Gray Wolf (Canis lupus)
Post-Delisting Monitoring Plan for the Gray Wolf Western Great Lakes Distinct Population Segment
Appendix: Responses to Public Comments
On June 4, 2007, U.S. Fish and Wildlife Service (Service) announced the availability of its draft plan to monitor the Western Great Lakes Distinct Population Segment (WGL DPS) of the Gray Wolf for public review and comment. The comment period closed on July 5, 2007. The plan is intended to fulfill the Service’s responsibility under the Endangered Species Act of 1973, as amended, to monitor the status of the WGL DPS for five years after its removal from the Federal List of Threatened and Endangered Wildlife and Plants. The Service announced the delisting of the WGL DPS on February 8, 2007 and the delisting became effective on March 12, 2007.
After the comment period closed, the Service reviewed each comment received and prepared comments in response to any substantive comments. Those comments and the Service’s responses are grouped and summarized below.
Accuracy, Precision, and Sensitivity of the Proposed Monitoring Plan
Comment – The precision of the ‘rangewide survey/local intensive study approach’ to monitoring that is used by Minnesota Department of Natural Resources (MN DNR) may not be sufficient to readily detect rapid population declines, which may result from increased lethal control of wolves.
Response: The Service will review mortality data annually for each state and will also evaluate ‘annual index’ data collected by MN DNR (e.g., autumn scent station surveys; MN DNR 2001:19). Although MN DNR plans to conduct statewide population estimates during only the first and fifth years after delisting, our review of mortality data and other indices of wolf population abundance would likely result in the detection of any sharp population decline between years.
Comment – The Service should consider the relative precision of each state’s population estimate, especially for Minnesota.
Response – The 2003/2004 survey and subsequent analysis by MN DNR resulted in an estimate of 3020 wolves in Minnesota with a 90% confidence interval ranging from 2301 to 3708. In other words, MN DNR may be 90% confident that the actual number of wolves in Minnesota during the winter of 2003/2004 was between 2301 and 3708. On the other hand, there may only be a 10% chance that the number of wolves in Minnesota was less than 2301 or greater than 3708. The Service agrees that it should consider the precision of statewide population estimates. Therefore, under the heading, “Events that might cause Consideration of Relisting or Emergency Relisting”, the Service will evaluate a decline that brings the Minnesota winter wolf population point estimate or 90% confidence interval to 1500 or fewer wolves.
Wisconsin DNR’s (WI DNR) methods do not allow it to quantitatively describe the precision of its population estimate, although its methods likely produce a highly accurate and precise estimate. Wisconsin typically reports its population estimate as a range and the Service will use the low end of the range when evaluating the state’s wolf population estimate against the review triggers.
As stated in the draft post-delisting monitoring plan, Michigan DNR (MI DNR) has recently modified its monitoring plans to allow for the calculation of confidence intervals. Thus, to calculate the total number of wolves in Michigan and Wisconsin, the Service will assume that the number of wolves in either state is equal to the lower end of the 90% confidence interval or the minimum of the reported range.
Comment – The population levels that would cause the Service to consider relisting gray wolves in the Western Great Lakes Distinct Population Segment are too low for Minnesota.
Response – In the draft post-delisting monitoring (PDM) plan, a decline that brought the Minnesota winter wolf population estimate to 1500 or fewer wolves would trigger the Service to consider relisting the gray wolf in the Western Great Lakes Distinct Population Segment. As stated above, the Service will modify this ‘trigger’ to state that the Service will consider relisting if the lower end of the 90% confidence interval is less than 1500. The Service’s recovery plan established a planning goal of 1,250–1,400 animals for the Minnesota wolf population (USFWS 1992:28), concluding that a population of this size would be necessary to ensure resilience against potentially harmful demographic and environmental events. In 1997, when wolf numbers in the Midwest appeared to be approaching the recovery criteria specified in the 1992 Plan, the Service reconvened its Recovery Team to reevaluate these criteria, which stated that the recovery criteria were ‘‘sufficient’’ (Peterson in litt. 1997, in litt. 1998). Furthermore, a separate group of peer reviewers supported the Service’s conclusion that the Western Great Lakes Distinct Population Segment of the Gray Wolf (WGL DPS) was recovered. No one among this group expressed concern with the 1992 recovery criteria. Therefore, we think that the plan to consider relisting if and when the 90% confidence interval falls below 1500 would be sufficiently sensitive to ensure a timely response to a situation in which the Minnesota population was at or approaching minimum recovery levels.
Comment – The monitoring methods used in the three states are inconsistent with one another. For example, they vary in accuracy and precision and the methods used in Minnesota would have overestimated the number of wolves in Wisconsin in 2004.
Response – There is no clear reason for the monitoring methods to be entirely consistent among the three states as long as each is sufficient to describe the status of wolves in its respective state. Thus far, each state has developed methods that have been sufficient for describing the numbers and distribution of gray wolves within its boundaries. The cost and delay that would result from each state attempting to modify its monitoring methods to align with a single methodology would be significant and may hinder comparisons to pre-delisting abundance and distribution within the WGL DPS. Nevertheless, each state may improve its monitoring methods as biologists find ways to improve the accuracy, precision, and efficiency of their methods.
Based on an analysis conducted by Wisconsin DNR (Wiedenhoeft 2005), the methods used in Minnesota to estimate wolf abundance and distribution there would not have been well suited for use in Wisconsin in 2004. This may be due, in part, to the fact that the wolf population in Wisconsin is still expanding and the Minnesota methods assume that all suitable habitat is occupied by wolves. That assumption may be valid for Minnesota, where all suitable habitat may already be occupied (Erb & Benson 2004), but would have overestimated wolf abundance in Wisconsin in 2004 where wolves were yet to inhabit all suitable habitat and where wolf habitat is more patchy (Wiedenhoeft 2005:12).
The Minnesota methods were also found to overestimate the area occupied by wolves in Michigan (D. Beyer, Michigan DNR, pers. comm. 8/10/06). In the Upper Peninsula, deer are sparse in some areas during winter. The habitat suitability model used in Minnesota is based on road and human density and does not consider winter deer density. Therefore, some areas where human and road densities are sufficiently low in Michigan have insufficient prey densities to support resident packs. The assumption that these areas were occupied by wolves resulted in an overestimate of wolf numbers in Michigan (D. Beyer, pers. comm. 7/27/07). These underlying ecological differences among the states provide further support for not attempting to force a uniform monitoring methodology.
Comment – The Minnesota monitoring methods may make it difficult to measure rapid population declines.
Response – This comment focused on the methods used to calculate statewide population estimates in Minnesota. The Service will not rely entirely on these statewide population estimates to assess trends in wolf abundance in Minnesota, but would also review wolf mortality data, law enforcement investigations of wolf mortality, verified or probable depredation incidents and associated follow-up actions, and wolf pack numbers on national forests, national parks, and national wildlife refuges. These additional sources of information, in conjunction with review of the periodic statewide population estimates, are likely to allow for timely detection of any significant population declines in Minnesota.
Comment – The Service should require the states to annually present confidence limits on these estimates.
Response – Wisconsin intensively monitors its wolf population using aerial radio tracking, intense snow track surveys, and collection of public reports of wolf observations and will continue to do so during the five-year federal monitoring period (Wydeven et al. 2007:13). Therefore, it likely provides a highly precise and conservative estimate of the statewide population. It is conservative because it is taken in late winter before pups are born and it underestimates lone wolves. Moreover, the Service would use the minimum value in the range to represent the size of the state population. Confidence intervals are more important when only a subset of the population is intensively monitored, as in Minnesota and Michigan.
Comment - The "Events that might cause Consideration of Relisting or Emergency Relisting" should be made more stringent. The scenarios presented appear to be based solely on baseline recovery population levels and do not consider the rate of decline or other factors. Steep rates of decline should also be considered a quantitative event which might cause consideration of relisting. This concept is considered under item 1 of the “Other factors indicated a potential cause for concern” section, but this should be elevated and incorporated into the “event” conditions.
Response – We will keep this concern where it was in the draft plan, but may take the following actions in response to a steep decline:
Comment – An “event” condition should also be developed based upon marked declines in the population indices that the MN DNR uses to monitor wolf population trends between state-wide surveys.
Response – The annual indices that MN DNR proposes to use to monitor wolf populations between statewide surveys include wolf depredation complaints, autumn scent station surveys, winter furbearer track surveys, and other observations of field personnel from all natural resources agencies (Minnesota Department of Natural Resources 2001:19). In general, these indices must be interpreted with caution and may not by themselves be reliable indicators of significant population declines. Nevertheless, the Service will review these data sources annually and may take the types of actions described in the immediately preceding comment, if appropriate.
Comment – The draft PDM plan stated that MN DNR’s statewide population estimate “can only provide trend information and is not a population count.”
Response – This comment in the draft PDM plan referred to the annual indices of wolf numbers and distribution (number of depredation complaints, scent post surveys, etc.) and did not refer to the five-year statewide population estimate.
Comment - Funding sources that will support the population monitoring activities proposed by the states are not identified. The Service must guarantee adequate funds are in place to support these plans. The Service’s plan must identify the resources that each state will use to support population monitoring activities.
Response – In 2000, MN DNR sent its recommendations for appropriations to implement its wolf management plan to the state legislature. These described funds necessary for population monitoring and to hire a wolf specialist, which it hired in 2007. The Service cannot guarantee that adequate funds are in place for the next five years of monitoring in each state. Nevertheless, each state has acted in good faith thus far in monitoring its wolf populations and has also demonstrated that it can acquire funds necessary to fully implement the monitoring components of its state plan. The states have a variety of sources from which to fund wolf population monitoring, including Endangered Species Act Section 6 Conservation Grants. The Service does not anticipate any of the states being unable or unwilling to implement the monitoring committed to in their state management plans. Nevertheless, if any of the three states substantially reduce the robustness of their monitoring program (e.g., relative to the description of its monitoring in the Service’s plan) the Service will consider revising the post-delisting monitoring plan.
Comment - Section 4(g) of the Endangered Species Act (ESA) mandates postdelisting monitoring (PDM) for a minimum of five years after a species is delisted. Because PDM is a federal requirement, federal funding should be provided to the states of Minnesota, Wisconsin, and Michigan to fulfill it. Furthermore, the level of federal funding provided should be commensurate with the standards and monitoring intensity required by the final PDM plan.
Response – The states are obviously critical in implementing the post-delisting monitoring described in the PDM plan. Nevertheless, there is a variety of federal assistance funds that could be used by states to support their efforts. These include Federal Aid in Wildlife Restoration, the State Wildlife Grant Program, and the Cooperative Endangered Species Conservation Fund.
Comment - The sampling protocol for necropsies and disease screening should be specifically stated to ensure that sampling is adequate to provide statistically significant results.
Response – Although starvation may be the major cause of pup mortality, disease may also be important during some years and may also infrequently play a significant role in adult mortality. Significant levels of mortality due to disease would be reflected in population surveys conducted by each state. Nevertheless, each state plans to implement some level of disease monitoring. Although we understand the commenter’s interest in a statistically robust disease monitoring program and the potential need for such monitoring in some cases, the continued population monitoring to be conducted by each state and the level of disease monitoring proposed by each state is sufficient for post-delisting monitoring of the Western Great Lakes DPS.
Below we summarize the disease monitoring proposed in each state’s wolf management plan (Michigan Department of Natural Resources 2007; Minnesota Department of Natural Resources 2001; Wisconsin Department Natural Resources 2006):
In its draft revised wolf management plan, MI DNR proposes to take the following actions to ensure diseases and parasites do not threaten the viability of wolves in Michigan:
Cooperation with Native American Tribal Governments
Comment – The paragraph on page 6 which discusses tribal management has a generally negative tone.
Response – The commenter also provided replacement language for this paragraph, which we have largely adopted in the final version of the plan.
Comment – Expand the list of information that the Service will request from tribal natural resource agencies (i.e., include “changes to management” and “other relevant information”) and request this information from tribal natural resource agencies within the range of wolf within the DPS, in general.
Response – The final version of the plan includes this slightly expanded list of information to be requested from tribal natural resource agencies and does not explicitly limit the information request to specific tribes.
Recommended Actions at End of Five-Year Monitoring Period
Comment – The Service indicates at the end of the 5 year period, it "may" request reviews by the Recovery Team; this should be a required action.
Response – The Service, in developing and implementing recovery plans, may procure the services of appropriate public and private agencies and institutions and other qualified persons in the form of recovery teams. Now that the gray wolf within the WGL DPS is delisted, the Service plans to disband the Eastern Gray Wolf Recovery Team. Therefore, we will change any reference to the recovery team to “former members of the recovery team” in the final plan. Nevertheless, the Service recognizes the substantial technical expertise of these persons and will likely seek their individual reviews of our findings, at least at the end of the five-year monitoring period.
Comment – The Service indicates that, except under fairly extreme circumstances, it believes a 5 year monitoring period will be adequate; the Service should retain an oversight role and program even after the five-year post-delisting period has ended.
Response – Now that the WGL DPS of gray wolves is no longer on the list of endangered and threatened species, the Service has no authority under the Endangered Species Act for formal oversight of wolf management. If data are sufficient to indicate that the gray wolf in the DPS will be effectively conserved without protection of the Endangered Species Act, then the Service should focus its limited resources on species that remain on the list of endangered and threatened species or that may warrant addition to the list (i.e., “candidate” and ‘at risk’ species).
Comment - A public attitude survey should be conducted near the end of the monitoring period to gain insight into the trends in public acceptance of wolves. Public attitudes may be the most significant factor in determining the long-term fate of the species in this DPS and it would be difficult to adequately determine if additional monitoring is necessary without an understanding of public attitudes and how they may be trending.
Response – The Service will annually review any reports or publications on public attitudes toward WGL DPS wolves and any educational materials, press releases, and other wolf-related public information/education materials produced by the states, tribes, or others. In addition, we will directly evaluate the impacts of the public on wolves in the DPS by reviewing wolf population estimates and trends, the numbers of wolves killed legally and illegally, summary data for all law enforcement investigations, and reports of wolf depredation incidents. Although the Service does not plan to commission any survey of public attitudes, it plans to review the results of any studies conducted by others (e.g., universities).
Status of Wolves in Lower Michigan
Comment – A population survey should be conducted in the northern lower portion of Michigan in the final year of the 5-year post-delisting monitoring period.
Response –There is no clear need for wolves to occur in this area to ensure that the species no longer meets the definition of endangered or threatened under the Endangered Species Act. Therefore, the Service’s PDM plan will not refer specifically to wolves in this particular area.
Other Comments Specific to Monitoring in Minnesota
Comment – MN DNR should conduct aerial wolf surveys and should not just gather “opinions” and data incidental to studies on other species. We would like to see a list of participants and break down of their field positions in order to assess their qualifications for making these wolf observations.
Response – The statewide survey is based on much more robust methods than that suggested by the commenter. MN DNR collects data from a variety of sources to prepare its five-year statewide population estimate. It relies, in part, on data collected from regular monitoring that is not focused solely on gray wolf, including scent post surveys and winter furbearer track surveys. There is nothing inherently wrong in using these types of data to ensure that all data revealing of wolf abundance and distribution contribute to the MN DNR’s understanding of wolf trends in the state. MN DNR also uses the best available information regarding the relationships between wolf densities and human population and road densities to describe occupied wolf range in the state. In addition, ongoing radio telemetry studies help DNR to refine estimates of pack territory sizes. We expect MN DNR to continue to investigate the most efficient methods to estimate its statewide wolf population as accurately and precisely as is feasible. In its 2003-2004 report on its most recent statewide estimate, for example, MN DNR stated that aerial sampling methods show promise, but “may be logistically challenging when applied to broad expanses of dense forest” (Erb and Benson 2004). Due to the logistical and other factors that each state must consider when designing its methods to monitor the widespread and dynamic wolf populations, it would not be appropriate for the Service to prescribe specific methodologies.
Comment – A significant portion of Minnesota’s wolf range does not have any scent post sites and two of the largest counties in prime wolf range (Itasca and Koochiching) have only one station each.
Response – MN DNR actually conducts annual surveys along 24 2.7-mile routes (ten scent stations each - 240 scent stations total) in Itasca County and an additional ten routes (100 scent stations total) in Koochiching County (J. Erb, Minnesota Department of Natural Resources, Grand Rapids, MN, pers. comm. 8/24/07). In the “Forest Zone”, which comprises the main portion of the wolf range in Minnesota, there were 173 scent station routes completed in 2006 (Erb 2006).
Comment – The draft monitoring plan mentioned that MN DNR would furnish independent annual indices and changes in occupied range of wolf in the state but they will not provide population estimates annually. Delisting and monitoring depend on population data. Using limited trend data is an arbitrary way to “monitor” a species just removed from the list of threatened species.
Response – It is uncommon for populations of any species to be counted in their entirety. Therefore, conservation agencies commonly use indices and population sampling to monitor population trends. Of the three states inhabited by gray wolf packs in the WGL DPS, only Wisconsin may continue to conduct what may approach a complete count or census of its late winter wolf population. Minnesota, however, may contain approximately six times the number of wolves as Wisconsin, distributed over a larger geographic area. The combined use of annual population indices and a five-year statewide population estimate is adequate for monitoring the post-delisting status of gray wolves in the state.
Scope of Plan
Comment – The post-delisting threats remain significant. The draft plan does not adequately acknowledge those threats nor does it provide an adequate process for addressing those threats.
Response – The Service determined that the current threats to the species no longer warranted its listing as endangered or threatened under the ESA. A reduction in threats to the species is the primary cause of the dramatic wolf population increase over the last 25 years and attainment of the numerical recovery criteria. The intent of the post-delisting monitoring plan is to determine whether or not threats to gray wolves in the WGL DPS are adequately addressed by states, tribes, and others (e.g., federal land management agencies) to preclude the need to list the species under the ESA during the five years following its delisting. For gray wolf WGL PDM purposes, we believe the most important threats to monitor are those that have been sufficiently reduced and contained, but not permanently eliminated, during the recovery process. For gray wolves in the WGL DPS, those threats are primarily the various forms of human-caused mortality that have been reduced by the provisions of the Act. Additionally, a variety of known wolf diseases and parasites are of concern. Furthermore, the possibility of new diseases represents a threat that requires vigilance. All these anticipated post-delisting threats are described in detail in “Summary of Factors Affecting the Species” in the preamble of the 2006 proposed delisting rule (75 FR 15277-15302) and are addressed by each state in their respective state management plans.
Comment – The same monitoring techniques should not be required both pre-and post delisting, particularly for populations that significantly exceed numerical delisting criteria outlined in recovery plans. In reality, states should only be required, through the PDM plan, to reliably demonstrate that there is at least the minimum number required by recovery plans for delisting purposes.
Response – The Service agrees that the most important purpose of population monitoring per the ESA’s PDM requirement is to determine, with sufficient confidence, that population levels exceed the objectives described in the recovery plan. Where feasible, however, the Service should also review trends in population estimates, indices of abundance (e.g., scent post surveys), mortality records, diseases, and prey abundance to determine whether or not significant problems for wolf populations may be developing during the PDM period.
Comment - The final PDM plan should include language that allows the states to investigate and adopt alternative methods and protocols so as long as the data are scientifically comparable to data obtained prior to delisting. States should have flexibility to refine and change monitoring protocols through time as new techniques are investigated and validated. This flexibility is especially important given the potential for limited and declining availability of funding as wolf distribution expands.
Response – In the final PDM plan the Service will attempt to accurately describe each state’s monitoring plans for the five years following delisting. There is nothing in the Service’s plan that would preclude changes by the states. The Service would review any changes, however, to ensure that the revised methods are likely to provide sufficiently accurate and precise information to effectively monitor the status of the species. In fact, Michigan has been in the process of revising its methods and the nature of those revisions is briefly described in the PDM plan.
Typographical, Clarification, and other Minor Errors in Draft
Comment - The PDM draft indicates actions (a) through (f) as potential actions USFWS might take after an annual review, but actions (e) and (f) are missing from the list on page 10 of the 04/23/07 draft.
Response – The draft plan should have said that the Service may take actions “(a) through (d)” listed below. There were no potential response actions that were missing from the draft plan.
Comment - The difference and the nature of the relationships between "quantitative events" with "qualitative factors" are not clear.
Response – The response to the ‘quantitative’ triggers would be a focus on the potential need to relist the species, whereas the response to the ‘qualitative’ factors would not necessarily focus on the potential need to relist the species. Situations that trigger one of the “qualitative events’ will prompt the Service to evaluate the situation in detail and its underlying causes, but will not necessarily prompt an assessment of the potential need to relist the species. We will attempt to make that more clear in the final PDM plan.
Potential Response of the Service to Monitoring Results
Comment - We agree with the general USFWS approach, to consider a variety of data sets, events, and factors that influence wolf population trajectory, in addition to their interactions. We agree that USFWS should not specify a set of strict triggers and automatic agency actions a priori. Instead, USFWS should consider the collective body of information and data, consult with independent experts if appropriate, and proceed accordingly.
Response – We agree that it would not be appropriate to state in the PDM plan that the Service would relist the species, for example, if certain events transpired. It is more appropriate to state, as clearly as is appropriate, what situations will prompt an evaluation by the Service to determine its appropriate response.
Comment – The PDM draft plan states that "in the event that WGL DPS declines are evident following an annual review, the Service may take any or all of the following actions." Previous paragraphs suggest that this is the list (a) through (f) of potential USFWS actions. But the list (a) through (d) published in the draft does not include the option of taking no action for a year. The final PDM plan should not absolutely require the USFWS to take any action after only a single year's decline. Wildlife populations are inherently variable and there is also variance associated with monitoring protocols, sampling, and population estimation procedures. For example, monitoring protocols in the Great Lakes states rely heavily on snow tracking surveys, but low snow pack and poor tracking conditions can result in poor quality data and an apparent population decline when the population may have actually increased.
Response – We agree that evidence of a population decline in some years may not warrant that the Service implement one of the four actions described in the draft plan. We will modify the plan to include ‘no action’ as a potential response, as appropriate.
Comment – As written, the Service could be required to take action after any single's year data shows "a decline”, but the draft is not clear with respect to whether the decline was in one of the quantitative measures or the qualitative measures. This should be clarified in the final DPM plan.
Response – We will attempt to clarify this in the final plan to indicate that the Service may act in response to annual declines in any of the ‘quantitative’ or ‘qualitative’ events or factors.
Comment – We encourage the Service to consider a combination of metrics (e.g., moving averages) and not a single metric of total number of wolves. Furthermore, more than a single year's decline (or whatever combination of metrics is in the final PDM) in a state’s wolf population should be required before extending the PDM period, initiating a status review, or an emergency relisting.
Response – The Service is likely to maintain a focus on total number of wolves or estimates thereof as described in the draft plan. We agree that such a focus will result in a high degree of sensitivity to population fluctuations, but we will strive to ensure that our response to any declines is appropriate and based on factors such as the magnitude of the decline and our ability to identify the cause and duration of the decline.
Erb, J. 2006. Carnivore Scent Station Survey Summary, 2006. Pages 67-74. Status of Wildlife Populations, 2007. Minnesota Department of Natural Resources, St. Paul, MN.
Erb, J. and S. Benson. 2004. Distribution and abundance of wolves in Minnesota, 2003-2004. in. Minnesota Department of Natural Resources. 5 p.
Michigan Department of Natural Resources. 2007. Draft Michigan wolf management plan. Lansing, MI. 76 p.
Minnesota Department of Natural Resources. 2001. Minnesota wolf management plan. St. Paul, MN. 36 p. [http://files.dnr.state.mn.us/natural_resources/animals/mammals/wolves/wolfplan2000.pdf]
Wiedenhoeft, J. E. 2005. Summary Report: "Minnesota-type" wolf survey for Wisconsin – GIS analysis. Wisconsin Department of Natural Resources, Madison, WI. 14 p.
Wisconsin Department Natural Resources. 2006. Wisconsin Wolf Management Plan, Addendum 2006. Madison, WI. 60 p. [http://dnr.wi.gov/org/land/er/publications/wolfplan/pdfs/WIWolfManagementPlanAdd2006.pdf]
Wydeven, A. P., J. E. Wiedenhoeft, R. P. Thiel, R. N. Schultz, and S. R. Boles. 2007. Progress report of wolf population monitoring in Wisconsin for the period, October 2006 - March 2007. Wisconsin Department of Natural Resources, Park Falls, WI. 25 p.