Why Arizona must keep Mexican wolves south of Interstate 40

In a recent opinion piece, Greta Anderson made misleading assertions regarding the Arizona Game and Fish Department’s role in Mexican wolf recovery.

She asserts that the department opposes recovery of Mexican wolves north of Interstate 40 but fails to note that this is considered inappropriate by every other state and federal agency involved in Mexican wolf recovery, including the National Park Service, Fish and Wildlife Service, Forest Service and the Bureau of Land Management.

These agencies, as well as other federal, state and county organizations with authority for Mexican wolf recovery, unanimously endorsed a management protocol on June 27, 2022, restricting Mexican wolves from establishing north of I-40.

In part, the protocol states, “If the wolf establishes wholly outside of the Mexican Wolf Experimental Population Area (MWEPA), plans for translocation will be initiated and implemented as soon as practical and with full consideration for the welfare of the wolf and the affected human environment where the wolf is located.”

Law requires wolves stay south of I-40

It is important to recognize the legal requirement that recovery occurs south of I-40, as stated in the 2022 10(j) rule for Mexican wolf recovery.

Further, the 2022 Mexican Wolf Recovery Plan, Second Revision, states, “We (the U.S. Fish and Wildlife Service) are focusing recovery implementation in the United States in the area south of Interstate 40, consistent with the range described by Parsons (1996).”

These are legal mandates from the Department of Interior, and all agencies are bound to comply. As a result of litigation, the Tucson District Court reviewed the 10(j) rule and did not find fault with the service’s I-40 boundary.

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Some advocate for releases north of this historical range. However, there is a robust collection of peer-reviewed scientific literature supporting the service’s goal of recovery within the historical range.

Noted scientists from as early as 1929 to as recent as 2022 provide scientific support that historical range is restricted to areas south of Interstate 40.

This is not an arbitrary decision, but rather one based on well-researched physical, genetic, ecological and historical data on the Mexican wolf.

Mexican wolf populations are rebounding

Ms. Anderson asserts that Mexican wolf recovery isn’t working. However, every metric for the U.S. population refutes this.

The 2022 annual count documented 242 wolves in the experimental population area, a 23% increase from the previous year and a six-fold increase from 42 wolves in 2009.

There were a record 32 breeding pairs documented at the end of 2022; breeding pairs are the reproductive foundation for producing further rapid population growth.

In 2022, the overall survival rate, inclusive of all age classes, was higher than the previous 10-year period. Eleven new packs and one new pair were documented at the end of 2022.

Genetic measures from 2018-21 also have shown a steady increase in gene diversity and an encouraging decrease in mean kinship (a measure of how related individual wolves are to each other), suggesting that our efforts to improve the genetic status of the population are beginning to exert a positive effect on improving genetic health in the wild, despite only seven founding members.

Changes in Mexico will go a long way

As pointed out, progress in Mexico has been challenging, as is common when recovering controversial carnivores, but the international partnership embodied in a June 2, 2022, International Letter of Intent shows strong commitment from all parties to retool recovery in Mexico.

The Mexican government is developing a depredation compensation program, which would pay for livestock killed by wolves, and investigating wolf release sites in another Mexican state.

There were times in the U.S. when success wasn’t certain, but recovery is driven by adaptive management in both countries. Changing plans in Mexico will help move forward in the binational recovery of Mexican wolves.

Clay Crowder is assistant director of wildlife management for the Arizona Game and Fish Department. Reach him at ccrowder@azgfd.gov.

This article originally appeared on Arizona Republic: Mexican gray wolves must remain south of Interstate 40