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Limiting Mountain Lion Predation on Desert Bighorn Sheep on Kofa National Wildlife Refuge, Yuma and La Paz Counties, AZ

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Fish and Wildlife Service, Interior.


Notice of availability of draft environmental assessment; request for comments.


We, the U.S. Fish and Wildlife Service (Service), announce that our draft environmental assessment (EA) for limiting mountain lion (Puma concolor) predation on desert bighorn sheep (Ovis canadensis mexicana) on the Kofa National Wildlife Refuge (Refuge) is available. The Refuge is located in southwest Arizona. The draft EA describes alternatives, including a proposed action alternative, that address how we intend to manage mountain lion predation to help achieve bighorn sheep population objectives.


To ensure consideration, we must receive your written comments on the draft EA 60 days from date of publication.


Please provide written comments to the Southwest Arizona National Wildlife Refuge Complex, by U.S. mail at U.S. Fish and Wildlife Service, 9300 East 28th Street, Yuma, AZ 85365; via facsimile at 928-783-8611; or electronically to You may obtain a copy of the draft EA by writing to the address above, or by download from​southwest/​refuges/​arizona/​kofa.

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Jose Viramontes, 505-248-6455 (phone); 505-248-6915 (fax); or (e-mail). If you use a telecommunications device for the deaf (TDD), you may call the Federal Information Relay Service (FIRS) at 1-800-877-8339, 24 hours a day, 7 days a week.

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The Refuge contains a major portion of the largest contiguous habitat for desert bighorn sheep in southwestern Arizona and historically has been home to a population averaging 760 bighorns. The Refuge has served as the primary source of bighorn sheep for translocations to reestablish and supplement extirpated or declining populations throughout southern Arizona, New Mexico, Texas, and Colorado. Population estimates from systematic aerial surveys indicate that a 50-percent decline in the Refuge sheep population occurred during the period 2000-2008.

In response to this decline, the Service and the Arizona Game and Fish Department (AZGFD) have conducted an analysis of the probable causes of the decline and are currently implementing a strategic management program intended to lead to the recovery of this important wildlife resource. Several studies and monitoring projects have been initiated or enhanced. Some of the more important aspects of this broad program include more frequent bighorn population surveys, monitoring and maintaining water availability, assessing body condition and disease in the bighorn population, monitoring disturbance attributable to human recreation, and monitoring the extent of predation and its impacts on the population. Many of the elements in this management program have been addressed through prior planning documents and require little additional review. Others, such as the proposed lethal control of mountain lions, have not been previously addressed and Start Printed Page 38668therefore require National Environmental Policy Act analysis and public review.

Draft Environmental Assessment

This draft EA identifies and evaluates three alternatives for managing mountain lion predation on desert bighorn sheep on the Refuge.

Alternative A: Under this alternative, the Refuge would continue to be managed as it has been in the past. We currently have no plan to guide the management of mountain lions. Current management efforts, described in the Refuge's general management plan, focus on maintaining critical wildlife water sources for bighorn sheep, and, in coordination with the AZGFD, monitoring desert bighorn sheep numbers, and considering desert bighorn sheep transplants to augment populations elsewhere. Research on wildlife and wildlife water sources would continue. We would not take action to prevent mountain lion predation on desert bighorn sheep within the Refuge boundaries under this alternative.

Alternative B: This is the our proposed action, which would allow the option of removing specific, individually identified offending mountain lions, through translocation or lethal removal, from the Refuge under certain circumstances, in order to recover and maintain an optimal population of desert bighorn sheep. The proposed action has several components. We would trap mountain lions and fit them with tracking devices to monitor their activities. When the Refuge bighorn sheep population estimate is below 600 animals, active mountain lion removal would occur. Active mountain lion control is the removal of mountain lions found to kill two or more bighorn sheep within a 6-month period. The Service, or its agents, would carry out the lethal removal or translocation. However, when the Refuge bighorn sheep population estimate is between 600 and 800 animals, active mountain lion control may or may not be employed based on the totality of the circumstances at the time. In order to meet the bighorn sheep population objectives while minimizing the necessary impacts to mountain lions, some flexibility is desired. Decisions regarding whether active mountain lion control is necessary will be based on an adaptive management approach and based on the following factors: The current sheep population estimate; the current sheep population trend; bighorn sheep lamb survival and recruitment; the estimate of the number of mountain lions currently using the Refuge; current and forecasted habitat conditions; and available funding and manpower. When the Refuge bighorn sheep population estimate is at or above 800 animals, active mountain lion control would not occur, although mountain lions on the Refuge would continue to be captured and fitted with tracking devices to aid in continuing research.

Alternative C: Under this alternative, there would be no attempts to radio collar and distinguish which mountain lions are preying on bighorn sheep. Mountain lions would be lethally removed or translocated at a rate of approximately 2 mountain lions per year from the area until the sheep population reaches an estimated 800 animals and has exhibited an increasing trend based on at least 3 sheep population surveys. Mountain lion removals would resume if the Refuge bighorn sheep population was found to again go below 800 animals.

Additional Refuge Information

Additional information on the history of the Refuge and its purpose, goals, objectives, and management strategies can be found in the Kofa National Wildlife Refuge & Wilderness and New Water Mountains Wilderness Interagency Management Plan and Environmental Assessment: EA-AZ-055-95-105, October 1996. Pertinent information can also be found in the April 2007 report titled Investigative Report and Recommendations for the Kofa Bighorn Sheep Herd, prepared jointly by the Service and the AZGFD. Both documents, along with other detailed information, are available at the following Web site:​southwest/​refuges/​arizona/​kofa.

Public Availability of Comments

Before including your address, phone number, e-mail address, or other personal identifying information in your comment, you should be aware that your entire comment—including your personal identifying information—may be made publicly available at any time. While you can ask us in your comment to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so.


The Environmental Review of this project will be conducted in accordance with the requirements of the National Environmental Policy Act (NEPA) of 1969, as amended (42 U.S.C. 4321 et seq.); NEPA Regulations (40 CFR parts 1500-1508); other appropriate Federal laws and regulations; Executive Order 12996; the National Wildlife Refuge System Improvement Act of 1997; and Service policies and procedures for compliance with those laws and regulations.

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Dated: April 3, 2009.

Benjamin N. Tuggle,

Regional Director, U.S. Fish and Wildlife Service, Albuquerque, New Mexico.

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[FR Doc. E9-18285 Filed 8-3-09; 8:45 am]