An Equal Opportunity Provider and Employer

July 10, 2018

Adam Carlesco, Staff Counsel 

Public Employees for Environmental Responsibility 

962 Wayne Ave, Suite 610 

Silver Spring, MD 20910 

Tel: 202.265.7337 

Fax: 202.265.4192 

Email: acarlesco@peer.org

Dear Mr. Carlesco:

We have reviewed your request for correction made pursuant to the Data Quality 

Act (DQA), dated December 20, 2017. Your request claims that the USDA Animal 

and Plant Health Inspection Service (APHIS), inappropriately relies on the 

University of California, Coop. Ext. Serv. Bulletin 1872 publication, Connolly, 

G.E. and W.M. Longhurst, 1975, The Effects of Control on Coyote Populations: A 

Simulation Model (“Connolly and Longhurst”). Your request included three 

recommendations for correction: 

1. Retract from current and future agency usage the USDA-funded study: 

Connolly, G.E., and W.M. Longhurst, 1975, The effects of control on coyote 

populations: A simulation model, University of California, Division of 

Agricultural Sciences Bulletin, Volume 1872, 37 pp.

2. Issue a public statement explaining the reasons for this retraction.

3. Send a letter to other relevant USDA offices, the Department of Interior, and 

all state game agencies requesting that they refrain from relying on this 

retracted study for any regulatory or public health purpose. 

APHIS disagrees with your characterization of Connolly and Longhurst, and the 

agency is not persuaded that a correction is warranted. First we’d like to address 

the claim that Connolly and Longhurst is inaccurate and unreliable. Although the 

DQA establishes that peer-reviewed studies are considered scientifically objective, 

the inverse that non-peer reviewed are by default biased and not objective is a false 

premise. At the time it was authored, Connolly and Longhurst used state of the art 

computing power to develop coyote population models that were innovative for 

their time. Despite shortcomings which were acknowledged by the authors 

themselves, subsequent population modeling published in peer-reviewed sources 

since have substantiated the original findings of Connolly and Longhurst. For 

instance, Pitt et al. (2001), A new approach to understanding canid populations 

using an individual-based computer model: preliminary results, used a different 

approach to model coyote populations but similarly found that the removal of at 

least 60% of the population each year for 50 years would be necessary to affect a 

population level change. These results are consistent with Connolly and 

Longhurst, and revisited by Connolly (1995), which indicated that coyote 

populations could withstand an annual removal of up to 70% of their numbers and 

Animal and Plant 

Health Inspection 

Service

Office of the WS 

Deputy Administrator

1400 Independence 

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DC 20250

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still maintain a viable population. Connolly and Longhurst’s use of a deterministic singlepopulation model was an important step in increasing our understanding of coyote 

population dynamics with and without management. This and subsequent efforts have 

resulted in the effective management of coyote depredation through both non-lethal and 

lethal methods, while coyote populations have remained robust and have been expanding in 

North America. 

Second, your letter mischaracterizes the underlying purpose of APHIS’s integrated wildlife 

damage management approach to manage coyote depredation on livestock. Specifically, 

you state: “The Connolly and Longhurst study lacks utility for USDA’s intended purpose of 

evaluating and authorizing large-scale coyote extermination.” Your request repeatedly refers 

to “eradication,” “extermination,” or wide-scale control. In fact, APHIS Wildlife Services’ 

mission is to provide Federal leadership for science-based wildlife – human conflict 

management to other wildlife management professionals, the public, external organizations, 

and research institutions that is both accountable and transparent. When APHIS conducts 

coyote damage management activities, its goal is to reduce livestock depredation while 

minimizing impacts on coyote populations. APHIS’s annual coyote take must be put in 

context with the continental scale of the population, and the relatively small geographic 

extent of APHIS coyote damage management activities. APHIS does not rely on Connolly 

and Longhurst to justify maximum allowable take levels, but rather to demonstrate that 

APHIS’s targeted removal is dramatically below levels that could be expected to impact 

coyote populations. 

Third, your request implies that APHIS relies solely on Connolly and Longhurst in reaching 

conclusions that our actions do not threaten the long term viability of coyote populations 

and healthy ecosystems. In fact, APHIS National Environmental Policy Act (NEPA) 

documents rely upon an extensive body of scientific evidence in the decision making 

process. Coyote damage management is undertaken after completion of an Environmental 

Assessment, which includes a public comment period and, if appropriate, issuance of a 

subsequent Finding of No Significant Impact. 

Therefore, after careful consideration of your claims, APHIS has determined that correction 

is not warranted, and it will not adopt the recommendations proposed in your request. 

APHIS will ensure that future environmental analyses clearly reference the entire relevant 

body of work related to coyote population dynamics. 

If you are dissatisfied with this response, you may submit a Request for Reconsideration 

(RFR). Please file your RFR within 90 days of receipt of this response. The RFR should 

reference this letter. Additional requirements for an RFR are listed on the USDA Correction 

Information website: https://www.ocio.usda.gov/policy-directives-recordsforms/guidelines-quality-information/correction-information.
 An Equal Opportunity Provider and Employer

An RFR should be submitted to the APHIS Information Quality Officer by mail, facsimile 

or email:

Ms. Connie Williams, USDA, APHIS, PPD 

Information Quality Officer

4700 River Road, Unit 120 

Riverdale, MD 20737 

Email: Connie.M.Williams@aphis.usda.gov

Fax: 301-734-5899 

Sincerely,

Janet L. Bucknall

Deputy Administrator

References:

Connolly, GE and WM Longhurst. 1975. The effects of control on coyote populations: a 

simulation model. Division of Agricultural Sciences, University of California, Davis, 

Bulletin1872. 

Connolly, G.E., 1995, April. The effects of control on coyote populations: another look. 

In Symposium Proceedings--Coyotes in the Southwest: A Compendium of Our Knowledge 

(1995) (p. 36). 

Pitt, W.C., Knowlton, F.F. and Box, P.W., 2001. A new approach to understanding canid 

populations using an individual-based computer model: Preliminary results. Endangered 

Species Update, 18, pp.103-106.