were some early pieces of conservation legislation that protected wolf subspecies?

Endangered Species Preservation Act of 1966

Endangered Species Act (1973), these subspecies were absorbed into the official federal list of endangered wildlife

1978: Consolidation at the Species Level - To streamline management:

USFWS reclassified the gray wolf as endangered species across the lower 48 states

Except Minnesota, where the population was large enough to be classified as Threatened

1994-1996: Reintroduction and "Experimental" Status - To jumpstart recovery, what did the FWS do?

approved a plan to reintroduce gray wolves into Yellowstone and central Idaho

Under the ESA, these wolves were designated as "nonessential experimental populations", what did this allow

for federal and state authorities to kill or relocate individual wolves that preyed on livestock or otherwise problematic

2003: DPS Framework - Seeking to scale back oversight, USFWS divided gray wolf in the lower 48 states into three Distinct Population Segments:

Eastern, Western, and Southwestern wolf population

In 2003, USFWS then "downlisted" the Eastern and Western segments to Threatened, which led to conservation groups doing what?

suing, arguing that the USFWS ignored major portions of the wolf's historic range. Federal courts nullified the USFWS rulings

2007-2009: Back-and-Forth Delisting - what did USFWS attempt?

targeted delistings (remove federal protections) for the Western Great Lakes DPS (2007) and the Northern Rocky Mountains DPS (2008)

2007-2009: Federal courts repeatedly blocked or vacated targeted delisting rulings, citing that:

agency's logic was legally flawed and that aggressive state hunting plans threatened recovery

Wolves were repeatedly returned to the federal endangered list after short windows of state control

2011 to Present: Recovery goals for the Northern Rocky Mountains achieved in 2003:

761 wolves and 51 breeding pairs (USFWS 2006)

Northern Rocky Mountains, wolves were delisted in:

Idaho & Montana (2011), and in Wyoming, Washington, & Oregon (by 2017)

Whagt were wolves in Colorado were designated as?

experimental, nonessential

Wolves remain listed as Endangered elsewhere, except:

Minnesota where they remain listed as Threatened

Hunting was allowed in Idaho, Montana, and Wyoming:

All the Northern Rocky Mountain states allow removal of problem wolves

Mexican Gray Wolf

1976: The Mexican Gray Wolf 'subspecies' was listed as:

Endangered, although it was extirpated in the US

Mexican Gray Wolf

1978: USFWS consolidated the 'subspecies' as part of:

the broader gray wolf listing

Mexican Gray Wolf

1998: Mexican Wolves reintroduced into the US and listed as:

experimental nonessential population under the ESA

Mexican Gray Wolf

2015: The Mexican Wolf again separately listed as:

Endangered

Estimated 319 in US (2025-2026), and 30-45 in Mexico